Production of Some Extracellular Hydrolases by Halophilic Bacteria Isolated from Mangrove Soil in Sumberkima Village, Bali, Indonesia

Abstract

Hydrolases are enzymes with broad industrial applications across the food, pharmaceutical, textile, detergent, and paper sectors. For commercial use, these enzymes are primarily sourced from microorganisms. Halophilic bacteria, which thrive in high-salinity environments, represent a promising yet underutilized source of novel hydrolases. This study aimed to isolate and screen halophilic bacteria from mangrove soil in Sumberkima Village, Buleleng Regency, Bali Province, Indonesia, for their ability to produce extracellular hydrolases. Soil samples were cultivated on Luria-Bertani (LB) media supplemented with 5% and 10% (w/v) NaCl. Putative colonies were isolated and screened for amylase, cellulase, and lipase production using starch, carboxymethyl cellulose, and rhodamine-olive oil agar, respectively. Enzymatic activities were quantified via spectrophotometry, and the most proficient isolates were identified through 16S rRNA gene phylogenetic analysis. The screening yielded several halophilic bacteria with significant extracellular hydrolase activity. The most proficient isolates identified were: amylase-producing Vibrio xiamenensis SKMG1(4) (0.44 U/mL), cellulase-producing Vibrio hepatarius SKMG1(3) (0.36 U/mL), and lipase-producing Salinivibrio kushneri SKMG2(5) (21.6 U/mL). Phylogenetic analysis confirmed the close taxonomic relationship of these isolates to their respective type strains. This study represents the first report of extracellular hydrolase production from these three halophilic bacterial species, highlighting their potential for specialized industrial applications.