Simultaneous production of amylases and proteases by Bacillus subtilis in brewery wastes.
The simultaneous production of amylase (AA) and protease (PA) activity by Bacillus subtilis UO-01 in brewery wastes was studied by combining the response surface methodology with the kinetic study of the process. The optimum conditions (T=36.0°C and pH=6.8) for high biomass production (0.92g/L) were similar to the conditions (T=36.8°C and pH=6.6) for high AA synthesis (9.26EU/mL). However, the maximum PA level (9.77EU/mL) was obtained at pH 7.1 and 37.8°C. Under these conditions, a considerably high reduction (between 69.9 and 77.8%) of the initial chemical oxygen demand of the waste was achieved. In verification experiments under the optimized conditions for production of each enzyme, the AA and PA obtained after 15h of incubation were, respectively, 9.35 and 9.87EU/mL. By using the Luedeking and Piret model, both enzymes were classified as growth-associated metabolites. Protease production delay seemed to be related to the consumption of non-protein and protein nitrogen. These results indicate that the brewery waste could be successfully used for a high scale production of amylases and proteases at a low cost.
Departamento de Fundamentos Químicos y Biológicos, Facultad de Ingeniería Química, sede Mella, Universidad de Oriente, Santiago de Cuba, Cuba.
Alina
A
Sánchez Blanco
Departamento de Fundamentos Químicos y Biológicos, Facultad de Ingeniería Química, sede Mella, Universidad de Oriente, Santiago de Cuba, Cuba.
Osmar
O
Palacios Durive
Departamento de Fundamentos Químicos y Biológicos, Facultad de Ingeniería Química, sede Mella, Universidad de Oriente, Santiago de Cuba, Cuba.
Sulema
S
Batista Pérez
Departamento de Fundamentos Químicos y Biológicos, Facultad de Ingeniería Química, sede Mella, Universidad de Oriente, Santiago de Cuba, Cuba.
Zoraida
Z
Díaz Montes
Departamento de Química Analítica y Alimentaria, Facultad de Ciencias, Campus de Ourense, Universidad de Vigo, Spain. Electronic address: nelsonpg@uvigo.es.
Nelson
N
Pérez Guerra
D000681:Amylases / Q000096:biosynthesis*; D001412:Bacillus subtilis / Q000378:metabolism*; D001711:Biotransformation; D050260:Carbohydrate Metabolism; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D010447:Peptide Hydrolases / Q000096:biosynthesis*; D013696:Temperature
D007220:Industrial Waste; D000681:Amylases; D010447:Peptide Hydrolases
Amylases; Bacillus subtilis; Brewery wastes; Proteases; Response surface methodology