Enhancing spinach (Spinacia oleracea L.) resilience in pesticide-contaminated soil: Role of pesticide-tolerant Ciceribacter azotifigens and Serratia marcescens in root architecture, leaf gas exchange attributes and antioxidant response restoration.

This study unveils the detoxification potential of insecticide-tolerant plant beneficial bacteria (PBB), i.e., Ciceribacter azotifigens SF1 and Serratia marcescens SRB1, in spinach treated with fipronil (FIP), profenofos (PF) and chlorantraniliprole (CLP) insecticides. Increasing insecticide doses (25-400 µg kg-1 soil) significantly curtailed germination attributes and growth of spinach cultivated at both bench-scale and in greenhouse experiments. Profenofos at 400 µg kg-1 exhibited maximum inhibitory effects and reduced germination by 55%; root and shoot length by 78% and 81%, respectively; dry matter accumulation in roots and shoots by 79% and 62%, respectively; leaf number by 87% and leaf area by 56%. Insecticide application caused morphological distortion in root tips/surfaces, increased levels of oxidative stress, and cell death in spinach. Application of insecticide-tolerant SF1 and SRB1 strains relieved insecticide pressure resulting in overall improvement in growth and physiology of spinach grown under insecticide stress. Ciceribacter azotifigens improved germination rate (10%); root biomass (53%); shoot biomass (25%); leaf area (10%); Chl-a (45%), Chl-b (36%) and carotenoid (48%) contents of spinach at 25 µg CLP kg-1 soil. PBB inoculation reinvigorated the stressed spinach and modulated the synthesis of phytochemicals, proline, malondialdehyde (MDA), superoxide anions (O2•-), and hydrogen peroxide (H2O2). Scanning electron microscopy (SEM) revealed recovery in root tip morphology and stomatal openings on abaxial leaf surfaces of PBB-inoculated spinach grown with insecticides. Ciceribacter azotifigens inoculation significantly increased intrinsic water use efficiency, transpiration rate, vapor pressure deficit, intracellular CO2 concentration, photosynthetic rate, and stomatal conductance in spinach exposed to 25 µg FIP kg-1. Also, C. azotifigens and S. marcescens modulated the antioxidant defense systems of insecticide-treated spinach. Bacterial strains were strongly colonized to root surfaces of insecticide-stressed spinach seedlings as revealed under SEM. The identification of insecticide-tolerant PBBs such as C. azotifigens and S. marcescens hold the potential for alleviating abiotic stress to spinach, thereby fostering enhanced and safe production within polluted agroecosystems.

The whole genome insight on condition-specific redox activity and arsenopyrite interaction promoting As-mobilization by strain Lysinibacillus sp. B2A1.

A gram-positive spore former, Lysinibacillus sp. B2A1 was isolated from a high arsenic containing groundwater of Beimen2A well, Chianan Plain area, Southwestern Taiwan. Noteworthy, in the subsurface-mimicking anoxic incubation with a Na-lactate amendment system, this isolate could interact with arsenic-source mineral arsenopyrite and enhance arsenic mobilization. Further, the isolate showed elevated levels of arsenic resistance, 200 mM and 7.5 mM for arsenate and arsenite, respectively. Lysinibacillus sp. B2A1 demonstrated condition-specific redox activities including salient oxic oxidation of arsenite and anoxic reduction of arsenate. The elevated rate of As(III) oxidation (Vmax = 0.13 µM min-1 per 106 cells, Km = 15.3 µM) under oxic conditions was potent. Correlating with stout persistence in an arsenic-rich niche, remarkably, the lesser toxic effects of arsenic ions on bacterial sporulation frequency and germination highlight this strain's ability to thrive under catastrophic conditions. Moreover, the whole genome analysis elucidated diverse metal redox/resistance genes that included a potential arsenite S-adenosylmethyltransferase capable of mitigating arsenite toxicity. Owing to its arsenic resistance, conditional redox activities and ability to interact with arsenic minerals leading to arsenic mobilization, the presence of such spore-forming strains could be a decisive indication towards arsenic mobilization in subsurface aquifers having a high concentration of soluble arsenic or its source minerals.

Salicibibacter kimchii gen. nov., sp. nov., a moderately halophilic and alkalitolerant bacterium in the family Bacillaceae, isolated from kimchi.

