DGGE diversity of manganese mine samples and isolation of a Lysinibacillus sp. efficient in removal of high Mn (II) concentrations

Manganese contamination has become a serious environmental problem in the world and bacterial removal plays an important role in global cycling of manganese. In this study, microorganism distribution within samples from a manganese mine was analyzed with PCR-DGGE technology. The results suggested that Manganese oxidizing bacteria (such as Bacillus, Hyphomicrobiaceae and Erythrobacter) were dominant in the soil. In addition, a Lysinibacillus sp. Isolate, strain MK-1, revealed robust growth at high Mn(II) concentrations up to 1 mM. At that concentration, 55.94% of added Mn(II) was oxidized and 36.23% of the Mn(II) was adsorbed by MK-1(total manganese removal reached 94.67%) after 7 days of culturing. By measuring its metabolic process, the great role of biological adsorption was found. Additionally, the spectroscopic result demonstrated that Mn(III) was an intermediate during the biological oxidation process. These findings increase the knowledge of biological manganese removal mechanisms and show some potentials to the operation of manganese treatment.

Marinococcus salis sp., nov., a moderately halophilic bacterium isolated from a salt marsh

A novel Gram-stain-positive, coccoid-shaped, facultative anaerobic, motile and halophilic bacterium strain 5M^T was isolated from Surajbari in India. Based on the 16S rRNA gene sequence analysis, it was identified as belonging to the genus Marinococcus and was most closely related to Marinococcus luteus KCTC 13214^T (99.3 %, sequence similarity), Marinococcus halotolerans KCTC 19045^T (99.0 %), Marinococcus halophilus LMG 17439^T (98.8 %) and Marinococcus tarijensis LMG 26930^T (98.7 %). However, the DNA-DNA relatedness of strain 5M^T with M. luteus KCTC 13214^T, M. halotolerans KCTC 19045^T, M. halophilus LMG 17439^T and M. tarijensis LMG 26930^T was 42.6 ± 0.8, 48.6 ± 0.8, 40.9 ± 0.8 and 39.8 ± 0.9 %, respectively. Strain 5M^T grows optimally at 5 % (w/v) NaCl, pH 7.5-8.5 and 37 °C. The cell-wall peptidoglycan of strain 5M^T contains meso-diaminopimelic acid. Polar lipids of the strain 5M^T include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a phospholipid and two unknown lipids. The predominant isoprenoid quinone was MK-7. DNA G+C content was 48.9 mol%, and anteiso-C_15:0 (40.9 %) was the predominant fatty acid. The results of phylogenetic, biochemical tests and chemotaxonomic allowed a clear differentiation of strain 5M^T from all of its nearest phylogenetic neighbours, which represents a novel member of the genus Marinococcus, for which the name Marinococcus salis sp., nov., is proposed. The type strain is 5M^T (=KCTC 33743^T = LMG 29101^T = CGMCC 1.15385^T).

Lysinibacillus endophyticus sp. nov., an indole-3-acetic acid producing endophytic bacterium isolated from corn root (Zea mays cv. Xinken-5)

A Gram-positive, aerobic, motile, rod-shaped bacterium, designated strain C9(T), was isolated from surface sterilised corn roots (Zea mays cv. Xinken-5) and found to be able to produce indole-3-acetic acid. A polyphasic taxonomic study was carried out to determine the status of strain C9(T). The major cellular fatty acids were found to contain iso-C15:0, anteiso-C15:0 and anteiso-C17:0, and the only menaquinone was identified as MK-7. The polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and an unidentified lipid. The cell wall peptidoglycan was found to be of the A4α L-Lys-D-Asp type and the whole cell sugar was found to be glucose. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain C9(T) belongs to the genus Lysinibacillus and is closely related to Lysinibacillus chungkukjangi NBRC 108948(T) (98.1 % similarity) and Lysinibacillus sinduriensis DSM 27595(T) (98.0 %). However, the low levels of DNA-DNA relatedness and some differential phenotypic characteristics allowed the strain to be distinguished from its close relatives. Therefore, it is concluded that strain C9(T) represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillus endophyticus sp. nov. is proposed. The type strain is C9(T) (=DSM 100506(T) = CGMCC 1.15291(T)).

