真菌对污染旱地红壤中苯并[a]芘共代谢降解研究

Effects of Fungi on Co-metabolic Degradation of Benzo[a]pyrene in Droughty Red Soil

在恒温和恒定转速培养条件下,模拟生物泥浆反应器法,选择从石油污染土壤中分离出来的青霉菌、黑曲霉、白腐真菌等3种真菌,在添加不同浓度菲和邻苯二甲酸作为共存底物情况下,研究其对旱地红壤中苯并[a]芘(B[a]P)的共代谢降解.结果表明,未灭菌土壤对B[a]P有降解能力,当土壤中添加菲时,提高了B[a]P在土壤中的降解率,100 mg.kg-1浓度菲处理的降解率显著高于200 mg.kg-1浓度菲处理,邻苯二甲酸对B[a]P降解影响不大.灭菌土壤中B[a]P几乎没有降解,添加共代谢底物后土壤中B[a]P降解率变化不明显.添加菲及邻苯二甲酸均促进了青霉菌对B[a]P的降解,提高其降解率,其中添加菲的效果更明显.与灭菌土壤相比,接种黑曲霉提高了B[a]P的降解率,但是添加菲与邻苯二甲酸却均抑制了黑曲霉菌对B[a]P的降解.白腐真菌对旱地红壤中B[a]P的降解能力较差,但当菲或邻苯二甲酸存在时能显著提高白腐真菌对B[a]P的降解,且菲比邻苯二甲酸效果好.

Simulated bioslurry remediation of PAHs contaminated soil was carried out.Penicillium,Aspergillus niger and white-rot fungus etc.three strains of fungi isolated from petroleum-contaminated soils were inoculated into droughty red soils differently in application rates of phenanthrene and phthalic acid,to investigate their effects of co-metabolic degradation of B[a]P.Results show that in natural soils,some native microorganisms were able to degrade B[a]P and with addition of low molecular weight PAHs-phenanthrene increased degradation rate of B[a]P in the soil.The effect was greater when the application rate of phenanthrene was 100 mg.kg-1 than 200 mg.kg-1.But the addition of phthalic acid did not show much effect.In sterilized soils,degradation of B[a]P in soils was hardly observed,and application of co-metabolism has no significant effect.However,inoculation of Penicillium stimulated degradation of B[a]P in all three treatments,i.e.phenanthrene at 100 mg.kg-1,phenanthrene at 200 mg.kg-1 and phthalic acid,but the effect of phenanthrene treatment was better than that of phthalic acid treatment.Inoculation of Aspergillus niger also showed similar effect,however,was inhibited by the presence of phenanthrene and phthalic acid in the soil.The degradation ability of white-rot fungus to B[a]P was very poor,but both kinds of phenanthrene concentration and phthalic acid treatments all could promote white-rot fungus to degrade B[a]P in soils,and the effect of phenanthrene was better than that of phthalic acid.