Strain G1 Research Articles

Growth and production of sixth generation of brown rice mutants in a high altitude location

This paper presents the result of an experiment which aimed to determine the growth and production of some 6th generation Sinjai brown rice mutants (M6) in the highlands. The experiment was conducted in an irrigated paddy field with a height of 750 meters above sea level. The arrangement was a randomized block design (RBD). The treatments consisted of 8 brown rice mutant lines (g1, g2, g3, g4, g5, g6, g7, g8) and Sinjai brown rice parent as control (g9). The results showed that the mutant lines g2 and g3 produced the highest grain production of 3.10 tons ha−1 and 3.13 tons ha−1 respectively. Mutant strains g2 and g3 were short in plant height with a high number of productive tillers, flowering age and a faster harvest time, as well as highest grain length. g2 and g3 strains are the most potential lines to be developed in the highlands. The growth character and production components that have a real positive correlation to production per hectare are production per clump and presentation of filled grain per panicle.

Differential Expression and PAH Degradation: What Burkholderia vietnamiensis G4 Can Tell Us?

Petroleum is the major energy matrix in the world whose refining generates chemical byproducts that may damage the environment. Among such waste, polycyclic aromatic hydrocarbons (PAH) are considered persistent pollutants. Sixteen of these are considered priority for remediation, and among them is benzo(a)pyrene. Amid remediation techniques, bioremediation stands out. The genus Burkholderia is amongst the microorganisms known for being capable of degrading persistent compounds; its strains are used as models to study such ability. High-throughput sequencing allows researchers to reach a wider knowledge about biodegradation by bacteria. Using transcripts and mRNA analysis, the genomic regions involved in this aptitude can be detected. To unravel these processes, we used the model B. vietnamiensis strain G4 in two experimental groups: one was exposed to benzo(a)pyrene and the other one (control) was not. Six transcriptomes were generated from each group aiming to compare gene expression and infer which genes are involved in degradation pathways. One hundred fifty-six genes were differentially expressed in the benzo(a)pyrene exposed group, from which 33% are involved in catalytic activity. Among these, the most significant genomic regions were phenylacetic acid degradation protein paaN, involved in the degradation of organic compounds to obtain energy; oxidoreductase FAD-binding subunit, related to the regulation of electrons within groups of dioxygenase enzymes with potential to cleave benzene rings; and dehydrogenase, described as accountable for phenol degradation. These data provide the basis for understanding the bioremediation of benzo(a)pyrene and the possible applications of this strain in polluted environments.

Characterisation of Burkholderia prophages and discovery of a novel inducible phage from B. vietnamiensis G4 that is widely distributed across the species

Burkholderia species have environmental, industrial and medical significance, and are important opportunistic pathogens in individuals with cystic fibrosis (CF). Approximately 10% of Burkholderia genomes (6-9 Mb) are horizontally acquired material, representing a rich source of mobile genetic elements including prophages. There is limited research on Burkholderia bacteriophages, their contributions to genome evolution, virulence and antimicrobial resistance, or biotechnological and therapeutic applications. We investigated prophage carriage in Burkholderia and aimed to isolate and characterise inducible bacteriophages from B. vietnamiensis. Burkholderia genomes were screened for prophages using PHASTER. Prophage genomes were compared using MASH and visualised with ProgressiveMauve. Phylogenomics was used to assess the distribution of prophages across B. vietnamiensis strains. Spontaneously induced phages were characterised to determine linkage between prophage regions and isolated phages, bacteriophage morphology and host range. Prophage carriage across 456 Burkholderia strains (spanning 43 species) was high; 716 intact prophages were discovered and polylysogeny was common. In B. vietnamiensis alone, 115 prophages were identified from 81 strains, with evidence of shared prophage carriage between related and diverse strains. Three novel inducible phages were isolated from B. vietnamiensis strain G4 and their genomic origins localised putatively. One phage (vB_BvM-G4P1; family Myoviridae) had inhibitory activity against multiple strains of 5 B. cepacia complex species, including species prevalent in CF infections. Prophages are numerous in Burkholderia genomes and contribute to strain diversity. There is huge potential for further investigation into the functional implications of prophage carriage and its impact on genome evolution, in addition to the isolation of novel bacteriophages.

