Strain GS1 Research Articles

Optimization of aflatoxin B1 degradation in corn by Ganoderma sinense through solid-state fermentation

Corn is a staple cereal worldwide, but it is frequently contaminated with aflatoxin B1 (AFB1) due to extreme weather or poor storage conditions. The consumption of AFB1-contaminated corn poses a significant health risk to humans and livestock. To address this issue, an environmentally friendly, cost-effective, and efficient method for eliminating AFB1 from corn is needed. In this study, Ganoderma sinense strain Gs-1 with the ability to secrete laccase was used to ferment AFB1-contaminated corn to degrade AFB1. The degradation conditions of AFB1 in corn were optimized through single factor experiments and response surface methodology under solid-state fermentation. The optimal conditions for G. sinense to degrade AFB1 were 12 days of fermentation, a moisture content of 65.2% in the corn substrate, an inoculation amount of 5 mL of G. sinense culture (containing 51.85 mg of G. sinense mycelia), and a fermentation temperature of 27.9 °C. Under these optimal conditions, the degradation rate of AFB1 in corn reached 94.03% through solid-state fermentation with G. sinense. This study provides an economical, environmentally friendly, and efficient strategy for degrading AFB1 in corn, which has great application potential in the food and feed industries.

A Novel Mitovirus PsMV2 Facilitates the Virulence of Wheat Stripe Rust Fungus.

Wheat stripe rust, caused by the obligate biotrophic fungus Puccinia striiformis f. sp. tritici (Pst), seriously affects wheat production. Here, we report the complete genome sequence and biological characterization of a new mitovirus from P. striiformis strain GS-1, which was designated as "Puccinia striiformis mitovirus 2" (PsMV2). Genome sequence analysis showed that PsMV2 is 2658 nt in length with an AU-rich of 52.3% and comprises a single ORF of 2348 nt encoding an RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis indicated that PsMV2 is a new member of the genus Unuamitovirus within the family Mitoviridae. In addition, PsMV2 multiplied highly during Pst infection and it suppresses programmed cell death (PCD) triggered by Bax. Silencing of PsMV2 in Pst by barley stripe mosaic virus (BSMV)-mediated Host Induced Gene Silencing (HIGS) reduced fungal growth and decreased pathogenicity of Pst. These results indicate PsMV2 promotes host pathogenicity in Pst. Interestingly, PsMV2 was detected among a wide range of field isolates of Pst and may have coevolved with Pst in earlier times. Taken together, our results characterized a novel mitovirus PsMV2 in wheat stripe rust fungus, which promotes the virulence of its fungal host and wide distribution in Pst which may offer new strategies for disease control.

Multi-Omics Techniques for Analysis Antifungal Mechanisms of Lipopeptides Produced by Bacillus velezensis GS-1 against Magnaporthe oryzae In Vitro.

Magnaporthe oryzae is a fungal pathogen that causes rice blast, a highly destructive disease. In the present study, the bacteria strain GS-1 was isolated from the rhizosphere soil of ginseng and identified as Bacillus velezensis through 16S rRNA gene sequencing, whole genome assembly, and average nucleotide identity analysis. B. velezensis strain GS-1 exhibited significant antagonistic activity to several plant fungal pathogens. Through whole genome sequencing, 92 Carbohydrate-Active Enzymes and 13 gene clusters that encoded for secondary metabolites were identified. In addition, strain GS-1 was able to produce the lipopeptide compounds, surfactin, fengycin, and plantazolicin. The inhibitory effects of lipopeptide compounds on M. oryzae were confirmed, and the antagonistic mechanism was explored using transcriptomics and metabolomics analysis. Differential expressed genes (DEGs) and differential accumulated metabolites (DAMs) revealed that the inhibition of M. oryzae by lipopeptide produced by GS-1 downregulated the expression of genes involved in amino acid metabolism, sugar metabolism, oxidative phosphorylation, and autophagy. These results may explain why GS-1 has antagonistic activity to fungal pathogens and revealed the mechanisms underlying the inhibitory effects of lipopeptides produced by GS-1 on fungal growth, which may provide a theoretical basis for the potential application of B. velezensis GS-1 in future plant protection.

Whole-Genome Sequence of Corynebacterium xerosis Strain GS1, Isolated from Yak in Gansu Province, China

We report here the isolation, sequencing of the complete closed genome, and annotation of Corynebacterium xerosis strain GS1. This strain was isolated from the liver lesion of a yak in Gansu Province, China. The genome consists of one chromosome with 2,738,835 bp and comprises 2,304 protein-coding genes.

