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338 records returned

Electrochemical selective detection of dopamine on microbial carbohydrate-doped multiwall carbon nanotube-modified electrodes.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Microbial carbohydrate-doped multiwall carbon nanotube (MWNT)-modified electrodes were prepared for the purpose of determining if 4-(2-aminoethyl)benzene-1,2-diol (3,4-dihydroxyphenylalanine; dopamine) exists in the presence of 0.5 mM ascorbic acid, a representative interfering agent in neurotransmitter detection. The microbial carbohydrate dopants were alpha-cyclosophorohexadecaose (alpha-C16) from Xanthomonas oryzae and cyclic-(1 --> 2)-beta-D: -glucan (Cys) from Rhizobium meliloti. The cyclic voltammetric responses showed that the highest sensitivity (5.8 x 10(-3) mA cm(-2) muM(-1)) is attained with the Cys-doped...
Source: Biotechnology Letters - November 17, 2009 Category: Biotechnology Authors: Jin JH, Cho E, Jung S Tags: Biotechnol Lett Source Type: journals

A series of novel directional cloning and expression vectors for blunt-end ligation of PCR products.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Novel directional cloning and expression vectors were developed for blunt-end ligation of PCR products that are suitable for high-throughput cloning and simplifying the screening procedure. The PCR products, without further processing, are cloned into vectors digested with SchI and, following transformation, the desired recombinants give typical blue colonies on selectable plates. The principle of this selection strategy is that the construction also generates a full-length ideal lacO gene. To the best of our knowledge, this is the first time that this lacO reconstruction strategy has been applied in the selection of r...
Source: Biotechnology Letters - November 14, 2009 Category: Biotechnology Authors: Wu Q, Zhong X, Zhai C, Yang J, Chen X, Chen L, Wang W, Ma L Tags: Biotechnol Lett Source Type: journals

Molecular activation of NF-kappaB, pro-inflammatory mediators, and signal pathways in gamma-irradiated mice.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The effects of gamma-irradiation on inflammatory gene expression, including NF-kappaB activation, in the kidney of C57/BL6 mice exposed to 1-9 Gy doses of (60)Co gamma-irradiation. Radiation enhanced the NF-kappaB activation and oxidative stress caused a dose-dependent disruption in the redox balance. The significance of this study is the new molecular information gained on gamma-irradiation effects through the activation of pro-inflammatory genes by NF-kappaB via the MAPK signaling pathway. Considering the exquisite sensitivity of NF-kappaB and other pro-inflammatory mediators to the redox status, we conclude that the...
Source: Biotechnology Letters - November 14, 2009 Category: Biotechnology Authors: Ha YM, Chung SW, Kim JM, Kim DH, Kim JY, Lee EK, Lee J, Kim YJ, Yoo MA, Jeong KS, Chung HY Tags: Biotechnol Lett Source Type: journals

Mild hyperthermia prior to electroporation increases transfection efficiency in HCT 116, HeLa S3 and SGC 7901 cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The change in transfection efficiency of electroporation by the combined treatment with mild preheating (40 degrees C for 30 min) was investigated. HCT 116, HeLa S3 and SGC 7901 cells were treated with electroporation in medium containing pBKCMV-Luc plasmid with or without preheating. After 24 h, luciferase activity was increased by 36, 28 and 77%; luciferase mRNA transcription was increased by 45, 50 and 68%; and fluorescein isothiocyanate-dextran accumulation was increased by 9, 35 and 15% in preheated groups, respectively. These results demonstrate that the transfection efficiency was enhanced by mild preheating. Th...
Source: Biotechnology Letters - November 8, 2009 Category: Biotechnology Authors: Wei ZL, Ogawa R, Takasaki I, Zhao QL, Zheng HC, Ahmed K, Hassan MA, Kondo T Tags: Biotechnol Lett Source Type: journals

Recovery of succinic acid from fermentation broth.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Succinic acid is of high interest as bio-feedstock for the chemical industry. It is a precursor for a variety of many other chemicals, e.g. 1,4-butandiol, tetrahydrofuran, biodegradable polymers and fumaric acid. Besides optimized production strains and fermentation processes it is indispensable to develop cost-saving and energy-effective downstream processes to compete with the current petrochemical production process. Various methods such as precipitation, sorption and ion exchange, electrodialysis, and liquid-liquid extraction have been investigated for the recovery of succinic acid from fermentation broth and are r...
Source: Biotechnology Letters - November 8, 2009 Category: Biotechnology Authors: Kurzrock T, Weuster-Botz D Tags: Biotechnol Lett Source Type: journals

Growth kinetics and ginsenosides production in transformed hairy roots of American ginseng-Panax quinquefolium L.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A thin, profusely branched, fast growing hairy root line of Panax quinquefolium (American ginseng) was established by co-culturing epicotyl explants with a wild type strain of Agrobacterium rhizogenes. The transformed roots grew by over 10-fold from the initial inoculum within 8 weeks. The crude ginsenosides content in the roots was about 0.2 g/g dry wt level up to the 10th week of culture. Ginsenosides Rb2, Rd, Re, Rf and Rg1 constituted 47-49% of the crude saponin fraction between 6 and 8 weeks of growth whereas, Rc ginsenoside was accumulated only after 9th weeks when the biomass started receding. PCR amplification ...
Source: Biotechnology Letters - November 8, 2009 Category: Biotechnology Authors: Mathur A, Gangwar A, Mathur AK, Verma P, Uniyal GC, Lal RK Tags: Biotechnol Lett Source Type: journals

