Functional Characterization of Recombinant Raw Starch Degrading ?-Amylase from Roseateles terrae HL11 and Its Application on Cassava Pulp Saccharification

Exploring new raw starch-hydrolyzing ?-amylases and understanding their biochemical characteristics are important for the utilization of starch-rich materials in bio-industry. In this work, a novel starch-degrading ?-amylase (HL11 Amy) from Roseateles terrae HL11 was firstly reported. Evolutionary analysis revealed that HL11Amy classified into glycoside hydrolase family 13 subfamily 32 (GH13_32). It contains four protein domains consisting domain A, B, C carbohydrate-binding module 20 (CMB20). The enzyme optimally worked at 50 °C, pH 4.0 with specific activity 6270 U/mg 1030 (RSD) against soluble starch. Remarkably, exhibited toward both gelatinized forms various substrates, highest catalytic efficiency (kcat/Km) on starch rice, followed by potato cassava, respectively. effectively hydrolyzed cassava pulp (CP) hydrolysis, reducing sugar yield 736 183 mg/g CP, equivalent to 72% 18% conversion based content substrate, These demonstrated represents promising potential applications modification saccharification.