A moderately halophilic and alkalitolerant bacterial strain NKC1-1T was isolated from commercial kimchi in Korea. Strain NKC1-1T was Gram-stain-positive, aerobic, rod-shaped, non-motile, and contained diaminopimelic acid-type murein. Cell growth was observed in a medium containing 0-25% (w/v) NaCl (optimal at 10% [w/v]), at 20-40°C (optimal at 37°C) and pH 6.5-10.0 (optimal at pH 9.0). The major isoprenoid quinone of the isolate was menaquinone-7, and the major polar lipids were phosphatidylglycerol and unidentified phospholipids. Cell membrane of the strain contained iso-C17:0 and anteiso-C15:0 as the major fatty acids. Its DNA G + C content was 45.2 mol%. Phylogenetic analysis indicated the strain to be most closely related to Geomicrobium halophilum with 92.7-92.9% 16S rRNA gene sequence similarity. Based on polyphasic taxonomic evaluation with phenotypic, phylogenetic, and chemotaxonomic analyses, the strain represents a novel species in a new genus, for which the name Salicibibacter kimchii gen. nov., sp. nov. is proposed (= CECT 9537T; KCCM 43276T).

Effects of plant- and animal-based high-fat diets on lipid storage and distribution in environmental bacteria-colonized gnotobiotic mice.

Different edible oils such as lard and soybean oil have been reported to interact with the gut microbiota, affecting host lipid metabolism. However, whether bacteria derived from the environment influence host lipid metabolism remains unclear. This study aimed to clarify the roles of environmental bacteria in host lipid storage and distribution with various edible oils. Gnotobiotic C57BL/6JNarl mice were inoculated with Lysinibacillus xylanilyticus and Paenibacillus azoreducens and then fed either a normal diet (LabDiet 5010, control group) or a diet containing 60% lard (L-group) or soybean oil (S-group) for 18 months. Interestingly, the S-group accumulated massive amounts of white adipose tissue compared to the L- and control groups, while the L-group displayed more hepatic steatosis and fatty droplets than the other groups. The expression of fatty acid synthase (FAS), hydroxymethylglutaryl-coenzyme A reductase (HMGCR), sterol regulatory element-binding protein 2 (SREBP2), and peroxisome proliferator-activated receptor gamma (PPARγ) in the livers of the L-group were markedly elevated compared to the S-group. FAS and PPARγ protein levels were also markedly elevated. However, there were no differences in the expression of the pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-α between the groups. Our results suggest that environmental bacteria may affect host hepatic inflammation and lipid distribution in the presence of high-fat diets, with different effects depending on the fat type consumed.

Biofilm characteristics and evaluation of the sanitation procedures of thermophilic Aeribacillus pallidus E334 biofilms.

The ability of Aeribacillus pallidus E334 to produce pellicle and form a biofilm was studied. Optimal biofilm formation occurred at 60 °C, pH 7.5 and 1.5% NaCl. Extra polymeric substances (EPS) were composed of proteins and eDNA (21.4 kb). E334 formed biofilm on many surfaces, but mostly preferred polypropylene and glass. Using CLSM analysis, the network-like structure of the EPS was observed. The A. pallidus biofilm had a novel eDNA content. DNaseI susceptibility (86.8% removal) of eDNA revealed its importance in mature biofilms, but the purified eDNA was resistant to DNaseI, probably due to its extended folding outside the matrix. Among 15 cleaning agents, biofilms could be removed with alkaline protease and sodium dodecyl sulphate (SDS). The removal of cells from polypropylene and biomass on glass was achieved with combined SDS/alkaline protease treatment. Strong A. pallidus biofilms could cause risks for industrial processes and abiotic surfaces must be taken into consideration in terms of sanitation procedures.

Application of ultrasound in combination with heat and pressure for the inactivation of spore forming bacteria isolated from edible crab (Cancer pagurus).

