Production of fatty acid derivatives

A genetically engineered bacterium for the production of a fatty acid ester, comprising an exogenous gene encoding an ester synthase (EC 2.3.1.75) polypeptide that has at least 90% sequence identity to SEQ ID NO:

• 18 and has an amino acid substitution at glycine 395, wherein said ester synthase polypeptide has an increased enzymatic activity compared to that of SEQ ID NO:
• 18, and wherein said exogenous gene encoding the ester synthase is obtained from Acidobacteria bacterium, Acidothermus cellulolyticus, Acinetobacter baumannii, Acinetobacter baylyi, Acinetobacter sp., Acinetobacter baumannii, Acinetobacter sp., Aeromonas hydrophila, Aeromonas salmonicida, Alcaligenes europhus, Alcanivorax borkumensis, Alcanivorax jadensis, Alteromonas macleodii, Anaeromyxobacter dehalogenans, Anaeromyxobacter, Anaeromyxobacter sp., Arabidopsis thaliana, Bradyrhizobium japonicum, Cryptococcus curvatus, Erythrobacter litoralis, Erythrobacter sp., Frankia sp., Fundibacter jadensis, gamma proteobacterium, Hahella chejuensis, Homo sapiens, Janibacter sp., Limnobacter sp., marine gamma proteobacterium, Marinobacter algicola, Marinobacter aquaeolei, Marinobacter hydrocarbonoclasticus, Marinobacter sp., Methylibium petroleiphilum, Microscilla marina, Moritella sp., Mortierella alpina, Mus musculus, Mycobacterium abscessus, Mycobacterium avium, Mycobacterium avium, Mycobacterium bovis, Mycobacterium gilvum, Mycobacterium leprae, Mycobacterium marinum, Mycobacterium smegmatis, Mycobacterium sp., Mycobacterium tuberculosis, Mycobacterium ulcerans, Mycobacterium vanbaalenii, Myxococcus xanthus, Natronomonas pharaonis, Nocardia farcinica, Nocardioides sp., Photobacterium profundum, Plesiocystis pacifica, Polaromonas naphthalenivorans, Polaromonas sp., Pseudomonas aeruginosa, Psychrobacter arcticus, Psychrobacter cryohalolentis, Psychrobacter sp., Reinekea sp., Rhodococcus opacus, Rhodoferax ferrireducens, Rhodococcus sp., Rhodoferax ferrireducens, Roseiflexus sp., Roseiflexus castenholzii, Saccharomyces cerevisiae, Saccharopolyspora erythraea, Salinibacter Tuber, Simmodsia chinensis, Solibacter usitatus, Sphingopyxis alaskensis, Stigmatella aurantiaca, Streptomyces avermitilis, Streptomyces coelicolor, Streptomyces griseus, Tenacibaculum sp., or Ustilago maydis, and wherein said glycine 395 is replaced with a basic amino acid.