An improved method for analysis of biomass sugars and galacturonic acid by anion exchange chromatography.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The most accurate analysis method for sugars in biomass, based on gas chromatography, requires a time consuming and laborious sample derivatation to trimethylsilanes or alditol acetates. In comparison, sample preparations for sugar analysis by liquid chromatography are simple water dilutions. However, HPLC methods either require long analysis times, use of expensive solvents, or do not give good resolution of sugars. A gradient method developed previously using a Dionex PA-1 column and pulsed-amperometric detection was modified to reduce analysis time from 75 to less than 40 min and provide good resolution of arabinose...
Source: Biotechnology Letters - November 7, 2009 Category: Biotechnology Authors: Widmer W Tags: Biotechnol Lett Source Type: journals

Selective inhibitory potential of silver nanoparticles on the harmful cyanobacterium Microcystis aeruginosa.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Silver nanoparticles (SNPs) at 1 mg/l inhibited the growth of the toxic cyanobacterium, Microcystis aeruginosa, by 87%. Similar results were obtained in field experiments. M. aeruginosa was more sensitive to SNPs than were green algae. SNPs may be a useful selective biocidal agent for the control of M. aeruginosa. PMID: 19898749 [PubMed - as supplied by publisher] (Source: Biotechnology Letters)
Source: Biotechnology Letters - November 7, 2009 Category: Biotechnology Authors: Park MH, Kim KH, Lee HH, Kim JS, Hwang SJ Tags: Biotechnol Lett Source Type: journals

Production of biologically active IgG hinge-tag soluble epidermal growth factor receptors (ErbB).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The extracellular domains (ECD) of epidermal growth factor receptors, ErbB1, 2, 3 and 4, were designed as soluble dimeric forms. Each ECD was fused to a short hinge region derived from IgG, such that the stable dimer could be formed with disulfide bridges. This hinge-tagged design minimized the molecular weight to approximately 50% of the conventional Fc-fusion design without an Fc domain of IgG. The refolded dimers could be easily analyzed and characterized by SDS-PAGE. Hinge-tagged soluble ErbBs demonstrated significant affinity for betacellulin and heregulin. The IgG hinge-tag should be a simple method to design sol...
Source: Biotechnology Letters - November 7, 2009 Category: Biotechnology Authors: Otani T, Hashizume T, Nagaoka T, Fukuda T, Tang CK, Salomon DS, Seno M Tags: Biotechnol Lett Source Type: journals

Production of ethanol from thin stillage by metabolically engineered Escherichia coli.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We report here the efficient production of ethanol from thin stillage by a metabolically engineered strain of Escherichia coli. Simultaneous utilization of glycerol and sugars was achieved by overexpressing either the fermentative or the respiratory glycerol-utilization pathway. However, amplification of the fermentative pathway (encoded by gldA and dhaKLM) led to more efficient consumption of glycerol and promoted the synthesis of reduced products, including ethanol. A previously constructed strain, EH05, containing mutations that prevented the accumulation of competing by-products (i.e. lactate, acetate, and succinate) a...
Source: Biotechnology Letters - November 7, 2009 Category: Biotechnology Authors: Gonzalez R, Campbell P, Wong M Tags: Biotechnol Lett Source Type: journals

Choice of plasmid preparation kit influences sequencing results.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Commercially available plasmid preparation kits are used in many laboratories to isolate plasmid DNA for subsequent dideoxy sequencing. We tested kits from seven different manufacturers for the purity of obtained plasmid preparations and compared the quality of sequencing results. The amount of RNA carry-over differed significantly (80-323 ng) and the usage of two kits led to protein remainders. Sequence read lengths (0-812 bases) and percentages of reading errors (1.6-100%) were also significantly different. We found the amount of protein contaminants to correlate with the percentage of reading errors (r = 0.63, P = 0...
Source: Biotechnology Letters - November 7, 2009 Category: Biotechnology Authors: Hoffmann P, Hoffmann C, Weimann A Tags: Biotechnol Lett Source Type: journals

Over-expression and characterization of recombinant prefoldin from hyperthermophilic archaeum Pyrococcus furiosus in E. coli.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Prefoldin is a hexameric chaperone that has been identified in eukaryotic cells and in Archaea. E. coli cells over-expressing the prefoldin gene from the hyperthermophilic, archaeum, Pyrococcus furiosus, grew well at 48 degrees C while control cells were unable to grow above 46 degrees C. The isolated and purified Pfu-prefoldin (specially the beta subunit and the prefoldin) thermally protected the activity of lysozyme. PMID: 19898753 [PubMed - as supplied by publisher] (Source: Biotechnology Letters)
Source: Biotechnology Letters - November 7, 2009 Category: Biotechnology Authors: Chen H, Yang L, Zhang Y, Yang S Tags: Biotechnol Lett Source Type: journals

Mutational analysis of the active site residues of a D: -psicose 3-epimerase from Agrobacterium tumefaciens.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
D: -Psicose 3-epimerase from Agrobacterium tumefacience catalyzes the conversion of D: -fructose to D: -psicose. According to mutational analysis, the ring at position 112, the negative charge at position 156, and the positive charge at position 215 were essential components for enzyme activity and for binding fructose and psicose. The surface contact area and distance to the bound substrate by molecular modeling suggest that the positive charge of Arg215 was involved in stabilization of cis-endiol intermediate. The distances between the catalytic residues (Glu150 and Glu244) and Mn(2+) are critical to the catalysis, a...
Source: Biotechnology Letters - October 27, 2009 Category: Biotechnology Authors: Kim HJ, Yeom SJ, Kim K, Rhee S, Kim D, Oh DK Tags: Biotechnol Lett Source Type: journals

