Srinivasan Krishnamurthi

Bacillus horneckiae sp. nov., isolated from a spacecraft-assembly clean room

Five Gram-stain-positive, motile, aerobic strains were isolated from a clean room of the Kennedy Space Center where the Phoenix spacecraft was assembled. All strains are rod-shaped, spore-forming bacteria, whose spores were resistant to UV radiation up to 1000 J m(-2). The spores were subterminally positioned and produced an external layer. A polyphasic taxonomic study including traditional biochemical tests, fatty acid analysis, cell-wall typing, lipid analyses, 16S rRNA gene sequencing and DNA-DNA hybridization studies was performed to characterize these novel strains. 16S rRNA gene sequencing and lipid analyses convincingly grouped these novel strains within the genus Bacillus as a cluster separate from already described species. The similarity of 16S rRNA gene sequences among the novel strains was >99 %, but the similarity was only about 97 % with their nearest neighbours Bacillus pocheonensis, Bacillus firmus and Bacillus bataviensis. DNA-DNA hybridization dissociation values were <24 % to the closest related type strains. The novel strains had a G+C content 35.6+/-0.5 mol% and could liquefy gelatin but did not utilize or produce acids from any of the carbon substrates tested. The major fatty acids were iso-C(15 : 0) and anteiso-C(15 : 0) and the cell-wall diamino acid was meso-diaminopimelic acid. Based on phylogenetic and phenotypic results, it is concluded that these strains represent a novel species of the genus Bacillus, for which the name Bacillus horneckiae sp. nov. is proposed. The type strain is 1P01SC(T) (=NRRL B-59162(T) =MTCC 9535(T)).

Description of Paenisporosarcina quisquiliarum gen. nov., sp. nov., and reclassification of Sporosarcina macmurdoensis Reddy et al. 2003 as Paenisporosarcina macmurdoensis comb. nov.

In the course of a study of the prokaryotic diversity of a landfill site in Chandigarh, India, a strain designated SK 55(T) was isolated and characterized using a polyphasic approach. Its 16S rRNA gene sequence showed closest similarity (98.3 %) to that of Sporosarcina macmurdoensis CMS 21w(T). The sequence similarity to strains of other hitherto described species of Sporosarcina was less than 95.5 %. Strain SK 55(T) contains peptidoglycan of the A4alpha type (l-Lys-d-Asp), MK-8 and MK-7 as the major menaquinones and iso-C(15 : 0) as the major fatty acid. Strain SK 55(T), Sporosarcina macmurdoensis and Sporosarcina ureae, the type species of the genus, had some polar lipids in common (diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a phospholipid and an unknown lipid). However, an aminolipid, an aminophospholipid and an unknown lipid found in the former two organisms are similar, though not identical, but quite different from the profile of S. ureae. The genomic DNA G+C contents of strain SK 55(T) (46.0 mol%) and S. macmurdoensis CMS 21w(T) (44.0 mol%) are higher than those reported for the majority of species of Sporosarcina (36-42 mol%). As revealed by 16S rRNA gene sequence analysis, strain SK 55(T) and S. macmurdoensis CMS 21w(T) form a clade which is distinct from the clade occupied by other species of Sporosarcina. On the basis of phenotypic characteristics including chemotaxonomic data and analysis of the 16S rRNA gene sequence, we conclude that strain SK 55(T) should be considered as a member of a novel genus and species, for which the name Paenisporosarcina quisquiliarum gen. nov., sp. nov. is proposed. The type strain of Paenisporosarcina quisquiliarum is SK 55(T) (=MTCC7604(T) =JCM 14041(T)). S. macmurdoensis CMS 21w(T) shows more similarity in its 16S rRNA gene sequence (98.3 %), DNA G+C content and polar lipid profile to strain SK 55(T) than to S. ureae DSM 2281(T). Phylogenetically, it forms a coherent cluster with strain SK 55(T) which is separate from the Sporosarcina cluster. Moreover, iso-C(15 : 0), anteiso-C(15 : 0) and C(16 : 1)omega7c alcohol are the three major fatty acids in both S. macmurdoensis CMS 21w(T) and SK 55(T). All these data suggest that S. macmurdoensis should be a member of the genus Paenisporosarcina. However, S. macmurdoensis can be differentiated from SK 55(T) in several physiological and biochemical characteristics, especially in the patterns of oxidation and acid production from carbohydrates. The genomic relatedness of S. macmurdoensis CMS 21w(T) and strain SK 55(T) was also very low (18.0 %). It is therefore logical to transfer Sporosarcina macmurdoensis to the newly created genus as Paenisporosarcina macmurdoensis comb. nov. The type strain is CMS 21w(T) (=MTCC4670(T) =DSM 15428(T)).

