A new biosurfactant-producing strain, Fictibacillus nanhaiensis ME46, isolated from an oil field in China

The genus Fictibacillus contains twelve species significant in the synthesis of cellulose-degrading enzymes and phenylalanine dehydrogenase, isolated mainly from marine sedimentary environments. Here, we report a new biosurfactant-producing strain, Fictibacillus nanhaiensis ME46, isolated from Daqing oil field in China. The biosurfactant extracted from Strain ME46 was determined as surfactin, one of the representative families of lipopeptide biosurfactants. The yield of the surfactin produced by strain ME46 was 0.62 g·L-1 as determined by high-performance liquid chromatography, and the critical micelle concentration (CMC) of the surfactin was estimated to be about 68 mg·L-1 and the surface tension at CMC was 35.1 mN·m-1. This study extended our knowledge about the role of the species Fictibacillus nanhaiensis in the ecosystem of natural environments such as the oil field.

Desertibacillus haloalkaliphilus gen. nov., sp. nov., isolated from a saline desert

Two Gram-stain-positive, rod-shaped and endospore-forming bacteria that represent a single species, designated strains KJ1-10-99^T and KJ1-10-93, were isolated from a saline desert of Little Rann of Kutch, Gujarat, India. Analysis of 16S rRNA gene sequences revealed that the isolates belonged to the family Bacillaceae and were closely related to each other with 16S rRNA gene sequence similarity of 99.9 %. However, these two isolates formed a novel phylogenetic branch within this family. Both strains were aerobic, catalase and oxidase positive, and could grow optimally at 37 °C and pH 9. Further, strains KJ1-10-99^T and KJ1-10-93 grew optimally at a NaCl concentration of 7.5 and 15 % (w/v), respectively. Both strains shared highest sequence similarity with Fermentibacillus polygoni IEB3^T (96.90 %) followed by Bacillus nanhaiisediminis NH3^T (96.3 %) and Bacillus alkalinitrilicus ANL-iso4^T (96.3 %). The major cellular fatty acids were anteiso-C15 : 0, anteiso-C17:0, C16 : 0, and iso-C15 : 0. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol in both strains. The predominant isoprenoid quinone was MK-7 in both the strains. The peptidoglycan contained meso-diaminopimelic acid (meso-DAP) as the diagnostic diamino acid. The DNA G+C content of strains KJ1-10-99^T and KJ1-10-93 were 48.7 and 48.9 mol% respectively. Both strains could be distinguished from closest phylogenetic neighbours based on a number of phenotypic properties. On the basis of polyphasic taxonomic analysis and phylogenetic data, we conclude that the strains KJ1-10-99^T (=LMG 29918^T=KCTC 33878^T) and KJ1-10-93 (=LMG 29919=KCTC 33877) represent a novel species of a new genus in the family Bacillaceae, order Bacillales, for which the name Desertibacillus haloalkaliphilus gen. nov., sp. nov. is proposed.

Fictibacillus halophilus sp. nov., from a microbial mat of a hot spring atop the Himalayan Range

A Gram-stain-positive staining, motile, endospore forming and moderately halophilic bacterium, designated as strain AS8T, was isolated from a microbial mat deposited at thermal discharges of Manikaran hot spring (with surface water temperature ~95 °C) located in Himachal Pradesh, India. 16S rRNA gene sequence based phylogenetic analysis revealed that strain AS8T belonged to the genus Fictibacillus with the highest sequence similarity to Fictibacillus nanhaiensis DSM 23009T (99.9 %) and Fictibacillus phosphorivorans Ca7T (99.9 %), followed by Fictibacillus barbaricus V2-BIII-A2T (99.1 %) and Fictibacillus arsenicus Con a/3T (97.4 %). The polar lipids fraction consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The cell-wall peptidoglycan was of the type A1γ based on directly cross-linked meso-diaminopimelic acid. The DNA G+C content of strain AS8T was found to be 46.9 mol%. The quinone system of strain AS8T consisted of MK-7 predominantly, and the polyamine pattern primarily contained spermidine and spermine. The major cellular fatty acids in strain AS8T were iso-C15:0, anteiso-C15:0 and iso-C16:0. The strain showed DNA-DNA relatedness of 52.7 % with F. nanhaiensis DSM 23009T, 50.7 % with F. phosphorivorans Ca7T, 34.8 % with F. barbaricus V2-BIII-A2T and 38.0 % with F. arsenicus Con a/3T. In spite of the high 16S rRNA gene sequence similarities, the DNA-DNA hybridization and gyr B gene sequencing results (≤87 %) supported by physiological and biochemical tests demonstrated that strain AS8T is a representative of a novel species, for which the name Fictibacillus halophilus sp. nov. is proposed. The type strain is AS8T (=MCC 2765T=DSM 100124T=KCTC 33758T).

