【摘要】 选择使用杏鲍菇菌丝富集重金属Pb2+,从本实验室菌种库中筛选出了8株能抗800 mg/L Pb2+的菌株。通过对其溶磷能力的检测,从中筛选到了2株溶磷能力较强的菌株CG8、FFT1以及2株溶磷能力较弱的菌株FFC6、FFC11,经16S r DNA序列分析鉴定,CG8为克雷伯菌(Klebsiella sp.),FFT1为假单胞菌(Pseudomonas sp.),FFC6和FFC11为芽孢杆菌(Bacillus sp.),其序列相似度均达99%。随后,研究了4株溶磷菌株对液体培养(Pb)条件下杏鲍菇(Pleurotus eryngii)菌丝的生物量、Pb富集量、脂质过氧化、巯基蛋白含量和抗氧化酶的影响。结果显示,在Pb胁迫条件下,具溶磷能力的菌株能在一定程度上增加菌丝生物量,促进菌丝对重金属的富集,同时,使菌丝的丙二醛(MDA)含量降低,菌丝抗氧化酶(SOD)和氧化物酶(POD)活性显著降低,菌丝巯基蛋白含量升高。实验证明,微生物溶磷能力可有效减轻重金属对杏鲍菇菌丝的毒害和重金属诱导的氧化胁迫。并且溶磷能力较强的菌株(CG8)对杏鲍菇菌丝富集与抵抗重金属诱导的氧化胁迫有更为明显的作用,重金属富集量增加96.1%,巯基蛋白增加量为91.3%。更多还原

【Abstract】 In this study Pleurotus eryngii was selected to enrich Pb2+,and 8 strains with capability against Pb2+ of 800 mg/L were screened from the strain library of our laboratory. Two strains CG8 and FFT1 with high phosphate-solubilizing capacity,as well as FFC6 and FFC11 with low phosphate-solubilizing capacity were selected. Using 16 S r DNA analysis,CG8 was identified as Klebsiella sp.,FFT1 as Pseudomonas sp.,FFC6 and FFC11 as Bacillus sp.;the similarity of their sequences reached 99%. Further,the effects of 4 strains of phosphate-solubilizing bacterium(PSB)on the mycelium growth,Pb accumulation,lipid peroxidation,the content of sulfhydryl-containing protein,and antioxidant enzyme of P. eryngii in Pb-contaminating liquid medium were investigated. The result showed that inoculation with PSB enhanced the hyphal biomass of P. eryngii and accumulation of heavy metals. Moreover,the content of MAD,and the activities of SOD and POD in mycelium decreased significantly,while the content of total sulfhydryl(TSH)increased. All results confirmed that PSB efficiently reduced the toxicity of heavy metals to P. eryngii mycelium and the oxidative stress induced by heavy metals. CG8 with the strongest capacity of solubilizing phosphate had more significant effects to resist the mycelium accumulating heavy metals and oxidative stress induced by heavy metals in P. eryngii,the accumulation of Pb increasing 96.1% and the PB-SH increasing 91.3%.更多还原