This research was performed to characterize the resistance of three different bacterial spore species isolated from pasteurized edible crab (Cancer pagurus) meat to heat treatments and to assess the potential of manosonication (MS) and manothermosonication (MTS) as an alternative for their inactivation. The spore-forming bacteria used in this study were Bacillus mycoides, Bacillus weihenstephanensis and Psychrobacillus psychrodurans. The thermal resistance of these three species was determined at different temperatures ranging from 80 to 110 °C and their resistance to ultrasound under pressure from 35 to 95 °C. Ginafit Excel tool was used to fit the Geeraerd's 'Log-linear + shoulder' and Bigelow & Easty's equations to the survival curves for heat and MS/MTS treatments. From the results obtained it can be concluded that the profile of the survival curves either for heat or for ultrasound treatments depended on the bacterial spore species. When shoulders were detected in the inactivation curves for heat they were also present in the curves for MS/MTS treatments, although the application of an ultrasonic field reduced the shoulder length. B. weihenstephanensis was found to be the most resistant species to heat, requiring 1.4 min to reduce 4log10 cycles at 107.5 °C (zT=7.1 °C) while B. mycoides was the most sensitive requiring 1.6 min at 95 °C (zT=9.1 °C). By contrast, B. mycoides was the most resistant to MS. The efficiency of the combination of ultrasonic waves under pressure with heat (MTS) for bacterial spore inactivation was directly correlated with the thermal resistance. Indeed, MTS showed a synergistic effect for the inactivation of the three spores. The highest percentage of synergism corresponded to the spore species with higher zT value (B. mycoides), but the highest temperature at which this synergism was detected corresponded to the most heat tolerant spore species (B. weihenstephanensis). This study revealed that MTS treatment is capable of inactivating spore-forming bacteria and that the inactivation efficiency of the combined treatment is correlated with the thermal resistance of the spore species.

Ornithinibacillus scapharcae sp. nov., isolated from a dead ark clam.

A novel Gram-positive, aerobic, motile, hemolytic, endospore-forming and rod-shaped bacterium TW25(T) was isolated from a dead ark clam during a mass mortality event on the South coast of Korea. The strain grew optimally at 30°C, at pH 8-9, and with 1% (w/v) NaCl. The 16S rRNA gene sequence analysis indicated that strain TW25(T) was associated with the genus Ornithinibacillus and that it was most closely related to the type strain of Ornithinibacillus californiensis (98.5% similarity). The dominant cellular fatty acids were iso-C15:0, anteiso-C15:0 and C16:0. The peptidoglycan amino acid type was A4ß, containing L: -ornithine and D: -aspartic acid. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, four unidentified phospholipids, two unidentified aminolipids and two unidentified lipids. The major respiratory quinone was menaquinone-7 (MK-7). The G + C content of genomic DNA was 36.7 mol%. DNA-DNA hybridization experiments with related strains revealed lower than 11 ± 3% relatedness. Based on this polyphasic taxonomic study, strain TW25(T) represents a novel species in the genus Ornithinibacillus, for which the name Ornithinibacillus scapharcae sp. nov. is proposed. The type strain is TW25(T) (=KACC 15116(T) = JCM 17314(T)).

Oceanobacillus neutriphilus sp. nov., isolated from activated sludge in a bioreactor.

A Gram-stain-positive, neutrophilic, rod-shaped bacterium, strain A1g(T), was isolated from activated sludge of a bioreactor and was subjected to a polyphasic taxonomic characterization. The isolate grew in the presence of 0-17.0 % (w/v) NaCl and at pH 6.0-9.0; optimum growth was observed in the presence of 3.0-5.0 % (w/v) NaCl and at pH 7.0. Strain A1g(T) was motile, formed cream-coloured colonies, was catalase- and oxidase-positive and was able to hydrolyse aesculin, Tween 40 and Tween 60. Chemotaxonomic analysis revealed menaquinone-7 as the predominant respiratory quinone and anteiso-C15:0, anteiso-C17:0, iso-C16:0 and iso-C15:0 as major fatty acids. The genomic DNA G+C content of strain A1g(T) was 36.3 mol%. Comparative 16S rRNA gene sequence analysis revealed that the new isolate belonged to the genus Oceanobacillus and exhibited closest phylogenetic affinity to the type strains of Oceanobacillus oncorhynchi subsp. incaldanensis (97.9 % similarity) and O. oncorhynchi subsp. oncorhynchi (97.5 %), but less than 97 % sequence similarity with respect to the type strains of other recognized Oceanobacillus species. Levels of DNA-DNA relatedness between strain A1g(T) and reference strains O. oncorhynchi subsp. incaldanensis DSM 16557(T), O. oncorhynchi subsp. oncorhynchi JCM 12661(T) and Oceanobacillus iheyensis DSM 14371(T) were 29, 45 and 38 %, respectively. On the basis of phenotypic and genotypic data, strain A1g(T) is considered to represent a novel species of the genus Oceanobacillus, for which the name Oceanobacillus neutriphilus sp. nov. is proposed. The type strain is A1g(T) (=CGMCC 1.7693(T) =JCM 15776(T)).

