NOVELTY - Producing renewable diesel or jet fuel comprises: (a) culturing population of microorganisms in fixed carbon source, where microorganisms accumulate at least 10% of their dry cell weight as lipid; and fixed carbon source is glycerol, depolymerized cellulosic material, sucrose, molasses, glucose, arabinose, galactose, xylose, fructose, arabinose, mannose, acetate, or its combination; (b) isolating lipid components from cultured microorganisms; and (c) subjecting isolated lipid components to chemical reactions to generate straight chain alkanes, where renewable diesel or jet fuel is produced.    USE - The methods are useful for producing renewable diesel or jet fuel; producing a molecule, e.g. lipid molecule, in a microbe; producing a fatty acid molecule having a specified carbon chain length in a microbe population; manufacturing a lipid molecule in a microbe; culturing a lipid-producing microbe; fermenting a microorganism; culturing a microalgae; manufacturing biodiesel; and for cultivating microalgae (all claimed).    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are: (1) a composition of liquid hydrocarbons made by the method above, where the composition conforms to the specifications of ASTM D975 or ASTM D1655; (2) a microalgae or yeast cell that has been genetically engineered and/or selected to express a lipid pathway enzyme at an altered level compared to a wild-type cell of the same species; (3) an oil-producing microbe containing exogenous genes, where the exogenous genes encode protein(s) selected from a fatty acyl-acyl carrier protein (ACP) thioesterase, a fatty acyl-CoA reductase, a fatty aldehyde reductase, a fatty acyl-coenzyme A (CoA)/aldehyde reductase, a fatty aldehyde decarbonylase, and an acyl carrier protein; (4) a microbe containing two exogenous genes, where a first exogenous gene encodes a fatty acyl-ACP thioesterase and a second exogenous gene encodes a protein selected from a fatty acyl-CoA reductase, a fatty acyl-CoA/aldehyde reductase, and an acyl carrier protein; (5) a method of producing a molecule, e.g. lipid molecule, in a microbe; (6) a method of producing a fatty acid molecule having a specified carbon chain length in a microbe population comprising culturing a population of lipid- producing microbes in a culture medium, where the microbes contain an exogenous gene encoding a fatty acyl-ACP thioesterase having an activity specific to a carbon chain length, and where the microbes synthesize a fatty acid linked to an ACP and the thioesterase catalyzes the cleavage of the fatty acid from the ACP when the fatty acid has been synthesized to the specific carbon chain length; (7) a microalgae cell containing an exogenous gene or two exogenous genes, where the exogenous gene encodes a protein selected from a lipase, a sucrose transporter, a sucrose invertase, a fructokinase, or a polysaccharide-degrading enzyme; (8) a method of manufacturing a lipid molecule in a microbe comprising: (a) culturing the microbe for a first period of time sufficient to increase the cell density, where the microbe contains an exogenous gene encoding a lipase; and/or an exogenous gene encoding a polysaccharide-degrading enzyme; where the exogenous gene(s) are in operable linkage with a promoter that is inducible in response to a stimulus; (b) providing the stimulus or providing a virus capable of infecting and lysing the microbe when in direct contact with the microbe; and (c) incubating the microbe for a second period of time in the presence of the stimulus or for a second period of time to produce lysed aqueous biomass; (9) a microalgae cell containing an exogenous gene, where the exogenous gene encodes a cofactor for a lipid pathway enzyme or encodes a protein that participates in the synthesis of the cofactor; (10) a method of culturing a lipid-producing microbe comprising culturing the microbe in the presence of a sufficient amount of cofactor(s) for a lipid pathway enzyme to increase microbial lipid yield over microbial lipid yield in the absence of the cofactors; (11) a method of fermenting a microorganism comprising providing a mixture comprising glucose and xylose as an energy source to the microorganism; or a method of fermenting comprising culturing a microorganism in the presence of glycerol and other fixed carbon source; (12) a method of culturing a microalgae comprising culturing the microalgae in a culture medium including a feedstock comprising carbon substrate selected from a cellulosic material, a 5-carbon sugar, a 6- carbon sugar, and acetate; or comprising placing microalgae cells in the presence of depolymerized cellulosic material; (13) a method of culturing a lipid-producing microbe comprising culturing the microbe in the presence of acetic acid and the absence of a fixed nitrogen source; (14) a microbial culture containing: (a) a population of microorganisms; and (b) a culture medium comprising glucose, xylose, and a molecule selected from lignin and species of furfural; (15) a method of biodiesel manufacturing comprising: (a) culturing a lipid-producing microorganism in a first microbial culture; (b) recovering lipid from the biomass produced by the first microbial culture; (c) subjecting the lipid to transesterification to produce fatty acid ester(s) and glycerol; and (d) adding the glycerol to a second microbial culture; (16) a fermentor comprising: (a) a population of microorganisms; (b) glycerol; and (c) sugar selected from xylose, glucose, and sucrose; (17) a method of fermenting a microorganism comprising providing byproduct glycerol from a transesterification process as a sole source of fixed carbon energy; (18) a microorganism containing an exogenous sucrose utilization gene; (19) a cell of the species Chlorella protothecoides, Chlorella emersonii, or Chlorella minutissima, where the cell contains an exogenous gene; (20) a microbial culture containing: (a) a population of microorganisms; and (b) a culture medium comprising sucrose, and a sucrose invertase enzyme or comprising molasses, and a sucrose invertase enzyme; or comprising sucrose; lignin; and a sucrose invertase enzyme; (21) a nucleic acid comprising: (a) a complementary DNA (cDNA) encoding a sucrose utilization gene; and (b) a cDNA encoding a protein conferring resistance to the antibiotic hygromycin or the antibiotic G418; and (22) a method of cultivating microalgae, comprising: (a) providing a microalgae cell capable of performing heterotrophic growth; (b) placing the microalgae cell in growth media, where the growth media comprises depolymerized cellulosic material; and (c) incubating the microalgae for a period of time sufficient to allow the cell to grow.