刘洪艳, 王珊
天津市海洋资源与化学重点实验室, 天津科技大学 海洋与环境学院, 天津 300457

摘要:
利用异化铁还原细菌处理Cr（VI）是重金属污染修复领域的一个新兴研究方向。本文以海洋沉积物中异化铁还原混合菌群为研究对象，分析铁还原细菌异化铁还原性质对重金属Cr（VI）还原效率的影响。菌群异化铁还原性质的实验结果表明，以柠檬酸铁和氢氧化铁为不同电子受体时，菌群异化铁还原的效率存在差异，培养体系累积Fe（Ⅱ）浓度分别为85.08 ±5.85 mg/L和32.55 ±4.78 mg/L。电子受体对混合菌群组成的影响主要表现在，以柠檬酸铁和氢氧化铁为电子受体时，混合菌群多样性Shannon指数分别是4.615和4.158，较对照组高（Shannon指数3.735）。异化还原Fe（Ⅲ）培养体系中，细菌种群的优势菌属是Clostridium，属于梭菌目Clostridiales，表明梭菌是参与Fe（Ⅲ）还原的主要优势菌。菌群异化铁还原性质对Cr（VI）还原效率影响的实验结果表明，柠檬酸铁为电子受体，细菌在Fe（Ⅲ）浓度为1 120 mg/L时异化铁还原效率高，并且还原Cr（VI）达100%。氢氧化铁为电子受体，Fe（Ⅲ）浓度1 680 mg/L时，异化铁还原Cr（VI）效率高（72%），是对照组4倍。研究结果为进一步应用微生物治理重金属Cr（VI）污染提供理论依据。
关键词:海洋沉积物异化铁还原细菌菌群组成Fe(III)还原Cr(VI)还原
DOI：10.11759/hykx20190211001
分类号:Q936
基金项目:国家自然科学基金项目（41606157）；天津市自然科学基金资助项目（16JCYBJC20900）

Characteristics of chromate reduction by Fe(Ⅲ) reduction using mixed bacteria from marine sediment
LIU Hong-yan, WANG Shan
Tianjin Key Laboratory of Marine Resources and Chemistry, College of Marine and Environmental Sciences, Tianjin University of Science & Technology, Tianjin 300457, China
Abstract:
Indirect Cr(VI) reduction by dissimilar Fe(Ⅲ)-reducing bacteria are considered an important process for the protection of Cr(VI)-polluted environments. This study aimed to investigate the characteristics of microbial Cr(VI) reduction by dissimilar Fe(Ⅲ)-reducing bacteria from marine sediment. Characteristic of Fe(Ⅲ) reduction by mixed bacteria using different electron acceptors was determined. The differences in Fe (Ⅲ)-reducing activity of the mixed culture using ferric citrate and ferric hydroxide as electron acceptors indicated that the Fe(Ⅱ) concentrations of the culture were 85.08 ±5.85 mg/L and 32.55 ±4.78 mg/L, respectively. The effect of electron acceptors on the microbial community of the mixed culture indicated that bacterial diversity, with Shannon indeces of 4.615 and 4.158 in the mixed culture with added Fe(Ⅲ), was higher than that of the control with a Shannon index of 3.735 without added Fe(Ⅲ). Sequencing data analysis showed that the dominant populations were Clostridium in the mixed culture under Fe(Ⅲ)-reducing conditions. The Cr(VI) reduction ratios in the mixed culture were determined in both the presence and absence of Fe(Ⅲ). Results showed that the highest ratio of Cr(VI) reduction was almost 100% at ferric citrate concentrations of 1120 mg/L. When the ferric hydroxide concentration was 1680 mg/L, Cr(VI) reduction was achieved at 72% under Fe(Ⅲ) reducing conditions, which increased Cr(VI) reduction by a factor of four compared with that of the control group with no adding of Fe(Ⅲ). The reduction of Cr(VI) was clearly stimulated by Fe(Ⅲ) reduction with the addition of Fe (Ⅲ) as an electron acceptor. These results indicated that dissimilar Fe(Ⅲ)-reducing bacteria could improve the rate of Cr(VI) reduction, which could, in turn, provide evidence for the application of microorganism to the treatment of heavy metal Cr(VI) pollution.
Key words:marine sedimentFe (III)-reducing bacteriamicrobial communityFe (III) reductionCr (VI) reduction





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