Characterization of a recombinant L: -fucose isomerase from Caldicellulosiruptor saccharolyticus that isomerizes L: -fucose, D: -arabinose, D: -altrose, and L: -galactose.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A recombinant L: -fucose isomerase from Caldicellulosiruptor saccharolyticus was purified as a single 68 kDa band with an activity of 76 U mg(-1). The molecular mass of the native enzyme was 204 kDa as a trimer. The maximum activity for L: -fucose isomerization was at pH 7 and 75 degrees C in the presence of 1 mM Mn(2+). Its half-life at 70 degrees C was 6.1 h. For aldose substrates, the enzyme displayed activity in decreasing order for L: -fucose, with a k (cat) of 11,910 min(-1) and a K (m) of 140 mM, D: -arabinose, D: -altrose, and L: -galactose. These aldoses were converted to the ketoses L: -fuculose, D: -ribulose...
Source: Biotechnology Letters - October 25, 2009 Category: Biotechnology Authors: Ju YH, Oh DK Tags: Biotechnol Lett Source Type: journals

Inhibitory effect of curcumin on liver injury in a murine model of endotoxemic shock.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The effect of curcumin on lipopolysaccharide/D: -galactosamine (LPS/GalN)-induced acute shock model of liver injury was examined in mice. The simultaneous administration of LPS (5-20 mug kg(-1), i.p.) and GalN (700 mg kg(-1), i.p.) markedly increased the serum tumor necrosis factor-alpha (TNF-alpha), glutamic oxaloacetic transaminase/glutamic pyruvic transaminase (GOT/GPT), and massive hepatic necrosis and inflammation, leading to 100% lethality. Pre-administration of curcumin (100 mg kg(-1), i.p.) 3 h before induction with LPS/GalN imparted a large extent of protection against acute elevation in serum TNF-alpha and se...
Source: Biotechnology Letters - October 25, 2009 Category: Biotechnology Authors: Yun SS, Kim SP, Kang MY, Nam SH Tags: Biotechnol Lett Source Type: journals

Immobilization of Escherichia coli cells with cis-epoxysuccinate hydrolase activity for D: (-)-tartaric acid production.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Immobilization of cis-epoxysuccinate hydrolase-containing E. coli for D: (-)-tartaric acid production was screened by various methods. The highest recovery of activity was obtained by entrapment in kappa-carrageenan gel. 23.6 g biomass/l and 43.4 g kappa-carrageenan/l were the best immobilization conditions optimized by response surface methodology with 83% yield (114 U/g). Cell autolysis was observed after immobilization. Immobilized cells showed high pH (5-10) stability, thermal (up to 65 degrees C) stability, conversion rate (>99.5%), enantioselectivity (ee > 99.6%), and were less affected by metal ions and su...
Source: Biotechnology Letters - October 20, 2009 Category: Biotechnology Authors: Pan H, Bao W, Xie Z, Zhang J, Li Y Tags: Biotechnol Lett Source Type: journals

Metabolic engineering of Streptomyces venezuelae for malonyl-CoA biosynthesis to enhance heterologous production of polyketides.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Using metabolic engineering, we developed Streptomyces venezuelae YJ028 as an efficient heterologous host to increase the malonyl-CoA pool to be directed towards enhanced production of various polyketides. To probe the applicability of newly developed hosts in the heterologous production of polyketides, we expressed type III polyketide synthase, 1,3,6,8-tetrahydroxynaphthalene synthase, in these hosts. Flaviolin production was doubled by expression of acetyl-CoA carboxylase (ACCase) and 4-fold by combined expression of ACCase, metK1-sp and afsR-sp. Thus, the newly developed Streptomyces venezuelae YJ028 hosts produce h...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Maharjan S, Park JW, Yoon YJ, Lee HC, Sohng JK Tags: Biotechnol Lett Source Type: journals

A novel bioreactor for immobilized phototrophs.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A novel configuration of photobioreactor is described in which filaments of alginate containing immobilized cells of a leaky mutant of Dunaliella parva are wound round a central light well which is located within a glass outer chamber so that a liquid medium is caused to flow in the annular space between the outside chamber and the alginate filaments. Glycerol production by D. parva was maintained for 700 h and the highest concentration of glycerol attained was approx. 12 mg l(-1). PMID: 19838629 [PubMed - as supplied by publisher] (Source: Biotechnology Letters)
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Fermont S, Shama G Tags: Biotechnol Lett Source Type: journals

Ammonium and phosphate limitation in 1,3-propanediol production by Klebsiella pneumoniae.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Excretion of 1,3-propanediol (1,3-PD) by K. pneumoniae was compared in ammonium- and phosphate-limited chemostat cultures running with an excess of glycerol. 59 and 43% catabolic flux were directed to 1,3-PD in ammonia-limited cultures and phosphate-limited cultures at dilution rate of 0.1 h(-1), respectively. Ammonia-limited fed-batch cultures produced 61 g 1,3-PD l(-1) and a total of 15 g l(-1) organic acid in 36 h. However, phosphate-limited fed-batch cultures excreted 61 g lactate l(-1) and 44 g 1,3-PD l(-1). PMID: 19838630 [PubMed - as supplied by publisher] (Source: Biotechnology Letters)
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Zheng ZM, Xu YZ, Wang TP, Dong CQ, Yang YP, Liu DH Tags: Biotechnol Lett Source Type: journals

