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

Abstract

This report describes cultivation-dependent diversity, phylogeny and enzymatic potential of the haloalkaliphilic bacteria isolated from the unvegetated desert soil of yet unexplored, saline desert of Little Rann of Kutch (LRK), India. The LRK is a unique ecosystem displaying a combination of Dry Rann and Wet Rann. A total of 25 bacteria were isolated and characterized on the basis of colony morphology, biochemical profile, sugar utilization, secretion of the extracellular enzymes and antibiotic sensitivity. Further, the identification and phylogenetic relatedness of 23 bacteria were established by the analysis of 16S rRNA gene sequences. The phylogenetic analysis indicated that the isolates belong to the phylum , comprising low G + C, Gram-positive bacteria, with different genera: (~ 39%), (~ 30%), (~ 13%), (~ 13%), (~ 4%). Majority of the bacterial isolates produced proteases (30% isolates) followed by cellulases (24% isolates), CMCases (24% isolates) and amylases (20% isolates). , and predominantly produced hydrolases, while many produced multiple enzymes at high salinity and alkaline pH. Highest antibiotic resistance was observed against Ampicillin and Penicillin (32%) followed by Cefaclor (20%); Colistin, Cefoperazone and Cefotaxime (16%); Cefuroxime (12%); Gentamycin and Cefixime (8%); Erythromycin, Cefadroxil, Azithromycin, Co-trimoxazole, Amoxycillin, Norfloxacin, Cefpodoxime, Amikacin and Augmentin (4%). KJ1-10-99 and KJ1-10-93 representing< 97% of 16S rRNA gene sequence similarity belong to a novel lineage within the family . Comparison of the phenogram and phylogram revealed the contradiction of the phenogram pattern and the phylogenetic placement of the isolates. The isolates belonging to same species have shown considerable phenotypic variation. The study on the cultivable haloalkaliphilic bacteria of an unexplored enigmatic niche reflects ecological and biotechnological significance.

Cloning, Expression, and Structural Elucidation of a Biotechnologically Potential Alkaline Serine Protease From a Newly Isolated Haloalkaliphilic Bacillus lehensis JO-26

“…However, only limited studies are available on the microorganisms of desert origin. The Little Rann of Kutch is a saline desert largely unexplored for its microbial diversity and biotechnological potential (Bhatt and Singh, 2016;Bhatt et al, 2017Bhatt et al, , 2018.…”

Kinetics of Halophilic Enzymes

“…This interest is due to their capacity to efficiently catalyze a process and show optimal activities at different salt concentrations. Halophiles are the most probable source of extremozymes, since they are also capable of tolerating alkaline pH and high temperatures, as reported by several authors [68][69][70][71][72][73][74][75][76][77][78][79].…”

“…Isolates capable of producing nitrate reductase were found among the genera Halobacillus and Halomonas. Another study on soils was carried out by Bhatt et al [78], who isolated halo-alkaliphile bacteria from the saline desert soil in Little Rann of Kutch, India. Phylogenetic analysis indicated that isolates belong to phylum Firmicutes, which comprises lower G + C Gram-positive bacteria of different genera.…”

Frequency of Dental Fluorosis in Population Drinking Water with High Fluoride Level in Thar

“…The geographical proximity of the Great Rann of Kutch (the largest salt marsh) and Arabian Sea in the South of Thar Desert render the underground water of Thar a marine environment. 5 Furthermore, the alluvial plains of Indus River and the coast make the underground water more salty. 6 The volcano in the region of Rajisthan may be the source.…”