title: Comparison of biooxidation with carbon dioxide assimilation during bacterial growth on ferrous ion or elemental sulfur.
abstract: Biomass and oxygen uptake activity profiles of a mixed bioleaching culture were studied and compared at various temperatures. Bacteria were grown on ferrous ion or elemental sulfur in a Micro-Oxymax respirometer apparatus that allowed measurement of both oxygen consumption and carbon dioxide assimilation. Balanced growth was observed between 10 degrees C and 35 degrees C, with an optimum at 30 degrees C, on both energy sources. No significant growth was observed at the lowest temperature used, 5 degrees C, or at the highest temperature used, 40 degrees C. The oxygen to carbon dioxide molar yield was 50:1 when growing on ferrous ion but only 17:1 when growing on elemental sulfur. Upon transfer from a sulfide ore to a new energy source, greater numbers in the inoculum reduced the duration of the lag phase. Lag phase duration was also reduced by proximity to the optimum growth temperature. A longer lag phase decreased the achievable growth rate of the cells exponentially, significantly affecting biooxidation activity.
authors.affiliation: Teck Cominco Ltd., P.O. Box 2000, Trail, BC, Canada, V1R 4S4. hector.lizama@teckcominco.com
authors.forename: H M
authors.initials: HM
authors.lastname: Lizama
authors.forename: P A
authors.initials: PA
authors.lastname: Zielinski
authors.forename: L D
authors.initials: LD
authors.lastname: Kerby
authors.forename: C C
authors.initials: CC
authors.lastname: Abraham
mesh_terms: D013856:Acidithiobacillus thiooxidans / Q000378:metabolism; D000332:Aerobiosis; D001419:Bacteria / Q000254:growth & development* / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D005296:Ferrous Compounds / Q000378:metabolism*; D007477:Ions / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*; D013696:Temperature; D013855:Thiobacillus / Q000378:metabolism
chemical_list: D005296:Ferrous Compounds; D007477:Ions; D002245:Carbon Dioxide; D013455:Sulfur