Quantitation of non-amplified genomic DNA by bead-based hybridization and template mediated extension coupled to alkaline phosphatase signal amplification.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Klenow I polymerase activity was combined with solid phase DNA hybridization to detect non-amplified genomic DNA (gDNA) sequences from Escherichia coli. Aminopropyl-controlled pore glass surface-bound oligonucleotides were hybridized to fragmented gDNA. The template-mediated extension at the 3'-terminus of the immobilized probe was then promoted in the presence of Klenow I polymerase and digoxigenin-labeled nucleotides. Detection of the extended probes was accomplished with an anti-digoxigenin alkaline phosphatase conjugate protocol coupled to colorimetric or fluorescent detection. Using the colorimetric protocol, the ...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Martins SA, Prazeres DM, Fonseca LP, Monteiro GA Tags: Biotechnol Lett Source Type: journals

Characterisation and expression of a novel holotype crystal protein gene, cry56Aa1, from Bacillus thuringiensis strain Ywc2-8.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Bacillus thuringiensis isolate Ywc2-8, from soil in Sichuan Basin in western China, contains a spherical crystal harbouring two insecticidal crystal proteins with masses of 70 kDa and 130 kDa. A novel cry-type gene, encoding a 664 amino acid protein with 34% homology to cry29Aa1, was found and cloned from this strain. This gene belongs to a novel holotype cry and is designated as cry56Aa1. It was expressed in E. coli. Insecticidal activity assays showed that recombinant Cry56Aa1 was toxic to both Dipteran (Aedes aegypti) and Lepidopteran (Plutella xylostella and Helicoverpa armigera) pests. Cloning of this gene may hel...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Zhu J, Zheng AP, Tan FR, Wang SQ, Deng QM, Li SC, Wang LX, Li P Tags: Biotechnol Lett Source Type: journals

New insights on O(2) uptake mechanisms in two-phase partitioning bioreactors.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The objective of this paper was to quantify the direct oxygen uptake from the vector/water interface in a culture of Pseudomonas putida, performed in a stirred tank reactor, using glucose as substrate and silicone oil as vector. Despite of a sufficient dissolved O(2) concentration in the vector phase (17 mg l(-1)) and a significant vector surface area (4,000 m(-1)) no significant direct O(2) uptake from the vector/water interface was observed, compared to O(2) uptake from the aqueous phase. From these results it was concluded that, direct O(2) or substrate uptake from the vector/water interface might not be significant in ...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Quijano G, Ordaz A, Muñoz R, Thalasso F Tags: Biotechnol Lett Source Type: journals

Recombinant canstatin inhibits tumor growth in an orthotopic AT-84 oral squamous cell carcinoma model.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The inhibitory effect of recombinant canstatin on tumor growth was investigated using an orthotopic oral squamous cell carcinoma (AT-84 cells) animal (C3H/HeN) model. Recombinant canstatin from stably transfected Drosophila S2 cells was purified to homogeneity using a simple one-step Ni NTA affinity fractionation. In our oral cancer model, the final volume and weight of tumors in groups treated with purified canstatin were both reduced to 44% of values for a control group treated with PBS. Blood or lymphatic vessel densities of tumors in the canstatin-treated group were reduced to 72% and 44% of control group values, r...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Hwang-Bo J, Yoo KH, Jeong HS, Chung IS Tags: Biotechnol Lett Source Type: journals

Conversion of alpha-amyrin into centellosides by plant cell cultures of Centella asiatica.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Plant cell cultures of Centella asiatica produce small quantities of centellosides: madecassosid > asiaticosid > madecassic acid > asiatic acid. To obtain a more efficient production system of these bioactive triterpenoid compounds, we developed a process where the substrate, alpha-amyrin, was converted into centellosides by cell suspensions of C. asiatica. When alpha-amyrin in acetone was added at 0.01 mg/ml(-1) to the culture medium, together with the permeabilizing agent DMSO, after 7 days nearly 50% had penetrated the plant cells, of which almost 84% was transformed into centellosides. The system therefore...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Hernandez-Vazquez L, Bonfill M, Moyano E, Cusido RM, Navarro-Ocaña A, Palazon J Tags: Biotechnol Lett Source Type: journals

Molecular characterization of OsPAP2: transgenic expression of a purple acid phosphatase up-regulated in phosphate-deprived rice suspension cells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A phosphate starvation-induced, purple, acid phosphatase cDNA was cloned from rice, Oryza sativa. The cDNA encoding the phosphatase (OsPAP2) has 1,893 bp with an open reading frame of 630 amino acid residues. The deduced amino acid sequence of OsPAP2 shows identities of 60-63% with other plant purple acid phosphatases and appears to have five conserved motifs containing the residues involved in metal binding. OsPAP2 expression is up-regulated in the rice plant and in cell cultures in the absence of phosphate (P( i )). The induced expression of OsPAP2 is a specific response to P( i ) starvation, and is not affected by t...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Hur YJ, Jin BR, Nam J, Chung YS, Lee JH, Choi HK, Yun DJ, Yi G, Kim YH, Kim DH Tags: Biotechnol Lett Source Type: journals

