Management of fish waste through composting to use as a low cost substrate for biosurfactant production by Bacillus species N3-1P
Khoshrooz Kazemi, Baiyu Zhang and Leonard M Lye
Memorial University of Newfoundland, Canada
: J Mar Biol Oceanogr
This research aims at developing a methodology for recovering fish waste in Newfoundland and Labrador, Canada. Fish waste was first be mixed with peat and treated through composting in an aerated reactor to produce compost. Extraction was then conducted to obtain liquid extract which can serve as the carbon and nitrogen sources for the growth of a biosurfactant producer, Bacillus N3-1P. The biosurfactant production process was enhanced by the response surface methodology (RSM) using factors including inoculum concentration, medium concentration, and fish waste compost extract concentration as a sole carbon and nitrogen source to screen the significant factors. The crude biosurfactant was further isolated from the fermenting reactor and purified. Parameters including the surface tension, emulsification activity, critical micelle dilution, and biosurfactant productivity were monitored. Results shows that the crude biosurfactant from fish waste compost extract decreased the surface tension from 72 mN/m to 29.8 mN/m. A production rate of 2.8 g/L was observed. The research confirmed that the liquid extract generated from fish compost had a great potential to be served as the nutrient source for biosurfactant production. As a result, the fish waste disposal could be reduced while valuable biosurfactant products would be produced in this novel strategy which could add up to an enormous sum of economic and ecological benefit.
Khoshrooz Kazemi obtained her BE in Civil Engineering from University of Tabriz, Iran in 2004 and her MEng in Civil/Environmental Engineering from Sharif university of Technology, Iran in 2008. She continued to pursue a Doctoral degree at Memorial university of Newfoundland. During the past years, she has been involved in multiple projects related to offshore oil spill remediation, wastewater treatment, optimization of composting process, and remediation. Currently, her PhD study investigates solid waste composting and biosurfactant production from low-cost substrates.