EFFECT OF NITROGEN-SOURCES ON THE REGULATION OF EXTRACELLULAR LIPASE PRODUCTION IN ACINETOBACTER-CALCOACETICUS STRAINS

Extracellular lipase production and lipA expression were studied in A. calcoaceticus strains in relation to the nitrogen sources. Addition o f casamino-acids or tryptone improved 2-3 times lipase yield as compar ed to ammonium, yeast extract or proteose-peptone. Further increase in lipase yield and enzyme stability were achieved when ammonium was als o added. Differences in yields were not related to lipA transcription. Proteolytic activity was detected in culture broths simultaneous with lipase degradation. Post- transcriptional processes including enzyme protection, inactivation and secretion must be considered as important factors affecting lipase production.