Whole-genome analysis of proteases and multidomain lignocellulolytic enzymes in halophilic Cellulosimicrobium sp. LC18 from Malaysian mangrove sediment

Abstract

Halophilic bacteria from mangrove sediments are valuable for enzymatic diversity in biotechnology. Cellulosimicrobium is a bacterial genus previously classified as Oerskovia, mainly known for cellulose degradability; little is known about its proteolytic ability. In this study, we present the whole genome sequence of Cellulosimicrobium sp. LC18, a strain isolated from mangrove soil collected at Matang Mangrove Forest Reserve Eco Park, Kuala Sepetang, Perak, Malaysia. The genome of Cellulosimicrobium sp. LC18 is 5 Mbp in size, with a G + C content of 73.68% and contains a total of 4371 protein-coding genes. Based on genomics approach, the results indicated that the genome of Cellulosimicrobium sp. LC18 encodes at least 17 genes for distinct multidomain carbohydrate-active enzymes. Among these, four glycoside hydrolases with carbohydrate binding modules (GH-CBM) are associated with cellulose degradation, 11 GH-CBM associated with hemicellulose degradation, with one having carbohydrate esterase (CE) in its GH-CBM multidomain, and one multidomain of auxiliary activity (AA) or lytic polysaccharide monooxygenase (LMPO-CBM). In addition, of the genome harbours 11 protein-degrading genes (serine and metalloproteases), ten of which contain signal peptides, this salt-tolerant strain LC18 also exhibits protease activity in vitro. This study reveals protein and carbohydrate degradation potential, highlighting its prospects for enzyme discovery.