Vol. 3, Issue 1, Part A (2021)

In this study, 48 actinomycetes isolates were obtained from Navsari Agricultural University farm soil and sediments of the Dandi coastal range, Navsari, Gujarat. Among these isolates, 10 were found to be positive for cellulase production and were further characterized based on their morphological features. Three potential isolates were selected for detailed biochemical assays, growth characteristics, and cellulase production. These isolates were identified as Streptomyces rochei B2II, Streptomyces viridochromogenes D1I, and Streptomyces iakyrus C1VI through 16S rDNA sequence analysis. The effect of various physico-chemical parameters on the growth and cellulase production of these isolates was investigated. Among the three isolates, S. iakyrus C1VI exhibited the highest cellulase production at an optimum temperature of 35 °C and pH 8. For S. rochei B2II and S. viridochromogenes D1I, the optimum cellulase production was observed at 35 °C and pH 10 and 8, respectively. Additionally, the concentration of 1% CMC was found to be optimal for the best CMCase production. Based on the optimum parameters, media were further optimized, and the enzyme activity, total protein, and dry biomass were estimated. Compared to the unoptimized conditions, the optimized cultural conditions for B2II, D1I, and C1VI resulted in an increase of 20.0%, 19%, and 22% in enzyme activity, 10.5%, 10%, and 14% in total protein, and 13%, 9%, and 19% in dry biomass, respectively. Furthermore, partial purification of the cellulase enzyme was carried out. Compared to the optimized conditions, the partially purified extracts of B2II, D1I, and C1VI showed an increase of 14%, 7%, and 18% in enzyme activity, and 10%, 9%, and 13% in total protein, respectively. These findings highlight the potential of these actinomycetes isolates for cellulase production and offer valuable insights into the optimization of cultural conditions for enhanced enzyme production.