Bacillus crassostreae sp. nov., isolated from an oyster (Crassostrea hongkongensis)

A novel Gram-stain-positive, motile, catalase- and oxidase-positive, endospore-forming, facultatively anaerobic rod, designated strain JSM 100118(T), was isolated from an oyster (Crassostrea hongkongensis) collected from the tidal flat of Naozhou Island in the South China Sea. Strain JSM 100118(T) was able to grow with 0-13% (w/v) NaCl (optimum 2-5%), at pH 5.5-10.0 (optimum pH 7.5) and at 5-50 °C (optimum 30-35 °C). The cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant respiratory quinone was menaquinone-7 and the major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, C16 : 0 and C16 : 1ω11c. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unknown glycolipid and an unknown phospholipid. The genomic DNA G+C content was 35.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 100118(T) belonged to the genus Bacillus , and was most closely related to Bacillus litoralis SW-211(T) (98.9% 16S rRNA gene sequence similarity), Bacillus halosaccharovorans E33(T) (98.3%), Bacillus niabensis 4T19(T) (97.8%) and Bacillus herbersteinensis D-1,5a(T) (97.1%). The combination of results from the phylogenetic analysis, DNA-DNA hybridization, and phenotypic and chemotaxonomic characterization supported the conclusion that strain JSM 100118(T) represents a novel species of the genus Bacillus , for which the name Bacillus crassostreae sp. nov. is proposed. The type strain is JSM 100118(T) ( = CTCC AB 2010452(T) =DSM 24486(T) =JCM 17523(T)).

Evolution in the Bacillaceae

The family Bacillaceae constitutes a phenotypically diverse and globally ubiquitous assemblage of bacteria. Investigation into how evolution has shaped, and continues to shape, this family has relied on several widely ranging approaches from classical taxonomy, ecological field studies, and evolution in soil microcosms to genomic-scale phylogenetics, laboratory, and directed evolution experiments. One unifying characteristic of the Bacillaceae , the endospore, poses unique challenges to answering questions regarding both the calculation of evolutionary rates and claims of extreme longevity in ancient environmental samples.

Pseudogracilibacillus auburnensis gen. nov., sp. nov., isolated from the rhizosphere of Zea mays

A Gram-positive-staining, aerobic, endospore-forming bacterium, strain P-207T, was isolated from a rhizosphere soil sample in Auburn, AL, USA. On the basis of 16S rRNA gene sequence comparisons, strain P-207T was grouped in the vicinity of representatives of the genera Virgibacillus , Ornithinibacillus , Cerasibacillus , Lentibacillus and Oceanobacillus , but could not be assigned clearly to any of these genera. The highest similarity was found to the sequence of Virgibacillus carmonensis LMG 20964T (94.4 %); however, the 16S rRNA gene sequence similarity to the type strain of the type species of Virgibacillus , Virgibacillus pantothenticus , was only 92.9 %. The quinone system of strain P-207T consisted predominantly of menaquinone MK-7. The polar lipid profile exhibited the major lipids diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine and moderate to minor amounts of several unidentified phospholipids, glycolipids and phosphoglycolipids, an aminophospholipid and an aminolipid. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid and the polyamine pattern contained predominantly spermidine and spermine. The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0 and iso-C15 : 0. The G+C content of the genomic DNA was 34 mol%. Because of the low sequence similarity of strain P-207T to all representatives of Virgibacillus , Ornithinibacillus , Cerasibacillus , Lentibacillus and Oceanobacillus , which was always <95 %, and its unique lipid pattern, we propose that strain P-207T represents a novel species in a new genus, for which the name Pseudogracilibacillus auburnensis gen. nov., sp. nov. is proposed. The type strain of Pseudogracilibacillus auburnensis is P-207T ( = CCM 8509T = LMG 28212T = CIP 110797T).