Microcosm-based interaction studies between members of two ecophysiological groups of bioemulsifier producer and a hydrocarbon degrader from the Indian intertidal zone

Isolates were obtained from intertidal zone site samples from all five western and one eastern coastal states of India and were screened. These ecophysiological groups of aerobic, mesophilic, heterotrophic, sporulating, and bioemulsifier-producing bacteria were from Planococcaceae and Bacillaceae. This is the first report of bioemulsifier production by Sporosarcina spp., Lysinibacillus spp., B. thuringiensis, and B. flexus. In this group, Solibacillus silvestris AM1 was found to produce the highest emulsification activity (62.5 %EI) and the sample that yielded it was used to isolate the ecophysiological group of non-bioemulsifier-producing, hydrocarbon-degrading bacteria (belonging to Chromatiales and Bacillales). These yielded hitherto unreported degrader, Rheinheimera sp. CO6 which was selected for the interaction studies (in a microcosm) with bioemulsifier-producing S. silvestris AM1. The gas chromatographic study of these microcosm experiments revealed increased degradation of benzene, toluene, and xylene (BTX) and the growth of Rheinheimera sp. CO6 in the presence of bioemulsifier produced by S. silvestris AM1. Enhancement of the growth of S. silvestris AM1 in the presence of Rheinheimera sp. CO6 was observed possibly due to reduced toxicity of BTX suggesting mutualistic association between the two. This study elucidates the presence and interaction between enhancers and degraders in a hydrocarbon-contaminated intertidal zone and contributes to the knowledge during application of the two in remediation processes.

Bacteria-based polythene degradation products: GC-MS analysis and toxicity testing

Polythene degradation leads to the production of various by-products depending upon the type of degradation process. The polythene degradation products (PEDP) in the culture supernatant of the two bacteria (Lysinibacillus fusiformis strain VASB14/WL and Bacillus cereus strain VASB1/TS) were analyzed with GC-MS technique. The major by-products in the PEDP in the culture supernatant of L. fusiformis strain VASB14/WL (1,2,3,4 tetra methyl benzene) and B. cereus strain VASB1/TS (1,2,3 trimethyl benzene, 1 ethyl 3,5-dimethyl benzene, 1,4 di methyl 2 ethyl benzene, and dibutyl phthalate) dissolved in diethyl ether were recorded. To assess the environmental applicability of polythene degradation using L. fusiformis strain VASB14/WL and B. cereus strain VASB1/TS at in vitro level. The effect of PEDP produced after 2 months of regular shaking at room temperature on both plants and animal system was studied. No significant decrease in the percent seed germination was recorded with the PEDP of both the bacteria. PEDP produced by L. fusiformis strain VASB14/WL did not report any significant change in germination index (GI) at 10 and 25 %, but least GI (39.66 ± 13.94) was documented at 50 % concentration of PEDP. Highest elongation inhibition rate (53.83 ± 15.71) of Sorghum was also recorded with L. fusiformis and at the same concentration.

Distribution and diversity of biosurfactant-producing bacteria in a wastewater treatment plant

The distribution and diversity of culturable biosurfactant-producing bacteria were investigated in a wastewater treatment plant (WWTP) using the Shannon and Simpson's indices. Twenty wastewater samples were analysed, and from 667 isolates obtained, 32 were classified as biosurfactant producers as they reduced the surface tension of the culture medium (71.1 mN/m), with the lowest value of 32.1 mN/m observed. Certain isolates also formed stable emulsions with diesel, kerosene and mineral oils. The 16S ribosomal RNA (rRNA) analysis classified the biosurfactant producers into the Aeromonadaceae, Bacillaceae, Enterobacteriaceae, Gordoniaceae and the Pseudomonadaceae families. In addition, numerous isolates carried the surfactin 4'-phosphopantetheinyl transferase (sfp), rhamnosyltransferase subunit B (rhlB) and bacillomycin C (bamC) genes involved in the biosynthesis of surfactin, rhamnolipid and bacillomycin, respectively. While, biosurfactant-producing bacteria were found at all sampling points in the WWTP, the Simpson's diversity (1 - D) and the Shannon-Weaver (H) indices revealed an increase in bacterial diversity in the influent samples (0.8356 and 2.08), followed by the effluent (0.8 and 1.6094) and then the biological trickling filter (0.7901 and 1.6770) samples. Numerous biosurfactant-producing bacteria belonging to diverse genera are thus present throughout a WWTP.

[Microbiological characteristics of a Lysinibacillus strain isolated from Populous euphratica]

OBJECTIVE

The aim of this study was to identify the microbiological characteristics of a Lysinibacillus strain isolated from storage liquid in the stems of Populus euphratica trees.

