Microbacterium sp. BD6在Cr（VI）污染农田土壤修复中的应用研究

doi:10.13560/j.cnki.biotech.bull.1985.2021-0194

摘要/Abstract

摘要：

旨在探究Cr（VI）还原菌在Cr（VI）污染土壤中的修复条件及效果,为实际Cr（VI）污染农田土壤的修复提供借鉴。采用单因素实验、盆栽实验、高通量测序及qPCR等方法研究了菌株Microbacterium sp. BD6修复Cr（VI）污染土壤的最佳条件、修复前后对于植物的毒性以及对土壤中微生物群落的影响。实验表明菌株BD6在土壤含水率为30%及以上,温度为25-40℃的条件下,96 h对土壤中100 mg Cr（VI）/kg土壤的Cr（VI）还原率可达90%以上。菌株BD6在其它重金属离子存在的条件下仍然可以对Cr（VI）进行还原,但还原效果会受到影响。Cr（VI）会对黄豆植株高度、发芽率等指标产生负面作用;经菌株BD6修复后的土壤,降低了Cr（VI）的毒性,明显改善植株的生长状况,且植株体内铬含量显著降低。Cr（VI）污染土壤中微生物丰度和多样性明显低于未污染的土壤;经菌株BD6修复后的Cr（VI）污染土壤,微生物多样性随着修复时间的增长呈恢复趋势。因此,菌株BD6可作为修复Cr（VI）污染土壤潜在候选菌株,在今后的实际污染土壤修复中具有一定的应用价值。

关键词: Microbacterium sp. BD6, Cr（VI）污染土壤, 生物修复, 微生物群落, 电子供体

Abstract:

The purpose of this paper is to optimize the conditions and investigate the effects in bioremediation of Cr（VI）-contaminated soil by Cr（VI）-reducing bacteria,and to provide reference in practical remediation of Cr（VI）-contaminated soil. The single factor experiments,the pot experiments,high-throughput sequencing and qPCR methods were used to study the optimal conditions for the bioremediation of Cr（VI）-contaminated soil by Microbacterium sp. BD6,the toxicity to plants before and after remediation,and the effects on soil microbial community in the soil. The experiments showed that the Cr（VI）reduction rate of 100 mg Cr（VI）/kg contaminated soil by strain BD6 was above 90% in 96 h under the conditions of soil moisture content 30% and temperature 25℃- 40℃. Strain BD6 still reduced Cr（VI）in presence of other heavy metal ions,but the reduction effects were impacted. Cr（VI）restrained the height,germination rate and other indicators of soybean plant. The toxicity of the soil remediated by strain BD6 was reduced,the growth of plants was significantly improved,and the chromium content in plants significantly decreased. The microbial abundance and diversity in Cr（VI）-contaminated soil were significantly lower than those in non-contaminated soil. The microbial abundance and diversity of Cr（VI）-contaminated soil after remediation by strain BD6 increased with the bioremediation proceeded continuously. In conclusion,strain BD6 can be used as a potential candidate strain for the remediation of Cr（VI）-contaminated soil in the future.

Key words: Microbacterium sp. BD6, Cr（VI）-contaminated soil, bioremediation, microbial community, electron donor

杨宗政, 赵晓宇, 刘丹, 许文帅, 吴志国. Microbacterium sp. BD6在Cr（VI）污染农田土壤修复中的应用研究[J]. 生物技术通报, 2021, 37(10): 81-90.

YANG Zong-zheng, ZHAO Xiao-yu, LIU Dan, XU Wen-shuai, WU Zhi-guo. Bioremediation of Cr（VI）-contaminated Farmland Soil by Microbacterium sp. BD6[J]. Biotechnology Bulletin, 2021, 37(10): 81-90.