Virgibacillus byunsanensis sp. nov., isolated from a marine solar saltern.

A Gram-variable, motile, endospore-forming and rod-shaped bacterial strain, ISL-24(T), was isolated from a marine solar saltern of the Yellow Sea, Korea, and its taxonomic position was investigated by a polyphasic study. Strain ISL-24(T) grew optimally at pH 7.0-8.0, at 30-37 degrees C and in the presence of 8 % (w/v) NaCl. It contained MK-7 as the predominant menaquinone and anteiso-C(15 : 0) as the predominant fatty acid. The DNA G+C content was 37.6 mol%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain ISL-24(T) fell within the genus Virgibacillus, clustering with Virgibacillus carmonensis LMG 20964(T) and Virgibacillus necropolis LMG 19488(T), with a bootstrap resampling value of 92.3 %, and exhibiting 97.3 and 97.4 % 16S rRNA gene sequence similarity, respectively, to these strains. Strain ISL-24(T) exhibited 94.8-96.8 % 16S rRNA gene sequence similarity to the type strains of the other Virgibacillus species. Mean DNA-DNA relatedness values between strain ISL-24(T) and V. carmonensis DSM 14868(T) and V. necropolis DSM 14866(T) were 11 and 19 %, respectively. Differential phenotypic properties of strain ISL-24(T), together with the phylogenetic and genetic distinctiveness, revealed that this strain is different from recognized Virgibacillus species. On the basis of phenotypic, phylogenetic and genetic data, strain ISL-24(T) represents a novel species of the genus Virgibacillus, for which the name Virgibacillus byunsanensis sp. nov. is proposed. The type strain is ISL-24(T) (=KCTC 13259(T) =CCUG 56754(T)).

Gracilibacillus saliphilus sp. nov., a moderately halophilic bacterium isolated from a salt lake.

A novel Gram-positive-staining, aerobic, spore-forming, rod-shaped bacterium, designated strain YIM 91119(T), was isolated from Ebinur Lake in Xinjiang Province, north-west China. Cells were motile, produced terminal endospores and grew at pH 6.0-8.0 (optimally at pH 7.0), 4-45 degrees C (optimally at 28-37 degrees C) and 1-22 % (w/v) NaCl, (optimally at 10-15 %, w/v). Comparative 16S rRNA gene sequence analysis showed that strain YIM 91119(T) belongs to the genus Gracilibacillus, exhibiting the highest sequence similarity with respect to the type strain of Gracilibacillus orientalis (97.8 %); the next most similar 16S rRNA gene sequences were those of the type strains of Gracilibacillus boraciitolerans (96.8 %), Gracilibacillus dipsosauri (96.5 %) and Gracilibacillus halotolerans (95.8 %). DNA-DNA hybridization with G. orientalis AS 1.4250(T) showed a relatedness of 55 %. The major fatty acids of strain YIM 91119(T) were anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0). The peptidoglycan type was A1gamma (directly cross-linked meso-diaminopimelic acid). The genomic DNA G+C content was 40.1 mol% and the predominant respiratory quinone was MK-7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. On the basis of the evidence from this polyphasic study, strain YIM 91119(T) represents a novel species of the genus Gracilibacillus, for which the name Gracilibacillus saliphilus sp. nov. is proposed, with YIM 91119(T) (=DSM 19802(T) =CCTCC AA 208015(T)) as the type strain.

Characterization of the glycine betaine biosynthetic genes in the moderately halophilic bacterium Halobacillus dabanensis D-8(T).

The gene cluster involved in the choline-glycine betaine conversion pathway was cloned from chromosomal DNA of the Gram-positive moderate halophile Halobacillus dabanensis D-8(T). Nucleotide sequence analysis revealed four genes, designated gbsT, gbsI, gbsA, and gbsB, which are clustered in a 5.1-kb fragment. After heterologous expression of gbsAB in the Escherichia coli mutant strain PD141, the transformed cells were able to grow in a selective M63 medium containing 0.7 M NaCl and 1 mM choline, in contrast to the mutant strain. Glycine betaine biosynthesis was restored and its accumulation was confirmed by using (13)C nuclear magnetic resonance spectroscopy.

