Growth and Protein Formation of Recombinant Aspergillus: Utility of Morphological Characterization by Image Analysis

Abstract

Three a-amilase producing strains of Aspergillus oryzae used for recombinant protein production have been studied with respect to growth and protein production. The three strains were 1) a wild-type, 2) a transformant of the wild-type containing additional copies of the a-amilase gene and 3) a morphological mutant of the transformant. Carbon balances were set up for continuous cultures of the wild-type and the average recovery of carbon was 99 ±2% revealing that all major carbon sources were measured Data from continuous and batch cultivations indicated that the a-amilase production was repressed at high glucose concentration. Image analysis was used to study the microscopic morphology of the fungus. Valuable information of the growth kinetics was obtained by comparing the three strains with respect to the tip extension rate and the branching frequency.