RATES OF SOLUBLE CARBOHYDRATE UTILIZATION IN SOILS FROM THE WINDMILL ISLANDS OASIS, WILKES LAND, CONTINENTAL ANTARCTICA

A time course study of the fate of glucose, sucrose, and arabitol adde d to surface soils collected from vegetated and bare sites near Casey Station, Wilkes Land, Antarctica, was performed using gas-liquid chrom atography. For both soils, hydrolysis of added sucrose was observed af ter 24 hours. Following 168 hours incubation at both 5-degrees-C and 1 5-degrees-C, hydrolysis of sucrose to glucose and fructose was greater than 95%. Maximum rates of sugar uptake were observed in soils from t he vegetated site incubated at 15-degrees-C. After 168 hours 44%, 52% and 94% of the added arabitol, glucose and sucrose respectively had be en consumed. There did not appear to be any cell-free extracellular en zymatic activity in the soils as levels of added sucrose, trehalose an d maltose within soil water extracts showed no change after 168 hours incubation. The results are discussed in relation to earlier work on t he microbial activity of Antarctic soils and the sources of carbohydra te input into this ecosystem.