浸矿微生物共培养体系在氟胁迫下的基因调控机理探索

Gene Regulation Mechanism of a Bioleaching Microbial Co-culture upon Fluoride Stress

为了探明混合浸矿微生物的耐氟性能及其基因调控机理,应用功能基因芯片(FGA-Ⅱ)研究了5株浸矿细菌(Acidithiobacillus ferrooxidans ATCC 23270,Leptospirillum ferriphilum YSK,Sulfobacillus thermosulfidooxidans ST,Acidithiobacills thiooxidans A01,Acidithiobacills caldus S1)所构成的共培养体系在4.8 mmol/L氟胁迫下的基因表达谱.结果表明,该共培养体系中与氟胁迫相关的基因主要涉及到硫代谢、细胞膜、电子传递、解毒、碳固定、氮代谢等多个方面功能的代谢途径,而且各个途径在短时间(<60 min)氟胁迫倾向于高效表达,而长时间(>120 min)氟胁迫各个途径更倾向于低效表达.芯片图谱分析表明,氟胁迫下共培养体系中起主导调节作用的是其中的优势种群,但是劣势种群在氟胁迫时很大程度上辅助了优势种群的生长及其氧化活性的保持.

In order to explore the fluoride tolerance and the gene regulation mechanisms of mixed bioleaching microorganisms, the gene expression profile of a co-culture including five typical bioleaching strains （Acidithiobacillus ferrooxidans ATCC 23270, Leptospirillum ferriphilum YSK,Sulfobacillus thermosulfidoox ithiobacills caldus S1 ） upon 4.8 mmol/L idans ST,AcidithiobaciUs thiooxidans A01 ,Acidfluoride stress was investigated using the functional gene array. The results showed, the genes associated with fluoride stress were involved with sulfur metabolism, cell membrane, electron transport, detoxification, carbon fixation, nitrogen metabolism, and so on. Additionally, majority of genes was induced upon the short time （ 〈60 min） fluoride stress,while repressed upon the long time （ 〉 120 min） fluoride stress. The effects of fluoride stress on different microbial population in the co-cul- ture were different. The results revealed that the dominant species in the co-culture played the crucial role for resisting fluoride stress,while the minor species to a large extent assisted the oxidation ability preservation and growth of the dominant species.