초록
<P>On the basis of <I>Thermomyces lanuginosus</I> lipase functionally displayed on the cell surface of <I>Yarrowia lipolytica</I> yeast, a new green, integrated, and sustainable bioprocess for fatty acid methyl esters (FAMEs) production was developed. It couples surface-displayed enzyme generation to enzymatic FAMEs production, in combination with simultaneous regeneration of in situ carbon source for yeast utilization. During FAMEs synthesis, in a one-pot fermentation flask containing growing cells displaying lipase, waste cooking oil, and methanol, the in situ formed byproduct glycerol was used as an alternative carbon source to support further cell growth and lipase generation. The partial consumption of glycerol pushed the reversible reactions (transesterification, esterification, hydrolysis) toward formation of FAMEs. In the growing cells integrated system, the production of FAMEs via hydrolysis-esterification or transesterification-esterification reactions was dependent on the time when methanol was added to the culture medium. Compared to the resting cells system with an 81% FAMEs yield after 16 h, the self-cycling of glycerol for cell consumption (allowing cell growth and lipase displaying for further FAMEs forming) in the growing cells system significantly increased FAMEs synthesis with a more than 91% yield obtained in less time (6-10 h). The cells recovered from growing cell systems still exhibited satisfactory reusability, showing more than 80% FAMEs yield during 12 successive batches.</P><P>Innovative system based on an engineered microorganism is developed for green manufacturing of alternative energy (biodiesel) using waste cooking oil as a resource.</P><BR>[FIG OMISSION]</BR>