Exogenous Production of Cold-Active Cellulase From Psychrophilic Actinobacteria With Increased Cellulose Hydrolysis Efficiency

Abstract Actinobacteria form the largest phylum consisting of diverse, ecologically unique and biologically active members. The actinobacteria are omnipresent and occur in various habitats such as cold environment, aquatic, desert and terrestrial ecosystems. Though the studies are available on actinobacteria at various habitats very few reports are available on cold tolerant/loving actinobacteria in the Southern Ocean part of the Antarctic Ocean. In this context, the present work was designed to isolate and characterize the actinobacteria in the Polar Front region of the Southern Ocean waters and species of Nocardiopsis and Streptomyces were identified. Among those, the psychrophilic actinobacterium, Nocardiopsis dassonvillei PSY13 was found to have good cellulolytic activity and it was further studied for the production and characterization of cold-active cellulase enzyme. The latter was found to have a specific activity of 6.36 U/mg and a molar mass of 48 kDa with a 22.9-fold purification and 5% recovery at an optimum pH of 7.5 and a temperature of 10 ºC. Given the importance of psychrophilic actinobacteria N. dassonvillei PSY13 can be further exploited for its benefits, meaning that the Southern Ocean harbours biotechnologically important microorganisms that can be further explored for versatile biotechnological and industrial applications.