%0 Journal Article %A Nichols, David S. %A McMeekin, Tom A. %A Nichols, Peter D. %T Manipulation of polyunsaturated, branchedchain and trans-fatty acid production in Shewanella putrefaciens strain ACAM 342 %D 1994 %J Microbiology, %V 140 %N 3 %P 577-584 %@ 1465-2080 %R https://doi.org/10.1099/00221287-140-3-577 %K psychrotrophs %K polyunsaturated fatty acids %K fatty acid production %K Shewanella putrefaciens ACAM 342 %I Microbiology Society, %X Shewanella putrefaciens strain ACAM 342 produced a range of polyunsaturated fatty acids (PUFA) including 18:2ω6, 18:3ω3, 18:3ω6, 18:4ω3 and 20:5ω3 (EPA). Under culture in Zobell's broth at 15 °C exponential-phase cultures produced 3.2 + 0.3% EPA, or 1.2 + 0.2 mg (g bacterial dry wt)-1. Alteration of growth phase, addition of biotin to the medium or a 10-fold decrease in nutrient levels had no significant effect (P>0.05) on levels of EPA. Growth in 7.0% NaCl medium markedly decreased the overall degree of fatty acid unsaturation (P<0.01), while growth on acetate as the sole carbon source increased the level of 18:2.6 from 0.4 + 0.1% to 7.1 % of total fatty acids through inhibition of branched-chain fatty acid synthesis. Addition of desaturase cofactors to the growth medium increased the proportion of EPA from 3.2 + 0.3% to 4.6%, but decreased the quantitative yield from 1.2. 0.2 to 0.9 mg (g bacterial dry wt)-1. This bacterium represents a model organism to study bacterial PUFA production. The trans-monounsaturated fatty acid 16:1ω7t was also produced under all culture conditions, together with four other trans-isomers, namely 14:1ω5t, 15:1ω6t, 17:1ωt and 18:1ω7t. Although the relative levels of trans-acids also changed under various culture conditions, there was no evidence that they were produced as a starvation or stress response. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-140-3-577