Autophagic Proteome in Two Saccharomyces cerevisiae Strains During Second Fermentation for Sparkling Wine Elaboration.

A correlation between autophagy and autolysis has been proposed in order to accelerate the acquisition of wine organoleptic properties during sparkling wine elaboration. In this context, a proteomic analysis was carried out in two industrial Saccharomyces cerevisiae strains (P29, conventional sparkling wine strain and G1, implicated in sherry wine elaboration) with the aim of studying the autophagy-related proteome and comparing the effect of CO2 overpressure during sparkling wine elaboration. In general, a detrimental effect of pressure and second fermentation development on autophagy-related proteome was observed in both strains, although it was more pronounced in flor yeast strain G1. Proteins mainly involved in autophagy regulation and autophagosome formation in flor yeast G1, and those required for vesicle nucleation and expansion in P29 strain, highlighted in sealed bottle. Proteins Sec2 and Sec18 were detected 3-fold under pressure conditions in P29 and G1 strains, respectively. Moreover, ‘fingerprinting’ obtained from multivariate data analysis established differences in autophagy-related proteome between strains and conditions. Further research is needed to achieve more solid conclusions and design strategies to promote autophagy for an accelerated autolysis, thus reducing cost and time production, as well as acquisition of good organoleptic properties.

Genetic Affinity of Echinococcus granulosus protoscolex in Human and Sheep in East Azerbaijan, Iran.

Echinococcosis caused by the larval form of Echinococcus granulosus (E. granulosus) is known as an important zoonotic disease in various parts of the world, including Iran. The genetic diversity of this parasite is very high, particularly in areas where the disease is endemic. It has been suggested in the literature from different parts of the world that diverse factors, such as parasite life cycle, transmission pathways, pathologic disease, immunization, and disease control can be affected by the genetic diversity of the parasite. Various studies indicated sheep strain G1 as the most common genotype throughout the world. This strain is commonly found in the liver and lung repeatedly causing echinococcosis in humans, sheep, and cattle. The present study was conducted to determine the genetic affinity between the protoscolex of E. granulosus in humans and sheep in East Azerbaijan province, Iran for the first time. A total of 120 hydatid cyst samples were collected, 60 of which were from people who referred to the hospitals of East Azerbaijan and 60 were from the sheep slaughtered in Tabriz slaughterhouse. Following DNA extraction, certain regions of the cox1 gene were amplified and evaluated by the polymerase chain reaction. The replicated parts in all isolates had the same size of 450 bp. Electrophoresis was followed by selecting a total of 60 suitable samples, including 30 human samples and 30 sheep samples and sending them for genome sequencing. The overlap of the samples was investigated using the BLAST software. The results of BLAST, sequencing, and overlap demonstrated a genetic linkage of approximately 91.76% between the protoscolex of E. granulosus in human and sheep.

Enhanced Cypermethrin Degradation Kinetics and Metabolic Pathway in Bacillus thuringiensis Strain SG4.

Cypermethrin is popularly used as an insecticide in households and agricultural fields, resulting in serious environmental contamination. Rapid and effective techniques that minimize or remove insecticidal residues from the environment are urgently required. However, the currently available cypermethrin-degrading bacterial strains are suboptimal. We aimed to characterize the kinetics and metabolic pathway of highly efficient cypermethrin-degrading Bacillus thuringiensis strain SG4. Strain SG4 effectively degraded cypermethrin under different conditions. The maximum degradation was observed at 32 °C, pH 7.0, and a shaking speed of 110 rpm, and about 80% of the initial dose of cypermethrin (50 mg·L−1) was degraded in minimal salt medium within 15 days. SG4 cells immobilized with sodium alginate provided a higher degradation rate (85.0%) and lower half-life (t1/2) of 5.3 days compared to the 52.9 days of the control. Bioaugmentation of cypermethrin-contaminated soil slurry with strain SG4 significantly enhanced its biodegradation (83.3%). Analysis of the degradation products led to identification of nine metabolites of cypermethrin, which revealed that cypermethrin could be degraded first by cleavage of its ester bond, followed by degradation of the benzene ring, and subsequent metabolism. A new degradation pathway for cypermethrin was proposed based on analysis of the metabolites. We investigated the active role of B. thuringiensis strain SG4 in cypermethrin degradation under various conditions that could be applied in large-scale pollutant treatment.

