NOVELTY - Making a biofuel comprises providing a nitrogen-limiting, minimal growth media comprising glycerol and/or sugars generated from cellulosic biomass and growing an oleaginous microbe to secrete an oil.    USE - The method, oleaginous microbe, and biofuel reactor are useful for making or producing a biofuel (all claimed).    DETAILED DESCRIPTION - Making a biofuel comprises: (a) providing a nitrogen-limiting, minimal growth media comprising glycerol and/or sugars generated from cellulosic biomass, under conditions in which an oleaginous microbe converts the growth media into triacylglycerol (TAG), neutral lipids, fatty acids, long-chain fatty acids, or hydrocarbons; or (b) growing an oleaginous microbe in a nitrogen-limiting, minimal media to late log phase and/or stationary phase, where the oleaginous microbe secretes an oil. INDEPENDENT CLAIMS are: (1) an oleaginous microbe that has been engineered to secrete enhanced amounts of oil by upregulating PI-3 kinase activity or by modulating the expression of autophagy-associated genes; (2) a method of reducing bioreactor waste comprising: (a) mixing a reaction waste product comprising glycerol with a growth media and an inoculum of Debaryomyces hansenii under conditions in which Debaryomyces hansenii converts the glycerol into long-chain fatty acids and hydrocarbons; and (b) recovering the long-chain fatty acids and hydrocarbons produced; (3) a method of reducing bioreactor waste comprising: (a) generating a biofuel by fermentation; (b) collecting a glycerol waste stream from the fermentation; (c) mixing a biofuel reactor waste product comprising glycerol with a growth media and an inoculum of Debaryomyces hansenii under conditions in which Debaryomyces hansenii converts the glycerol into long-chain fatty acids and hydrocarbons; and (d) recovering the long-chain fatty acids and hydrocarbons produced; and (4) a biofuel reactor comprising: (a) a vessel comprising an internal volume capable of holding a growth medium; (b) a microbe capable of converting glycerol into a long-chain fatty acids and hydrocarbons in the growth medium; and (c) a source of glycerol.