Degradation of Long Chain Polymer (Dextran) Using Thermostable Dextranase from Hydrothermal Spring Isolate (Bacillus megaterium)

Bacillus megaterium KIBGE-IB31 was isolated from a hydrothermal spring that is proficient in the hyper-production of extracellular dextranase. The distinctive features of this strain include its aerobic and thermophilic nature. The data regarding thermophilic organisms which are capable of producing dextranase is sparse, therefore, the geothermal springs were explored with the purpose to isolate a bacterium capable of hydrolyzing dextran. Strain characterization was based on the phenotypic and genotypic analysis. The thermophile produced dextranase under specific fermentation conditions. Micro and macronutrients were tested while exploring the fermentation parameters for maximum enzyme titers. Maximum production of 464.68 U/ml with a specific activity of 160.2 U/mg was achieved when 10.0 kDa dextran (15.0 g/l) was amalgamated with various trace elements and nitrogen sources at 60 °C up to 24 h of fermentation time. Inoculum size and agitation speed also had a positive impact on maximum enzyme yield. Hydrolytic action of dextranase was observed by studying the surface topology of dextran through scanning electron microscopy. The results indicate that the dextranase synthesized by this thermophile can be used for the hydrolysis of the biopolymer.