RESUMO
Rapeseed oil is one of the major raw materials for biodiesel production. The bottleneck of rapeseed oil-based biodiesel production at present is high cost of raw materials, which generally accounts for about 75% of total production cost. Current status and principal problems concerned in the production of biodiesel from rapeseed oil in China and other countries were introduced, based on which it was proposed to grow high-erucic acid rape in existing winter fallow fields and jointly produce biodiesel, erucic acid and its derivative products, and other highly valuable by-products such as glycerin and sterols from high-erucic acid rapeseed oil. The feasibility of this development strategy was analyzed in terms of product and market demand potential, economic benefits of enterprises, techniques and conditions of production, and source of raw materials. It was believed that the implementation of the strategy in China was of great significance in realizing rise and sustainable development of rapeseed oil-based biodiesel production, improving quality of biodiesel, promoting the development of biochemical engineering and many other industries, as well as in building a socialist new countryside.
RESUMO
1.6 kb ?4-desaturase gene(FAD4)was amplified by PCR using plasmid pGEM-TFAD4 as template.The fragment was subcloned into the HindⅢ/XbaⅠrestriction site of pYES2.0 vector.Recombinant plasmid pYFAD4 was transformed into Saccharomyces cerevisiae strain INVScl for expression.It was found to exhibit ?4-fatty acid desaturase activity in the recombinant S.cerevisiae YFAD4 in the presence of exogenous fatty acid substrate docosapentaenoic acid(100?mol/L)under introduction of GAL1.Expression of the FAD4 under appropriate media and temperature conditions led to the production of DHA and it reached 41.13% of the total yeast fatty acid by GC detection.It was suggested that the protein encoded by FAD4 could specifically catalyze DPA into DHA.