Two strategies of converting industrial wastes to microbial lipid and direct transesterification of obtained
lipid into biodiesel were attempted. Several oleaginous yeasts were cultivated on industrial wastes. The
yeasts grew well on the wastes with low C/N ratio (i.e. serum latex) but accumulated high lipid content
only when the wastes had a high C/N ratio (i.e. palm oil mill effluent and crude glycerol). The yeast lipids
have similar fatty acid composition to that of plant oil indicating their potential use as biodiesel feedstocks.
The combination of these wastes and two-phase cultivation for cell growth and lipid accumulation
improved lipid productivity of the selected yeast. The direct transesterification process that
eliminates cell drying and lipid extraction steps, gave comparable yield of biodiesel (fatty acid methyl
ester >70% within 1 h) to that of conventional method. These two successful strategies may contribute
greatly to industrializing oil production from microbes and industrial wastes