Screening of Cellulolytic Actinomycetes for Decomposition of Agricultural Waste

Each year, Viet Nam produces around 37 Mt of rice, 17-18 Mt of sugarcane and 4.5 Mt of maize and the total waste created by agriculture is estimated more than 50 Mt. Approximately nearly half of the straw is burned on the field, which is a common practice in intensive rice cultivation systems in this region and significantly impacts greenhouse gas emissions in the country. It has been a challenge for the government to reduce the burning of straw. Using microbials is a potential solution for the reason that fertilized straw, which contains essential nutrients as nitrogen, phosphorous and potassium, can be used as compost to enrich the soil. This study aims to screen for Actinomycetes with high cellulase activities for the decomposition of agricultural wastes. Among 21 isolated actinomycetes, 7 isolates including G1, G3, G11, D4, D5, DE2, X1 were selected with high enzymatic activities. The incubation of selected strains with rice straw and cane bagasse indicated that the ability of all these strains to degrade agricultural wastes. Rice straw showed better degradation results in comparison to sugarcane bagasse. The strains G3 and D4 showed the best degradation performance after 12 d of incubation. The remaining substrate including rice straw and sugarcane bagasse after incubation in turn with D4 and G3 were both 10.5%.

Denitrification characteristics and pathways of a facultative anaerobic denitrifying strain, Pseudomonas denitrificans G1

Excessive nitrate in aquaculture systems has attracted wide attention. To isolate novel aerobic denitrifying strain and characterize its nitrogen removal processes, a facultative anaerobic denitrification bacterium, identified as Pseudomonas denitrificans G1, was isolated from marine sediments. Strain G1 could grow and remove 90-98% of nitrate and 97-99% of nitrite under an aerobic or anaerobic condition in 24h, with the total nitrogen removal rate of 33-38% (87-100mg/L). The highest denitrification rate could reach 15.1 mg/(L·h). The suitable condition for the denitrification of G1 is C/N ratio 5-22, dissolved oxygen 0-4.68mg/L, salinity 0-30g NaCl/L, pH 7-9.5. Under the aerobic condition, G1 grew fast; however, the mass spectrographic analysis showed that the gas product was N2O. Under the anaerobic conditions, G1 grow relatively slowly, but could also achieve effective denitrification and the final product was N2. In denitrification of aquaculture wastewater, strain G1 can remove 60.57% of nitrate and 36.36% of total nitrogen; meanwhile, there was a slight accumulation of ammonia nitrogen. P.denitrificans strain G1 has potential in denitrification processes for the treatment of aquaculture wastewater. However, the regulation of reaction conditions and gas products needs to be further studied.

Antioxidant activity in endophytic fungi isolated from Gynostemma pentaphyllum Makino

Gynostemma pentaphyllum Makino is a well known edible and medicinal plant in oriental countries, its dominant active constituents are mainly Gypenosides(GP). Endophytic fungi with antioxidant activity were screened and identified from gynostemma pentaphyllum, and gynostemma pentaphyllum saponin (GP) was used as host. A total of 10 strains of endophytic fungi were isolated from the root of healthy, living, and symptomless tissues of Gynostemma pentaphyllum Makino. The extract from a strain (G4) showed antioxidant activity and had the same RF value in TLC, because the retention time of real gynostemma pentaphyllum saponin (GP) and its extract was the same as that of natural gynostemma pentaphyllum (GP) in HPLC. So the strain G4 of endophytic fungus appears to produce the same components as its host.