METHODS

Bacterial morphology and cultivation characteristics were studied by conventional cultivation and dyeing method. Biochemical characteristics, fatty acid components, menaquinone, polar lipids, phylogenetic analyses of 16S rRNA, determination of (G + C) mol% content and DNA- DNA hybridization were studied by polyphasic taxonomic approach.

RESULTS

Strain ML-64 is Gram-positive, endospore-forming and rod-shaped. Colonies are pale-yellow, circular and entire margin. Temperature range for growth is between 10 and 45 degrees C (optimum at 37 degrees C ). The pH range for growth is between 6. 0 and 9.0 (optimum at 7.0). NaCl concentration range for growth is between 0 and 6% (optimum 3% ). Cells were positive for lipid esterase, Arginine dihydrolase, urease and Voges-Proskauer test. No sugars were fermented in the API 50CH strips. L-Serine, Methyl Pyruvate, α-Keto-Butyric, Acetoacetic Acid were oxidized. Resistant to polymyxin b (30 μg), novobiocin (30 μg), peillin G (10 U). 16S rRNA gene sequence demonstrated that strain ML-64 was closely related to Lysinibacillus chungkukjangi 2RL3-2T (100%) , Lysinibacillus sinduriensis BLB-1T (99.1%). DNA-DNA relatedness were 82% and 50. 9% with Lysinibacillus chungkukjangi 2RL3-2T and Lysinibacillus massiliensis CIP108446T, respectively. The genomic DNA G + C content of strain ML-64 was 36. 8% (mol). Major fatty acids were iso-C,,, (55. 05% ) and anteiso-C15,0 (20. 70% ). The predominant menaquinone is MK-7. Based on the phenotypic phylogenetic and genotypic analyses, the strain ML-64 is concluded to represent a new mutant strain of the Lysinibacillus chungkukjangi species, GenBank accession number is KC609752.

CONCLUSION

As an endophytic bacterium of Populus euphratica, genomic structure of the strain ML-64 was greatly differentiated from the closest strain L. chungkukjangi, and suitably adapted to the endophytic environment of Populus euphratica.

Conductive iron oxide minerals accelerate syntrophic cooperation in methanogenic benzoate degradation

Recent studies have suggested that conductive iron oxide minerals can facilitate syntrophic metabolism of the methanogenic degradation of organic matter, such as ethanol, propionate and butyrate, in natural and engineered microbial ecosystems. This enhanced syntrophy involves direct interspecies electron transfer (DIET) powered by microorganisms exchanging metabolic electrons through electrically conductive minerals. Here, we evaluated the possibility that conductive iron oxides (hematite and magnetite) can stimulate the methanogenic degradation of benzoate, which is a common intermediate in the anaerobic metabolism of aromatic compounds. The results showed that 89-94% of the electrons released from benzoate oxidation were recovered in CH4 production, and acetate was identified as the only carbon-bearing intermediate during benzoate degradation. Compared with the iron-free controls, the rates of methanogenic benzoate degradation were enhanced by 25% and 53% in the presence of hematite and magnetite, respectively. This stimulatory effect probably resulted from DIET-mediated methanogenesis in which electrons transfer between syntrophic partners via conductive iron minerals. Phylogenetic analyses revealed that Bacillaceae, Peptococcaceae, and Methanobacterium are potentially involved in the functioning of syntrophic DIET. Considering the ubiquitous presence of iron minerals within soils and sediments, the findings of this study will increase the current understanding of the natural biological attenuation of aromatic hydrocarbons in anaerobic environments.

Therapeutic intervention and molecular characterizations of bacteriocin producing Lysinibacillus sp., nov., isolated from food sample