Fontibacillus aquaticus gen. nov., sp. nov., isolated from a warm spring

A novel facultatively anaerobic strain, designated GPTSA 19(T), was isolated from a warm spring and characterized using a polyphasic approach. The strain behaved as Gram-negative in the Gram staining procedure but showed a Gram-positive reaction in the aminopeptidase test. The novel strain was a mesophilic rod with ellipsoidal endospores. On the basis of 16S rRNA gene sequence analysis, the strain showed closest similarity (96.0 %) with Paenibacillus motobuensis MC10(T). The gene sequence similarity of the novel strain with other species of the genus Paenibacillus was <95.8 %. The novel strain also had PAEN 515F and 682F signature sequence stretches in the 16S rRNA gene that are usually found in most species of the genus Paenibacillus. The strain possessed anteiso-C(15 : 0) as the major fatty acid and MK-7 as the predominant menaquinone. Polar lipids included diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), six unknown phospholipids (PLs), one aminophospholipid (PN), three glycolipids (GLs), two aminolipids (ALs), one aminophosphoglycolipid (APGL) and three unknown lipids (ULs). The polar lipid profile of the novel strain, especially as regards ALs, GLs and PLs, distinguished it from the recognized type species of the genus Paenibacillus, Paenibacillus polymyxa, as well as from its closest relative P. motobuensis. Based on phenotypic and chemotaxonomic characteristics and analysis of the 16S rRNA gene sequence, the new strain merits the rank of a novel genus for which the name Fontibacillus gen. nov. is proposed. The type species of the new genus is Fontibacillus aquaticus gen. nov., sp. nov. with the type strain GPTSA 19(T) (=MTCC 7155(T)=DSM 17643(T)).

Psychrobacillus gen. nov. and proposal for reclassification of Bacillus insolitus Larkin & Stokes, 1967, B. psychrotolerans Abd-El Rahman et al., 2002 and B. psychrodurans Abd-El Rahman et al., 2002 as Psychrobacillus insolitus comb. nov., Psychrobacillus psychrotolerans comb. nov. and Psychrobacillus psychrodurans comb. nov.

The taxonomic status of three Bacillus species, Bacillus insolitus, B. psychrodurans and B. psychrotolerans was reexamined using a polyphasic approach. In our analysis, these three Bacillus species formed a cluster separate from other members of Bacillus rRNA group 2 [5] and from Bacillus sensu stricto. These three species shared high 16S rRNA gene sequence similarities between them (97.8-99.7%) and showed closest sequence similarity (95.3-96.3%) to Paenisporosarcina quisquiliarum gen. nov., sp. nov. [18]. Sequence similarities with other related genera ranged between 90.9% and 94.5%. Phylogenetic coherence of the three species was supported by phenotypic characteristics, such as growth at low temperatures, negative oxidation and assimilation of many carbohydrates, MK8 as the major isoprenoid quinine and broadly similar polar lipid profiles. All three species had a similar peptidoglycan type of the variation A4β and similar genomic G+C contents (35.7-36.6 mol% [1]). Genomic relatedness among them was shown to be less than 70% and justified their separate species status [1]. These three species could be differentiated from each other and from related taxa on the basis of phenotypic, including chemotaxonomic, characteristics and ribotype patterns. On the basis of our analysis, we propose a new genus Psychrobacillus gen. nov. and to transfer B. insolitus, B. psychrodurans and B. psychrotolerans to the new genus as Psychrobacillus insolitus comb. nov. (type species of the genus; type strain W16B(T)=DSM 5(T)), P. psychrodurans comb. nov. (type strain 68E3(T)=DSM 11713(T)) and P. psychrotolerans comb. nov. (type strain 3H1(T)=DSM 11706(T)).

Arthrobacter pokkalii sp nov, a Novel Plant Associated Actinobacterium with Plant Beneficial Properties, Isolated from Saline Tolerant Pokkali Rice, Kerala, India.

