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Backgroundγ-Aminobutyric acid (GABA) bypasses the TCA cycle via GABA shunt, suggesting a relationship with respiration. However, little is known about its role in seed germination under salt conditions.ResultsIn this study, exogenous GABA was shown to have almost no influence on mungbean seed germination, except 0.1 mM at 10 h, while it completely alleviated the inhibition of germination by salt treatment. Seed respiration was significantly inhibited by 0.1 and 0.5 mM GABA, but was evidently enhanced under salt treatment, whereas both were promoted by 1 mM GABA alone or with salt treatment. Mitochondrial respiration also showed a similar trend at 0.1 mM GABA. Moreover, proteomic analysis further showed that 43 annotated proteins were affected by exogenous GABA, even 0.1 mM under salt treatment, including complexes of the mitochondrial respiratory chain.ConclusionsOur study provides new evidence that GABA may act as a signal molecule in regulating respiration of mungbean seed germination in response to salt stress.How to citeJi J, Shi S, Chen W, et al. Effects of exogenous γ-Aminobutyric acid on the regulation of respiration and protein expression in germinating seeds of mungbean (Vigna radiata) under salt conditions. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.05.005  相似文献   

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BackgroundPoly-3-hydroxybutyrate (PHB) can be efficiently produced in recombinant Escherichia coli by the overexpression of an operon (NphaCAB) encoding PHB synthetase. Strain improvement is considered to be one of critical factors to lower the production cost of PHB in recombinant system. In this study, one of key regulators that affect the cell growth and PHB content was confirmed and analyzed.ResultS17-3, a mutant E. coli strain derived from S17-1, was found to be able to achieve high cell density when expressing NphaCAB with the plasmid pBhya-CAB. Whole genome sequencing of S17-3 revealed genetic alternations on the upstream regions of csrA, encoding a global regulator cross-talking between stress response, catabolite repression and other metabolic activities. Deletion of csrA or expression of mutant csrA resulted in improved cell density and PHB content.ConclusionThe impact of gene deletion of csrA was determined, dysfunction of the regulators improved the cell density of recombinant E. coli and PHB production, however, the detail mechanism needs to be further clarified.How to cite: Wu H, Li S, Ji M, et al. Improvement of polyhydroxybutyrate production by deletion of csrA in Escherichia coli. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.04.005.  相似文献   

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BackgroundTraditionally, microbial genome sequencing has been restrained to the species grown in pure culture. The development of culture-independent techniques over the last decade allows scientists to sequence microbial communities directly from environmental samples. Metagenomics is the study of complex genome by the isolation of DNA of the whole community. Next generation sequencing (NGS) of metagenomic DNA gives information about the microbial and taxonomical characterization of a particular niche. The objective of the present research is to study the microbial and taxonomical characterization of the metagenomic DNA, isolated from the frozen soil sample of a glacier in the north western Himalayas through NGS.ResultsThe glacier community comprised of 16 phyla with the representation of members belonging to Proteobacteria and Acidobacteria. The number of genes annotated through the Kyoto Encyclopedia of Genes and Genomes (KEGG), GO, Pfam, Clusters of Orthologous Groups of proteins (COGs), and FIG databases were generated by COGNIZER. The annotation of genes assigned in each group from the metagenomics data through COG database and the number of genes annotated in different pathways through KEGG database were reported.ConclusionResults indicate that the glacier soil taken in the present study, harbors taxonomically and metabolically diverse communities. The major bacterial group present in the niche is Proteobacteria followed by Acidobacteria, and Actinobacteria, etc. Different genes were annotated through COG and KEGG databases that integrate genomic, chemical, and systemic functional information.How to cite: Gupta V, Singh I, Rasool S, et al. Next Generation sequencing and microbiome’s taxonomical characterization of frozen soil of North Western Himalayas of Jammu and Kashmir, India. Electron J Biotechnol 2020;45. https://doi.org/10.1016/j.ejbt.2020.03.003.  相似文献   

