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1.
BackgroundThe use of agro-industrial wastes to produce high value-added biomolecules such as biosurfactants is a promising approach for lowering the total costs of production. This study aimed to produce biosurfactants using Rhizopus arrhizus UCP 1607, with crude glycerol (CG) and corn steep liquor (CSL) as substrates. In addition, the biomolecule was characterized, and its efficiency in removing petroderivatives from marine soil was investigated.ResultsA 22 factorial design was applied, and the best condition for producing the biosurfactant was determined in assay 4 (3% CG and 5% CSL). The biosurfactant reduced the surface tension of water from 72 to 28.8 mN/m and produced a yield of 1.74 g/L. The preliminary biochemical characterization showed that the biosurfactant consisted of proteins (38.0%), carbohydrates (35.4%), and lipids (5.5%). The compounds presented an anionic character, nontoxicity, and great stability for all conditions tested. The biomolecule displayed great ability in dispersing hydrophobic substrates in water, thereby resulting in 53.4 cm2 ODA. The best efficiency of the biosurfactant in removing the pollutant diesel oil from marine soil was 79.4%.ConclusionsThis study demonstrated the ability of R. arrhizus UCP1607 to produce a low-cost biosurfactant characterized as a glycoprotein and its potential use in the bioremediation of the hydrophobic diesel oil pollutant in marine soil.How to cite: Pele MA, Ribeaux DR, Vieira ER, et al. Conversion of renewable substrates for biosurfactant production by Rhizopus arrhizus UCP 1607 and enhancing the removal of diesel oil from marine soil. Electron J Biotechnol 2019;38. https://doi.org/10.1016/j.ejbt.2018.12.003. 相似文献
2.
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
3.
BackgroundChia seeds are gaining increasing interest among food producers and consumers because of their prohealth properties.ResultsThe aim of this work was to evaluate the potential of chia seeds to act as acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. The highest inhibitory activity against AChE and BChE was observed for colored seed ethanol extracts. A positive correlation was found between the presence of quercetin and isoquercetin as well as protocatechuic, hydroxybenzoic, and coumaric acids and the activity of extracts as AChE and BChE inhibitors. It has also been shown that grain fragmentation affects the increase in the activity of seeds against cholinesterases (ChE). Furthermore, seeds have been shown to be a source of substances that inhibit microbial growth.ConclusionsIt was found that the chia seed extracts are rich in polyphenols and inhibit the activity of ChEs; therefore, their use can be considered in further research in the field of treatment and prevention of neurodegenerative diseases.How to cite: Kobus-Cisowska J, Szymanowska D, Maciejewska P, et al. In vitro screening for acetylcholinesterase and butyrylcholinoesterase inhibition and antimicrobial activity of chia seeds (Salvia hispanica). Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.10.002 相似文献
4.
BackgroundFreeze-drying is known as one of the best methods to preserve bacterial strains. Protectant is the key factor affecting the survival rate of freeze-dried strains. In addition, salinity, bacterial suspension concentration, drying time, and other factors can also affect the survival rate of strains to varying degrees. At present, there are relatively few studies on freeze-drying preservation of marine bacteria. In the present study, we performed the freeze-drying protectant screening and optimized the preservation conditions for Pseudoalteromonas nigrifaciens, which is widely distributed in marine environment. The protective effects of the screened protectants were verified by 18 other marine bacterial strains.ResultsThe results indicated that the combination of 5.0% (w/v) lactose, 5.0% (w/v) mannitol, 5.0% (w/v) trehalose, 10.0% (w/v) skim milk powder, 0.5% (w/v) ascorbic acid and 0.5% (w/v) gelatin was the best choice for the preservation of P. nigrifaciens. The suggested salinity and concentration of initial cell suspension were 10 g/L NaCl and 1.0 × 109 CFU/mL, respectively. Furthermore, stationary-phase cells were the best choice for the freeze-drying process. The highest survival rate of P. nigrifaciens reached 52.8% when using 5–10% (w/v) skim milk as rehydration medium. Moreover, the other 18 marine strains belonging to Pseudoalteromonas, Vibrio, Photobacterium, Planomicrobium, Edwardsiella, Enterococcus, Bacillus, and Saccharomyces were freeze-dried under the abovementioned conditions. Their survival rates were 2.3–95.1%.ConclusionCollectively, our results supported that the protectant mixture and parameters were beneficial for lyophilization of marine bacteria.How to cite: Zhang Z, Yu Y, Wang Y, et al. Development of new protocol for freeze-drying preservation of Pseudoalteromonas nigrifaciens and its protective effect on other marine bacteria. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2019.12.006. 相似文献
