Abstract
Aims:The objective of this study was to demonstrate that fish-processing by-products could be used as sole raw material to sustain the growth of Staphylococcus xylosus for lipase production. Methods and Results:Bacterial growth was tested on supernatants generated by boiling (100C for 20min) of tuna, sardine, cuttlefish and shrimp by-products from fish processing industries. Among all samples tested, only supernatants generated from shrimp and cuttlefish by-products sustained the growth of S. xylosus. Shrimp-based medium gave the highest growth (A sub(600)=22) after 22h of culture and exhibited the maximum lipase activity (28Uml super(-1)). This effect may be explained by better availability of nutrients, especially, in shrimp by-products. Standard medium (SM) amendments to sardine and tuna by-product-based media stimulated the growth of S. xylosus and the highest A sub(600) values were obtained with 75% SM. Lipase activity, however, remained below 4Uml super(-1) for both sardine and tuna by-product-based media. Conclusions:Fish by-products could be used for the production of highly valuable enzymes. Significance and Impact of the Study:The use of fish by-products in producing S. xylosus-growth media can reduce environmental problems associated with waste disposal and, simultaneously, lower the cost of biomass and enzyme production.