Expression of Trichoderma reesei endo-beta-glucanase II in silkworm, Bombyx mori L. by using BmNPV/Bac-to-Bac expression system and its bioactivity assay.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The silkworm, Bombyx mori, was used to produce recombinant endo-beta-glucanase II (rEGII). The EGII gene (egl2) was cloned from the cellulolytic fungus Trichoderma reesei and inserted into B. mori nucleopolyhedrovirus (BmNPV) genome using BmNPV/Bac-to-Bac expression vector. For expression of rEGII, both the BmN cells and B. mori larvae were infected with the recombinant virus. The putative rEGII yield was about 386 mug per larva and the enzyme activity of the purified rEGII was approx 352 U/mg of rEGII. The optimal activity of this purified protein was observed at 55 degrees C and pH 4, respectively. PMID: 19838637...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Zhou L, Wu X, Lan L, Liu J Tags: Biotechnol Lett Source Type: journals

Cloning of a novel lipase gene, lipJ08, from Candida rugosa and expression in Pichia pastoris by codon optimization.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A novel lipase gene, lipJ08, was cloned from Candida rugosa ATCC14830, along with the already reported five lipase genes (lip1-lip5). Nucleotide sequencing indicated that the lipJ08 gene contains a 1650 bp open reading frame (ORF) without introns. The deduced amino acid sequence corresponds to 534 amino acid residues, including a putative signal sequence of 15 amino acid residues. Seventeen of the non-universal serine codons (CTG) of lipJ08 were converted into universal serine codons (TCT) by PCR-based mutagenesis. The native and codon-optimized lipJ08 genes were expressed in Pichia pastoris. The hydrolytic activity of...
Source: Biotechnology Letters - October 16, 2009 Category: Biotechnology Authors: Xu L, Jiang X, Yang J, Liu Y, Yan Y Tags: Biotechnol Lett Source Type: journals

Soluble pig lymphocyte activation gene-3 (LAG-3; CD223) inhibits human-to-pig xenogeneic mixed lymphocyte reaction.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we constructed soluble pig LAG-3 containing a critical binding site (D1 and D2 region) to MHC class II molecules, combined with a constant region of an immunoglobulin (Ig) heavy chain. Flow cytometry analyses indicated that soluble pig LAG-3 binds to both pig and human MHC class II molecules. Moreover, soluble pig LAG-3 can inhibit human lymphocyte proliferation in the human-pig xenogeneic mixed lymphocyte reaction in a dose-dependent manner. These results indicate that soluble pig LAG-3 may be useful for controlling the xenogeneic T cell immune responses between the human and pig. PMID: 19834647 [PubMed...
Source: Biotechnology Letters - October 15, 2009 Category: Biotechnology Authors: Kim SS, Byun HJ, Kim SH, Lee HH, Lee SJ, Kim SJ, Park CG, Chun T Tags: Biotechnol Lett Source Type: journals

In vitro myogenic and adipogenic differentiation model of genetically engineered bovine embryonic fibroblast cell lines.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Our current understanding of muscle and adipose tissue development has been largely restricted to the study of murine myogenic and adipogenic cell lines, since attempts to establish these cell lines from other species have met with only limited success. Here we report that a spontaneously immortalized bovine embryonic fibroblast cell line (BEFS) undergoes differentiation into adipogenic or myogenic lineages when ectopically transduced with PPARgamma2 (an adipogenic lineage determinant) or MyoD (a myogenic lineage determinant) and grown in adipogenic and myogenic differentiation culture media (ADCM and MDCM, respectivel...
Source: Biotechnology Letters - October 15, 2009 Category: Biotechnology Authors: Yin J, Jin X, Beck S, Kang DH, Hong Z, Li Z, Jin Y, Zhang Q, Choi YJ, Kim SC, Kim H Tags: Biotechnol Lett Source Type: journals

Enhanced ascorbic acid accumulation in transgenic potato confers tolerance to various abiotic stresses.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
L: -Ascorbic acid (Vitamin C, AsA) is an important component of human nutrition. Plants and several animals can synthesize their own ascorbic acid, whereas humans lack the gene essential for ascorbic acid biosynthesis and must acquire from their diet. In the present study, we developed transgenic potato (Solanum tuberosum L. cv. Taedong Valley) over-expressing L: -gulono-gamma-lactone oxidase (GLOase gene; NCBI Acc. No. NM022220), isolated from rat cells driven by CaMV35S constitutive promoter that showed enhanced AsA accumulation. Molecular analyses of four independent transgenic lines performed by PCR, Southern and R...
Source: Biotechnology Letters - October 10, 2009 Category: Biotechnology Authors: Hemavathi , Upadhyaya CP, Akula N, Young KE, Chun SC, Kim DH, Park SW Tags: Biotechnol Lett Source Type: journals

Fungal endophytes-induced abscisic acid is required for flavonoid accumulation in suspension cells of Ginkgo biloba.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Treatment of suspension cells of Ginkgo biloba with fungal endophytes resulted in accumulation of flavonoids, increased abscisic acid (ABA) production and activation of phenylalanine ammonia-lyase (PAL). Fluridone, an inhibitor of ABA biosynthesis, was effective in inhibiting fungal endophytes-induced ABA biosynthesis, increase of PAL activity and flavonoids accumulation. Moreover, exogenous application of ABA enhanced PAL activity and increased accumulation of flavonoids in G. biloba cells with or without fungal endophytes elicitor. These finding suggest a causal relationship between ABA release and both PAL activity ...
Source: Biotechnology Letters - October 10, 2009 Category: Biotechnology Authors: Hao G, Du X, Zhao F, Ji H Tags: Biotechnol Lett Source Type: journals