Oceanobacillus caeni sp. nov., isolated from a Bacillus-dominated wastewater treatment system in Korea.

A Gram-positive, rod-shaped, spore-forming bacterium, strain S-11T, was isolated from the activated sludge of a Bacillus-dominated wastewater treatment system in South Korea and was characterized using a polyphasic approach in order to determine its taxonomic position. Cells (0.5-0.6 x 2.0-2.2 microm) were motile by means of a single subpolar flagellum. They bore ellipsoidal endospores that lay in a central position in swollen sporangia. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain S-11T was a member of the genus Oceanobacillus. 16S rRNA gene sequence similarity values and DNA-DNA relatedness of strain S-11T to the type strains of other Oceanobacillus species were less than 96.2 and 66.0 %, respectively. Strain S-11T showed distinct differences in the G+C content of the genomic DNA (33.6 mol%). The major cellular fatty acids were iso-C14 : 0, iso-C15 : 0, anteiso-C15 : 0 and iso-C16 : 0. The major isoprenoid quinone was MK-7. There were also some physiological differences in comparison with the type strains of Oceanobacillus species: tests for production of acetoin and acid production from dulcitol, erythritol, myo-inositol and sorbitol were positive. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain S-11T from the six Oceanobacillus species and subspecies with validly published names. Strain S-11T therefore represents a novel species, for which the name Oceanobacillus caeni sp. nov. is proposed, with the type strain S-11T (=KCTC 13061T =CCUG 53534T =CIP 109363T).

Halobacillus seohaensis sp. nov., isolated from a marine solar saltern in Korea.

A Gram-positive or Gram-variable, motile, moderately halophilic, rod-shaped bacterial strain, ISL-50(T), was isolated from a marine solar saltern in Korea and subjected to a polyphasic taxonomic study. Strain ISL-50(T) grew optimally at pH 7.0-8.0 and 37 degrees C in the presence of 8 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain ISL-50(T) belonged to the genus Halobacillus. Strain ISL-50(T) exhibited 16S rRNA gene sequence similarity values of 95.3-98.2 % with respect to the type strains of recognized Halobacillus species. The cell-wall peptidoglycan was based on meso-diaminopimelic acid, the predominant menaquinone was MK-7 and the major fatty acids were anteiso-C(15 : 0) and anteiso-C(17 : 0). The DNA G+C content was 39.3 mol%. DNA-DNA relatedness data and differential phenotypic properties revealed that strain ISL-50(T) was distinguishable from the recognized Halobacillus species. On the basis of phenotypic, chemotaxonomic, phylogenetic and genetic data, strain ISL-50(T) represents a novel species of the genus Halobacillus, for which the name Halobacillus seohaensis sp. nov. is proposed. The type strain is ISL-50(T) (=KCTC 13145(T)=CCUG 54358(T)).

Virgibacillus kekensis sp. nov., a moderately halophilic bacterium isolated from a salt lake in China.

A Gram-positive, moderately halophilic, motile, strictly aerobic, endospore-forming, oxidase- and catalase-positive, rod-shaped bacterium, strain YIM kkny16(T), was isolated from a saline mud sample collected from the Keke salt lake in the Qaidam Basin, north-west China. This isolate grew in the presence of 0-25 % (w/v) NaCl and at pH 6.0-10.0 and 10-50 degrees C; optimum growth was observed with 10 % (w/v) NaCl and at pH 7.0 and 37 degrees C. Strain YIM kkny16(T) had meso-diaminopimelic acid as the diagnostic diamino acid, MK-7 as the predominant respiratory quinone, with a significant amount of MK-6, and anteiso-C(15 : 0), iso-C(14 : 0) and C(16 : 1)omega7c alcohol as major fatty acids. Major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C content was 41.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences confirmed that strain YIM kkny16(T) was a member of the genus Virgibacillus, exhibiting sequence similarities of 94.9-97.3 % to the type strains of recognized Virgibacillus species. Strain YIM kkny16(T) could be differentiated from recognized Virgibacillus species based on phenotypic characteristics, chemotaxonomic differences, phylogenetic analysis and DNA-DNA hybridization data. On the basis of evidence from this polyphasic study, strain YIM kkny16(T) is considered to represent a novel species of the genus Virgibacillus, for which the name Virgibacillus kekensis sp. nov. is proposed. The type strain is YIM kkny16(T) (=DSM 17056(T)=CGMCC 1.6298(T)).

