Studies on a mixed culture system of Thiobacillous and Acidiphilium for biohydrometallurgy

Research Project

Project/Area Number	61560122
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	発酵・醸造
Research Institution	Okayama University Faculty of Agriculture
Principal Investigator	TANO Tatsuo Okayama University Faculty of Agriculture;professor, 農学部, 教授 (60032976)
Co-Investigator(Kenkyū-buntansha)	SUGIO Tsuyoshi Okayama University Faculty of Agriculture; Associate professor, 農学部, 助教授 (20033269)
Project Period (FY)	1986 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥1,600,000 (Direct Cost: ¥1,600,000) Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1986: ¥1,300,000 (Direct Cost: ¥1,300,000)
Keywords	Thiobacillus / Acidiphilium / Acidophilic heterotrophic bacteria / Mixed culture / 湿式冶金 / ポリアミン / ピルビン酸 / 金属耐性 / Acidiphilium属 / 好酸性独立栄養細菌 / 湿式治金 / ピルビン酸,ポリアミン
Research Abstract	This project was undertaken to confirm that mixed culture of thiobacilli and Acidiphilium has effect uopn both the rate and extent of leaching of metales from ore. 1. Acidophilic heterotrolphic bacteria were isolated from acidic mine drainage and weakly acidic environments such as sewage and soils. 2. Twenty three strains among them were nickel-resistant and 16 strains were cobaltous-resistant in the presence of ferrous-iron. 3. Mutant which was able to grow on pyruvate as a carbon source was prepared from Acidiphilium sp. 24R. Pyruvate which is toxic to the thiobacilli could remove from cultures of Thiobacillus thiooxidans by culturing them with the mutant. 4 The addition of Acidiphilium to the leaching liqure contining thiobacilli stimulated the population density of thiobacilli. Ferric iron and its regeneration by bacterial reoxidation of ferrous iron is essential for bacterial leaching. The thiobacilli produce the lexiviant. The more thiobacilli there are, the more lixiviant is produced and the faster the rate of and greater the extent of leaching.