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BackgroundThe increasing rate of breast cancer globally requires extraordinary efforts to discover new effective sources of chemotherapy with fewer side effects. Glutaminase-free l-asparaginase is a vital chemotherapeutic agent for various tumor malignancies. Microorganisms from extreme sources, such as marine bacteria, might have high l-asparaginase productivity and efficiency with exceptional antitumor action toward breast cancer cell lines.Resultsl-Asparaginase-producing bacteria, Bacillus velezensis isolated from marine sediments, were identified by 16S rRNA sequencing. l-Asparaginase production by immobilized cells was 61.04% higher than that by free cells fermentation. The significant productivity of enzyme occurred at 72 h, pH 6.5, 37°C, 100 rpm. Optimum carbon and nitrogen sources for enzyme production were glucose and NH4Cl, respectively. l-Asparaginase was free from glutaminase activity, which was crucial medically in terms of their severe side effects. The molecular weight of the purified enzyme is 39.7 KDa by SDS-PAGE analysis and was ideally active at pH 7.5 and 37°C. Notwithstanding, the highest stability of the enzyme was found at pH 8.5 and 70°C for 1 h. The enzyme kinetic parameters displayed Vmax at 41.49 μmol/mL/min and a Km of 3.6 × 10−5 M, which serve as a proof of the affinity to its substrate. The anticancer activity of the enzyme against breast adenocarcinoma cell lines demonstrated significant activity toward MDA-MB-231 cells when compared with MCF-7 cells with IC50 values of 12.6 ± 1.2 μg/mL and 17.3 ± 2.8 μg/mL, respectively.ConclusionThis study provides the first potential of glutaminase-free l-asparaginase production from the marine bacterium Bacillus velezensis as a prospect anticancer pharmaceutical agent for two different breast cancer cell lines.How to cite: Mostafa Y, Alrumman S, Alamri S, et al. Enhanced production of glutaminase-free L-asparaginase by marine Bacillus velezensis and cytotoxic activity against breast cancer cell lines. Electron J Biotechnol 2019;42. https://doi.org/10.1016/j.ejbt.2019.10.001. 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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BackgroundFermentation strategies for bioethanol production that use flocculating Saccharomyces cerevisiae yeast need to account for the mechanism by which inhibitory compounds, generated in the hydrolysis of lignocellulosic materials, are tolerated and detoxified by a yeast floc.ResultsDiffusion coefficients and first-order kinetic bioconversion rate coefficients were measured for three fermentation inhibitory compounds (furfural, hydroxymethylfurfural, and vanillin) in self-aggregated flocs of S. cerevisiae NRRL Y-265. Thièle-type moduli and internal effectiveness factors were obtained by simulating a simple steady-state spherical floc model.ConclusionsThe obtained values for the Thiéle moduli and internal effectiveness factors showed that the bioconversion rate of the inhibitory compounds is the dominant phenomenon over mass transfer inside the flocs.How to cite: Landaeta R, Acevedo F, Aroca G. Effective diffusion coefficients and bioconversion rates of inhibitory compounds in flocs of Saccharomyces cerevisiae. Electron J Biotechnol 2019;42. https://doi.org/10.1016/j.rjbt.2019.08.001 相似文献
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BackgroundPyruvic acid (PA), a vital α-oxocarboxylic acid, plays an important role in energy and carbon metabolism. The oleaginous yeast Yarrowia lipolytica (Y. lipolytica) has considerable potential for the production of PA. An increased NaCl concentration reportedly increases the biomass and PA yield of Y. lipolytica.ResultsTo increase the yield of PA, the NaCl-tolerant Y. lipolytica A4 mutant was produced using the atmospheric and room temperature plasma method of mutation. The A4 mutant showed growth on medium containing 160 g/L NaCl. The PA yield of the A4 mutant reached 97.2 g/L at 120 h (0.795 g/g glycerol) in a 20-L fermenter with glycerol as the sole carbon source, which was 28.9% higher than that of the parental strain.ConclusionThe PA yield from Y. lipolytica can be improved by increasing its NaCl tolerance.How to cite: Yuan W, Lin X, Zhong S, et al. Enhanced pyruvic acid yield in an osmotic stress-resistant mutant of Yarrowia lipolytica. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.002. 相似文献
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BackgroundBioremoval of phenolic compounds using fungi and bacteria has been studied extensively; nevertheless, trinitrophenol bioremediation using modified Oscillatoria cyanobacteria has been barely studied in the literature.ResultsAmong the effective parameters of bioremediation, algal concentration (3.18 g·L−1), trinitrophenol concentration (1301 mg·L−1), and reaction time (3.75 d) were screened by statistical analysis. Oscillatoria cyanobacteria were modified by starch/nZVI and starch/graphene oxide in a bubble column bioreactor, and their bioremoval efficiency was investigated. Modifiers, namely, starch/zero-valent iron and starch/GO, increased trinitrophenol bioremoval efficiency by more than 10% and 12%, respectively, as compared to the use of Oscillatoria cyanobacteria alone.ConclusionsIt was found that starch/nano zero-valent iron and starch/GO could be applied to improve the removal rate of phenolic compounds from the aqueous solution.How to cite: Bavandi R, Emtyazjoo M, Saravi HN, et al. Study of nano-structure zero-valent iron and graphene-oxid capability onbioremoval of trinitrophenol from wastewater in a bubble column bioreactor. Electron J Biotechnol 2019;39. https://doi.org/10.1016/j.ejbt.2019.02.003. 相似文献
10.