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BackgroundManno-oligosaccharides (MOS) is known as a kind of prebiotics. Mannanase plays a key role for the degradation of mannan to produce MOS. In this study, the mannanases of glycoside hydrolase (GH) families 5 Man5HJ14 and GH26 ManAJB13 were employed to prepare MOS from locust bean gum (LBG) and palm kernel cake (PKC). The prebiotic activity and utilization of MOS were assessed in vitro using the probiotic Lactobacillus plantarum strain.ResultsGalactomannan from LBG was converted to MOS ranging in size from mannose up to mannoheptose by Man5HJ14 and ManAJB13. Mannoheptose was got from the hydrolysates produced by Man5HJ14, which mannohexaose was obtained from LBG hydrolyzed by ManAJB13. However, the same components of MOS ranging in size from mannose up to mannotetrose were observed between PKC hydrolyzed by the mannanases mentioned above. MOS stability was not affected by high-temperature and high-pressure condition at their natural pH. Based on in vitro growth study, all MOS from LBG and PKC was effective in promoting the growth of L. plantarum CICC 24202, with the strain preferring to use mannose to mannotriose, rather than above mannotetrose.ConclusionsThe effect of mannanases and mannan difference on MOS composition was studied. All of MOS hydrolysates showed the stability in adversity condition and prebiotic activity of L. plantarum, which would have potential application in the biotechnological applications.How to cite: Zhang R, Li X-Y, Cen X-L, et al. Enzymatic preparation of manno-oligosaccharides from locust bean gum and palm kernel cake, and investigations into its prebiotic activity. Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.11.001  相似文献   

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BackgroundThe preparation of broad bean koji is a key process in the production of Pixian broad bean paste (PBP). Protease is essential for the degradation of proteins during PBP fermentation. To obtain broad bean koji with high protease activity using the cocultivated strains of Aspergillus oryzae QM-6 (A. oryzae QM-6) and Aspergillus niger QH-3 (A. niger QH-3), the optimization of acid and neutral protease activities was carried out using Box–Behnken design with response surface methodology (RSM).ResultsThe optimum conditions were found to be as follows: inoculation proportion (X1), 3:1 (A. oryzae QM-6: A. niger QH-3, w/w); culture temperature (X2), 33°C; inoculum size (X3), 0.5% (w/w); incubation time (X4), 5 d. The acid and neutral protease activities were 605.2 ± 12.4 U/g and 1582.9 ± 23.7 U/g, respectively, which were in good agreement with the predicted values. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles revealed that the broad bean koji extracellular proteins in the case of cocultivation were richer compared to those in the case of A. oryzae QM-6 or A. niger QH-3 strain only. In addition, the free amino acids (FAAs) in the fermentation product were 55% higher in the cocultivation process than in that involving only A. oryzae QM-6, further confirming the diversity of proteases in the fermentation products.ConclusionsThe optimal conditions of koji-making in PBP were obtained using RSM. The cocultivation of A. oryzae and A. niger increases the overall enzyme activities in the culture medium and the FAAs content, which would thus have potential application in the PBP industry.How to cite: Tang J, Chen T, Hu Q, et al. Improved protease activity of Pixian broad bean paste with cocultivation of Aspergillus oryzae QM-6 and Aspergillus niger QH-3. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.001.  相似文献   

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BackgroundThe harmful effects of type 2 diabetes mellitus and its complications have become a major global public health problem. In this study, the effects of Momordica charantia saponins (MCS) on lipid metabolism, oxidative stress, and insulin signaling pathway in type 2 diabetic rats were investigated.ResultsMCS could attenuate the tendency of weight loss of the model rats. It could also improve glucose tolerance; reduce fasting blood glucose, nonesterified fatty acid, triglyceride, and total cholesterol; and increase the insulin content and insulin sensitivity index of the rats. The activity of superoxide dismutase and catalase increased, and the content of malondialdehyde decreased in the liver and pancreas tissues of rats in MCS-treated groups significantly. In addition, the expression of p-IRS-1 (Y612) and p-Akt (S473) increased, and the expression of p-IRS-1 (S307) decreased in the liver tissues and pancreas tissues of rats in MCS-treated groups significantly.ConclusionMCS has an antidiabetic effect, which may be related to its improving the lipid metabolism disorder, reducing oxidative stress level, and regulating the insulin signaling pathway.How to cite: Jiang S, Xu L, Xu X, et al. Anti-diabetic effect of Momordica charantia saponins in rats induced by high-fat diet combined with STZ. Electron J Biotechnol 2020;43. https://doi.org/10.1016/j.ejbt.2019.12.001.  相似文献   