Simultaneous reduction of nitrate and Cr(VI) by Pseudomonas aeruginosa strain G12 in wastewater.

The interference of toxic heavy metals in the process of microbial aerobic denitrification is a hot issue in industry wastewater treatment in recent years. In this study, a multifunctional aerobic denitrifying bacterium - Pseudomonas aeruginosa G12 isolated from sewage sludge was used to explore the simultaneous removal ability to NO3--N and Cr(VI) in wastewater by a series of batch experiments. The results showed that G12 could effectively remove NO3--N (500mgL-1) and Cr(VI) (10mgL-1) by 98% and 93%, respectively. Meanwhile, the study found that the strain G12 had the potential to adapt to the complex external environment, including different carbon resources, nitrogen sources, and the coexisting heavy metals (Mn2+ and Cu2+). The strain G12 also had the considerable tolerance to initial NO3--N (100-700mgL-1) and Cr(VI) (1-20mgL-1) concentrations. The instrument analysis methods-Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), from the molecular level, further confirmed that the strain G12 could remove NO3--N by aerobic denitrification, and the reduced functional groups (amino group, amide group, hydroxyl group and carboxyl group) on the surface of bacteria could transform Cr(VI) to Cr(III) (mainly CrCl3). This study will offer a promising new microbial resource for nitrogen and Cr(VI) removal in industry wastewater treatment.

Viral agents of gastroenteritis and their correlation with clinical symptoms in rotavirus-vaccinated children

Background and objectivesEnteric viral infections are among the leading causes of gastroenteritis in children up to five years of age worldwide. This study was aimed to determine the disease severity, incidence, and molecular genotyping of rotaviruses, noroviruses, astroviruses, and enteric adenoviruses as gastroenteritis agents among children up to five years old. Materials and methodsGastroenteritis severity was determined by using the Ruuska and Vesikari score, whereas the incidence of enteric infections and their genotyping were determined by reverse transcription-polymerase chain reaction (RT-PCR) and sequence analysis. ResultsRotaviruses were observed to possess the highest incidence with 10% (18/179) of the cases positives; nevertheless, noroviruses had the highest severe gastroenteritis score (13 ± 3 points). Results indicated that 56% (10/18) of the detected rotavirus strains were genotype G12P[8], 50% (4/8) of noroviruses were GII.4 and 25% (2/8) were genotype GI.8. Out of the sapovirus positive samples, 30% (2/6) were genotyped as GI·I and GII·I. Sixty percent of the astrovirus strains (3/5) were genotype HAstV-2, and 20% (1/5) were genotype HAstV-6. Additionally, one of the adenovirus strains was identified as human mastadenovirus C type 6 specie. ConclusionsThe diarrhea severity reduction in children provides evidence that the rotavirus vaccination program in the northwest of Mexico has been successful, even among children infected by the rotavirus emergent strain G12, however, norovirus resulted as the leading severe gastroenteritis-causing agent in children with rotavirus vaccine.

Encapsulation of Bifidobacterium pseudocatenulatum Strain G4 within Bovine Gelatin-Genipin-Sodium Alginate Combinations: Optimisation Approach Using Face Central Composition Design-Response Surface Methodology (FCCD-RSM).

Bovine gelatin is a biopolymer which has good potential to be used in encapsulating matrices for probiotic candidate Bifidobacterium pseudocatenulatum strain G4 (G4) because of its amphoteric nature characteristic. Beads were prepared by the extrusion method using genipin and sodium alginate as a cross-linking agent. The optimisation of bovine gelatin-genipin-sodium alginate combinations was carried out using face central composition design (FCCD) to investigate G4 beads' strength, before and after exposed to simulated gastric (SGF), intestinal fluids (SIF), and encapsulation yield. A result of ANOVA and the polynomial regression model revealed the combinations of all three factors have a significant effect (p < 0.05) on the bead strength. Meanwhile, for G4 encapsulation yield, only genipin showed less significant effect on the response. However, the use of this matrix remained due to the intermolecular cross-linking ability with bovine gelatin. Optimum compositions of bovine gelatin-genipin-sodium alginate were obtained at 11.21% (w/v), 1.96 mM, and 2.60% (w/v), respectively. A model was validated for accurate prediction of the response and showed no significant difference (p > 0.05) with experimental values.