Bacillus fengqiuensis sp. nov., isolated from a typical sandy loam soil under long-term fertilization

A Gram-staining-positive, endospore-forming, moderately alkaliphilic bacterium, strain NPK15(T), was isolated from a typical sandy loam soil under long-term NPK fertilization in northern China and was subjected to a polyphasic taxonomic study. The diamino acid of the cell-wall peptidoglycan of strain NPK15(T) was found to be meso-diaminopimelic acid and the cell-wall sugars were xylose, glucose and traces of mannose. The only respiratory quinone found in strain NPK15(T) was menaquinone 7 (MK-7). The major cellular fatty acids were iso-C(15 : 0), anteiso-C(15 : 0), C(16 : 0) and C(16 : 1)ω6c/C(16 : 1)ω7c. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. Phylogenetic analysis of the strain based on its 16S rRNA gene sequence showed that it was related most closely to 'Bacillus thaonhiensis' KACC 17216 (99.59%), B. songklensis KCTC 13881(T) (99.52%) and B. abyssalis CCTCC AB 2012074(T) (99.00%). DNA-DNA hybridization results indicated that the strain was distinct from other species of the genus Bacillus, the degree of relatedness being 35.4% with B. abyssalis CCTCC AB 2012074(T), 39.7% with B. songklensis KCTC 13881(T) and 51.2% with 'B. thaonhiensis' KACC 17216. The DNA G+C content of strain NPK15(T) was 45.5 mol%. Phenotypic, chemotaxonomic and molecular analyses identified strain NPK15(T) as a member of a novel species of the genus Bacillus, for which the name Bacillus fengqiuensis sp. nov. is proposed. The type strain is NPK15(T) ( = DSM 26745(T) = CCTCC AB 2013156(T)).

Bacillus oceani sp. nov., a new slightly halophilic bacterium, isolated from a deep sea sediment environment

A strictly aerobic, Gram-stain positive, slightly halophilic strain, designated SCSIO 04524(T), was isolated from a deep sea sediment sample collected from the northern South China Sea at a depth of 3415 m. The isolate slightly embedded into the medium after 72 h incubation at 30 °C. Growth was found to occur on media with 0-10 % NaCl but extremely weak growth occurred without supplying NaCl. The predominant menaquinone was determined to be MK-7. The major cellular fatty acid identified was iso-C15:0. The diagnostic polar lipids were determined to be diphosphatidylglycerol, phosphatidyl methylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA G+C content was determined to be 38 mol%. 16S rRNA gene sequences analysis showed that this strain had the highest similarities with Bacillus carboniphilus JCM 9731(T) (94.7 %) and Bacillus endophyticus 2DT(T) (94.3 %). Phylogenetic analysis revealed that strain SCSIO 04524(T) formed a distinct lineage with Bacillus chungangensis CAU 348(T) and B. carboniphilus JCM 9731(T). Physiological characteristics including utilization of sole nitrogen and carbon sources, and chemotaxonomic properties of cellular fatty acids and polar lipids could readily distinguish strain SCSIO 04524(T) from its most closely related species. Based on this polyphasic taxonomic data, a new species, Bacillus oceani sp. nov., is proposed, with the type strain SCSIO 04524(T) (=DSM 26213(T) = KCTC 33077(T)).