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BackgroundThe intestinal bacterial community has an important role in maintaining human health. Dysbiosis is a key inducer of many chronic diseases including obesity and diabetes. Kunming mice are frequently used as a model of human disease and yet little is known about the bacterial microbiome resident to the gastrointestinal tract.ResultsWe undertook metagenomic sequencing of the luminal contents of the stomach, duodenum, jejunum, ileum, cecum, colon, and rectum of Kunming mice. Firmicutes was the dominant bacterial phylum of each intestinal tract and Lactobacillus the dominant genus. However, the bacterial composition differed among the seven intestinal tracts of Kunming mice. Compared with the small intestine, the large intestine bacterial community of Kunming mice is more stable and diverse.ConclusionsTo our knowledge, ours is the first study to systematically describe the gastrointestinal bacterial composition of Kunming mice. Our findings provide a better understanding of the bacterial composition of Kunming mice and serves as a foundation for the study of precision medicine.How to cite: Han X, Shao H, Wang Y, et al. Composition of the bacterial community in the gastrointestinal tract of Kunming mice. Electron J Biotechnol 2020;43. https://doi.org/10.1016/j.ejbt.2019.11.003  相似文献   

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BackgroundEndometritis is the most common disease of dairy cows and traditionally treated with antibiotics. Lactic acid bacteria can inhibit the growth of pathogens and also have potential for treatment of endometritis. Using PacBio single-molecule real-time sequencing technology, we sequenced the full-length l6S rRNA of the microbiota in uterine mucus samples from 31 cows with endometritis, treated with lactic acid bacteria (experimental [E] group) and antibiotics (control [C] group) separately. Microbiota profiles taken before and after treatment were compared.ResultsAfter both treatments, bacterial species richness was significantly higher than before, but there was no significant difference in bacterial diversity. Abundance of some bacteria increased after both lactic acid bacteria and antibiotic treatment: Lactobacillus helveticus, Lactococcus lactis, Lactococcus raffinolactis, Pseudomonas alcaligenes and Pseudomonas veronii. The bacterial species that significantly decreased in abundance varied depending on whether the cows had been treated with lactic acid bacteria or antibiotics. Abundance of Staphylococcus equorum and Treponema brennaborense increased after lactic acid bacteria treatment but decreased after antibiotic treatment. According to COG-based functional metagenomic predictions, 384 functional proteins were significantly differently expressed after treatment. E and C group protein expression pathways were significantly higher than before treatment (p < 0.05).ConclusionsIn this study, we found that lactic acid bacteria could cure endometritis and restore a normal physiological state, while avoiding the disadvantages of antibiotic treatment, such as the reductions in abundance of beneficial microbiota. This suggests that lactic acid bacteria treatment has potential as an alternative to antibiotics in the treatment of endometritis in cattle.How to cite: Yang L, Huang W, Yang C, et al. Using PacBio sequencing to investigate the effects of treatment with lactic acid bacteria or antibiotics on cow endometritis. Electron J Biotechnol 2021:51. https://doi.org/10.1016/j.ejbt.2021.02.004  相似文献   

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BackgroundVibrio species display variable and plastic fitness strategies to survive and interact with multiple hosts, including marine aquaculture species that are severely affected by pathogenic Vibrios. The culturable Vibrio sp. strain ArtGut-C1, the focus of this study, provides new evidence of such phenotypic plasticity as it accumulates polyhydroxybutyrate (PHB), a biodegradable polymer with anti-pathogen activity, particularly in the marine larviculture phase. The strain was isolated from the gut of laboratory-reared Artemia individuals, the live diet and PHB carrier used in larviculture. Its main phenotypic properties, taxonomic status and genomic properties are reported based on the whole-genome sequencing.ResultsVibrio sp. ArtGut-C1 yielded 72.6% PHB of cells’ dry weight at 25°C. The genomic average nucleotide identity (ANI) shows it is closely related to V. diabolicus (ANI: 88.6%). Its genome contains 5,236,997-bp with 44.8% GC content, 3,710 protein-coding sequences, 96 RNA, 9 PHB genes functionally related to PHB metabolic pathways, and several genes linked to competing and colonizing abilities.ConclusionsThis culturable PHB-accumulating Vibrio strain shows high genomic and phenotypic variability. It may be used as a natural pathogen biocontrol in the marine hatchery and as a potential cell factory for PHB production.How to cite: Yévenes M, Quiroz M, Maruyama F, et al. Vibrio sp. ArtGut-C1, a polyhydroxybutyrate producer isolated from the gut of the aquaculture live diet Artemia (Crustacea). Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.10.003  相似文献   

