Effect of physical factors on pellet morphology of Aspergillus awamori MTCC 9166 and polygalacturonase production

Polygalacturonase enzyme has its industrial application in extraction and clarification of fruit juices. Growth as pellet is an important character for any industrial fungal strain as product recovery becomes easy and simple. The simultaneous effect of fermentation conditions like pH, temperature, agitation and inoculum size were studied on pellet morphology and polygalacturonase production by Aspergillus awamori MTCC 9166 in submerged fermentation using crude pectin. The studies were done by unidimensional approach in which conventionally one parameter was selected and studied at a time. Optimum fermentation conditions for maximum polygalacturonase production were at pH 5.5, temperature 28 °C, agitation speed 200 rpm and inoculum size 1×106 spores/ml. The highest enzyme production at these conditions was 17.8 U/ml. The study revealed a significant fact that the same optimum fermentation conditions promoted both pellet formation and maximum enzyme production.