Lentibacillus salinarum sp. nov., isolated from a marine solar saltern in Korea.

A Gram-positive, motile, moderately halophilic and rod-shaped bacterium, strain AHS-1(T), was isolated from a marine solar saltern in Korea, and its exact taxonomic position was investigated by use of a polyphasic study. Strain AHS-1(T) grew optimally at pH 6.5-7.0 and 37-40 degrees C in the presence of 10-12% (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain AHS-1(T) belonged to the genus Lentibacillus. Strain AHS-1(T) exhibited a 16S rRNA gene sequence similarity value of 97.0% to the type strain of Lentibacillus salarius and values of 95.0-96.7% to the type strains of other recognized Lentibacillus species. Strain AHS-1(T) had cell-wall peptidoglycan based on meso-diaminopimelic acid. It contained MK-7 as the predominant menaquinone. The major fatty acids (>10% of total fatty acids) were anteiso-C(15:0) and anteiso-C(17:0), and the major polar lipids were phosphatidylglycerol, diphosphatidylglycerol and two unidentified glycolipids. The DNA G+C content was 49.0 mol%. Strain AHS-1(T) shared a mean level of DNA-DNA relatedness of 8.5% with L. salarius KCTC 3911(T). Strain AHS-1(T) could also be distinguished from recognized Lentibacillus species based on several phenotypic properties. On the basis of phenotypic, chemotaxonomic, phylogenetic and genetic data, strain AHS-1(T) is considered to represent a novel species of the genus Lentibacillus, for which the name Lentibacillus salinarum sp. nov. is proposed. The type strain is AHS-1(T) (=KCTC 13162(T)=CCUG 54822(T)).

Halobacillus mangrovi sp. nov., a moderately halophilic bacterium isolated from the black mangrove Avicennia germinans.

A moderately halophilic, spore-forming, Gram-positive, short-rod-shaped bacterium, designated strain MS10(T), was isolated from the surface of leaves of the black mangrove Avicennia germinans and was subjected to a polyphasic taxonomic study. Strain MS10(T) was able to grow at NaCl concentrations in the range 5-20% (w/v) with optimum growth at 10% (w/v) NaCl. Growth occurred at temperatures of 10-50 degrees C (optimal growth at 33-35 degrees C) and pH 6.0-9.0 (optimal growth at pH 7.0). Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain MS10(T) fell within the branch encompassing members of the genus Halobacillus and was most closely related to Halobacillus dabanensis JCM 12772(T) (99.2% 16S rRNA gene sequence similarity). The DNA G+C content of strain MS10(T) was 45.7 mol%, the major respiratory isoprenoid quinone was MK-7 and the cell-wall peptidoglycan was of the L-Orn-D-Asp type, characteristics consistent with its affiliation to the genus Halobacillus. Strain MS10(T) showed a level of DNA-DNA hybridization with H. dabanensis JCM 12772(T) of 29% and levels below 70% were also obtained with respect to other recognized members of the genus Halobacillus. The major fatty acids of strain MS10(T) were iso-C(16:0), anteiso-C(15:0), iso-C(14:0) and iso-C(15:0). Overall, the phenotypic, genotypic and phylogenetic results presented in this study demonstrate that strain MS10(T) represents a novel species of the genus Halobacillus, for which the name Halobacillus mangrovi sp. nov. is proposed. The type strain is MS10(T) (=CECT 7206(T)=CCM 7397(T)).

Halobacillus faecis sp. nov., a spore-forming bacterium isolated from a mangrove area on Ishigaki Island, Japan.