A novel yellow colony-forming bacterium, strain P3B162T was isolated from the pokkali rice rhizosphere from Kerala, India, as part of a project study aimed at isolating plant growth beneficial rhizobacteria from saline tolerant pokkali rice and functionally evaluate their abilities to promote plant growth under saline conditions. The novel strain P3B162T possesses plant growth beneficial traits such as positive growth on 1-aminocyclopropane-1-carboxylic acid (ACC), production of indole acetic acid (IAA) and siderophore. In addition, it also showed important phenotypic characters such as ability to form biofilm and utilization of various components of plant root exudates (sugars, amino acids and organic acids), clearly indicating its lifestyle as a plant rhizosphere associated bacterium. Taxonomically, the novel strain P3B162T was affiliated to the genus Arthrobacter based on the collective results of phenotypic, genotypic and chemotaxonomic analyses. Moreover, molecular analysis using 16S rRNA gene showed Arthrobacter globiformis NBRC 12137T, Arthrobacter pascens DSM 20545T and Arthrobacter liuii DSXY973T as the closely related phylogenetic neighbours, showing more than 98% 16S rRNA similarity values, whereas the recA gene analysis displayed Arthrobacter liuii JCM 19864T as the nearest neighbour with 94.7% sequence similarity and only 91.7% to Arthrobacter globiformis LMG 3813T and 88.7% to Arthrobacter pascens LMG 16255T. However, the DNA-DNA hybridization values between strain P3B162T, Arthrobacter globiformis LMG 3813T, Arthrobacter pascens LMG 16255T and Arthrobacter liuii JCM 19864T was below 50%. In addition, the novel strain P3B162T can be distinguished from its closely related type strains by several phenotypic characters such as colony pigment, tolerance to NaCl, motility, reduction of nitrate, hydrolysis of DNA, acid from sucrose, cell wall sugars and cell wall peptidoglycan structure. In conclusion, the combined results of this study support the classification of strain P3B162T as a novel Arthrobacter species and we propose Arthrobacter pokkalii sp.nov.as its name. The type strain is P3B162T (= KCTC 29498T = MTCC 12358T).

Tamilnaduibacter salinus gen. nov., sp. nov., a halotolerant gammaproteobacterium within the family Alteromonadaceae, isolated from a salt pan in Tamilnadu, India.

Two novel Gram-stain-negative, slow-growing, halotolerant strains with rod-shaped cells, designated as strains Mi-7T and Mi-8, which formed pin-point colonies on halophilic media were isolated during a study into the microbial diversity of a salt pan in the state of Tamilnadu, India. Both the strains had an obligate requirement for 1 % (w/v) NaCl for growth and were halotolerant, growing at NaCl concentrations of up to 20 % (w/v) in media. The strains, however, showed an inability to utilize the majority of substrates tested as sole carbon sources for growth and in fermentation reactions. Molecular phylogenetic analyses, based on 16S rRNA gene sequence revealed their closest phylogenetic neighbours to be members of the genus Marinobacter, with whom they showed the highest sequence similarity of 93.6 % and even less with the type strain of the type species, Marinobacter hydrocarbonoclasticus DSM 8798T (91.1 %). Similarities with other genera within the family Alteromonadaceae were below 91.0 %. However, the two strains were very closely related to each other with 99.9 % sequence similarity, and DNA–DNA hybridization analyses confirmed their placement in the same species. The DNA G+C content of both strains was 65 mol%. Using the polyphasic taxonomic data obtained from this study, strains Mi-7T and Mi-8 represent two strains of the same species of a novel genus for which the name Tamilnaduibacter salinus gen. nov., sp. nov., is proposed; the type strain of the novel species is Mi-7T ( = MTCC 12009T = DSM 28688T).

Proposal for transfer of Pelagibacillus goriensis Kim et al. 2007 to the genus Terribacillus as Terribacillus goriensis comb. nov.

The phenotypic, chemotaxonomic and genotypic characteristics of two recently described genera were compared. Terribacillus saccharophilus and Pelagibacillus goriensis (both type species of their respective genera) are similar in many phenotypic characteristics and in their fatty acid profiles, both have MK-7 as the major menaquinone and they have similar G+C contents. Comparison of the 16S rRNA gene sequence of P. goriensis CL-GR16(T) with those of T. saccharophilus 002-048(T) and Terribacillus halophilus 002-051(T) showed high degrees of sequence similarity, respectively 99.8 and 98.9 %. Phylogenetically, these three taxa are closely related and form a coherent cluster in the phylogenetic tree. The genomic relatedness of P. goriensis DSM 18252(T) with T. saccharophilus JCM 21759(T) and T. halophilus JCM 21760(T) is 51.7 and 35.6 %, respectively, which is well below the value of 70 % recommended for delineation of species. P. goriensis differs from T. saccharophilus in motility, the Voges-Proskauer test and acid production from and utilization of some carbohydrates. Based on these analyses, we conclude that Pelagibacillus should not be considered a separate genus and hence Pelagibacillus goriensis should be transferred to the genus Terribacillus as Terribacillus goriensis comb. nov., with the type strain CL-GR16(T) (=KCCM 42329(T) =DSM 18252(T)).

