Characterization of Low-Temperature Enzymatic Reactions through Heterologous Expression and Functional Analysis of Two Beta-Glucosidases from the Termite Symbiotic Bacterium Elizabethkingia miricola Strain BM10

Lower termites need symbiotic microbes for cellulose digestion. Elizabethkingia miricola strain BM10 has been proposed as a microbe that assists in low-temperature digestion and metabolism of Reticulitermes speratus KMT1, termite on Bukhan Mountain, Seoul, Korea. In E. BM10, β-glucosidase genes expressed at 10°C were identified, the psychrophilic enzymatic characteristic was confirmed by heterogeneously proteins. Crude culture broth showed specific properties, its substrate affinity 4.69 times higher than Cellic CTec2. Among β-glucosidase, two genes, bglB_1 bglA_2, whose gene expression more doubled 30°C, identified. They Escherichia coli identified enzymes with an optimal reaction temperature about 20°C–25°C. this study, bacterium lower termites, produced β-glucosidases contribute to spread habitat termite, R. KMT1.