Many bacteriocins from Lactobacilli have been reported as immunostimulatory, preservatives, anticancerous and biocontroling. However, antimicrobial potential of Lysinibacillus is not much reported. In this study, an attempt was made to isolate and anticipate therapeutic potential of Lysinibacillus from spoiled food sample. We screened 125 Lactobacilli for their antagonistic nature against food borne and disease causing bacterial and fungal pathogens. Among them, one Bacillus was phenotypically, and 16S rRNA based, molecularly identified as Lysinibacillus species given with accession numbers JX416855 in NCBI. The type strain JX416855 has shown the 99% identity with the Lysinibacillus fusiformis, Lysinibacillus sphaericus and Lysinibacillus xylanilyticus. It was amylase, protease, gelatinase, nitrate reductase and urease negative and catalase positive. The growth conditions and bacteriocin activity were found optimum with MRS media at pH 7-10, Temp-35-40°C and salt tolerance at 1-3% which was optimized with MRS broth at pH 7.4, 37 °C, 1.5% NaCl for 48 h in shaking conditions @ 100 rpm. The isolate showed broad-spectrum antibacterial activity against gram positive (10-13 mm) and gram-negative (20mm) bacteria. It also strongly inhibited to fungus Aspergillus, Fusarium and Trichoderma. Bacteriocin from 60% ammonium sulphate fraction strongly inhibited to gram-negative R. planticola and Pseudomonas aeruginosa, which showed three protein bands of high molecular weight (nearly 40-70 kD) by SDS-PAGE analysis.

[Formation of huntite by Lysinibacillus sp. GW-2 strain]

OBJECTIVE

We studied the formation of carbonate minerals induced by microorganism to explore the possibility of mineral capture.

METHODS

Culture experiments of carbonate precipitation were done using B4 medium with 6:1 molar ration of Mg/Ca for 50 days. The same medium without inoculation was used as the control. During the cultivation, bacterial density, precipitate quantities, pH and conductivity of the medium, calciumand magnesium concentration were determined. The morphologies of precipitated carbonates were observed using scanning electron microscopy, and mineral species of carbonate were determined by X-ray diffraction.

RESULTS

The main results were: (1) In the inoculation process of the Lysinibacillus sp. (GW-2 strain), we found that precipitate quantities were gradually increased with time, while precipitate was not collected in the aseptic experiments; (2) There were significant positive correlations between bacterial density and average precipitation rate (r = 0. 67, P < 0.05), precipitate quantities and pH value (r = 0.79, P < 0.05); (3) Precipitate quantities negatively correlated with conductivity, Ca2+ and Mg2+ concentration with correlation coefficients r of 0.89, 0.93, 0.98 (P < 0.001), respectively; (4) The three carbonate minerals by Lysinibacillus sp. formed according to following trend: amorphous calcium carbonate --> Huntite --> High-Mg calcite.

CONCLUSIONS

The main conclusions were: (1) Lysinibacillus sp. (GW-2 strain) might induce the formation of carbonate minerals precipitation; (2) The bacterial density directly affected the precipitation of carbonate minerals, whereas pH value indirectly controlled the precipitation of carbonate minerals; (3) Decreased of conductivity, calcium and magnesium concentration of the medium could indirectly indicate the occurrence of carbonate precipitate; (4) Huntite might be formed through ageing of amorphous calcium carbonate, whereas high-Mg calcite might be formed through demagnesium of the huntite.

Exploiting the efficacy of Lysinibacillus sp. RGS for decolorization and detoxification of industrial dyes, textile effluent and bioreactor studies

Complete decolorization and detoxification of Reactive Orange 4 within 5 h (pH 6.6, at 30°C) by isolated Lysinibacillus sp. RGS was observed. Significant reduction in TOC (93%) and COD (90%) was indicative of conversion of complex dye into simple products, which were identified as naphthalene moieties by various analytical techniques (HPLC, FTIR, and GC-MS). Supplementation of agricultural waste extract considered as better option to make the process cost effective. Oxido-reductive enzymes were found to be involved in the degradation mechanism. Finally Loofa immobilized Lysinibacillus sp. cells in a fixed-bed bioreactor showed significant decolorization with reduction in TOC (51 and 64%) and COD (54 and 66%) for synthetic and textile effluent at 30 and 35 mL h(-1) feeding rate, respectively. The degraded metabolites showed non-toxic nature revealed by phytotoxicity and photosynthetic pigments content study for Sorghum vulgare and Phaseolus mungo. In addition nitrogen fixing and phosphate solubilizing microbes were less affected in treated wastewater and thus the treated effluent can be used for the irrigation purpose. This work could be useful for the development of efficient and ecofriendly technologies to reduce dye content in the wastewater to permissible levels at affordable cost.