Identification of geosmin biosynthetic gene in geosmin-producing colonial cyanobacteria Coelosphaerium sp. and isolation of geosmin non-producing Coelosphaerium sp. from brackish Lake Shinji in Japan

Geosmin is an earthy-muddy smelling compound produced in aquatic ecosystems by microorganisms including cyanobacteria. An increase in geosmin levels affecting the local fishery occurred in May 2007 in Lake Shinji, Japan, and geosmin-producing colonial cyanobacterium, Coelosphaerium sp. G2, was isolated from a water sample from the lake and identified. Cyanobacteria Coelosphaerium sp. is commonly found in Lake Shinji; however, prior to 2007, earthy-muddy odors were not a frequent issue. Further, there was no information regarding the geosmin biosynthetic gene in colonial cyanobacteria. Here, the geosmin biosynthetic gene (geoA) in strain G2 was identified and its nucleotide sequence was determined. It was found that geoA had 79% and 78% identity with geoA from filamentous geosmin-producing cyanobacteria Fischerella sp. PCC 9431 and geoA2 from Phormidium sp. P2r, respectively. The deduced amino acid sequence of GeoA consisted of two domains that were annotated as terpene cyclase. In 2015, geosmin non-producing Coelosphaerium sp. S3C5 was isolated from Lake Shinji and identified by morphological and genetic analyses. There was no difference in morphology or nucleotide sequences of 16S rRNA and 16S-23S internal transcribed spacer (ITS) between geosmin-producing and non-producing strains, which are therefore closely related and can exist in Lake Shinji. Distinguishing the two strains by observation under a microscope and sequencing of 16S rRNA and 16S-23S ITS have proven difficult. Inconsistency between the appearance of Coelosphaerium cells and the detection of the odor in water samples could therefore be attributed to dominance by the geosmin-producing strain or the non-producing strain. The increase in earthy smell is assumed to be caused by an increase in the geosmin-producing strain in Lake Shinji. Genetic analysis of geoA in Coelosphaerium sp. and the relative abundances of geosmin-producing and non-producing Coelosphaerium strains in Lake Shinji can be used to mitigate the economic damages caused by geosmin. Development of a molecular method to monitor the geosmin-producing strain in water ecosystems is equally important to alleviate the earthy smell caused by this particular strain.

Co-Occurrence of Colistin and Meropenem Resistance Determinants in a Stenotrophomonas Strain Isolated from Sewage Water

Development of antibiotic resistance can be achieved either by mutation or by acquiring a resistance gene from foreign sources, with some resistance genes likely originating in microbial populations to counteract antibiotics present in natural ecosystems. In this study, we describe the first report of a strain of nonclinical multidrug-resistant Stenotrophomonas sp. strain G4 with high-level resistance to colistin and meropenem, phylogenetically distinct from well-studied multiple drug-resistant species of Stenotrophomonas maltophilia. As the high-level colistin resistance of this strain was of great concern, the genome of this strain was completely sequenced. Only one chromosome was identified, and no plasmids were found. Chromosomal gene variants and other potential genetic determinants conferring resistance to colistin and meropenem were comparatively analyzed, and results showed that strain G4 harbored two putative colistin resistance determinants (named mcr-5.3 and mcr-8.2) and four extended-spectrum β-lactamase genes. In addition, 12 genes potentially encoding seven different types of efflux pumps were identified, which may have a major role in acquisition/transfer of colistin resistance. Our discovery of multiple antibiotic resistance determinants in this environmental strain extensively expands our understanding of the extent of dissemination of colistin and meropenem resistance.

