@article{mbs:/content/journal/micro/10.1099/00221287-107-1-131, author = "JUSTIN, PAULINE and KELLY, D. P.", title = "Metabolic Changes in Thiobacillus denitrificans Accompanying the Transition from Aerobic to Anaerobic Growth in Continuous Chemostat Culture", journal= "Microbiology", year = "1978", volume = "107", number = "1", pages = "131-137", doi = "https://doi.org/10.1099/00221287-107-1-131", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-107-1-131", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = " Thiobacillus denitrificans grew exclusively aerobically in thiosulphate-limited chemostat culture at all dissolved oxygen concentrations between 12 and 216 μ m. Nitrate reduction did not occur in aerobic cultures and nitrate and nitrite reductases only reached high levels under complete anaerobiosis. Growth yield was greatest [11.50 g dry wt (mol thiosulphate oxidized)–1] at the lowest dissolved oxygen concentration (12 μ m) and decreased at higher dissolved oxygen concentrations, indicating oxygen to be a growth-inhibitory substrate; the anaerobic yield was only 77 % of the maximum aerobic yield (all tested at a dilution rate of 0.08 h–1) in agreement with thermodynamic calculations. Low activities of thiosulphate-oxidizing enzyme and sulphur-oxidizing enzyme were detected in aerobic cultures, but activities were even lower in anaerobic cultures. Efficient energy coupling mechanisms with respect to sulphur and thiosulphate oxidations are indicated.", }