230 Aquaculture Microbiology and Biotechnology
Other Microorganisms
A mixture of fi sh waste and peat was composted and extracts from this
compost were sterilised and inoculated at a ratio of 5% (v/v) before use
as a substrate for the acid-resistant microorganism Scytalidium acidophilum
ATCC 26774 (150 rpm, 25.0°C, pH 2.0 ± 0.1, 8-10 d) (Fig. 9.3). The results
showed that the acid extracts of compost had higher concentrations of
nutrients (lipids, carbohydrates, and protein) than the compost. Compost
extracts can be effectively utilised as a substrate for the growth of the
microorganism S. acidophilum, for the biofi ltration of liquid and gas
effl uents, and in the growth of mushrooms (Martin, 1999).
Peat
(bulking
agent)
Fish waste
Composting in a
passively aerated
composting system
Compost
Dilute
H 2 SO 4
Autoclave
(121±1
o
C,2h)
Pressing/Filtration
Compost extracts
Sterilization
Substrate for
fungus
Scytalidium
acidophilum
Fig. 9.3 A fundamental process for conversion of fi sheries processing waste to valuable
compost (Source; Martin, 1999; Arvanitoyannis and Kassaveti, 2008).