Hydrolytic activities of hydrolase enzymes from halophilic microorganisms

Abstract

Biomass is normally processed using acidic or basic catalysts, which both have their drawbacks. One suitable alternative is the application of hydrolytic enzymes that can convert biomass into simpler molecules, which can be fermented and processed into biofuel. Hydrolytic enzymes include proteases, lipases, amylases, cellulases, mannanases, chitinases, and xylanases. To discover sources of these enzymes, 19 halophilic strains of microorganisms that are significantly resistant to high salt concentrations were analyzed. The objective of this research was to identify halophilic microorganisms that produce the target enzymes with high activities, and to characterize these enzymes according to their salt tolerances. The results obtained indicated that Pseudolateromonas phenolica, Micrococcus luteus, Pseudoalteromonas peptidolytica, Halomonas socia, Marinobacter maritimus, and Exiguobacterium aurantiacum strain 2 produced the highest protease, lipase, amylase, cellulase, mannanase, chitinase, and xylanase relative activities, respectively. Except for protease from P. phenolica, all the enzymes tested for salt resistance either maintained or increased their activities with increasing NaCl concentration.