BackgroundRice sheath blight (caused by Rhizoctonia solani) and tobacco mosaic virus are very important plant diseases, causing a huge loss in global crop production. Paenibacillus kribbensis PS04 is a broad-spectrum biocontrol agent, used for controlling these diseases. Previously, extracellular polysaccharides (EPS) from P. kribbensis PS04 had been purified and their structure was inferred to be fructosan. This study aimed to evaluate the effects of exogenous EPS treatment on plant–pathogen interactions.ResultsPlant defense genes such as phenylalanine ammonia-lyase, catalase, chitinase, allene oxide synthase, and PR1a proteins were significantly induced by exogenous EPS treatment. Moreover, subsequent challenge of EPS-pretreated plants with the pathogens (R. solani or tobacco mosaic virus) resulted in higher expression of defense-associated genes. Increased activities of defense-associated enzymes, total phenols, and flavonoids were also observed in EPS pretreated plants. The contents of malondialdehyde in plants, which act as indicator of lipid peroxidation, were reduced by EPS treatment.ConclusionsThis study comprehensively showed that EPS produced from P. kribbensis PS04 enhances disease resistance in plants by the activation of defense-associated genes as well as through the enhancement of activities of defense-related enzymes.How to citeCanwei S, Xiaoyun H, Ahmed N, et al. Fructosan form Paenibacillus kribbensis PS04 enhance disease resistance against Rhizoctonia solani and tobacco mosaic virus. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.07.002 相似文献
11.
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
12.
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
13.
BackgroundThe main objective of this study was to isolate fungi associated with Anthopleura xanthogrammica and measure their antimicrobial and enzymatic activities. A total of 93 fungal strains associated with A. xanthogrammica were isolated in this study, of which 32 isolates were identified using both morphological characteristics and internal transcribed spacer (ITS) sequence analysis. The antibacterial activities of 32 fungal isolates were tested against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Edwardsiella tarda, Vibrio harveyi, Fusarium oxysporum, and Pyricularia oryzae by agar diffusion assay. Extracellular hydrolytic enzyme activities of the fungal isolates were determined by agar diffusion assays. Enzyme activities were detected from clear halo size.ResultsThe isolated fungi belonged to 18 genera within 7 taxonomic orders of 1 phylum. The genera Aspergillaceae were the most diverse and common. The antimicrobial activities of 32 isolates were evaluated, and 19 (59.4%) of fungi isolate displayed unique antimicrobial activities. All fungal strains displayed at least one enzyme activity. The most common enzyme activities in the fungi isolates were amylase and protease, while the least common were pectinase and xylanase.ConclusionsThis is first report on the sea anemone-derived fungi with antimicrobial and enzyme activities. Results indicated that sea anemone is a hot spot of fungal diversity and a rich resource of bioactive natural products.How to cite: Liu S, Ahmed S, Zhang C, et al. Diversity and antimicrobial activity of culturable fungi associated with sea anemone Anthopleura xanthogrammica. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.003 相似文献
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15.
BackgroundAcidithiobacillus ferrooxidans is a facultative anaerobe that depends on ferrous ion oxidation as well as reduced sulfur oxidation to obtain energy and is widely applied in metallurgy, environmental protection, and soil remediation. With the accumulation of experimental data, metabolic mechanisms, kinetic models, and several databases have been established. However, scattered data are not conducive to understanding A. ferrooxidans that necessitates updated information informed by systems biology.ResultsHere, we constructed a knowledgebase of iron metabolism of A. ferrooxidans (KIMAf) system by integrating public databases and reviewing the literature, including the database of bioleaching substrates (DBS), the database of bioleaching metallic ion-related proteins (MIRP), the A. ferrooxidans bioinformation database (Af-info), and the database for dynamics model of bioleaching (DDMB). The DBS and MIRP incorporate common bioleaching substrates and metal ion-related proteins. Af-info and DDMB integrate nucleotide, gene, protein, and kinetic model information. Statistical analysis was performed to elucidate the distribution of isolated A. ferrooxidans strains, evolutionary and metabolic advances, and the development of bioleaching models.ConclusionsThis comprehensive system provides researchers with a platform of available iron metabolism-related resources of A. ferrooxidans and facilitates its application.How to citeZhou Z, Ma W, Liu Y, et al. Potential application of a knowledgebase of iron metabolism of Acidithiobacillus ferrooxidans as an alternative platform. Electron J Biotechnol 2021;51; https://doi.org/10.1016/j.ejbt.2021.04.003 相似文献
16.
