Alkalimonas mucilaginosa sp. nov. and Alkalimonas cellulosilytica sp. nov. isolated from alkaline Lonar lake, India.

Two alkaliphilic, Gram-stain-negative bacterial strains (MEB004 ^T and MEB108 ^T ) were isolated from water samples collected from Lonar lake, India. The phylogenetic analysis of their 16S rRNA gene sequences showed the highest similarity to A. delamerensis DSM 18314 ^T (98.4%), followed by A. amylolytica DSM 18337 ^T and A. collagenimarina JCM 14267 ^T (97.9%). The genome sizes of strains MEB004 ^T and MEB108 ^T were determined to be 3,858,702 and 4,029,814 bp, respectively, with genomic DNA G + C contents of 51.4 and 51.9%. Average Nucleotide Identity, DNA-DNA Hybridization and Amino Acid Identity values between strains (MEB004 ^T and MEB108 ^T ) and A. amylolytica DSM 18337 ^T were (82.3 and 85.5), (25.0 and 29.2) and (86.7 and 90.2%). Both novel strains produced industrially important enzymes, such as amylase, lipase, cellulase, caseinase, and chitinase at pH 10 evidenced by the genomic presence of carbohydrate-active enzymes encoding genes. Genomic analyses further identified pH tolerance genes, affirming their adaptation to alkaline Lonar Lake. Dominant fatty acids were Summed feature 8 (C _18:1 ω7c and/or C _18:1 ω6c), C _16:0, Summed feature 3, Sum In Feature 2 and C _12:0 3OH. The prevalent polar lipids included phosphatidyl ethanolamine, phosphatidyl glycerol, and diphosphatidyl glycerol. The major respiratory quinone was ubiquinone-8. Based on the polyphasic data, we propose the classification of strains MEB004 ^T and MEB108 ^T as novel species within the genus Alkalimonas assigning the names Alkalimonas mucilaginosa sp. nov. and Alkalimonas cellulosilytica sp. nov., respectively. The type strains are MEB004 ^T (= MCC 5208 ^T  = JCM 35954 ^T  = NCIMB 15460 ^T ) and MEB108 ^T (= MCC 5330 ^T  = JCM 35955 ^T  = NCIMB 15461 ^T ).
(© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)