title: Increased production of free fatty acids in Aspergillus oryzae by disruption of a predicted acyl-CoA synthetase gene.
abstract: Fatty acids are attractive molecules as source materials for the production of biodiesel fuel. Previously, we attained a 2.4-fold increase in fatty acid production by increasing the expression of fatty acid synthesis-related genes in Aspergillus oryzae. In this study, we achieved an additional increase in the production of fatty acids by disrupting a predicted acyl-CoA synthetase gene in A. oryzae. The A. oryzae genome is predicted to encode six acyl-CoA synthetase genes and disruption of AO090011000642, one of the six genes, resulted in a 9.2-fold higher accumulation (corresponding to an increased production of 0.23 mmol/g dry cell weight) of intracellular fatty acid in comparison to the wild-type strain. Furthermore, by introducing a niaD marker from Aspergillus nidulans to the disruptant, as well as changing the concentration of nitrogen in the culture medium from 10 to 350 mM, fatty acid productivity reached 0.54 mmol/g dry cell weight. Analysis of the relative composition of the major intracellular free fatty acids caused by disruption of AO090011000642 in comparison to the wild-type strain showed an increase in stearic acid (7 to 26 %), decrease in linoleic acid (50 to 27 %), and no significant changes in palmitic or oleic acid (each around 20-25 %).
authors.affiliation: Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, Hokkaido, 062-8517, Japan, tamano-k@aist.go.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Tamano
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Bruno
authors.forename: Hideaki
authors.initials: H
authors.lastname: Koike
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ishii
authors.forename: Ai
authors.initials: A
authors.lastname: Miura
authors.forename: Myco
authors.initials: M
authors.lastname: Umemura
authors.forename: David E
authors.initials: DE
authors.lastname: Culley
authors.forename: Scott E
authors.initials: SE
authors.lastname: Baker
authors.forename: Masayuki
authors.initials: M
authors.lastname: Machida
mesh_terms: D001236:Aspergillus oryzae / Q000235:genetics* / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003066:Coenzyme A Ligases / Q000235:genetics* / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism*; D005816:Genetic Complementation Test; D005818:Genetic Engineering / Q000379:methods; D010802:Phylogeny; D014280:Triglycerides / Q000032:analysis
chemical_list: D005227:Fatty Acids; D014280:Triglycerides; D003066:Coenzyme A Ligases