TECHNOLOGY FOCUS - BIOLOGY - Preferred Microorganism: The microorganism is capable of increasing in cell number or producing lipid when cultured on a carbon source containing xylose. The microorganism converts xylose to triglyceride. The microorganism is capable of accumulating 10, 20, 30, 40, 50, 60, 70, or 80% triglyceride by dry cell weight when cultured using glucose as a carbon source. The microorganism is capable of accumulating at least 10, 20, 30, 40, 50, 60, 70, or 80% triglyceride by dry cell weight when cultured on pure xylose. The microorganism is capable of accumulating at least 50% triglyceride by dry cell weight when cultured on glucose as a carbon source and is capable of accumulating at least 20% triglyceride by dry cell weight when cultured on pure xylose. The microorganism is cultured on a carbon source that is 60% glucose and 40% xylose under nitrogen limiting conditions, where the cells produce lipid in which the carbon atoms are at least 5, 10, 20, 30, 40, or 50% derived from carbon atoms of xylose, as measured by isotopic tracing. The microorganism is capable of consuming at least 90% of the xylose in a culture media having 2.5% xylose as a sole carbon source in less than or equal to 21, less than or equal to 14 or less than or equal to 7 days. The microorganism is of the subkingdom Viridiplantae; or infrakingdom or phyla Chlorophytae, of the subphylum Tetraphytina, the class Trebouxiophyceae, or the order Chlorellales. The microorganism is of the genus Chlorella or Prototheca; or of the species Prototheca moriformis or Chlorella protothecoides. The microorganism further comprises a recombinant modification operable to alter the fatty acid profile of lipid produced by the microorganism. The microbe is selected from microalgae, oleaginous yeast, oleaginous fungi, and oleaginous bacteria (preferably microalgae, especially Prototheca moriformis. The microbial biomass comprises microbial lipid. The culture medium comprises a carbon source that is greater than 50% xylose. The carbon source is greater than 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% xylose. Preferred Composition: In the lipid composition (C1), the culture medium further comprises glucose; the culture medium comprises a carbon source that is greater than 50% (preferably greater than 55% 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%) xylose. The culture medium comprises xylose as the sole carbon source. The composition (C1) is produced by propagating or cultivating the microbe involving: providing the microbe in a culture medium; adding depolymerized cellulosic material to the culture medium, where the cellulosic material comprises xylose; propagating or cultivating the microbe until the microbe accumulates at least 20% of its dry weight as lipid; and lysing the microbe and isolating the microbial lipid composition. The xylose concentration of the depolymerized cellulosic material is at least 100 (preferably at least 400) g/l. The depolymerized cellulosic material further comprises glucose, where the glucose concentration of the depolymerized cellulosic material is at least 100 (preferably at least 400) g/l. The total concentration of xylose and glucose of the depolymerized cellulosic material is at least 100 (preferably at least 400, especially at least 600, particularly at least 800) g/l. The microbe is capable of growth or lipid production in a culture medium comprising a carbon source that is greater than 50% (preferably greater than 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%) xylose. The microbe is capable of growth or lipid production in a culture medium comprising xylose as the sole carbon source.    TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Components: The recombinant nucleic acid is operable to encode at least one of an active xylose transporter, a xylulose-5-phosphate transporter, a xylose isomerase, a xylulokinase, a xylitol dehydrogenase, or a xylose reductase. The recombinant nucleic acid encodes an active xylulose-5-phosphate transporter in operable linkage with a plastid-targeting signal sequence, where the xylulose-5-phosphate transporter is operable to transport xylulose-5-phosphate into a plastid. The recombinant nucleic acid is operable to encode (a) a xylulose-5-phosphate transporter protein with a plastid-targeting signal sequence, so as to cause transport of xylulose-5 -phosphate into a plastid, (b) a xylulokinase, and (c) either a xylose isomerase, or both of a xylitol dehydrogenase and a xylose reductase. The recombinant modification comprises an exogenous gene that encodes an active acyl-ACP thioesterase, ketoacyl-ACP synthase or a fatty acid desaturase, or is operable to reduce or ablate an acyl-ACP thioesterase, ketoacyl-ACP synthase or fatty acid desaturase. In the recombinant microbe, exogenous gene has been codon-optimized for expression in the recombinant oleaginous microbe; a native plastid targeting sequence of the xylose translocator has been replaced with a plastid targeting sequence from microalgae. The xylose translocator comprises the amino acid sequence of the XPT protein from the genus Arabidopsis. When the exogenous gene is operable to encode oxidoreductase pathway protein, a xylose isomerase pathway protein, or a xylose transporter protein, then the microbe further comprises at least one additional exogenous gene, where the additional exogenous gene is operable to encode a protein that is selected from the group consisting of a sucrose invertase, a fatty acyl-ACP thioesterase, a fatty acyl-Co A/aldehyde reductase, a fatty acyl-CoA reductase, a fatty aldehyde reductase, a fatty aldehyde decarbonylase, an acyl carrier protein, a desaturase, a polysaccharide degrading enzyme, and a protein that imparts resistance to an antibiotic. The exogenous gene is operable to encode an oxidoreductase pathway protein that is selected from a xylose reductase, a xylitol dehydrogenase, and a xylulokinase, where the xylulokinase comprises the amino acid sequence of the XYL3 protein from the genus Pichia, the xylitol dehydrogenase comprises the amino acid sequence of the XYL2 protein from the genus Pichia, and the xylose reductase comprises the amino acid sequence of the XYL1 protein from the genus Pichia. The xylose isomerase pathway protein is selected from a xylose isomerase and a xylulokinase. The xylose isomerase comprises the amino acid sequence of the XYLA protein from the genus Piromyces. The exogenous gene is operable to encode a protein selected from XYLA, XYL2, XYL3, and XPT. The native plastid targeting sequence of the xylose translocator has been replaced with a plastid targeting sequence from microalgae. In the recombinant microbe, xylose tranporter comprises the amino acid sequence of the XPT protein from the genus Arabidopsis. The xylose transporter comprises the amino acid sequence of the XLT1 protein from the genus Trichoderma. The recombinant oleaginous microbe comprises a first exogenous gene that encodes at least one xylose translocator protein selected from GPT-A-XPT (SEQ ID NO: 45), GPT-F-XPT (SEQ ID NO: 47) or S106SAD-XPT (SEQ ID NO: 49); a second exogenous gene that encodes at least one xylose transporter protein selected from SUT1 (SEQ ID NO: 37), GXS1 (SEQ ID NO: 39), XLT1 (SEQ ID NO: 43) or symporter (SEQ ID NO: 41), a third exogenous gene that encodes at least one oxidoreductase pathway protein selected from XylA (SEQ ID NO: 15) or XYL3 (SEQ ID NO: 51), and a fourth exogenous gene that encodes at least one xylose isomerase pathway protein selected from XYL1 (SEQ ID NO: 35), XYL2 (SEQ ID NO: 50) or XYL3 (SEQ ID NO: 51), where all sequences are available on WIPO web site. The recombinant oleaginous microbe comprises exogenous genes operable to encode Xy1A, XYL3, SUT1, and GPT-F-XPT; Xy1A, XYL2, XYL3, XLT1, and S106SAD-XPT; Xy1A, XYL1, XYL3, XLT1, and S106SAD-XPT; Xy1A, XYL1, XYL3, GXS1, and GPT-A-XPT; XYL1, XYL2, XYL3, symporter, and GPT-F-XPT; XYL1, XYL2, XYL3, GXS1, and GPT-F-XPT; XYL2, XYL3, symporter, and S106SAD-XPT; XYL2, XYL3, XLT1, and S106SAD-XPT; or XYL2, XYL3, GXS1, and GPT-A-XPT. EXAMPLE - No suitable example given.