Control of producting sulfuric acid in drain by protozoa preying on Thiobacillus thiooxidans

从废弃马托矿某中和厂采集的硫氧化细菌在元素硫的富集中培养。在培养中，我们确认了原生动物，属于Bodo edax，没有硫氧化细菌和真菌。本研究描述了富硫培养中细菌和原生动物之间的相互作用。为了研究这种相互作用，在不同条件下进行了硫氧化实验。结果表明：(1)在纯培养条件下，细菌对元素硫的氧化速度快于富硫培养。在这种情况下，细菌和原生动物之间的相互作用(2)原生动物与硫氧化细菌的比例基本不变，pH>0.6时原生动物数量增加，pH<0.6时原生动物数量减少；(3)纯培养中，Cu2+和Lt的浓度对硫氧化细菌生长有抑制作用；原生动物随着浓度的增加而增加，但生长量减少，在100mgdm；-3；-3；时，原生动物不再增加，在1000mgdm；-3；-3h后，原生动物完全不能被确认。硫氧化菌在富集培养中生长的产量因子取决于原生动物的存在。无原生动物培养条件下硫氧化细菌生长的产率约为有原生动物培养时的7倍。(6)在pH值小于0.6时，细菌的氧化速率上升，这可能是由于原生动物死亡细胞分解营养盐循环所致。

Sulfur-oxidizing bacteria,collected from a neutralization plant of the abandoned Matuo mine,has been cultured in an enrichment with elemental sulfur.In the culture,we have confirmed protozoa which belongs to Bodo edax without sulfur-oxidizing bacteria and fungus.This study describes interaction between bacteria and protozoa in an enrichment culture.To investigate the interaction,sulfur oxidation experiments are performed under the various conditions.The results obtained are summarized as follows:(1)The elemantal sulfur oxidaition by the bacteria in pure culture is faster than in enrichment.In the case,the yield factor of sulfur-oxidizing bacteria growth in pure culture is about 3 times as large as that in enrichment culture.(2)The ratio of protozoa to sulfur-oxidizing bacteria is nearly constant.At pH value above 0.6,protozoa can increase,but decrease at pH value than 0.6.(3)In pure culture,sulfur-oxidizing bacteria is inhibited at the concentration of Cu^<2+> above lmgdm^<-3> .In enrichiment cultre,the bactreia is in the same as the case of pure culture.Protozoa increases at the concentration of Cu^<2+> ,1,10mgdm^<-3>,but the amount of growth decreases.At 100mgdm^<-3>,protozoa can not increase,and at 1000mgdm^<-3>it can not be confirmed at all after about 200 hours.(4)In the case of subculture with Cu^<2+>, sulfur-oxidizing bacteria is accompanied with Cu^<2+>-resistant ,but protozoa can not do.(5)The yield factor of sulfur-oxidizing bacteria growth in enrichment culture depends on protozoa existence.The value in the protozoa-free case is about 7 times as large as when there exists protozoa.(6)The oxidation rate by the bacteria rises at pH value less than 0.6.This phenomenon may be due to a cycle of nutritive salts through the decomposition of protozoa death cells.