(121c) Microbial Oils From Seafood Processing Waste

Biodiesel is a displacement fuel for traditional petroleum-derived diesel. Unfortunately biodiesel is an expensive fuel due in large part to the high cost of feedstocks. Oils derived from byproducts with no value could potentially be a cheap source of biodiesel. The byproducts from shrimp processing are heads and shells which contain a wealth of carbon and could be converted into oils via microorganisms. The objective of this investigation is to determine the feasibility of using oleaginous microorganisms to convert the shrimp byproducts into oil.

Initial screening experiments were conducted among R. glutinis, R. opacus, C. curvatus,etc, which have been shown by MSU and others to accumulate greater than 50% of its dry weight as oil. These experiments were initially conducted using n-acetyl glucosamine, which is the major sugar product from the hydrolysis of Seafood Processing Waste, at a concentration of 50 g/L. Results suggested that oleaginous yeast Cryptococcus curvatus was the optimal tested microorganism for the production of microbial oil from n-acetyl glucosamine. Cell mass of C. curvatus increased continuously within 118.8 hours to 18.4 g/l under the increase of pH. The oil content in C. curvatus was accumulated from 4.7 % at 13.7 hours to 28.4 % at 167.7 hours.

The C. curvatus was then selected to grow in the media made of actual acid hydrolysis of shrimp processing waste as sole carbon and energy source for the lipid production. In these experiments, the lipid accumulation in the cells of C. curvatus from the carbons in the acid hydrolysate and fatty acid profiles of the accumulated lipids were investigated.