Isolation, identification, and characterization of neopullulanase from Thermomonas hydrothermalis GKE 08

Abstract

The production of neopullulanase from thermophiles, such as Thermomonas hydrothermalis GKE 08, has great importance due to the enzyme’s unique thermophilic nature. This characteristic results in enhanced stability and functionality at elevated temperatures. It is known that this is a very important issue for industrial processes that require efficient catalysis under extreme conditions. The investigation of pullulanase from T. hydrothermalis GKE 08 showed significant results. Optimal conditions for enzyme production were determined, with peak activity observed in the presence of 1.5% soluble pullulan and 0.5% peptone. The study delved into the pH and temperature dynamics, identifying an optimal pH of 7.0 and a temperature of 55°C. Notably, the neopullulanase exhibited time-dependent stability, retaining 72% activity after 1 hour but declining to 50% after 2 hours. Purified pullulanase from T. hydrothermalis GKE 08 displayed optimal activity at pH 7.0, with a subsequent time-dependent decline observed during incubation at this pH: retaining 72% activity after 1 hour, approximately 50% after 2 hours, and a significant 77% loss after one day. Furthermore, the enzyme displayed remarkable thermostability at 60°C, with 88% activity after 30 minutes. Metal ion studies indicated susceptibility to inhibition by Cu2+, Mg2+, and Zn2+, while Ca2+ stimulated activity up to 138% at higher concentrations. The enzyme’s response to specific reagents revealed sensitivity to SDS and EDTA, while urea surprisingly enhanced activity to 85%. The study enhances understanding of pullulanase behavior, offering valuable insights for biotechnological and industrial applications.