Biological and chemical phosphorus solubilization from pyrolytical biochar in aqueous solution

Biochar, a massive byproduct of biomass pyrolysis during biofuel generation, is a potential P source for the mitigation of P depletion. However, the chemical and biological effect of the release of P from biochar is still unclear. In this study, two types of Lysinibacillus strains (Lysinibacillussphaericus D-8 and Lysinibacillus fusiformis A-5) were separated from a sediment and their P-solubilizing characteristics to biochar was first reported. Compared with the bacterial mixture W-1 obtained from a bioreactor, the introduction of A-5 and D-8 significantly improved P solubilization. The release of P from biochar by A-5 and D-8 reached 54% and 47%, respectively, which is comparable to that under rigorous chemical conditions. SEM images and XPS spectra demonstrated that the physicochemical properties of the biochar surface have changed in the process which may be caused by the activities of the microbes.

Oxidative stress response in dye degrading bacterium Lysinibacillus sp. RGS exposed to Reactive Orange 16, degradation of RO16 and evaluation of toxicity

Lysinibacillus sp. RGS degrades sulfonated azo dye Reactive Orange 16 (RO16) efficiently. Superoxide dismutase and catalase activity were tested to study the response of Lysinibacillus sp. RGS to the oxidative stress generated by RO16. The results demonstrated that oxidative stress enzymes not only protect the cell from oxidative stress but also has a probable role in decolorization along with an involvement of oxidoreductive enzymes. Formation of three different metabolites after degradation of RO16 has been confirmed by GC-MS analysis. FTIR analysis verified the degradation of functional groups of RO16, and HPTLC confirmed the removal of auxochrome group from the RO16 after degradation. Toxicity studies confirmed the genotoxic, cytotoxic, and phytotoxic nature of RO16 and the formation of less toxic products after the treatment of Lysinibacillus sp. RGS. Therefore, Lysinibacillus sp. RGS has a better perspective of bioremediation for textile wastewater treatment.

Isolation and characterization of a Lysinibacillus strain B1-CDA showing potential for bioremediation of arsenics from contaminated water

The main objective of this study was to identify and isolate arsenic resistant bacteria that can be used for removing arsenic from the contaminated environment. Here we report a soil borne bacterium, B1-CDA that can serve this purpose. B1-CDA was isolated from the soil of a cultivated land in Chuadanga district located in the southwest region of Bangladesh. The morphological, biochemical and 16S rRNA analysis suggested that the isolate belongs to Lysinibacillus sphaericus. The minimum inhibitory concentration (MIC) value of the isolate is 500 mM (As) as arsenate. TOF-SIMS and ICP-MS analysis confirmed intracellular accumulation and removal of arsenics. Arsenic accumulation in cells amounted to 5.0 mg g(-1) of the cells dry biomass and thus reduced the arsenic concentration in the contaminated liquid medium by as much as 50%. These results indicate that B1-CDA has the potential for remediation of arsenic from the contaminated water. We believe the benefits of implementing this bacterium to efficiently reduce arsenic exposure will not only help to remove one aspect of human arsenic poisoning but will also benefit livestock and native animal species. Therefore, the outcome of this research will be highly significant for people in the affected area and also for human populations in other countries that have credible health concerns as a consequence of arsenic-contaminated water.

Simultaneous decolorization of reactive Orange M2R dye and reduction of chromate by Lysinibacillus sp. KMK-A

Azo dyes constitute the largest and diverse group of dyes, widely used in number of industries that are contributing toward organic and inorganic load of effluent treatment. In the present study, Lysinibacillus sp. KMK-A was able to effectively decolorize Orange M2R dye up to 2000 mg l(-1) (Vmax of 19.6 mg l(-1) h(-1) and Km of 439 mg l(-1)) and reduce Cr(VI) up to 250 mg l(-1) (Vmax of 3.6 mg l(-1) h(-1) and Km 28.3 mg l(-1)). It also has an ability of simultaneous decolorization of Orange M2R dye (200-1000 mg l(-1)) with reduction of Cr(VI) (50-200 mg l(-1)). Significant reduction in total organic carbon content, chemical and biological oxygen demand along with spectroscopic and chromatographic analysis confirmed the biotransformation of Orange M2R. Involvement of enzymes namely azoreductase and chromate reductase was observed during biotransformation. The phyto and geno toxicity studies demonstrated that metabolites of dye degradation were non-toxic. Higher tolerance with simultaneous decolorization and detoxification of azo dyes in presence of Cr(VI) makes Lysinibacillus sp. KMK-A, a potential candidate for eco-friendly remediation of metal contaminated dye effluents.

