Research On Biological Degradation Of Harmful Materials And Mutation Of Penicillium Simplicissimum

phenols and anilines are important chemical raw materials and intermediates, and Remazal Brilliant Blue R is one of the anthraquinone dyes, they have been widely used in industrial production, thereafter they enter the environment such as water, soil with industrial wastewater. But due to their steady chemical feature, long persistence and high toxicity, they are considered as the main organic pollutants in environment. Therefore the biohazards, transportation, transformation and degradation about them have been the hot topic all over the world.To provide research foundation about the degradation of the resistant biodegradation organic matters, the degradation of several phenol and aniline materials, and Remazal Brilliant Blue R by Penicillium simplicissimum were studied. Meanwhile in order to obtain a high laccase producing strains, Penicillium simplicissimum was mutated by the methods of physical mutation and chemical mutagenesis.Firstly, in order to study the growth of Penicillium simplicissimum exposed to phenols and anilines, and the degradation of these toxic substances, several different concentrations of phenols and anilines were respectively added into the culture system, which was cultured for4days with Penicillium simplicissimum. And the laccase activities of Penicillium simplicissimum were detected under the conditions of liquid cultivation. The results show that low concentrations of phenols and anilines can promote the growth of Penicillium simplicissimum, on the contrary, the growth would be restrained under the culture of high concentrations. The trends of laccase activity over time were similar with the degradation of phenols and anilines with time. Meanwhile, Penicillium simplicissimum could catalyze and oxidize phenol,2,4-dichlorophenol and aniline effectively. When the concentration of phenol was controlled at500μg·ml-1,2,4-dichlorophenol was50μg·ml-1, and aniline was1000μg·ml-1, the degradation rates of phenol,2,4-dichlorophenol and aniline were all close to100%. When the concentration of2,4-dichlorophenol was controlled at60-125μg·ml-1and aniline was2000-5000μg·ml-1, the degradation rates were respectively over60%and65%. However, the degradation effects of p-nitrophenol and p-nitroaniline by Penicillium simplicissimum were worse, and every degradation rate of them was only about10%. Secondly, The discoloration of RBBR by penicillium simplicissimum was studied under different conditions with only a single variable among parameters such as substrate concentration, inoculation amount of strains, pH, incubation time and temperature. The results show that the discoloration of RBBR by penicillium simplicissimum was due to biological adsorption and biodegradation. The discoloration of60μg·ml-1RBBR reached96.96%when RBBR was added into the culture system (pH=6), which containing4ml spore suspension of penicillium simplicissimum was cultured in37℃shaking incubator for4days.Finally, in order to obtain a high laccase producing strains, Penicillium simplicissimum was induced by chemical reagent and ultraviolet radiation. When PDA-RBBR plate fade better, the mutant strains were screened to culture in solid fermentation culturing medium for the determination of enzyme activity. After these processes, a high laccase-producing strains C5E4was obtained, and it was cultured for5generations to measure the laccase activity. The results show that When5ml diethyl sulfate (2%) was mixed along with5ml spore suspension for30min, chemical mutagenesis reached its best condition, the rate of lethal mutation was reached75.46%. And the optimum conditions of UV mutagenesis were that spore suspension was irradiated for4minutes under15W UV lamp at a distance of30cm. The highest activity of C5E4strains was4.80U·g-1over28%higher than the maximum laccase activity of original microorganism. And though5generations culture, C5E4strains can product laccase stably of the five subcultures.