Studies on the Physiology of Achlya Megasperma Humphrey Occurring In Ponds on the Accra Plains with Special Reference to Its Tolerance To Organic and Inopganig Pollution

Abstract

Achlya megasperma sporulated best s.t 30°C and at pH 7.0 to 9.0. Light had no effect on forration of the sporangia. Certain concentrations of CaCl-,., ^ulcitol. Mg SO^^H^O, Malt extract, neptone and Yeast extract enhanced sporangial formation. The mineral salts, CuS04 .5H20, FeCljs MnS04 .4H20 and Zn Cl2 depressed sporangial formation. Gemmae were produced in great quantities in solutions of 0.1, 0.2 and 0,4 per cent haemoglobin and 1x0 ^ and 0_5M Zn Cl^. Sporangial formation was also inhibited by the carbohydrates, Fructose, Galactose, Glucose, Lactose and Mannose, the polyhydrol alcohols Glycerol and Mannitol and, by Potato dextrose broth. Vegetative growth was, however, greatly improved by Potato dextrose broth, Fructose, Glucose, Mannose, Malt extract, Peptone and Yeast extract, and there was considerable hyphal branching in solutions of Fructose Glucose, Malt extract,Peptone and Yeast extract and in Potato dextrose broth. In the mineral salt solutions the range of concentration permitting sporangial formation was narrower than that Supporting vegetative growth. Snorangia which had been delimited from the supporting hyphae were prevented from further development by pfH , provided by distilled water adjusted with 0.5N HC1, and by cow-dunp solution of 10 and dun? per litre of distilled water. There was total inhibition of sporanfrial formation at dunp concentration of 30g per litre of suspending medium. Sporanpia formed under conditions of poor snorulation were markedly smaller in size. A particularly pronounced effect was produced by 20°C, pH 5, lxlO-3 to O.lf CaCl2s lxlO-7 and 1x10'SM CuS04.5H20 and MnS04.4H20, 1x10~5M FeCl^ and 1x10 M ZnCl^ and by the alcohols, Glycerol and Mannitol.