BackgroundAPETALA3 (AP3) has significant roles in petal and stamen development in accordance with the classical ABC model.ResultsThe AP3 homolog, CDM19, from Chrysanthemum morifolium cv. Jinba was cloned and sequenced. Sequence and phylogenetic analyses revealed that CDM19 is of DEF/AP3 lineage possessing the characteristic MIKC-type II structure. Expression analysis showed that CDM19 was transcribed in petals and stamens of ray and disc florets with weak expression in the carpels. Ectopic expression of CDM19 in Arabidopsis wild-type background altered carpel development resulting in multi-carpel siliques. CDM19 could only partially rescue the Arabidopsis ap3‐–3 mutant.ConclusionsOur results suggest that CDM19 may partially be involved in petal and stamen development in addition to having novel function in carpel development.How to cite: Githeng’u SK, Ding L, Zhao K, et al. Ectopic expression of Chrysanthemum CDM19 in Arabidopsis reveals a novel function in carpel development. Electron J Biotechnol 2020;45. https://doi.org/10.1016/j.ejbt.2020.03.001. 相似文献
17.
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
18.
BackgroundWheat is one of the most important crops cultivated all over the world. New high-yielding cultivars that are more resistant to fungal diseases have been permanently developed. The present study aimed at the possibility of accelerating the process of breeding new cultivars, resistant to eyespot, by using doubled haploids (DH) system supported by marker-assisted selection.ResultsTwo highly resistant breeding lines (KBP 0916 and KBH 4942/05) carrying Pch1 gene were crossed with the elite wheat genotypes. Hybrid plants of early generations were analyzed using endopeptidase EpD1 and two SSR markers linked to the Pch1 locus. Selected homozygous and heterozygous genotypes for the Pch1-linked EpD1b allele were used to produce haploid plants. Molecular analyses were performed on haploids to identify plants possessing Pch1 gene. Chromosome doubling was performed only on haploid plants with Pch1 gene. Finally, 65 DH lines carrying eyespot resistance gene Pch1 and 30 lines without this gene were chosen for the eyespot resistance phenotyping in a field experiment.ConclusionsResults of the experiment confirmed higher resistance to eyespot of the genotypes with Pch1 in comparison to those without this gene. This indicates the efficiency of selection at the haploid level.How to cite: Wiśniewska H, Majka M, Kwiatek M, et al. Production of wheat doubled haploids resistant to eyespot supported by marker-assisted selection. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.10.003 相似文献
19.
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
20.
BackgroundProtein glutaminase specifically deamidates glutamine residue in protein and therefore significantly improves protein solubility and colloidal stability of protein solution. In order to improve its preparation efficiency, we exploited the possibility for its secretory expression mediated by twin-arginine translocation (Tat) pathway in Bacillus licheniformis.ResultsThe B. licheniformis genome-wide twin-arginine signal peptides were analyzed. Of which, eleven candidates were cloned for construction of expression vectors to mediate the expression of Chryseobacterium proteolyticum protein glutaminase (PGA). The signal peptide of GlmU was confirmed that it significantly mediated PGA secretion into media with the maximum activity of 0.16 U/ml in Bacillus subtilis WB600. A mutant GlmU-R, being replaced the third residue aspartic acid of GlmU twin-arginine signal peptide with arginine by site-directed mutagenesis, mediated the improved secretion of PGA with about 40% increased (0.23 U/ml). In B. licheniformis CBBD302, GlmU-R mediated PGA expression in active form with the maximum yield of 6.8 U/ml in a 25-l bioreactor.ConclusionsPGA can be produced and secreted efficiently in active form via Tat pathway of B. licheniformis, an alternative expression system for the industrial-scale production of PGA.How to cite: Niu D, Li C, Wang P, et al. Twin-arginine signal peptide of Bacillus licheniformis GlmU efficiently mediated secretory expression of protein glutaminase. Electron J Biotechnol 2019;42. https://doi.org/10.1016/j.ejbt.2019.10.006 相似文献