Production of biodiesel from Chlorella sp. enriched with oyster shell extracts.
This study investigated the cultivation of the marine microalga Chlorella sp. without supplying an inorganic carbon source, but instead with enriching the media with extracts of oyster shells pretreated by a high-pressure homogenization process. The pretreated oyster shells were extracted by a weak acid, acetic acid, that typically has harmful effects on cell growth and also poses environmental issues. The concentration of the residual dissolved carbon dioxide in the medium was sufficient to maintain cell growth at 32 ppm and pH 6.5 by only adding 5% (v/v) of oyster shell extracts. Under this condition, the maximum cell density observed was 2.74 g dry wt./L after 27 days of cultivation. The total lipid content was also measured as 18.1 (%, w/w), and this value was lower than the 23.6 (%, w/w) observed under nitrogen deficient conditions or autotrophic conditions. The fatty acid compositions of the lipids were also measured as 10.9% of C16:1 and 16.4% of C18:1 for the major fatty acids, which indicates that the biodiesel from this culture process should be a suitable biofuel. These results suggest that oyster shells, environmental waste from the food industry, can be used as a nutrient and carbon source with seawater, and this reused material should be important for easily scaling up the process for an outdoor culture system.
Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 200-701, Republic of Korea.
Cheol Soon
0000-0002-6405-6017
CS
Choi
Department of Biomedical Materials Engineering, Kangwon National University, Chuncheon 200-701, Republic of Korea.
Woon Yong
WY
Choi
Korea Institute of Ocean Science & Technology (KIOST), P.O. Box 29, Ansan, Seoul 426-744, Republic of Korea.
Do Hyung
DH
Kang
Department of Food Science and Engineering, Seowon University, Cheongju 361-742, Republic of Korea.
Hyeon Yong
HY
Lee
D060105:Animal Shells / Q000737:chemistry*; D000818:Animals; D056804:Biofuels / Q000382:microbiology*; D001709:Biotechnology / Q000379:methods*; D002245:Carbon Dioxide / Q000494:pharmacology; D002708:Chlorella / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D045424:Complex Mixtures / Q000494:pharmacology*; D003470:Culture Media / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000096:biosynthesis; D009584:Nitrogen / Q000172:deficiency; D010125:Ostreidae / Q000737:chemistry*; D012623:Seawater
D056804:Biofuels; D045424:Complex Mixtures; D003470:Culture Media; D008055:Lipids; D002245:Carbon Dioxide; D009584:Nitrogen