title: Mutagenesis and genetic characterisation of amylolytic Aspergillus niger.
abstract: Aspergillus niger FCBP-198 was genetically modified for its ability to reveal extra cellular alpha-amylase enzyme activity. From 76 efficient mutants isolated after ultraviolet (UV) irradiation, An-UV-5.6 was selected as the most efficient UV mutant, with 76.41 units mL(-1) of alpha-amylase activity compared to wild (34.45 units mL(-1)). In case of ethyl methane sulphonate (EMS), among 242 survivors, 74 were assayed quantitatively and An-Ch-4.7 was found to be the most competent, as it exhibited a three-fold increase in alpha-amylase activity (89.38 units mL(-1)) than the parental strain. Genetic relationships of the mutants of A. niger FCBP-198 were analysed with a randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). Results obtained from the comparison between genotypes of A. niger FCBP-198 showed differences in the sizes and numbers of amplified fragments per primer for each isolate. The dendrogram showed that genotypes An-Ch-4.7 and An-Ch-4.2 were distinctly classified into one category, while the isolates An-UV-5.6, An-UV-5.1 and A. niger FCBP-198 have the nearest genetic relationship. The five isolates from A. niger FCBP-198 genotypes shared an average of 65% bands.
authors.affiliation: Institute of Mycology and Plant Pathology, University of the Punjab, Lahore, Pakistan. sobiya_shafique@hotmail.com
authors.forename: Sobiya
authors.initials: S
authors.lastname: Shafique
authors.forename: Rukhsana
authors.initials: R
authors.lastname: Bajwa
authors.forename: Shazia
authors.initials: S
authors.lastname: Shafique
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D005020:Ethyl Methanesulfonate / Q000633:toxicity; D005656:Fungal Proteins / Q000235:genetics; D005838:Genotype; D016296:Mutagenesis / Q000187:drug effects / Q000235:genetics; D009153:Mutagens / Q000633:toxicity; D019105:Random Amplified Polymorphic DNA Technique; D000516:alpha-Amylases / Q000235:genetics / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D009153:Mutagens; D005020:Ethyl Methanesulfonate; D000516:alpha-Amylases