[Preparation of PVA-SA-PHB-AC composite carrier and m-cresol biodegradation by immobilized Lysinibacillus cresolivorans]

Due to the effects of outer environment and concentration limit on the biodegradation of m-cresol, a carrier with adsorption ability was synthesized. A PVA-SA-PHB-AC composite membrane was prepared by adding SA, PHB and AC into PVA immobilization carrier using the combination of freezing-thawing and boric acid methods. A highly-effective m-cresol-degrading strain Lysinibacillus cresolivorans was entrapped in it and the effects of structural properties such as micro-structure, stability and diffusion coefficient on m-cresol biodegradation were investigated. The results showed that PVA-SA-PHB-AC composite membrane had uniform pore opening, of which the average pore size, specific surface area, m-cresol adsorption capacity and diffusion coefficient was 33.68 nm, 15.30 m2 x g(-1), 3.86 mg x g(-1) and 5.62 x 10(-8) m2 x min(-1), respectively. It could be reused for more than two months, m-Cresol removal by immobilized L. cresolivorans was the coupling of adsorption and biodegradation, and the removal rate was jointly determined by mass-transfer rate and biodegradation rate. When the initial concentration of m-cresol was lower than 350 mg x L(-1), the mass-transfer rate of PVA-SA-PHB-AC was smaller than the biodegradation rate. The m-cresol removal rate depended on the mass-transfer rate, when the concentration was higher than 380 mg x L(-1), it was determined by the biodegradation rate. The addition of adsorbent could decrease the mass transfer coefficient in the carrier, while the higher concentration of substrate could be tolerated and the efficient biodegradation could be achieved in a wider range of concentrations. The biodegradation of m-cresol by immobilized microorganism showed that the modified carrier increased the reaction kinetics in a range of initial concentrations.

Lysinibacillus chungkukjangi sp. nov., isolated from Chungkukjang, Korean fermented soybean food

One bacterial strain 2RL3-2(T) was isolated from Chungkukjang, a traditional Korean fermented food made from soybeans, and determined to be a Gram-positive, aerobic, spore-forming rod. Growth of the novel strain was optimal at 30°C and pH 7.0. The 16S rRNA gene of strain 2RL3-2(T) showed the highest level of sequence similarity to Lysinibacillus sinduriensis BLB-1(T) (99.0%), Lysinibacillus massiliensis 4400831(T) (97.1%), Lysinibacillus xylanilyticus XDB9(T) (97.0%), and Lysinibacillus odysseyi 34hs-1(T) (96.8%). Phylogenetic analysis showed that strain 2RL3-2(T) formed a robust cluster with L. sinduriensis BLB-1(T), L. massiliensis 4400831(T), and L. odyssey 34hs-1(T). The major fatty acids were anteiso-C15:0 (47.3%), iso-C16:0 (16.3%), and anteiso-C17:0 (11.3%), and the only menaquinone was MK-7. Diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were the major polar lipids, along with an unknown phospholipid and two unknown lipids. The peptidoglycan type was A4α, with an interpeptide bridge of l-Lys-d-Asp. DNA-DNA hybridization values between strain 2RL3-2(T) and closely related Lysinibacillus species were below 43±4%. Therefore, based on phenotypic, chemotaxonomic, and phylogenetic characteristics, it was determined that strain 2RL3-2(T) represents a novel species of the genus Lysinibacillus, for which the name Lysinibacillus chungkukjangi sp. nov. is proposed. The type strain is 2RL3-2(T) (=KACC 16626(T) =NBRC 108948(T)).

Lysinibacillus mangiferahumi sp. nov., a new bacterium producing nematicidal volatiles

A Gram-positive bacterium, designated M-GX18(T), was isolated from the rhizosphere soil of mango (Guangxi Province, China). The isolate produced nematicidal volatile compounds with activities against the root-knot nematode Meloidogyne incognita. The organism was motile, catalase- and oxidase-positive, spore-forming and rod shaped. The predominant menaquinone was MK-7 and the major cellular fatty acid profiles were iso-C(15:0), anteiso-C(15:0) and iso-C(16:0). The DNA G+C content was 38.9%. A phylogenetic analysis based on 16S rRNA gene sequences showed that this organism represented a new species of the genus Lysinibacillus. Strain M-GX18(T) exhibited high 16S rRNA gene sequence similarity with its closest neighbors Lysinibacillus sphaericus (98.5%), Lysinibacillus fusiformis (98.1%) and Lysinibacillus xylanilyticus (98.6%). The physiological, biochemical and chemotaxonomic data, including DNA-DNA hybridization relatedness data, indicate that strain M-GX18(T) can be distinguished from all the related species of the genus Lysinibacillus. Therefore, on the basis of the polyphasic taxonomic data presented, a new species of the genus Lysinibacillus, Lysinibacillus mangiferahumi, with the type strain M-GX18(T) (=DSM 24076(T) = CCTCC AB 2010389(T)) is proposed.

