TY  - JOUR
AU  - Téllez-Espino, Edgar Arturo 
AU  - Trejo-Estrada, Sergio Rubén 
AU  - Cerna-Hernández, Carla De la 
AU  - Plascencia-Espinosa, Miguel Ángel 
AU  - Hidalgo-Lara, María Eugenia 
AU  - Sosa-Peinado, Alejandro 
PY  - 2017
TI  - Brevibacillus Thermoruber 9X-GLC, Bacteria Isolated from Hot Compost, Producer of a Beta-Glucosidase Resistant to Glucose Inhibition
JF  - American Journal of Biochemistry and Biotechnology
VL  - 13
IS  - 4
DO  - 10.3844/ajbbsp.2017.157.166
UR  - https://thescipub.com/abstract/ajbbsp.2017.157.166
AB  - The thermotolerant strain Brevibacillus thermoruber 9X-GLC produces large amounts of β-D-glucosidase and cellobiohydrolase when grown on cellobiose and avicel. 9X-GLC was isolated from hot compost of sugarcane bagasse and filter mud and selected for its high enzymatic activity from a Bacilli collection of 77 isolates from soils and compost. Culture supernatants and ultrafiltered concentrates from shaken flask cultures of 9X-GLC were tested for their β-D-glucosidase activity and stability under different conditions of temperature, pH and glucose concentration. The concentrated supernatant from 9X-GLC cultures on cellobiose as sole carbon source had its highest β-D-glucosidase activity at 55°C; pH= 6.0 and retained 60% of its activity at a glucose concentration of up to 200 mM. The effect of different carbon sources on growth and β-D-glucosidase activity of concentrated supernatants was tested in 48 h shaken flask cultures of 9X-GLC. Glucose, cellodextrin and cellobiose supported high cell densities (>2×108 CFU/ml), whereas cellobiose and cellodextrin provided the best substrates for β-D-glucosidase production. The putative gene encoding β-D-glucosidase from 9X-GLC was obtained from PCR amplification and sequenced. The sequence of the putative structural gene of 2085 bp reveals 6 catalytic domains with high (>90%) homology to bacterialglycosidases.