Taxogenomics of Alkalihalobacterium chitinilyticum sp. nov.: an alkaliphilic chitin degrading bacterial strain isolated from Lonar Lake, India, with potential biotechnological applications

• Published in: Antonie van Leeuwenhoek Vol. 116; no. 11; pp. 1103 - 1112
• Main Authors: Thite, Sonia, Tarwadge, Kamakshi, Mengade, Purva, Lodha, Tushar, Joseph, Neetha, Thakkar, Lucky, Joshi, Amaraja
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-11-2023; Springer Nature B.V
• Subjects: Bacteria; Biomedical and Life Sciences; Biotechnology; Carbohydrates; Carbon sources; Cardiolipin; Cellulose; Chitin; Ectoine; Elongation; Enzymes; Fatty acids; Genomes; Genomics; Lakes; Life Sciences; Lipids; Medical Microbiology; Microbiology; New species; Original Paper; Phosphatidylethanolamine; Phosphatidylglycerol; Phospholipids; Phylogeny; Plant Sciences; rRNA 16S; Similarity; Sodium chloride; Soil Science & Conservation; India; Chitinase; Alkaliphilic bacteria; Lonar Lake; pH homeostasis
• ISSN: 0003-6072; 1572-9699
• DOI: 10.1007/s10482-023-01872-7

A novel chitin degrading alkaliphilic bacterial strain (MEB 203
 T
) was isolated from sediment collected from Lonar lake, India. The strain exhibited its maximum growth at a temperature of 37 °C, with an optimal pH of 10 and a NaCl concentration of 2%. 16S rRNA gene based phylogenetic tree showed that strain was closely related to
Alkalihalobacterium elongatum
MCC 2982
 T
(98.64% similarity) followed by
A. alkalinitrilicum
DSM 22532
 T
(97.84% similarity). The genome size was 4.9 Mb with DNA G + C content of 37.7%. The dDDH value between strain MEB 203
 T
and
A. elongatum
MCC 2982
 T
was 26.4 ± 2.4% while OrthoANI value was 82.1%. Genome analysis revealed the presence of genes responsible for L-ectoine and cation/proton antiporter which may facilitate growth of strain in alkaline-saline habitat of Lonar lake. Strain MEB 203
 T
was able to utilize complex sugars such as chitin, cellulose, and starch as a carbon source at alkaline conditions which was also corroborated from the genomic presence of carbohydrate active enzymes (CAZymes). It was also able to produce biotechnologically important enzymes such as lipases and proteases which were stable at pH (9–10). The bacterium is majorly composed of C
15:0
iso, C
16:0
iso, and C
17:0
iso (> 10%) fatty acids while diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and unidentified phospholipid (PL3) were identified as the predominant polar lipids. Based on differential physiological, biochemical, and genomic features of strain MEB 203
 T
, a novel species
Alkalihalobacterium chitinilyticum
sp. nov. (Type strain MEB 203
 T
 = MCC 3920
 T
 = NCIMB 15407
 T
 = JCM 35078
 T
) is proposed.