Microbial Diversity in Water and Biofilm Samples from Well Sources in Ilorin Metropolis, Nigeria

The aim of the study was to investigate the microbial populations of water and biofilm samples from seven hand dug wells in Ilorin, Nigeria, which are for private and public use. Physicochemical parameters such as pH, turbidity, total dissolved solids, temperature, conductivity, dissolved oxygen and biological oxygen demand were determined. Biofilm growths were induced from water samples obtained from selected wells. Twenty bacteria isolated were identified using morphological and biochemical characteristics as well as molecular methods and includes Shigella sonnei, Shigella dysenteriae, Micrococcus luteus, Bacillus sphaericus, Salmonella enteritidis, Proteus mirabilis strain IK-MB4-518F, Bacillus licheniformis strain RH104, Bacillus subtilis, Erwinia sp., Proteus vulgaris, Yersina sp., Bacillus cereus, Staphylococcus aureus, Serratia marcescens, Pseudomonas aeruginosa strain GS1, Pseudomonas aeruginosa strain 218B, Staphylococcus epidermidis, Vibrio sp., Escherichia coli and Bacillus pasteurii. Total bacterial count ranged from 1.8×104-1.53×106 cfu/ml. Water samples from these wells are therefore not potable and some of the isolates are potential health hazards to human population.

Permanent draft genome sequence of Geobacillus thermocatenulatus strain GS-1

Geobacillus thermocatenulatus strain GS-1 is a thermophilic bacillus having a growth optimum at 60°C, capable of degrading alkanes. It was isolated from the formation water of a high-temperature deep oil reservoir in Qinghai oilfield, China. Here, we report the draft genome sequence with an estimated assembly size of 3.5Mb. A total of 3371 protein-coding sequences, including monooxygenase, alcohol dehydrogenase, aldehyde dehydrogenase, fatty acid-CoA ligase, acyl-CoA dehydrogenase, enoyl-CoA hydrogenase, hydroxyacyl-CoA dehydrogenase and thiolase, were detected in the genome, which are involved in the alkane degradation pathway. Our results may provide insights into the genetic basis of the adaptation of this strain to high-temperature oilfield ecosystems.

Antimicrobial and anticoagulation activity of silver nanoparticles synthesized from the culture supernatant of Pseudomonas aeruginosa

Here, we describe biosynthesis of silver nanoparticles by reduction of aqueous Ag+ ions with the culture supernatant of Pseudomonas aeruginosa. The morphological, physiological, biochemical and molecular level identification of the strain GS1 resembles P. aeruginosa. The nanoparticles synthesized by P. aeruginosa were characterized by UV–vis spectroscopy, dynamic light scattering (DLS) and scanning electron microscopy (SEM). The size-distribution of nanoparticles was determined using a particle-size analyzer and the average particle-size was found to be 80nm. The biological activities of the synthesized silver nanoparticles like antimicrobial activity were confirmed against Escherichia coli and Staphylococcus aureus and it have stable anti-coagulant effect.

Characterisation of Bacillus strains from volcanic area Gunung Sibayak able to degrade 2,2-dichloropropionic acid

Halogenated compounds are mainly found in agricultural area. The problem arose because these compounds are toxic to human and are persistent in environment. The aim of the present study was to isolate 2,2-dichloropropionic acid (2,2-DCP) degrading bacteria that can grow at higher temperature rather than at normal 25 to 30°C temperature. A soil bacterium was isolated from the surrounding volcanic area at the feet of Gunung Sibayak, Indonesia using streak plate method. The sample was repeatedly streaked onto 20 mM of 2,2-DCP to get a pure culture. The culture was incubated for 2 days at 30, 40 and 60°C incubator shaker aerobically. The isolated bacterium grew best at 40°C but failed to grow at 60°C. Based on partial 16S rDNA gene sequence, the isolated strain GS1 showed high sequence identity to Bacillus megaterium strain 0 to 2, whereas, using biochemical tests suggested that the genus belongs to Bacillus sp. as expected. Strain GS1 was a Gram positive, rod in shape and produced spore. The results also suggested that, strain GS1 could degrade 20 mM (2,2-DCP) based on growth experiment. In conclusion, the molecular method identified Bacillus genus showing no discrepencies from the biochemical test results. This is the first report of Bacillus strains associated with 2,2-DCP degradation using above normal temperature for growth. Key words: 2,2-Dichloropropionic, Bacillus strain GS1, degradation, 16S rDNA andpollutant.

