Effect of carbon dioxide concentration on pigmentation in the blue-green alga Anacystis nidulans

The pigment content in the blue-green alga Anacystis nidulanswas found to be dependent upon CO₂ concentration during growth.In cells grown with 1% CO₂ in air the total pigment constituted20.5% of the dry weight while it was only 11.1% of dry weightof cells grown in air (0.03% CO₂). This decrease in total pigmentwas found to be almost entirely ascribable to decrease in phycocyanin.Since light absorbed by phycocyanin has been shown to providenearly equal rates of photoreactions I and II, the "CO₂ control"of phycocyanin is viewed as an effective means of regulationof the photoreactions without upsetting the balance of operationof the two photoreactions. (Received December 25, 1970; )     

A micro-chamber for continuous microscopic monitoring of anaerobic bacteria

A recently developed apparatus is described that allows continuous microscopic monitoring of bacteria grown in anaerobic conditions. Four species of Bacteroides were tested using this equipment and normal and reproducible growth rates were obtained in all cases.