Advanced fermentation strategies to enhance lipid production from lignocellulosic biomass

This chapter discusses the related researches on microbial lipid biosynthetic processes, the inhibitor tolerance of lipid-producing microorganisms, and high cell density culture strategies for lipid production from lignocellulosic biomass. The aspects covered here mainly focused on the elucidation of lipid accumulations of oleaginous microorganisms in different fermentation modes including batch, fed-batch, and continuous cultivation coupled with multistage strategies for increasing cell densities of oleaginous microbes thereby improving lipid yield, titer, and productivity. Furthermore, because of the inhibitors generated during hydrolysis processes as by-products that influence the lipid biosynthesis, the strategies to enhance the lipid content through metabolic engineering approach including blocking of competing pathways and multigene methods were discussed in this chapter. It is suggested that the efficiency of the lignocellulosic lipid-based biorefinery process would be greatly improved if the cultivation platform of oleaginous microorganisms could integrate both micro-manipulations for the gene expression and fermentation strategies with the online control-feedback system.