%0 Journal Article %A Silva, Humberto J. %A Pirt, S. John %T Carbon Dioxide Inhibition of Photosynthetic Growth of Chlorella %D 1984 %J Microbiology, %V 130 %N 11 %P 2833-2838 %@ 1465-2080 %R https://doi.org/10.1099/00221287-130-11-2833 %I Microbiology Society, %X Chlorella cultures were grown in a tubular loop reactor which facilitated both irradiation of the culture and gas mixing compared with a conventional stirred vessel with vortex aeration. Measurements of the inhibition of maximum specific growth rate (proportional to photosynthetic rate) in the tubular reactor showed that CO2 behaves as a typical inhibitory substrate at partial pressures (PCO2 ) up to 0·6 atm. The PCO2 for 50% reduction in maximum specific growth rate was 0·36 atm. At 0·6 atm there was a discontinuity in the inhibitory effect with a sharp increase in the inhibitory effect at higher PCO2 values. Cultures rapidly adjusted to step changes in the PCO2 up to 0·6 atm. At a PCO2 of 1 atm inhibition was complete but the inhibitory effect was readily reversed. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-130-11-2833