The effect of CO2 availability on the growth, iron oxidation and CO2 fixation rates of pure cultures of Leptospirillum ferriphilum and Acidithiobacillus ferrooxidans
The effect of CO2 availability on the growth, iron oxidation and CO2 fixation rates of pure cultures of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum was investigated in a batch stirred tank system to determine the minimum concentrations required to promote bacterial growth from a stationary culture and investigate the relationship between CO2 availability and culture performance. The minimum inlet CO2 concentrations required to promote the growth of At. ferrooxidans and L. ferriphilum were 25 ppm and 70 ppm, respectively, under these conditions. The maximum growth rate of At. ferrooxidans increased with increasing inlet CO2 concentration up to 100 ppm and decreased thereafter. However, the amount of CO2 fixed per new cell produced increased with increasing C02 concentration above 100 ppm. The amount of iron oxidised per new cell produced decreased with increasing CO2 inlet concentration up to 100 ppm, whereafter it increased with increasing CO2 concentrations above 240 ppm. At inlet CO2 concentrations greater than 240 ppm new cell numbers produced decreased, while total C02 fixed by the culture remained the same. The maximum growth rate of L. ferriphilum increased with increasing inlet C02 concentration up to 160 ppm, after which there was no substantial change. The amount of iron oxidised and CO2 fixed per new L. ferriphilum cell was less affected by inlet CO2 concentration, but showed similar trends to At. ferrooxidans. Where an actively growing L.ferriphilum inoculum was used, the maximum growth, CO2 fixation and iron oxidation rates were higher at lower inlet C02 concentrations. The maximum CO2 fixation rates of both organisms increased with increasing inlet CO2 concentration up to ~ 160 ppm, stabilising thereafter. Maximum iron oxidation rates followed a similar trend, but continued to increase steadily with increasing inlet CO2 concentrations greater than ~ 160 ppm. The differences in the way these two organisms respond to CO2 availability can be correlated with differences in their CO2 fixation pathways. At. ferrooxidans performed better than L. ferriphilum at lower CO2 availabilities, and was less affected by CO2 starvation.
CO2 fixation iron oxidation growth rate acidithiobacillus ferrooxidans leptospirillum ferriphilum
C. G. Bryan C. Davis N. van Wyk D. Dew D. Rautenbach S. T. L. Harrison
Centre for Bioprocess Engineering Research (CeBER), Department of Chemical Engineering, University o BHP Billiton, Antofagasta, Chile Centre for Bioprocess Engineering Research (CeBER), Department of Chemical Engineering, University o Consultant Bioleaching Technology
国际会议
The 19th International Biohydrometallurgy Symposium(第19届国际生物湿法冶金大会 IBS2011)
长沙
英文
229-237
2011-09-18（万方平台首次上网日期，不代表论文的发表时间）