Fictibacillus phosphorivorans gen. nov., sp. nov. and proposal to reclassify Bacillus arsenicus, Bacillus barbaricus, Bacillus macauensis, Bacillus nanhaiensis, Bacillus rigui, Bacillus solisalsi and Bacillus gelatini in the genus Fictibacillus

A Gram-positive-staining, aerobic, endospore-forming bacterium (Ca7(T)) was isolated from a bioreactor showing extensive phosphorus removal. Based on 16S rRNA gene sequence similarity comparisons, strain Ca7(T) was grouped in the genus Bacillus, most closely related to Bacillus nanhaiensis JSM 082006(T) (100 %), Bacillus barbaricus V2-BIII-A2(T) (99.2 %) and Bacillus arsenicus Con a/3(T) (97.7 %). Moderate 16S rRNA gene sequence similarities were found to the type strains of the species Bacillus gelatini and Bacillus rigui (96.4 %), Bacillus macauensis (95.1 %) and Bacillus solisalsi (96.1 %). All these species were grouped into a monophyletic cluster and showed very low sequence similarities (<94 %) to the type species of the genus Bacillus, Bacillus subtilis. The quinone system of strain Ca7(T) consists predominantly of menaquinone MK-7. The polar lipid profile exhibited the major compounds diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. In addition, minor compounds of an unidentified phospholipid and an aminophospholipid were detected. No glycolipids were found in strain Ca7(T), which was consistent with the lipid profiles of B. nanhaiensis, B. barbaricus, B. arsenicus, B. rigui, B. solisalsi, B. macauensis and B. gelatini, but in contrast to B. subtilis. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid and the polyamine pattern contained predominantly spermidine and spermine. The major fatty acids, which were iso-C15 : 0, anteiso-C15 : 0 and C16 : 0, supported the grouping of strain Ca7(T) in the family Bacillaceae. The strain showed DNA-DNA similarities of 48 % (reciprocal 47 %) to B. nanhaiensis DSM 23009(T), 31 % (reciprocal 36 %) to B. barbaricus V2-BIII-A2(T) and 29 % (reciprocal 39 %) to B. arsenicus DSM 15822(T), respectively. These results clearly demonstrate that strain Ca7(T) is a representative of a novel species, which can be differentiated from its closest relatives by physiological and biochemical tests. Because of the low sequence similarity of strain Ca7(T) to B. subtilis, which was shared by B. nanhaiensis, B. barbaricus, B. arsenicus, B. gelatini, B. rigui, B. solisalsi and B. macauensis, and their unique lipid patterns, we propose that strain Ca7(T) represents a novel species in a novel genus for which the name Fictibacillus phosphorivorans gen. nov., sp. nov. is proposed. The type strain is Ca7(T) (= CCM 8426(T) = LMG 27063(T)). In addition we propose the reclassification of B. nanhaiensis, B. barbaricus, B. arsenicus, B. rigui, B. macauensis, B. solisalsi and B. gelatini as Fictibacillus nanhaiensis comb. nov., Fictibacillus barbaricus comb. nov., Fictibacillus arsenicus comb. nov., Fictibacillus rigui comb. nov., Fictibacillus macauensis comb. nov., Fictibacillus solisalsi comb. nov. and Fictibacillus gelatini comb. nov., respectively [type strains JSM 082006(T) (= DSM 23009(T) = KCTC 13712(T)), V2-BIII-A2(T) ( = CCM 4982(T) = DSM 14730(T)), Con a/3(T) ( = MTCC 4380(T) = DSM 15822(T) = JCM 12167(T)), WPCB074(T) ( = KCTC 13278(T) = JCM 16348(T)), ZFHKF-1(T) ( = JCM 13285(T) = DSM 17262(T)), YC1(T) ( = KCTC 13181(T) = CGMCC 1.6854(T)) and LMG 21881(T) ( = DSM 15866(T)), respectively].