Bacillus encimensis sp. nov. isolated from marine sediment.

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium designated SGD-V-25(T) was isolated from Veraval sediment sample, India. Strain SGD-V-25(T) was capable of growing at 25-50 °C (optimum 37 °C), pH 6-12 (optimum pH 7.0) and with 0-5% (w/v) NaCl. The taxonomic position of this strain was deduced using a polyphasic approach and the 16S rRNA gene sequence analysis showed that the isolate belongs to the phylum Firmicutes , forming the cluster with Bacillus badius MTCC 1548(T), with which it shares highest similarity of 99.1% with 13 nt differences. Other type strains of the genus Bacillus showed less than 96% similarity. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The polar lipid profile of strain SGD-V-25(T) showed the presence of diphosphatidylglycerol, phosphatidylglycerol, phsophoglycolipid and two aminophospholipids. The predominant isoprenoid quinone was MK-7. The major cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0, C16 : 1ω11c and C16 : 0. The genomic DNA G+C content of strain SGD-V-25(T) was 37.6 mol%. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA hybridization, strain SGD-V-25(T) could be clearly distinguished from closely related members of the genus Bacillus , and the name Bacillus encimensis sp. nov., is proposed to accommodate this strain. The type strain is SGD-V-25(T) ( =NCIM 5513(T) =DSM 28241(T)).

Rhodococcus enclensis sp. nov., a novel member of the genus Rhodococcus

A novel actinobacterial strain, designated, NIO-1009(T), was isolated from a marine sediment sample collected from Chorao Island, Goa, India. Phylogenetic analysis comparisons based on 16S rRNA gene sequences between strain NIO-1009(T) and other members of the genus Rhodococcus revealed that strain NIO-1009(T) had the closest sequence similarity to Rhodococcus kroppenstedtii DSM 44908(T) and Rhodococcus corynebacterioides DSM 20151(T) with 99.2 and 99.1%, respectively. Furthermore, DNA-DNA hybridization results showed that R. kroppenstedtii DSM 44908(T) and R. corynebacterioides DSM 20151(T) were 39.5 (3.0%) and 41.7 (2.0%) with strain NIO-1009(T), respectively, which were well below the 70% limit for any novel species proposal. Phylogenetically strain NIO-1009(T) forms a stable clade with and R. kroppenstedtii DSM 44908(T) and R. corynebacterioides DSM 20151(T) with 100% bootstrap values. Strain NIO-1009(T) contained meso-diaminopimelic acid as the diagnostic diamino acid and galactose and arabinose as the cell wall sugars. The major fatty acids were C(16 : 0), C(18 : 1)ω9c, C(16 : 1)(ω6c and/or ω7c) and 10-methyl C(18 : 0). The only menaquinone detected was MK-8(H2), while the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and one unknown phospholipid. The G+C content of the genomic DNA was 66.9 mol%. The phenotypic and genotypic data showed that strain NIO-1009(T) warrants recognition as a novel species of the genus Rhodococcus for which the name Rhodococcus enclensis sp. nov., is proposed; the type strain is NIO-1009(T) ( = NCIM 5452(T) = DSM 45688(T)).

Exiguobacterium enclense sp. nov., isolated from sediment.

A Gram-stain-positive bacterium, designated strain NIO-1109(T), was isolated from a marine sediment sample from Chorao Island, Goa, India. Phenotypic and chemotaxonomic characteristics and data from phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NIO-1109(T) was related to the genus Exiguobacterium . Strain NIO-1109(T) exhibited >98.0% 16S rRNA gene sequence similarity with respect to Exiguobacterium indicum HHS 31(T) (99.5%) and Exiguobacterium acetylicum NCIMB 9889(T) (99.1%); the type strains of other species showed <98% similarity. Levels of DNA-DNA relatedness between strain NIO-1109(T) and E. acetylicum DSM 20416(T) and E. indicum LMG 23471(T) were less than 70% (33.0 ± 2.0 and 37 ± 3.2%, respectively). Strain NIO-1109(T) also differed from these two closely related species in a number of phenotypic traits. Based on phenotypic, chemotaxonomic and phylogenetic data, strain NIO-1109(T) is considered to represent a novel species of the genus Exiguobacterium , for which the name Exiguobacterium enclense sp. nov. is proposed. The type strain is NIO-1109(T) ( =NCIM 5457(T) =DSM 25128(T)  = CCTCC AB 2011124(T)).