Microbial synergistic interactions for reductive dechlorination of polychlorinated biphenyls

Dehalococcoides usually work closely with other beneficial microorganisms for removal of halogenated organic compounds at contaminated sites. Traditional microbial cultivation is necessary but not enough to gain insights into key microbial populations and their interactions in complex communities. In this study, we cultivated and characterized two D. mccartyi strains (CG3 and SG1), and further revealed interspecies synergistic interactions in PCB-dechlorinating microbial communities via metagenomic analysis. Strain CG3 and SG1 originated from distinct geographic sites employ reductive dehalogenase CG3-RD11 (PcbA1-like) and SG1-RD28 (PcbA4/5-like), respectively, to catalyze chlorine-removal from PCBs. In their parent mixed cultures CG-3 and SG-1, as well as in previously enriched PCB-dechlorinating cultures CG-1, CG-4 and CG-5, Methanosarcina and Desulfovibrio were found as major non-dechlorinating populations which may play roles in mediating acetate- and H2-sources for D. mccartyi. They together form a stable microbial community for interspecies carbon- and electron-transfers to facilitate organohalide respiration of D. mccartyi, being confirmed in a synthetic microbial community consisting of the Dehalococcoides, Methanosarcina and Desulfovibrio. The results provide insights into which and how other microorganisms support D. mccartyi to dechlorinate PCBs, and suggest that Methanosarcina may play a larger role in PCB-dechlorinating communities than currently appreciated.

Improving bio-desilication of a high silica bauxite by two highly effective silica-solubilizing bacteria

Bacteria play an important role in bio-desilication of high silica bauxites. However, low bio-desilication efficiency and unknown mechanisms limit the use of bacteria in bio-desilication of bauxite. In this study, two highly effective Si-solubilizing bacteria (Arthrobacter pascens H19 and Burkholderia anthina G21) were obtained and characterized for their impact on Si and Al release from a high-silica (18.1%) bauxite and the mechanisms involved. Dissolved Si and Al concentrations in the culture medium were 3.3–13.9 mM and 0.04–0.41 mM, and total Si and Al released from the bauxite were 2.76–11.64 mg and 0.03–0.39 mg, respectively, in the presence of these strains. Strain G21 released more Si from the bauxite than strain H19 at the end of the experiment. These strains produced malic (791–1700 µM), citric (94–447 µM), and succinic (228–494 µM) acids, and expolyssaccharides (EPS) (39–420 mg L−1) during the bio-desilication processes. Furthermore, strain G21 produced more organic acids (19–65%) than strain H19, while strain H19 produced more EPS (1.7–4.9-fold) than strain G21. The metabolites (fermentation broth, organic acids, and EPS) of these strains also significantly increased dissolved Si concentration compared to the control. Notably, the ratios of Al2O3 to SiO2 in the bauxite treated with strains H19 and G21 were 9.14 and 9.64, respectively, which met the requirement in the Bayer process for alumina production. The results showed distinct and high bio-desilication effectiveness of these strains and suggested that the highly effective Si-solubilizing bacterial strains increased bio-desilication efficiency through the production of organic acids and EPS.

Complete genome sequence of the dissimilatory azo reducing thermophilic bacterium Novibacillus thermophiles SG-1

With the isolation and identification of efficient azo-dye degradation bacteria, bioaugmentation with specific microbial strains has now become an effective strategy to promote the bioremediation of azo dye. However, Azo dye wastewater discharged at high temperature restricted the extensive application of the known mesophilic azoreducing microorganisms. Here we present the complete genome sequence of a bacterium capable of reducing azo dye under thermophilic condition, Novibacillus thermophiles SG-1 (=KCTC 33118T =CGMCC 1.12363T). The complete genome of strain SG-1 contains a circular chromosome of 3,629,225 bp with a G + C content of 50.44%. Genome analysis revealed that strain SG-1 possessed genes encoding riboflavin biosynthesis protein that would secrete riboflavin, which could act as electron shuttles to transport the electrons to extracellular azo dye in decolorization process. HPLC analysis showed that the concentration of riboflavin increased from 0.01 μM to 0.255 μM with the growth of strain SG-1 under azo dye reduction. Quantitative real-time PCR analysis further demonstrated that the gene encoding riboflavin biosynthesis protein would be involved in the azo dye decolorization. The results from this study would be beneficial to research the mechanism of anaerobic reduction of azo dye under thermophilic conditions.

