QUANTITATIVE ASSESSMENT OF THE DOMINANT GENOME IN FUSANT CULTURES

Selection of fusant cultures, producers of bioactive compounds is of significant importance for the biotechnology industry. Protoplast fusion between prototrophic strains of Aspergillus oryzae PP, producer of alfa-amylase and Apergillus awamori K1, producer of xylanase was obtained. The interspecific nature of the fusants was determined by morphology and screening for combined enzymatic activity. The aim of this investigation was to quantitate the dominant parental genome in the fusants by applying whole genome typing strategy based on the Amplified Fragment Length Polymorphisms (AFLP) technique. In addition we investigated the genome decomposition of the fusant cultures from first to fourth generation. Our results demonstrate that the appearances of the fusants varied but they basically resembled Aspergillus awamori. On the bases of more than 80 polymorphic markers, the genomic analysis confirmed that Aspergillus awamori is the dominant genome (>85%) in the fusants. The stability of the fusants was examined by successive subcultures. The genomic decomposition of the fusants between first and forth generation is as little as 3%. From our studies we could conclude that AFLP is an efficient and discriminatory method for evaluation of the dominant genome in fusant cultures and the extent of genomic decomposition in the generations.