Millet Cobs: A Source of Microbial Enzymes

Abstract

Microbial enzymes have significant biotechnological application in industries. The purpose of this study was to isolate and identify microorganisms associated with millet cobs, determine the enzyme activity (lipase, protease, pectinase, cellulase and amylase) of the millet cob samples, screen the isolated microorganisms for enzyme production and determine the physicochemical parameters of the degrading medium. A total of seven bacteria and twelve fungi consisting of yeasts and moulds were isolated during the study. Day 20 of the degradation period has the highest enzyme activity for all the enzymes in the degraded millet cobs; lipase has the highest enzyme activity with a value of 0.496 mg/mL/min while protease has the lowest with a value of 0.003 mg/mL/min. All of the isolated microorganisms exhibited enzymatic activity except Zygosaccharomyces rouxii in which Bacillus spp were screened positive for all the enzymes assayed for. The temperature (ºC), pH and titratable acidity (%) ranged from 24.03-28.47, 3.81-6.50 and 2.31-4.21 respectively. This study contributes to catalogue of microorganisms that has been identified as enzyme producers and provides additional information to support future research about the industrial potential of these microorganisms that may produce enzymes and other metabolites of industrial importance.