耐锰细菌HM-12的重金属耐受性及锰胁迫下的转录组学分析

Heavy Metal Tolerance and Transcriptome Analysis of Mn Stress by HM-12 Strain

为解决锰铁矿开采后带来的尾矿处理及被污染土壤的修复治理等问题,基于生物修复及环境治理研究,从锰铁尾矿中筛选出了一株具有高耐锰性能的菌株HM-12.通过研究HM-12对其他类型重金属的耐受程度,发现HM-12菌株可以耐受高浓度的Zn(II),Cu(II),Ni(II),Cd(II),Pb(II),Fe(III)和As(III),最高耐受浓度分别为2 000 mg/L,1 200 mg/L,800 mg/L,300 mg/L,1 000 mg/L,1 000 mg/L和500 mg/L.对这七种重金属离子的去除效果研究,结果显示:HM-12菌株对这些重金属离子均具有去除能力,其中,对Zn(II),Pb(II)和Fe(III)的去除效果较强,分别达到94.03%、99.60%和96.12%.此外,还进一步对锰胁迫下的HM-12转录组学进行研究,GO分析发现与金属离子相互作用相关的基因出现不同程度的转录调节,其中,上调基因数量多于下调基因,且上调基因中的copA,copZ和znuA基因转录差异尤为显著.KEGG分析发现与菌株代谢相关的基因下调数量高于上调基因.这些结果表明HM-12在锰胁迫下展现出多种适应性基因转录调控方式.针对HM-12菌株的深入研究,将为微生物资源开发和土壤生物修复提供科学依据.

In order to solve the problems of tailings treatment and remediation of contaminated soil brought about by ferromanganese mining, a strain HM-12 with high manganese tolerance was screened from ferromanganese tailings based on the studies of bio-remediation and environmental governance.By studying the tolerance of HM-12 to other types of heavy metals, it was found that HM-12 could tolerate high concentrations of Zn(II),Cu(II),Ni(II),Cd(II),Pb(II),Fe(III) and As(III).Their maximum concentrations were 2 000 mg/L,1 200 mg/L,800 mg/L,300 mg/L,1 000 mg/L,1 000 mg/L,and 500 mg/L,respectively.Moreover, the removal effect on these seven metal ions showed that HM-12 exhibited a positive ability to remove them, among which the removal rate of Zn(II),Pb(II) and Fe(III) reached 94.03%,99.60% and 96.12%,respectively.Furthermore, the transcriptome of HM-12 was further studied under the conditions of Mn stress.It showed that genes related to the interaction with metal ion were presented in different transcription regulation by GO analysis, among which the gene quantity of upregulation was more than the downregulation.It’s worth noting that the transcription of copA,copZ and znuA gene were particularly significant upregulation.In addition, KEGG analysis displayed that the gene quantity of downregulation exceeded the upregulation.These results indicated that HM-12 exhibited multiple adaptively transcriptional regulation under the Mn stress.These findings will give scientific foundation for microbial resource exploitation and soil remediation.