图/表 6

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土壤修复情况 Soil remediation	土壤Cr（VI）含量Cr（VI） content in soil/（mg·kg^-1）	发芽率 Germination rate/%	植株高度 Hight of plants/mm	植株鲜重 Fresh weight of plants（g/plant）	植株铬含量Chromium content in plants/（mg·kg^-1）
未修复 Non-remediated	0	100.0 a	104±2.1 a	0.64±0.04 a	未检出 g
	5	100.0 a	89±0.42 b	0.51±0.02 c	0.8±0.1 f
	10	100.0 a	55±1.6 c	0.49±0.02 c	1.1±0.3 f
	20	100.0 a	30±0.9 d	0.37±0.02 d	1.6±0.1 e
	30	100.0 a	29±0.8 d	0.36±0.01 de	2.1±0.1 d
	50	100.0 a	25±1.2 e	0.33±0.02 ef	2.6±0.3 c
	80	100.0 a	15±0.3 f	0.30±0.01 f	3.8±0.1 b
	100	88.9±4.84 b	12±0.1 g	0.26±0.01g	5.0±0.4 a
已修复Remediated	100	100.0 a	87±0.9 b	0.56±0.03 b	未检出 Unolected

土壤修复情况 Soil remediation	土壤Cr（VI）含量Cr（VI） content in soil/（mg·kg^-1）	发芽率 Germination rate/%	植株高度 Hight of plants/mm	植株鲜重 Fresh weight of plants（g/plant）	植株铬含量Chromium content in plants/（mg·kg^-1）
未修复 Non-remediated	0	100.0 a	104±2.1 a	0.64±0.04 a	未检出 g
	5	100.0 a	89±0.42 b	0.51±0.02 c	0.8±0.1 f
	10	100.0 a	55±1.6 c	0.49±0.02 c	1.1±0.3 f
	20	100.0 a	30±0.9 d	0.37±0.02 d	1.6±0.1 e
	30	100.0 a	29±0.8 d	0.36±0.01 de	2.1±0.1 d
	50	100.0 a	25±1.2 e	0.33±0.02 ef	2.6±0.3 c
	80	100.0 a	15±0.3 f	0.30±0.01 f	3.8±0.1 b
	100	88.9±4.84 b	12±0.1 g	0.26±0.01g	5.0±0.4 a
已修复Remediated	100	100.0 a	87±0.9 b	0.56±0.03 b	未检出 Unolected

Sample ID	Ace	Chao1	Shannon	Simpson	Coverage
Y	2527.894±43.237 a	2500±70.335 a	9.284±0.035 a	0.991±0.001 a	0.987±0.002
Cr	1785.987±91.525 e	1811.426±77.381 de	8.336±0.368 b	0.972±0.004 ab	0.994±0.006
A-96h	1974.381±83.318 cd	1887.949±47.887 cd	5.209±0.837 e	0.796±0.071 d	0.982±0.001
G-96h	2317.543±142.074 b	2262.373±90.249 b	6.911±0.386 cd	0.921±0.009 c	0.982±0.001
A-10d	1850.619±60.012 de	1691.645±54.171 e	6.071±0.265 de	0.936±0.011 bc	0.983±0.001
G-10d	2001.833±81.225 cd	1878.924±93.194 cd	6.791±0.078 cd	0.971±0.005 ab	0.983±0.000
A-15d	2079.836±96.326 c	1963.311±68.010 c	7.228±0.368 c	0.977±0.002 ab	0.981±0.003
G-15d	1548.096±74.238 f	1482.651±72.5451 f	6.522±1.014 cd	0.965±0.003 abc	0.986±0.002

Sample ID	Ace	Chao1	Shannon	Simpson	Coverage
Y	2527.894±43.237 a	2500±70.335 a	9.284±0.035 a	0.991±0.001 a	0.987±0.002
Cr	1785.987±91.525 e	1811.426±77.381 de	8.336±0.368 b	0.972±0.004 ab	0.994±0.006
A-96h	1974.381±83.318 cd	1887.949±47.887 cd	5.209±0.837 e	0.796±0.071 d	0.982±0.001
G-96h	2317.543±142.074 b	2262.373±90.249 b	6.911±0.386 cd	0.921±0.009 c	0.982±0.001
A-10d	1850.619±60.012 de	1691.645±54.171 e	6.071±0.265 de	0.936±0.011 bc	0.983±0.001
G-10d	2001.833±81.225 cd	1878.924±93.194 cd	6.791±0.078 cd	0.971±0.005 ab	0.983±0.000
A-15d	2079.836±96.326 c	1963.311±68.010 c	7.228±0.368 c	0.977±0.002 ab	0.981±0.003
G-15d	1548.096±74.238 f	1482.651±72.5451 f	6.522±1.014 cd	0.965±0.003 abc	0.986±0.002