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BackgroundAgkistrodon acutus, a traditional Chinese medicine, clinically used in the treatment of rheumatism, tumor, and cardiovascular and cerebrovascular diseases. Due to the unique medicinal value and the difficulty of artificial breeding of Agkistrodon acutus, the supply of Agkistrodon acutus on the market exceeds the demand, and a large number of its adulterants are found on the market. In this study, the cytb gene sequences of Agkistrodon acutus and 9 snakes were compared and analyzed, specific primers were designed, and specific PCR methods were established to detect Agkistrodon acutus medicinal samples on the market.ResultsThis method was successfully applied to distinguish the snake from other adulterated species, and tested 18 Agkistrodon acutus samples randomly purchased from six cities. Twelve samples were counterfeit and six were genuine. The standard reference material of Agkistrodon acutus was cloned by molecular cloning and sequencing, and the gene sequence difference with other species was significant. It shows that the region could be used as the fingerprint region of the target species.ConclusionsThe proposed method can be used as a species-specific marker and can be highly distinguished from other adulterated snake species, which is helpful to effectively avoid the problem of false sale of Agkistrodon acutus.How to cite: Yingnuo L, Yanshuang W, Mingcheng Li, et al. Development of a species-specific PCR assay for authentication of Agkistrodon acutus based on mitochondrial cytochrome b gene. Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.07.005  相似文献   

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BackgroundPiercing/sucking insect pests in the order Hemiptera causes substantial crop losses by removing photoassimilates and transmitting viruses to their host plants. Cloning and heterologous expression of plant-derived insect resistance genes is a promising approach to control aphids and other sap-sucking insect pests. While expression from the constitutive 35S promoter provides broad protection, the phloem-specific rolC promoter provides better defense against sap sucking insects. The selection of plant-derived insect resistance genes for expression in crop species will minimize bio-safety concerns.ResultsPinellia ternata leaf agglutinin gene (pta), encodes an insecticidal lectin, was isolated and cloned under the 35S and rolC promoters in the pGA482 plant transformation vector for Agrobacterium-mediated tobacco transformation. Integration and expression of the transgene was validated by Southern blotting and qRT-PCR, respectively. Insect bioassays data of transgenic tobacco plants showed that expression of pta under rolC promoter caused 100% aphid mortality and reduced aphid fecundity up to 70% in transgenic tobacco line LRP-9. These results highlight the better effectivity of pta under rolC promoter to control phloem feeders, aphids.ConclusionsThese findings suggested the potential of PTA against aphids and other sap sucking insect pests. Evaluation of gene in tobacco under two different promoters; 35S constitutive promoter and rolC phloem-specific promoter could be successfully use for other crop plants particularly in cotton. Development of transgenic cotton plants using plant-derived insecticidal, PTA, would be key step towards commercialization of environmentally safe insect-resistant crops.How to citeUmer N, Naqvi RZ, Rauf I, et al. Expression of Pinellia ternata leaf agglutinin under rolC promoter confers resistance against a phytophagous sap sucking aphid, Myzus persicae. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.07.004.  相似文献   

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BackgroundThis paper presents micro- and nano-fabrication techniques for leachable realgar using the extremophilic bacterium Acidithiobacillus ferrooxidans (A. ferrooxidans) DLC-5.ResultsRealgar nanoparticles of size ranging from 120 nm to 200 nm were successfully prepared using the high-energy ball mill instrument. A. ferrooxidans DLC-5 was then used to bioleach the particles. The arsenic concentration in the bioleaching system was found to be increased significantly when compared with that in the sterile control. Furthermore, in the comparison with the bioleaching of raw realgar, nanoparticles could achieve the same effect with only one fifth of the consumption.ConclusionEmphasis was placed on improving the dissolvability of arsenic because of the great potential of leachable realgar drug delivery in both laboratory and industrial settings.How to cite: Xu R, Song P, Wang J, et al. Bioleaching of realgar nanoparticles using the extremophilic bacterium Acidithiobacillus ferrooxidans DLC. Electron J Biotechnol 2019;38. https://doi.org/10.1016/j.ejbt.2019.01.001.  相似文献   

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