ANALYSIS OF GENETIC VARIATION BETWEEN WILD AND MUTANT STRAINS OF HYPER‐PECTINOLYTIC Aspergillus niger USING RAPD‐ PCR

Abstract

Improving the value of agrowastes generated via fungi degradation has become a priority in most large biomass generating countries for economic and ecological reasons.Wild strain of Aspergillus niger previously isolated from agrowastes in Lagos Nigeria, was subjected to UV‐mutagenesis; through the use of a selective culture medium containing pectin and 2 deoxy D glucose (2dg) to isolate hyper pectinolytic mutant strains. The polymerase chain reaction (PCR) that includes random amplified polymorphic DNA (RAPD) was employed to investigate the influence of UV‐mutagenesis in inducing mutation in the wild strain.Genetic relationship among isolates was determined by pair‐wise comparisons of the shared number of DNA bands on an agarose gel. The results showed that there was considerable genetic variation among isolates. The wild and the mutant strains of the fungal isolates shared an average of only 20% and 42 % of the bands in their RAPD profiles using OPA 2 and OPA 4 respectively, while they shared an average of 60 and 56% of the bands using OPC 3 and 8 respectively. The results indicated that there is genetic variability between the wild and mutant strains; signifying the possibility of the use of UV mutagenesis for generation of hyper‐pectinolytic fungi for effective biodegradation of agrowastes and enzyme production.