A Gram-positive, spore-forming, rod-shaped halophilic bacterial strain, IGA7-4T, was isolated from a mangrove area on Ishigaki Island (Japan), and was characterized taxonomically using a polyphasic approach. Strain IGA7-4T was strictly aerobic and non-motile and formed central endospores. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain IGA7-4T is affiliated to the genus Halobacillus, and exhibits sequence similarities of 99.6-98.0% to the type strains of Halobacillus species. Levels of DNA-DNA relatedness between strain IGA7-4T and the type strains of Halobacillus species were 9.5-46.6%. The DNA G+C content of strain IGA7-4T was 46.5 mol%. The cell-wall peptidoglycan type (Orn-Asp), major cellular fatty acids (anteiso-C15:0, anteiso-C17:0, iso-C15:0 and iso-C16:0) and quinone type (MK-7) of the isolate support its affiliation to the genus Halobacillus. On the basis of phylogenetic analysis, phenotypic characteristics and chemotaxonomic data, the isolate represents a novel species of the genus Halobacillus, for which the name Halobacillus faecis sp. nov. is proposed. The type strain is IGA7-4T (=MBIC08268T=IAM 15427T=KCTC 13121T).

Amphibacillus sediminis sp. nov., an endospore-forming bacterium isolated from lake sediment in Japan.

A facultatively anaerobic, moderately alkaliphilic, Gram-positive, spore-forming and rod-shaped bacterial strain, Shu-P-Ggiii25-2T, was isolated from lake sediment in Shizuoka, Japan, and was characterized taxonomically using a polyphasic approach. Analysis of the 16S rRNA gene sequence indicated that the novel isolate clustered with the type strain of Amphibacillus xylanus and it exhibited sequence similarities of 94.9-95.6% to the type strains of species of the genus Amphibacillus. Isoprenoid quinones and oxidase and catalase activities were not detected for strain Shu-P-Ggiii25-2T. The DNA G+C content was 42.3 mol%, the cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid and the major cellular fatty acids were iso-C14:0, iso-C15:0, anteiso-C15:0, C16:0 and iso-C16:0. On the basis of phylogenetic position and phenotypic properties, strain Shu-P-Ggiii25-2T represents a novel species of the genus Amphibacillus, for which the name Amphibacillus sediminis sp. nov. is proposed. The type strain is Shu-P-Ggiii25-2T (=MBIC08269T=IAM 15428T=KCTC 13120T). An emended description of the genus Amphibacillus is also given.

Cysteine metabolism-related genes and bacterial resistance to potassium tellurite.

Tellurite exerts a deleterious effect on a number of small molecules containing sulfur moieties that have a recognized role in cellular oxidative stress. Because cysteine is involved in the biosynthesis of glutathione and other sulfur-containing compounds, we investigated the expression of Geobacillus stearothermophilus V cysteine-related genes cobA, cysK, and iscS and Escherichia coli cysteine regulon genes under conditions that included the addition of K2TeO3 to the culture medium. Results showed that cell tolerance to tellurite correlates with the expression level of the cysteine metabolic genes and that these genes are up-regulated when tellurite is present in the growth medium.

Halobacillus campisalis sp. nov., containing meso-diaminopimelic acid in the cell-wall peptidoglycan, and emended description of the genus Halobacillus.

A Gram-positive or variable, motile and coccoid or oval-shaped bacterial strain, ASL-17(T), was isolated from a marine solar saltern of the Yellow Sea in Korea and its exact taxonomic position was investigated by a polyphasic approach. Strain ASL-17(T) grew optimally at pH 7.0-8.0 and 37 degrees C. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ASL-17(T) is most closely affiliated phylogenetically to the genus Halobacillus. Strain ASL-17(T) exhibited 16S rRNA gene sequence similarity values of 97.7-98.6 % to the type strains of recognized Halobacillus species. Interestingly, strain ASL-17(T) had cell-wall peptidoglycan based on meso-diaminopimelic acid, unlike other Halobacillus species. It contained MK-7 as the predominant menaquinone. The major fatty acids were anteiso-C(15 : 0), anteiso-C(17 : 0) and iso-C(16 : 0). The DNA G+C content was 42.1 mol%. DNA-DNA relatedness data and differential phenotypic properties demonstrated that strain ASL-17(T) can be differentiated from recognized Halobacillus species. On the basis of phenotypic, chemotaxonomic, phylogenetic and genetic data, strain ASL-17(T) represents a novel species of the genus Halobacillus, for which the name Halobacillus campisalis sp. nov. is proposed. The type strain is ASL-17(T) (=KCTC 13144(T) =CCUG 54360(T)).