Isolation, characterization, and genome sequencing of a novel chitin deacetylase producing Bacillus aryabhattai TCI-16

Abstract

Chitin deacetylase (CDA) is a chitin degradation enzyme that catalyzes the conversion of chitin to chitosan by the deacetylation of N-acetyl-D-glucosamine residues, playing an important role in the high-value utilization of waste chitin. The shells of shrimp and crab are rich in chitin, and mangroves are usually recognized as an active habitat to shrimp and crab. In the present study, a CDA-producing bacterium, strain TCI-16, was isolated and screened from the mangrove soil. Strain TCI-16 was identified and named as Bacillus aryabhattai TCI-16, and the maximum CDA activity in fermentation broth reached 120.35 ± 2.40 U/mL at 36 h of cultivation. Furthermore, the complete genome analysis of B. aryabhattai TCI-16 revealed the chitin-degrading enzyme system at genetic level, in which a total of 13 putative genes were associated with carbohydrate esterase 4 (CE4) family enzymes, including one gene coding CDA, seven genes encoding polysaccharide deacetylases, and five genes encoding peptidoglycan-N-acetyl glucosamine deacetylases. Amino acid sequence analysis showed that the predicted CDA of B. aryabhattai TCI-16 was composed of 236 amino acid residues with a molecular weight of 27.3 kDa, which possessed a conserved CDA active like the known CDAs. However, the CDA of B. aryabhattai TCI-16 showed low homology (approximately 30%) with other microbial CDAs, and its phylogenetic tree belonged to a separate clade in bacteria, suggesting a high probability in structural novelty. In conclusion, the present study indicated that the novel CDA produced by B. aryabhattai TCI-16 might be a promising option for bioconversion of chitin to the value-added chitosan.

Chitin Deacetylase from Bacillus aryabhattai TCI-16: Heterologous Expression, Characterization, and Deacetylation Performance

“…Therefore, some microorganisms in mangrove sediment may have the function of degrading and utilizing natural chitin during the natural domestication selection process. In our previous study, 22 a CDA-producing bacterium, Bacillus aryabhattai TCI-16 was isolated from mangrove soil. Besides, the complete genome analysis of B. aryabhattai TCI-16 showed that there was a functional gene for encoding CDA, and the primary structure, spatial conformation, amino acid sequence analysis, and phylogenetic analysis indicated that B. aryabhattai TCI-16 CDA (BaCDA) might have a novel structure compared with the CDA proteins from other microorganisms.…”

“…Therefore, some microorganisms in mangrove sediment may have the function of degrading and utilizing natural chitin during the natural domestication selection process. In our previous study, a CDA-producing bacterium, Bacillus aryabhattai TCI-16 was isolated from mangrove soil. Besides, the complete genome analysis of B.…”

Isolation and screening of a chitin deacetylase producing Bacillus cereus and its potential for chitosan preparation

“…Chitin deacetylase (CDA) is a metalloenzyme that specifically deacetylates chitin with a green reaction process, stable product quality and uniform acetylation ( Chakraborty et al, 2016 ; Yang et al, 2022 ). The microbial sources of CDAs are narrow, with fungi such as Absidia coerulea, Aspergillus nidulans , and Penicillium oxalicum as the main ones, and bacteria such as Bacillus and Vibrio ( Win and Stevens, 2001 ; Liu et al, 2017 ; Liang et al, 2022 ). Presently, there is no industrial method in existence for generating this enzyme, primarily due to factors including insufficiency of promising microbial varieties and intricate fermentation prerequisites for chitin deacetylase output in numerous reported strains ( Suresh et al, 2014 ).…”