Isolation, characterisation and enzymatic activity of Streptomyces sp. and its pH control during fermentation process

Streptomyces sp. with grey white mycelium was isolated from Kodiyakkarai marine segment of east coastal of India. The isolate produced spiny spores and did not produce any diffusible pigments. Various biochemical tests were carried out to confirm the isolate classification. The amylolytic enzyme activity was estimated using the isolated strain which was confirmed by golden yellowish zone formation after using the Gram's iodine stain. The amount of amylase produced by the isolate was 6.15 U/ml. Higher living cells always produce better enzymes, so that the process parameters especially pH was maintained in fermentation chamber for higher growth and also for large-scale growth. For maintaining the pH a mathematical process model was developed using the data obtained during the process. The addition of Kalman's filter along with proportional-integral-derivative controller gave better stability in pH. By maintaining of pH 7, growth rate was significantly increased from 0.51to 0.59 gm/l on day 5 which are discussed in the results and discussions.