Surface display of active lipase in Saccharomyces cerevisiae using Cwp2 as an anchor protein.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Lipase Lip2 from Yarrowia lipolytica was displayed on the cell surface of Saccharomyces cerevisiae using Cwp2 as an anchor protein. Successful display of the lipase on the cell surface was confirmed by immunofluorescence microscopy and halo assay. The length of linker sequences was further examined to confirm that the correct conformation of Lip2 was maintained. The results showed that the displayed Lip2 exhibited the highest activity at 7.6 +/- 0.4 U/g (dry cell) when using (G(4)S)(3) sequence as the linker, with an optimal temperature and pH at 40 degrees C and pH 8.0. The displayed lipase did not lose any activity a...
Source: Biotechnology Letters - October 10, 2009 Category: Biotechnology Authors: Liu W, Zhao H, Jia B, Xu L, Yan Y Tags: Biotechnol Lett Source Type: journals

Enhanced proliferation capacity of porcine tenocytes in low O(2) tension culture.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, low O(2) tension culture can significantly enhance the expansion capacity of tenocytes without affecting their phenotype and functions. PMID: 19821074 [PubMed - as supplied by publisher] (Source: Biotechnology Letters)
Source: Biotechnology Letters - October 10, 2009 Category: Biotechnology Authors: Zhang Y, Wang B, Zhang WJ, Zhou G, Cao Y, Liu W Tags: Biotechnol Lett Source Type: journals

Post-culture treatment protocols for PLGA membrane scaffolds.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The interactions of post-culture treatments reagents used for fixing, lysing and cell quantification on poly(lactide-co-glycolide) (PLGA) flat sheet membrane scaffolds are presented. Lysing with Alkaline buffer solution/Triton X-100/MilliQ water (ATM) and fixing with 10% Neutral Buffered Formalin (10% NBF) had no affect on membrane structure while fixing with 95% ethanol caused smoothing of the surface, shrinkage and a reduction in surface area of 55, 48 and 33, for 100:0, 75:25 and 50:50 (PLA:PGA), respectively. PicoGreen assay was selected for cell (560pZIPv.neo) quantification since the background noise would not af...
Source: Biotechnology Letters - October 10, 2009 Category: Biotechnology Authors: Ellis MJ, Forsey R, Chaudhuri JB Tags: Biotechnol Lett Source Type: journals

Evaluation of ultrasound velocity measurements for estimating protease activities using casein as substrate.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Ultrasonic resonator technology (URT) was compared with the well established UV-Vis/ninhydrin assay to estimate protease activities in defined buffer systems. Hydrolysis of casein was measured using subtilisin, trypsin, halophilic protease from Haloferax mediterranei and Bacillus lentus alkaline protease. Sensitivity, reproducibility, working range as well as the limit of detection and the limit of quantification were comparable for both methods. Salt concentrations (0.5 M NaCl) interfered with the URT method. The quantification of protease activity by URT was possible when the product concentration measured by the UV-...
Source: Biotechnology Letters - October 10, 2009 Category: Biotechnology Authors: Born K, Manns A, Dzeyk K, Lutz-Wahl S, Gau D, Fischer L Tags: Biotechnol Lett Source Type: journals

Screening for conditions of enhanced production of a recombinant beta-glucanase secreted into the medium by Escherichia coli.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The extracellular production of a hybrid bacterial beta-glucanase using Escherichia coli was studied by using combinations of promoters of varying strength for both a beta-glucanase as the target protein and the Kil protein as the releasing factor. Four strains with different combinations of promoter strengths were cultivated in shake-flasks on four different media to assess the cross-influence of promoter and medium in a general manner. Promoters were taken from natural as well as synthetic sequences known to exhibit either weak or strong promoter strength. By far the highest extracellular glucanase activity (>200 ...
Source: Biotechnology Letters - October 8, 2009 Category: Biotechnology Authors: Spexard M, Beshay U, Risse JM, Miksch G, Flaschel E Tags: Biotechnol Lett Source Type: journals

Validation of extraction methods for total RNA and miRNA from bovine blood prior to quantitative gene expression analyses.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The benefit and precision of blood diagnosis by quantitative real-time PCR (qPCR) is limited by sampling procedures and RNA extraction methods. We have compared five different RNA extraction protocols from bovine blood regarding RNA and miRNA yield, quality, and most reproducible data in the qRT-PCR with the lowest point of quantification. Convincing results in terms of highest quantity, quality, and best performance for mRNA qPCR were obtained by leukocyte extraction following blood lysis as well as extraction of PAXgene stabilized blood. The best microRNA qPCR results were obtained for samples extracted by the leukoc...
Source: Biotechnology Letters - September 29, 2009 Category: Biotechnology Authors: Hammerle-Fickinger A, Riedmaier I, Becker C, Meyer HH, Pfaffl MW, Ulbrich SE Tags: Biotechnol Lett Source Type: journals

Potential adenovirus-mediated gene therapy of glioma cancer.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Malignant gliomas are typically characterized by rapid cell proliferation and a marked propensity to invade and damage surrounding tissues. They are the main brain tumors notoriously resistant to currently available therapies, since they fail to undergo apoptosis upon anticancer treatments. With recent advances in neuroscience and improved understanding of the molecular mechanisms of invasive migration, gene therapy provides a new strategy for treating glioma cancer. Brain tumor gene therapy using viral vectors and stem cells has shown promise in animal model and human patient studies. Here, we review recent studies on...
Source: Biotechnology Letters - September 26, 2009 Category: Biotechnology Authors: Fu YJ, Du J, Yang RJ, Yin LT, Liang AH Tags: Biotechnol Lett Source Type: journals

