Abstract
To obtain an industrial strain with high lipid yield, the wild strain G0 of Geotrichum robustum was mutated by means of nitrogen ions implantation. Mutagenic effects of strain G0 by low energy N+ ion implantation were studied. The experimental results indicated that the survival rate curve took a "saddle" shape, and the positive mutation rate was increased to 22.00% at the dose of nitrogen ions 2.0 x 1015 ions/cm2 when the survival rate was 28.60%. By repeated screening, a high lipid producing strain G9 was obtained. The biomass, lipid content and lipid yield of the mutant can reach 40.25 g/L, 71.14% and 28.63 g/L after cultured in a 5L fermenter for 8 days, increasing by 52.81%, 68.82% and 157.93% to those of wild strain, respectively. Analysis results on fatty acids composition and relative content by gas chromatography and mass spectrometry showed that the lipid in strain G9 was mainly composed of 16-carbon and 18-carbon fatty acids, including 37.360% oleic acid, 23.631% palmitic acid, 4.458% linoleic acid and 26.465% stearic acid. Such compositional features were quite similar to plant oil. Geotrichum robustum strain G9 may be an ideal high lipid producing strain for biodiesel production.
Upon acceptance of an article by the journal, authors will be asked to transfer the copyright to Electronic Journal of Biotechnology, which is committed to maintain the electronic access to the journal and to administer a policy of fair control and ensure the widest possible dissemination of the information. The author can use the article for academic purposes, stating clearly the following: "Published in Electronic Journal of Biotechnology at DOI:10.2225/volXX-issueX-fulltext-XX".
The Copyright Transfer Agreement must be submitted as a signed scanned copy to biotec@ucv.cl. All authors must send a copy of this document.