Characterization of boron resistant and accumulating bacteria Lysinibacillus fusiformis M1, Bacillus cereus M2, Bacillus cereus M3, Bacillus pumilus M4 isolated from former mining site, Hokkaido, Japan

Boron is known to be widespread environmental contaminant that is relatively mobile in soil when compared to other metal contaminants. The present study made an attempt to isolate and characterize the boron resistant and accumulating bacteria from former mining site at Hokkaido, Japan. Four potential strains M1, M2, M3 and M4 were selected based on high degree of boron and heavy metal resistances. The morphological, biochemical and 16S rDNA sequencing analysis of mining bacteria revealed that the isolates were highly homology to Lysinibacillus fusiformis M1 (99 %), Bacillus cereus M2 (99 %), Bacillus cereus M3 (99 %) and Bacillus pumilus M4 (99 %) respectively. The strains M1, M2, M3 and M4 showed resistance to several heavy metals such as As (III), As (V) and Cr (VI), Cu, Ni, Pb and Zn. The selected strains were found to be arsenic oxidizing bacteria confirmed by Silver nitrate test. The resting and growing cells of mining bacteria were used for boron accumulation analysis. Selected strains were found to be efficiently accumulating boron concentration ranging from 0.1-2.3 mg L (-1) and 1.5-4.7 mg L (-1) at 24 h and 168 h, respectively. The following results conclude that the mining bacteria act as potent bioaccumulator of boron and its resistant, removal characteristic can be valuable in boron bioremediation.

Characterization of alginase and elicitor-active oligosaccharides from Gracilibacillus A7 in alleviating salt stress for Brassica campestris L

Alginase was purified from Gracilibacillus A7 and evaluated for its ability to produce elicitor-active oligosaccharides. The optimum conditions for the alginase reaction are as follows: temperature, 40 °C; pH, 8.0; alginate content, 0.3-0.7%; and the presence of Na(+) and Mg(2+) metal ions. The degree of polymerization (DP) decreased as the reaction time of the alginase progressed, achieving values of 5.4 and 3.3 after 240 and 300 min, respectively. The relative root length (RRL) of the Brassica campestris L. increased with the addition of oligosaccharides with reduced DP values. The oligosaccharides with lower DP values are effective in reducing the effect of salt stress on the activity of the superoxide dismutase (SOD) and guaiacol peroxidase (POD), and oligosaccharides with moderate DP values can reduce the increase in lipid peroxidation activities (as malondialdehyde content) induced by salt stress. These results suggest that oligosaccharides may act as osmoprotective agents during the plant germination process.

Decolorization of sulfonated azo dye Metanil Yellow by newly isolated bacterial strains: Bacillus sp. strain AK1 and Lysinibacillus sp. strain AK2

Two different bacterial strains capable of decolorizing a highly water soluble azo dye Metanil Yellow were isolated from dye contaminated soil sample collected from Atul Dyeing Industry, Bellary, India. The individual bacterial strains Bacillus sp. AK1 and Lysinibacillus sp. AK2 decolorized Metanil Yellow (200 mg L(-1)) completely within 27 and 12h respectively. Various parameters like pH, temperature, NaCl and initial dye concentrations were optimized to develop an economically feasible decolorization process. The maximum concentration of Metanil Yellow (1000 mg L(-1)) was decolorized by strains AK2 and AK1 within 78 and 84 h respectively. These strains could decolorize Metanil Yellow over a broad pH range 5.5-9.0; the optimum pH was 7.2. The decolorization of Metanil Yellow was most efficient at 40°C and confirmed by UV-visible spectroscopy, TLC, HPLC and GC/MS analysis. Further, both the strains showed the involvement of azoreductase in the decolorization process. Phytotoxicity studies of catabolic products of Metanil Yellow on the seeds of chick pea and pigeon pea revealed much reduction in the toxicity of metabolites as compared to the parent dye. These results indicating the effectiveness of strains AK1 and AK2 for the treatment of textile effluents containing azo dyes.

