EFFECT OF SOME CHEMICAL MUTAGENS ON PSEUDOMONAS AERUGINOSAH3 ALGINATE PRODUCTION

This study was aimed to investigate the effect of chemical mutagens on the ability of Pseudomonas aeruginosa H3 in alginate production, using N-methyl-N-nitro-Nnitrosoguanidine (MNNG) and Mitomycin C (MMC). It was achieved by incubating fresh cultures of Pseudomonas aeruginosa H3 with MNNG and MMC separately for 60min., then 100μl of each culture was spread on LB agar plates and incubated at 37 °C for 24 hrs. From the survival colonies that arise after subjection to lethal effect of mutagen that causes 90% killing or more, thirty colonies were selected randomly and screened for their ability in alginate production. Results showed that chemical mutagenesis using MNNG and MMC causes an increase in the ability of P. aeruginosa H3 in alginate production through out the presence of some alginate over producer mutants. Alginate concentration produced by the most highly over producer mutants H3R78, and H3R97 was 160mg/ml after subjection to MNNG and MMC, respectively in comparison with 70mg/ml produced by the wild type of Pseudomonas aeruginosa H3.Results of FT-IR spectroscopy showed that there are no any structural differences in the chemical structure of alginate produced by the wild type of P. aeruginosa H3 and the over-producer mutants H3R78 and H3R97.