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

Abstract

Two Gram-stain-positive, rod-shaped and endospore-forming bacteria that represent a single species, designated strains KJ1-10-99 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 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 (96.90 %) followed by Bacillus nanhaiisediminis NH3 (96.3 %) and Bacillus alkalinitrilicus ANL-iso4 (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 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 (=LMG 29918=KCTC 33878) 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.

Phylogeny, novel bacterial lineage and enzymatic potential of haloalkaliphilic bacteria from the saline coastal desert of Little Rann of Kutch, Gujarat, India

“…3), indicating that these two isolates might represent a novel species in a new genus. Later, polyphasic taxonomic analysis of these isolates confirmed their status as a novel genus in Bacillaceae family (Bhatt et al 2017).…”

“…Sequence similarity greater than or equal to 97% is widely considered for the genus level match, while a species level match is based on a similarity greater than or equal to 99% (Guesmi et al 2013). Based on the polyphasic taxonomic analysis, the two phylotypes were identified as the type species of novel genus recently described as Desertibacillus haloalkaliphilus KJ1-10-99 T (Bhatt et al 2017).…”

Bacillus caeni sp. nov., isolated from mangrove sediment

“…The genus Bacillus was first proposed by Cohn in 1872 [1], it is a large collection of aerobic or facultatively anaerobic bacteria in the phylum Firmicutes , Gram-stain-positive or -variable, rod-shaped and endospore-forming. With the accumulation of further sequence data, the genus Bacillus has been divided into more manageable and better-defined groups [2]. Some species formerly placed in Bacillus have been reclassified as other genera, such as Brevibacillus [3], Paenibacillus [4] and Geobacillus [5].…”

Radiobacillus deserti gen. nov., sp. nov., a UV-resistant bacterium isolated from desert soil

“…The growth rate of strain TKL69 T at different temperatures (4,10,20,30,35,40, 50 °C) was tested at pH 7.5 and with 2 % (w/v) NaCl; NaCl tolerance (0-20 %, w/v, at intervals of 2 % units) was tested at pH 7.5 and at 35 °C; the pH range for growth (pH 3.0-10.0, at intervals of 0.5 units) was examined with 2 % (w/v) NaCl and at 35 °C by incubating the cells on marine broth agar 2216 medium. The anaerobic growth of strain TKL69 T was tested in marine broth 2216 medium according to the method described by Yang et al [45].…”

“…Although desert is a biotope with strong UV radiation and extreme aridity, it is inhabited by a large number of micro-organisms. Many bacterial groups have been isolated from the desert, such as Mongoliimonas [19], Desertibacillus [20], Siccirubricoccus [21], Jiangella [22], Desertibacter [23], Streptomyces [24] and Planobacterium [25]. Accordingly, many new radiation-resistant bacteria, such as Deinococcus deserti [26], Hymenobacter actinosclerus [27] and Lysobacter xinjiangensis [28], have been discovered in deserts.…”