Characterization and genomic analysis of a highly chromate resistant and reducing bacterial strain Lysinibacillus fusiformis ZC1

Lysinibacillus fusiformis ZC1 isolated from chromium (Cr) contaminated wastewater of a metal electroplating factory displayed high chromate [Cr(VI)] resistance with a minimal inhibitory concentration (MIC) of 60mM in R2A medium. L. fusiformis ZC1 showed resistances to multiple metals (Cu, Ni, Co, Hg, Cd and Ag) and a metalloid (As). This bacterium exhibited an extremely rapid Cr(VI) reduction capability. It almost completely reduced 1mM K(2)CrO(4) in 12h. The Cr(VI) reduction ability of L. fusiformis ZC1 was enhanced by sodium acetate and NADH. By whole genome sequence analysis, strain ZC1 was found to contain large numbers of metal(loid) resistance genes. Specifically, a chrA gene encoding a putative chromate transporter conferring chromate resistance was identified. The chromate resistance was constitutive in both phenotypic and gene expression analyses. Furthermore, we found a yieF gene and several genes encoding reductases that were possibly involved in chromate reduction. Expression of adjacent putative chromate reduction related genes, nitR and yieF, was found to be constitutive. The large numbers of NADH-dependent chromate reductase genes may be responsible for the rapid chromate reduction in order to detoxify Cr(VI) and survive in the harsh wastewater environment.

Acquisition of iron by alkaliphilic bacillus species

The biochemical and molecular mechanisms used by alkaliphilic bacteria to acquire iron are unknown. We demonstrate that alkaliphilic (pH > 9) Bacillus species are sensitive to artificial iron (Fe³+) chelators and produce iron-chelating molecules. These alkaliphilic siderophores contain catechol and hydroxamate moieties, and their synthesis is stimulated by manganese(II) salts and suppressed by FeCl₃ addition. Purification and mass spectrometric characterization of the siderophore produced by Caldalkalibacillus thermarum failed to identify any matches to previously observed fragmentation spectra of known siderophores, suggesting a novel structure.

Thermophilic bacteria from Mexican thermal environments: isolation and potential applications

Extremophiles are microorganisms that possess application possibilities in several industrial fields, including agricultural, chemical, laundry, pharmaceutical, food, petroleum and bioremediation. This work reports the isolation of 19 thermophilic, alkalitolerant and halotolerant bacterial strains from two thermal sites in Veracruz, México: El Carrizal thermal pool and Los Baños hot spring. These strains belong to the Geobacillus, Anoxybacillus and Aeribacillus genera. The strains produce lipases, proteases, and amylases under thermophilic conditions. They may have good potential for application in microbial enhanced oil recovery, since they are thermophilic and halotolerant, produce exopolymers (up to 11.8 mg/mg) and acids, show emulsifying activity (E24 up to 7.5%), and are able to grow in kerosene as carbon source; these strains may also be used in biodesulphurization since they can grow in dibenzothiophene producing 2-hydroxybiphenyl under thermophilic conditions (up to 2.9 mg/L).

Streptohalobacillus salinus gen. nov., sp. nov., a moderately halophilic, Gram-positive, facultative anaerobe isolated from subsurface saline soil

A Gram-stain-positive, rod-shaped, non-sporulating, motile and moderately halophilic bacterium, designated strain H96B60(T), was isolated from a saline soil sample of the Qaidam basin, China. The strain was facultatively anaerobic. Major end products formed from glucose fermentation were acetate, ethanol and lactic acid. The cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The isoprenoid quinone component was menaquinone-6 (MK-6). The predominant cellular fatty acids were C(16: 0), anteiso-C(13 : 0) and anteiso-C(15 : 0). The genomic DNA G+C content of strain H96B60(T) was 36.2 mol%. Phylogenetic analysis based on comparative 16S rRNA gene sequences indicated that strain H96B60(T) represented a novel phyletic lineage within the family Bacillaceae and was related most closely to Halolactibacillus species (96.1-96.4 % similarity). Based on the phenotypic, chemotaxonomic and phylogenetic data presented, strain H96B60(T) is considered to represent a novel species of a new genus, for which the name Streptohalobacillus salinus gen. nov., sp. nov. is proposed. The type strain of Streptohalobacillus salinus is H96B60(T) ( = DSM 22440(T)  = CGMCC 1.7733(T)).