title: Isolation and study of two strains of Leptospirillum-like bacteria from a natural mixed population cultured on a cobaltiferous pyrite substrate.
abstract: Two strains of Leptospirillum-like bacteria, L6 and L8, have been isolated from a mixed inoculum, also containing Thiobacillus ferrooxidans and T. thiooxidans, cultured for one year with a colbaltiferous pyrite as energy substrate in a 100 l continuous bioleaching laboratory unit. Several physiological properties of the strains are described. The vibrio-shaped microorganisms grew at pH values lower than 1.3. Their growth rate was maximum between 2.5 and 8.0 g l1 ferrous iron. The optimal growth temperature was 37.5 degrees C. Ferric iron had a stimulative effect on bacterial development up to 8 g l-1, and growth was as rapid at 14 g l-1 ferric iron as at 8 g l-1. The negative influence of cobalt on the final cell concentration was observed at 0.5 g l-1, but the growth rate was not affected up to 2 g l-1. The G + C content of strains L8 is 55.6 mol%.
authors.affiliation: ORSTOM laboratoire de Microbiologie, Université de Provence, Marseille, France.
authors.forename: F
authors.initials: F
authors.lastname: Battaglia
authors.forename: D
authors.initials: D
authors.lastname: Morin
authors.forename: J L
authors.initials: JL
authors.lastname: Garcia
authors.forename: P
authors.initials: P
authors.lastname: Ollivier
mesh_terms: D003035:Cobalt / Q000378:metabolism; D004269:DNA, Bacterial; D005296:Ferrous Compounds / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism; D012988:Soil Microbiology; D013440:Sulfides / Q000378:metabolism; D013696:Temperature; D013855:Thiobacillus / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D005296:Ferrous Compounds; D013440:Sulfides; C011342:pyrite; D003035:Cobalt; D007501:Iron