Molecular Analysis of Dehalogenase Gene in Genomic DNA of Bacillus megaterium Strain GS1 Isolated from Volcanic Area Gunung Sibayak

Molecular Analysis of Dehalogenase Gene in Genomic DNA of Bacillus megaterium Strain GS1 Isolated from Volcanic Area Gunung Sibayak

Screening and denitrification characteristics of a slight halophilic heterotrophic nitrobacteria

A slight halophilic heterotrophic nitrobacteria named gs1 was separated from the matured activated sludge. According to the morphological observation, physiological biochemical tests and sequence analysis of the 16S rDNA, strain gs1 was identified to be as Pseudomonas sp. Sodium acetate and ammonium chloride were used as carbon and nitrogen sources, respectively, to investigate the characteristics of the bacterium. When cultured for 24 h under aerobic conditions, with the removal rates of the NH4+-N and COD being 82.2% and 74.73%, respectively, strain gs1 will have a nitrification function of producing NO2−-N. When cultured for 24 h under aerobic conditions in nitrite medium, the removal rate of the NO2−-N became 100%, and when cultured for 24 h under aerobic conditions in nitrate medium, the removal rate of the NO3−-N became 97%. The result shows that this strain functions for either nitrification or denitrification, i.e., it can complete the full process of biological deoxidation.

Bioconversion of Terephthalate by Resting Cells of Alkaliphilic Dietzia sp. Strain GS-1.

Disodium terephthalate (DT) was degraded by the resting cells of alkaliphilic Dietzia sp. strain GS-1. The degradation occurred at pH 7.0-10.0. The optimal pH for the degradation was around 8.0. Oxygen uptake experiments with the resting cells showed that oxygen was utilized for degrading DT by strain GS-1. Thin layer chromatography (TLC) analysis revealed three degradation products in the resting cells reaction at pH 10. The products absorbed light at around 265 nm and were likely aromatic compound having hydroxyl and/or carboxyl group. The resting cells reaction was strongly inhibited by a,a'-dipyridyl, suggesting DT-degrading enzyme is likely metalloenzyme. The cell-free extracts degraded DT at the velocity of 0.885 μM min - 1 mg-protein - 1 .

好アルカリ性細菌ＧＳ‐１株によるテレフタル酸二ナトリウムの分解

An alkaliphilic bacterium strain GS-1 assimilating disodium terephthalate as the sole carbon and energy sources was isolated from soil. The strain GS-1 degraded 19.3mM(1M=mol/dm3) of disodium terephtalate in 168h at alkaline condition(pH10) with the growth. The cultures showed degradation lag phase of 72h before growth commenced. The greatest degradation occurred between 72 and 100h. The maximum degradation rate was 0.46mM/h. The doubling time was 9.3h.

Microbial degradation of disodium terephthalate by alkaliphilic Dietzia sp. strain GS-1.

An alkaliphilic Dietzia sp., strain GS-1, which degraded disodium terephthalate (DT), was isolated from soil. Strain GS-1 degraded 19.3 mM of DT in 168 h at pH 10. The maximum degradation velocity was 0.46 mM/h. The resting cells efficiently degraded 28.7 mM of DT in 51 h at 28 degrees C and pH 10. The degradation velocity was 0.41 mM/(h g-wet cell).

Production of ethanol from straw and bamboo pulp by primary isolates of Clostridium thermocellum

Clostridium thermocellum strains SS8 and GS1 grew poorly on crude blopolymers but termented them easily after alkall treatment. With 1% alkall-extracted rice straw (AERS) and dellgnified bamboo pulp (DBP), the ethanol-to-substrate (E/S) ratios were almost the same as those obtained when using fillter paper. Increasing the substrate concentrations decreased the percentage substrate degraded and the E/S ratio and concomitantly increased the amount of reducing sugars accumulated. A maximum amount of 8.6 g ethanol/l was produced by strain SS8 out of 37.5 g DBP degraded. Strain GS1 accumulated reducing sugars at substrate concentrations >50 g/l, thereby accounting for about 70% of AERS degraded. This strain produced cellulase on both cellulose and cellobiose. Both the strains grew in the presence of 1.5% (v/v) ethanol. Strain SS8 fermented starch, but the ethanol yield was low compared to that from cellulose. About 75% of starch degraded accumulated as reducing sugars at a substrate concentration of 40 g/l. The Inhibitory effects of ethanol (2 to 4%) were less drastic when growing cultures were challenged than when they were formed in situ. The effect of ethanol depended upon the phase of the culture.