Culture of Staphylococcus xylosus in fish processing by-product-based media for lipase production.
OBJECTIVE
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.


RESULTS
Bacterial growth was tested on supernatants generated by boiling (100 degrees C for 20 min) 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(600) = 22) after 22 h of culture and exhibited the maximum lipase activity (28 U ml(-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(600) values were obtained with 75% SM. Lipase activity, however, remained below 4 U ml(-1) for both sardine and tuna by-product-based media.


CONCLUSIONS
Fish by-products could be used for the production of highly valuable enzymes.


CONCLUSIONS
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.
Ben Rebah
F
F
Institut National des Sciences et Technologies de la Mer-Sfax, Sfax, Tunisia.
Frikha
F
F
Kamoun
W
W
Belbahri
L
L
Gargouri
Y
Y
Miled
N
N
D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D003470:Culture Media / Q000032:analysis / Q000378:metabolism; D005399:Fishes; D005525:Food-Processing Industry; D007220:Industrial Waste / Q000032:analysis; D008049:Lipase / Q000378:metabolism*; D013210:Staphylococcus / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D018505:Waste Management / Q000379:methods*
D001426:Bacterial Proteins; D003470:Culture Media; D007220:Industrial Waste; D008049:Lipase