Thymidine production by overexpressing NAD(+) kinase in an Escherichia coli recombinant strain.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Intracellular NADPH/NADP(+) ratio in cells grown on various production media with different carbon and nitrogen sources had a positive correlation with the thymidine production. To improve thymidine production in a previously engineered E. coli strain, NAD(+) kinase was overexpressed in it resulting in the NADPH/NADP(+) ratio shifting from 0.184 to 0.267. The [NADH + NADP(+)]/[NAD(+) + NADPH] ratio was, however, not significantly altered. In jar fermentation, 740 mg thymidine l(-1) was produced in parental strain, while 940 mg l(-1) of thymidine was produced in NAD(+) kinase-expressing strain. PMID: 19774345 [PubMe...
Source: Biotechnology Letters - September 22, 2009 Category: Biotechnology Authors: Lee HC, Kim JS, Jang W, Kim SY Tags: Biotechnol Lett Source Type: journals

Rolling circle amplification of genomic templates for inverse PCR (RCA-GIP): a method for 5'- and 3'-genome walking without anchoring.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We have devised an improved method of genome walking, named rolling circle amplification of genomic templates for Inverse PCR (RCA-GIP). The method is based on the generation of circular genomic DNA fragments, followed by rolling circle amplification of the circular genomic DNA using varphi29 DNA polymerase without need for attachment of anchor sequences. In this way from the circular genomic DNA fragments, after RCA amplification, a large amount of linear concatemers is generated suitable for Inverse PCR template that can be amplified, sequenced or cloned allowing the isolation of the 3'- and 5'- of unknown ends of ge...
Source: Biotechnology Letters - September 16, 2009 Category: Biotechnology Authors: Tsaftaris A, Pasentzis K, Argiriou A Tags: Biotechnol Lett Source Type: journals

Production of pure beta-glucan by Aureobasidium pullulans after pullulan synthetase gene disruption.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
By disruption of the pullulan synthetase gene (pul) of Aureobasidium pullulans IMS822 KCTC11179BP, we constructed a mutant strain, A. pullulans NP1221, which produced a pure beta-glucan exopolysaccharide. The mutant NP1221 was white, whereas the wild-type strain produced a black dye. When we compared fermentation kinetics between wide-type and mutant strains, the mutant NP1221 did not produce pullulan. Substrate uptake rate and beta-glucan production were similar in both strains. However, the biomass yield of mutant NP1221 was 2.3-fold (9.2 g l(-1)) greater than that of wild-type. PMID: 19760116 [PubMed - as suppli...
Source: Biotechnology Letters - September 16, 2009 Category: Biotechnology Authors: Kang BK, Yang HJ, Choi NS, Ahn KH, Park CS, Yoon BD, Kim MS Tags: Biotechnol Lett Source Type: journals

Pr-1, a novel antifungal protein from pumpkin rinds.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A novel antifungal protein, M(r) = ca. 40 kDa, was isolated from pumpkin rind and designated Pr-1. When purified by anion exchange chromatography and HPLC, it inhibited growth of several fungi including Botrytis cinerea, Fusarium oxysporum, Fusarium solani and Rhizoctonia solani, as well as the yeast, Candida albicans, at 10-20 muM. It did not inhibit growth of Escherichia coli or Staphylococcus aureus even at 200 muM. Laser scanning microscopy of fungal cells exposed to rhodamine-labeled Pr-1 revealed that the protein accumulated and was localized on the cell surface. Uptake of the vital stain, SYTOX Green, was enhanc...
Source: Biotechnology Letters - September 16, 2009 Category: Biotechnology Authors: Park SC, Lee JR, Kim JY, Hwang I, Nah JW, Cheong H, Park Y, Hahm KS Tags: Biotechnol Lett Source Type: journals

Diastereoselective synthesis of L: -threo-3,4-dihydroxyphenylserine by low-specific L: -threonine aldolase mutants.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Diastereoselectivity-enhanced mutants of L: -threonine aldolase (L: -TA) for L: -threo-3,4-dihydroxyphenylserine (L: -threo-DOPS) synthesis were isolated by error-prone PCR followed by a high-throughput screening. The most improved mutant was achieved from the mutant T3-3mm2, showing a 4-fold increase over the wild-type L: -TA. When aldol condensation activity was examined using whole cells of T3-3mm2, its de was constantly maintained at 55% during the batch reactions for 80 h, yielding 3.8 mg L: -threo-DOPS/ml. PMID: 19760118 [PubMed - as supplied by publisher] (Source: Biotechnology Letters)
Source: Biotechnology Letters - September 16, 2009 Category: Biotechnology Authors: Gwon HJ, Baik SH Tags: Biotechnol Lett Source Type: journals

Fed-batch operation of an industrial cell culture process in shaken microwells.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Recently we have demonstrated batch suspension culture of mammalian cells in microwell plates. Here we describe a method for fed-batch culture of an industrially relevant GS-CHO (Glutamine Synthetase-Chinese Hamster Ovary) cell line in shaken 24-standard round well (24-SRW) plates. Use of a commercially available 'sandwich lid' and appropriate dilution of the bolus feeds counteracted liquid evaporation from the wells resulting in similar cell growth and antibody formation kinetics in both 24-SRW plates (800 mul) and shaken flasks (50 ml). Peak viable cell densities obtained were 8 +/- 0.5 x 10(6) and 9 +/- 1.3 x 10(6) ...
Source: Biotechnology Letters - September 16, 2009 Category: Biotechnology Authors: Silk NJ, Denby S, Lewis G, Kuiper M, Hatton D, Field R, Baganz F, Lye GJ Tags: Biotechnol Lett Source Type: journals

