Isolation, Indentification And The Mechanism Of Inorganic Sulfur Compounds Oxidation Of Acidithiobacillus

Acidithiobacillus generally have the ability to derive energy from inorganic sulfur compounds, such as elemental sulfur, polysulfide, and metal sulfide. This ability has been applied to the bacterial leaching of sulfide ores, desulfurization of coal and so on.In this paper, a strain if Acidithiobacillus thiooxidans was isolated from acid mine drainage, and named At. thiooxidans LD-1. By morphological characters, LD-1 length l-2um, G^-, single polar flagella. For the growth feature, it can growth under pH 0.5-5.0, and temperature 25-35℃. The optimal condition for growth is pH 1.75, 30℃. LD-1 is able to derive energy from elemental sulfur and other inorganic sulfur compounds, use amino nitrogen as nitrogen source and CO₂ as carbon source. Based on 16S rDNA and G+C mole ratio, LD-1 belongs to At. thiooxidans. In order to preferable adapt to industry leaching environment, higher concentration of ores was used to domesticate LD-1 step by step. By this method, LD-1 can tolerate 40g/l Ni²⁺.A tetrathionate hydrolase that catalyzes tetrathionate hydrolyzes to other sulfur compounds was purified from LD-1, also from BY-3 and ATCC 19859. The purified enzyme had optimum activety about pH 3.0 and 40℃ in LD-1, pH 3.0 and 45℃ in BY-3. Differentiation of the enzyme active in different strain was detected. In the condition of pH 3.0, 30℃, LD-1 and BY-3 had higher enzyme activeity than ATCC 19859 either in cell culture or purifyied enzyme.