Preparation and testing of Sardinella protein hydrolysates as nitrogen source for extracellular lipase production by Rhizopus oryzae.
Résumé
Various fish protein hydrolysates (FPH) from sardinella (Sardinella aurita) were used as nitrogen sources for the
production of extracellular lipase by the filamentous fungus Rhizopus oryzae. The best results were obtained with
defatted meat–fish protein hydrolysates (DMFPH), indicating the presence in the lipid fraction of some constituents
which may repress lipase synthesis. Furthermore, it was found that the extensive hydrolysis of fish proteins resulted
in a higher lipase production. The use of 40 g DMFPH. l-1 for the growth of Rhizopus oryzae in medium R1 resulted
in a lipase production of 394 U ml-1, higher than the yield obtained with standard soy peptone as nitrogen source
(373 U ml-1). The most appropriate medium for the growth and the production of lipase is composed only of
24 g DMFPH l-1 and 10 g glucose l-1, indicating that the strain can obtain its nitrogen and salts requirements
directly from fish substrate.