Preparation of cross-linked carboxymethyl chitosan for repairing sciatic nerve injury in rats.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A successful nerve regeneration process was achieved with nerve repair tubes made up of 1-ethyl-3(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) cross-linked carboxymethyl chitosan (CM-chitosan) with improved biodegradability. Chitosan has a very slow degradation rate, while the EDC cross-linked CM-chitosan tubes degraded to 30% of original weight during 8 weeks of incubation in lysozyme solution. In vitro cell culture indicated that the CM-chitosan films presented no cytotoxicity to Schwann cells. From in vivo studies using a 10 mm rat sciatic nerve defect model investigated by histomorphometry analysis, the ...
Source: Biotechnology Letters - September 16, 2009 Category: Biotechnology Authors: Wang G, Lu G, Ao Q, Gong Y, Zhang X Tags: Biotechnol Lett Source Type: journals

Constitutive production of the receptor-binding domain of the F18 fimbriae on the surface of Lactococcus lactis using synthetic promoters.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Nine synthetic constitutive promoters with different activities were produced for the surface display of the receptor-binding domain of the F18 fimbrial adhesin FedF in Lactococcus lactis. The promoters were synthesized from an oligonucleotide, designed to allow for randomization of bases between defined lactococcal promoter consensus regions. However, promoters with spontaneous modifications were selected for fedF expression, indicating that the consensus promoter was too strong. The amount of FedF on the surface of the best performing promoter clone was comparable to the amount of FedF produced by a L. lactis strain ...
Source: Biotechnology Letters - September 16, 2009 Category: Biotechnology Authors: Lindholm A, Palva A Tags: Biotechnol Lett Source Type: journals

Residue Tyr224 is critical for the thermostability of Geobacillus sp. RD-2 lipase.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A thermophilic lipase (lipGRD) from Geobacillus sp. RD-2, isolated from a hot spring in Yunnan, China, was cloned and over-expressed in Escherichia coli. The function of the conserved residue, Tyr224, near the presumed temperature switch site was analyzed by site-directed saturation mutagenesis. The activity of the wild type lipGRD was optimal at 55 degrees C and pH 7.5, but that from mutant Y224C was optimally active at 35 degrees C, whereas Y224P lipase was optimally active at 65 degrees C. Furthermore, the latter lipase retained 60% of its activity after incubation at 65 degrees C for 5 h. The conserved residue Tyr2...
Source: Biotechnology Letters - September 8, 2009 Category: Biotechnology Authors: Wu L, Liu B, Hong Y, Sheng D, Shen Y, Ni J Tags: Biotechnol Lett Source Type: journals

Stability of transgenes in long-term micropropagation of plants of transgenic birch (Betula platyphylla).Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The stability of integration and expression level of transgenes in long-term micropropagation clones of transgenic birch (Betula platyphylla Suk.) was examined. Multiplexed PCR and reverse primer PCR demonstrated stable integration of transgenes into regenerated plants. Expression levels of the bgt and gus genes among shoot plantlets, subcultured 4, 7, 9 and 15 times, were significantly different. The transcriptional expression level of extraneous genes in regenerated plants decreased with increasing subculture number. Transcriptional gene silencing (TGS) occured in regenerated transgenic lines. The silencing rate of G...
Source: Biotechnology Letters - September 2, 2009 Category: Biotechnology Authors: Zeng F, Qian J, Luo W, Zhan Y, Xin Y, Yang C Tags: Biotechnol Lett Source Type: journals

Cellulose hydrolysis by immobilized Trichoderma reesei cellulase.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Cellulose hydrolysis by immobilized Trichoderma reesei cellulase in the presence of a low viscosity ionic liquid, 1-ethyl-3-methylimidazolium diethyl phosphate (EMIM-DEP), was investigated. Preparation of the carrier-free immobilized cellulase was optimized with respect to concentration of the cross-linker and the type of precipitant. The addition of 2% (v/v) EMIM-DEP during hydrolysis gave an initial reaction rate 2.7 times higher than the hydrolysis rate with no ionic liquid. The initial yield after 2 h was 0.7 g glucose/g cellulose, and the carrier-free immobilized cellulase (CFIC) was effectively re-used five times...
Source: Biotechnology Letters - September 2, 2009 Category: Biotechnology Authors: Jones PO, Vasudevan PT Tags: Biotechnol Lett Source Type: journals

Electricity generation coupled to oxidation of propionate in a microbial fuel cell.Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Propionate was used as fuel to enrich an electrochemically-active microbial consortium in a microbial fuel cell, and the bacterial consortium was analyzed by culture-independent methods including denaturing gradient gel electrophoresis (DGGE) of the 16S rDNA, and by fluorescent in situ hybridization (FISH). MFCs fed with propionate produced a current of 4.88 +/- 0.1 mA stably on 100 mg propionate/l as COD within 3 weeks of the enrichment. When the MFCs were fed with H(2)-saturated fuel containing propionate, the current dropped to 3.82 +/- 0.07 mA. The maximum current generated was up to 8.8 mA when MFCs were fed with ...
Source: Biotechnology Letters - September 2, 2009 Category: Biotechnology Authors: Jang JK, Chang IS, Hwang HY, Choo YF, Lee J, Cho KS, Kim BH, Nealson KH Tags: Biotechnol Lett Source Type: journals