TECHNOLOGY FOCUS - BIOLOGY - Preferred Components: The microorganism is a bacterium, yeast or is of the species Escherichia coli. The microorganism is of the species Escherichia coli and has reduced expression of fhuA; is of the species Escherichia coli and has reduced expression of fadE.    TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Method: When beta-hydroxy esters include beta-hydroxy methyl esters, then the conditions include the presence of methanol. The methanol is included in or added to the culture; is produced by the recombinant microorganism. When the composition comprises beta-hydroxy ethyl esters, then the conditions include the presence of ethanol. The ethanol is included in or added to the culture; or is produced by the recombinant microorganism. The recombinant microorganism is engineered to have reduced expression of a fatty acid degradation enzyme or an outer membrane protein receptor. The method (M1) further involves: separating fatty acid methyl or ethyl esters from the culture to form an enriched fatty acid methyl or ethyl ester fraction; polishing the enriched fatty acid methyl or ethyl ester fraction; purifying the beta-hydroxy fatty esters to form a beta-hydroxy fatty ester enriched fraction. Preferred Components: The recombinant microorganism further comprises a heterologous polynucleotide sequence encoding a thioesterase (EC 3.1. 2.14 or EC 3.1.1.5) and/or acyl-coenzyme A (CoA) synthase EC 2.3.1.86). The microorganism comprises a thioesterase having at least 90% amino acid identity to the thioesterase encoded by tes A or tes A from Escherichia coli; an acyl-CoA synthase having at least 90% amino acid identity to the CoA synthase encoded by fadD from Escherichia coli. The thioesterase is a tesA engineered to have enhanced ability to use acyl- acyl carrier protein (ACP) as a substrate, relative to the corresponding wild-type tesA. The polynucleotide sequence encoding the polypeptide having ester synthase (EC 2.3.1.75) activity is located on a plasmid. The polynucleotide encoding a polypeptide having ester synthase (EC 2.3.1.75) activity is integrated into a chromosome of the microorganism. The polypeptide having ester synthase activity has at least 90% amino acid identity to (SEQ ID NO: 18) as available on WIPO website, of US 20110072714.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The beta-hydroxy esters include beta-hydroxy methyl esters. The composition has a fatty acid methyl or ethyl ester titer of at least 5 g/l; has a fatty acid methyl ester titer of at least 45 g/l. The beta-hydroxy methyl or ethyl esters comprise at least 5% of the total methyl or ethyl esters. The fatty acid methyl esters comprise beta-hydroxyl esters (at least 5%). The carbon source is biomass. Preferred Composition: The composition comprises beta-hydroxy ethyl esters. The composition has fatty ester composition, where the percentage of total fatty esters is as follows (%): methyl octanoate (C8:0) (0-5); methyl decanoate (C10:0) (0-2); methyl dodecanoate (C12:0) (0-5); methyl dodecenoate (C12:1) (0-10); methyl tetradecanoate (C14:0) (30-50); methyl 7-tetradecenoate (C14:1) (0-10); methyl hexadecanoate (C16:0) (0-15); methyl 9-hexadecenoate (C16:1) (10-40); and methyl 11-octadecenoate (C18:1) (0-15). The composition is biodiesel composition.