两株微生物的Cr(Ⅵ)还原特性研究

Study on the Reduction Characteristics of Cr(Ⅵ)by Two Species of Microorganisms

旨为研究2株微生物对Cr(Ⅵ)的还原能力及特性。在实验室条件下,通过连续培养,探究2株微生物的还原特性及pH、电子供体对其还原Cr(Ⅵ)影响,并结合表征手段研究寡养单胞菌对Cr(Ⅵ)的解毒机理。结果显示,寡养单胞菌和胶冻样芽孢杆菌对Cr(Ⅵ)的耐受性达400和200 mg/L,中性条件下,72 h内对45.5和18.5 mg/L的Cr(Ⅵ)去除率为100%;2株微生物在弱碱性条件下活性较强,在pH=8时,寡养单胞菌和胶冻样芽孢杆菌72 h内对50 mg/L的Cr(Ⅵ)去除率达98.1%和49.2%;寡养单胞菌在乙酸钠和乳酸钠的作用下,对50 mg/L的Cr(Ⅵ)的去除率可在60 h内达到100%,乳酸钠和葡萄糖可使胶冻样芽孢杆菌72 h内对50 mg/L的Cr(Ⅵ)去除率从49.2%提升至61.9%和73.2%;还原产物表征分析表明,寡养单胞菌表面在还原Cr(Ⅵ)的过程中吸附Cr(Ⅵ)于机体表面,并将Cr(Ⅵ)高效还原为Cr(Ⅲ)。寡养单胞菌和胶冻样芽孢杆菌可作为修复重金属Cr(Ⅵ)污染的优质菌种。

This work aims to study the reduction ability and characteristics of two species of microorganisms to Cr(Ⅵ).The abilities of two species of microorganisms to reduce Cr(Ⅵ)and the influence of pH and electron donor on its reduction of Cr(Ⅵ)were explored by continuous culturing in lab condition,combining characterization methods the detoxification mechanism of Stenotrophomonas sp.was studied The results showed that the tolerance of Stenotrophomonas sp.and Bacillus mucilaginosus to Cr(Ⅵ)was 400 and 200 mg/L.Under neutral conditions,the removal rate of 45.5 and 18.5 mg/L Cr(Ⅵ)within 72 h was 100%.Under weakly alkaline conditions,the activities of both microorganisms were strong.At pH 8,removal rates of 50 mg/L Cr(Ⅵ)by Stenotrophomonas sp.and B.mucilaginosus within 72 h were 98.1% and 49.2% respectively.Sodium acetate and sodium lactate promoted the removal rate of 50 mg/L Cr(Ⅵ)by Stenotrophomonas sp.to be 100% within 60 h.Sodium lactate and glucose increased the removal rate of 50 mg/L Cr(Ⅵ)by B.mucilaginosus from 49.2% to 61.9% and 73.2% within 72 h,respectively.The analysis of the reduced products showed that Stenotrophomonas sp.adsorbed Cr(Ⅵ)on the surface of the body and efficiently reduced Cr(Ⅵ)to Cr(Ⅲ).Stenotrophomonas sp.and B.mucilaginosus can be used as high quality strain for remediation of heavy metal Cr(Ⅵ)pollution.