皂角苷强化白腐真菌Phlebia brevispora降解林丹的研究

Enhancement of Saponin for Biodegradation of γ-HCH by White Rot Fungus Phlebia brevispora

【目的】为了提高环境中持久性有机氯农药的生物降解效果。【方法】利用平衡振荡法研究了生物表面活性剂皂角苷对有机氯农药林丹的增溶作用,并通过液相培养法研究了皂角苷对白腐真菌Phlebia brevispora生长以及降解林丹的强化效果。【结果】皂角苷能大幅度增加林丹的溶解度,实验浓度范围内增溶倍数最高可达到7.4。皂角苷作为生长基质可促进P.brevispora的生长,提高其生物量,但浓度在达到1.0 g/L时,菌株生物量几乎不再继续增加。在0.05~1.0 g/L浓度范围内,皂角苷能显著提高菌株对溶液中林丹的降解效果(P<0.05),且降解率随着皂角苷浓度的增加而增加,降解率最大可提高14.1%。添加0.5和1.0 g/L的皂角苷处理时,菌株胞内粗酶液对林丹的降解率显著高于不添加皂角苷的处理(P<0.05)。皂角苷对林丹的增溶效果随着无机盐的加入而提高,20 mmol/L的Na Cl和Na_2SO_4使林丹的溶解度提高了1.17和1.26倍;而在含有皂角苷的降解体系中,Na Cl的添加进一步促进了林丹的生物降解效果,降解率提高了10%以上。【结论】本研究结果表明,利用皂角苷强化微生物降解去除环境中的有机污染物是可行的,具有一定的实际应用价值。

[Objective]The present study was conducted to improve the effect on biodegradation of persistent organoehlorine pesticides. [ Method] The effects of biosurfactant saponin on solubilization of chlorinated pesticides γ-HCH, and biodegradation of γ-HCH by fungus Phlebia brevispora were investigated using balance vibration method and liquid culture method respectively. [ Result] The results of salubiliza- tion indicate that the solubility of γ-HCH could be enhanced by saponin at 0.05 - 1.0 g/L. The fungal biomass of P. brevispora with saponin of high concentration were larger than that without saponin and that with saponin of low concentration. The saponin could significantly in- crease the degradation rate of γ-HCH by P. brevispora and the degradation efficiency increased with incresing saponin concentration. The highest efficiency was increased by 14.1% compared to the control. It was also found that saponin at 0.5 and 1.0 g/L significantly in- creased degradation rate of γ-HCH by intracellular enzyme from P. brevispora, after 60 min of degradation. The solubility and biodegradation rate of γ-HCH were enhanced by addition of inorganic salts including NaC1 and Na2SO4 of 20 mmol/L.