Studies on the the Production & Properties of Microbial L - Asparaginases

In the present work, various microbial cultures including 13 bacteria, 26 yeasts and 18 mould cultures were screened for their ability to produce L-asparaginases. The screening studies were made using L-asparagine - yeast ext¬ract liquid medium and under the aerobic condition of growth for the cultures under investigation. The results revealed wide variations with respect to tine levels of L-asparaginases in the bacterial cultures. The highest levels of L-asparaginases were detected in the cells of Erwinia aroideae (NRRL-134), Arthrobactoer citreus (UCD - 2399), Ewinia aroidgae (a local isolate) ,. ,Serratia marcecens (HRRL - B284) and some local strains of Bacillus subtilis and Erwinia sp . In yeasts, significant amounts of L-asparainases were detected in the cells of two strains of Rhodotorula rubra (UCD 046 A arid UCD .68 - 295), followed by Dobaryomyces vanriji (UCD 69 -225), Schwanniomyces albuvius (UCD 69-49) , Sporobolomyces salmonicolor (UCD 68 - 371) and Gandida albicans (IF 1060). In the filamentous fungal cult urea , the highest L-asparaginase le¬vels; WERE OBSERVED IN THE CELLS OF FUSARIUM EQUISETI (No. 8) and Fusarium oxysporm (Ho, 6) . The enzyme levels were gene¬rally higher in frozen rather than in fresh cells of the same organism. This could be attributed to the destruction of the permeability barrier by freezing, thus, allowing bettor available; of the substrate to the enzyme.