Comparative studies on the biochemistry of Penicillium albicans (alkalosensitive) and Vertiallium lateritium, (facultative alkalophile) with special reference to the role of sodium ion in alkalophily

Abstract

High alkalinity inhibited sugar utilization by the alkalosensitive fungus ( P. albicans) and increased the polysaccharide content in its fungal mats. The total amino-N content decreased in the culture of P. albicans, whereas its quantity increased in the biomass with progressive alkalinity. Alkalinity inhibited nitrogen uptake and protein synthesis leading to a corresponding decline in growth, and hence apparent alkalosensitivity. High alkalinity caused enhancement of sugar uptake by the facultative alkalphile V. lateritium associated with higher reducing sugar contents and decreased polysaccharide accumulation in mycelial mats. The amino-N content increased in the culture medium of V. lateritium and decreased in the biomass with pH increase. The utilization of soluble nitrogen increased, accompanied by increased protein synthesis, leading to maximum growth at higher pHs, and hence apparent alkalophilicity. The sodium content in the medium of the alkalosensitive fungus decreased at high pHs associated with a respective increase in the biomass. In contrast, in the alkalophilic fungus, the sodium content increased in the culture and decreased in the biomass with increased alkalinity, indicating an important role played by this ion. No clear relationship could be obtained between phosphorus content in cultures or biomass of the two tested fungi and alkalophilicity.