Biocontrol and plant-growth-promoting capacities of actinobacterial strains from the Algerian Sahara and characterisation of Streptosporangium becharense SG1 as a promising biocontrol agent

ABSTRACTSixteen actinobacterial strains isolated from various ecological niches in the Algerian Sahara were screened for their biocontrol potential in root rot disease caused by Fusarium culmorum and their promotion of durum wheat growth. All actinobacteria were studied for in vitro antagonistic activity and plant-growth-promotion traits, for the production of cyanhydric acid, siderophores, chitinases and indole-3-acetic acid, and for the solubilisation of inorganic phosphate. Strongly antagonistic actinobacteria were selected for the biocontrol of F. culmorum in vivo and for the growth promotion of durum wheat plants in autoclaved and non-autoclaved soils. The Streptosporangium becharense strain SG1 exhibited remarkable positive results in all trials. Compared to untreated wheat seeds, the root rot severity index was decreased significantly (P < 0.05) by all seed bacterization treatments. However, the highest protective effect was obtained by the strain SG1, which reduced the disease severity index from 77.8% to 16%, whereas it was only reduced to 24.2% by chemical seed treatment with Dividend®. Moreover, strain SG1 led to significant increases in the shoot length, root length and dry weight of plants, thus opening up interesting perspectives for possible exploration in crop enhancement.

Biological Leaching and Chemical Precipitation Methods for Recovery of Co and Li from Spent Lithium-Ion Batteries

Spent Li-ion batteries (LIBs) are highly rich in cobalt and lithium that need to be recovered to reduce shortages of these valuable metals and decrease their potential environmental risks. This study applied bioleaching using Aspergillus niger strains MM1 and SG1 and Acidithiobacillus thiooxidans 80191 for removal of Co and Li from spent LIB under type 1 and type 2 conditions. Moreover, metal recovery was attempted from the fungal leaching solution by sodium sulfide, sodium hydroxide, and sodium oxalate for Co and then for Li using sodium carbonate. The findings of this work show that metal removal in fungal bioleaching under type 2 system was highly comparable or even better than bacterial or acid leaching. A significant quantity of Co (82%) and Li (100%) dissolution was observed in strain MM1; however, metal solubilization was poor in strain 80191 because only 22% Co and 66% Li solubilized. A high amount of Co precipitated potentially as cobalt sulfide (100%), cobalt hydroxide (100%), or cobalt oxalate ...

Whole Genome Sequence and Comparative Genomics Analysis of Multi-drug Resistant Environmental Staphylococcus epidermidis ST59.

Staphylococcus epidermidis is a major opportunistic pathogen primarily recovered from device-associated healthcare associated infections (DA-HAIs). Although S. epidermidis and other coagulase-negative staphylococci (CoNS) are less virulent than Staphylococcus aureus, these bacteria are an important reservoir of antimicrobial resistance genes and resistance-associated mobile genetic elements that can be transferred between staphylococcal species. We report a whole genome sequence of a multidrug resistant S. epidermidis (strain G6_2) representing multilocus sequence type (ST) 59 and isolated from an environmental sampling of a hotel room in London, UK. The genome of S. epidermidis G6_2 comprises of a 2408357 bp chromosome and six plasmids, with an average G+C content of 32%. The strain displayed a multi-drug resistance phenotype which was associated with carriage of 7 antibiotic resistance genes (blaZ, mecA, msrA, mphC, fosB, aacA-aphD, tetK) as well as resistance-conferring mutations in fusA and ileS. Antibiotic resistance genes were located on plasmids and chromosome. Comparative genomic analysis revealed that antibiotic resistance gene composition found in G6_2 was partly preserved across the ST59 lineage.