Evaluation of Leptospirillum ferrooxidans for leaching

Journal Article · Wed Jan 01 04:00:00 EST 1992 · Applied and Environmental Microbiology; (United States)

OSTI ID:5691433

Sand, W; Rohde, K; Sobotke, B; Zenneck, C ^[1]

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1. Univ. Hamburg (West Germany)

The importance of Leptospirillum ferroxidans for each leach processes has been evaluated by studying the lithotrophic flora of three mine biotopes and a heap leaching operation, by percolation experiments with inoculated, sterilized ore, and by morphological, physiological, and genetic investigations of pure and mixed cultures of L. ferrooxidans, Thiobacillus ferrooxidans, and Thiobacillus thiooxidans. In biotopes of 20C or above, Leptospirillum-like bacteria are as abundant as T. ferrooxidans. Leptospirilli represent at least one-half of the ferrous-iron-oxidizing population. Percolation experiments confirmed this result. Leptospirilli were as numerous as T. ferrooxidans. At reduced temperatures, the generation times of leptospirilli increase more so than those of T. ferroxidans. At 14C, Leptospirillum grows slowly and T. ferrooxidans dominates the population. Physiological investigations indicate that L. ferroxidans is a strict chemolithoautotroph, metabolizing only ferrous iron and pyrite. Even an addition of 0.05% (wt/vol) yeast extract inhibited its growth. The maximum ferrous-iron-oxidizing activity of L. ferrooxidans amounts of about 40% of the activity of T. ferrooxidans. After growth on sulfidic ore, both species exhibit reduced iron-oxidizing activities, L. ferrooxidans exhibiting one-third and T. ferrooxidans exhibiting one-seventh of their maximum activities. Surprisingly, the absolute values are similar. For indirect leaching, L. ferrooxidans is an important as T. ferrooxidans. This was confirmed by the results of percolation experiments. L. ferrooxidans together with T. thiooxidans mobilized metals at least as well as T. ferrooxidans did. The best results were obtained with a mixed culture of all three species.

• OSTI ID: 5691433
• Journal Information: Applied and Environmental Microbiology; (United States), Journal Name: Applied and Environmental Microbiology; (United States) Vol. 58:1; ISSN 0099-2240; ISSN AEMID
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540210* -- Environment
Terrestrial-- Basic Studies-- (1990-)
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
DISSOLUTION
ECOLOGY
ELEMENTS
GROWTH
LEACHING
METALS
MICROORGANISMS
MINES
PHYSIOLOGY
SEPARATION PROCESSES
SULFUR-OXIDIZING BACTERIA
UNDERGROUND FACILITIES