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An isomer of the conjugated linoleic acid (CLA) produced from linoleic acid by Lactobacillus plantarum was identified as cis-9,trans-11-octadecadienoic acid by proton nuclear magnetic resonance spectroscopy. Together with earlier results, we concluded that the bacterium produces two CLA isomers, cis-9,trans-11- and trans-9,trans-11-octadecadienoic acid from linoleic acid. The addition of L-serine, glucose, AgNO3, or NaCl to the reaction mixture reduced production of the latter.

Ricinoleic acid (12-hydroxy-cis-9-octadecaenoic acid) was an effective substrate for conjugated linoleic acid (CLA) production by washed cells of Lactobacillus plantarum AKU 1009a. The CLA produced was a mixture of cis-9,trans-11- and trans-9,trans-11-octadecadienoic acids. Addition of alpha-linolenic acid to the culture medium increased the CLA productivity of the washed cells. In the presence of lipase, castor oil, in which the main fatty acid component is ricinoleic acid, also was a substrate for CLA.

Mead acid (MA; 20:3ω9) is one of the ω9 series of polyunsaturated fatty acids (PUFAs). MA is used to inhibit the inflammation of joints and is applied to the medicinal or health food field. We aimed to construct MA-producing strains with disruption of the Δ12-desaturase gene (Δ1 2ds) via an efficient gene-targeting system using the lig4 -disrupted strain of Mortierella alpina 1S-4 as the host. The transformants showed a unique fatty acid composition that only comprised ω9-PUFAs and saturated fatty acids, while ω6-and ω3-PUFAs were not detected, and the total composition of ω9-PUFAs, including oleic acid (18:1ω9), 18:2ω9, 20:1ω9, 20:2ω9, and MA, was up to 68.4% of the total fatty acids. The MA production in the Δ1 2ds -disruptant reached 0.10 g/L (8.5%), which exceeded 0.050 g/L (4.6%) in the conventional Δ1 2ds -defective mutant JT-180. [ABSTRACT FROM AUTHOR]

Abstract Sporosarcina species are psychrotolerant endospore-forming bacteria that are predominantly isolated from processed minced fish meat (surimi). Their levels should be controlled to maintain the quality of surimi-based food products. Our previous study suggested that the fatty acid composition of the cell membrane is an important factor for the growth of Sporosarcina species under cold conditions. In this study, we examined the effects of alkyl gallates, fatty acids, and acylglycerols on the growth of Sporosarcina sp. S92h in TSB medium at 10 °C and 30 °C. The results illustrated that the alkyl gallates isoamyl gallate, octyl gallate, and lauryl gallate; the fatty acids oleic acid, linoleic acid, and α-linolenic acid; and the acylglycerol monolaurin inhibited the growth of Sporosarcina sp. S92h for 10 days at 10 °C at a concentration of 0.2 mM. We found that compounds that exerted significant growth-inhibitory effects have similar molecular weights (range, 240.3–338.4) and ACD/LogP values (range, 3.48–7.70). These data will be useful for exploring more effective compounds to inhibit the growth of Sporosarcina species and contribute to quality control for surimi-based foods. Highlights • Growth inhibition of Sporosarcina to control quality of surimi-based foods. • Effects of alkyl gallates, fatty acids, and acylglycerols on the growth. • Relationship between physicochemical properties and growth-inhibitory effects. [ABSTRACT FROM AUTHOR]

Oleaginous fungus Mortierella alpina 1S-4 accumulates arachidonic acid (20:4ω6) as a major polyunsaturated fatty acid. However, 20:4ω6 is not essential for the growth of M. alpina 1S-4, because various mutants that produce no 20:4ω6 were isolated. M. alpina JT-180, a Δ12 desaturation-defective mutant that was derived from M. alpina 1S-4 by treatment with a chemical mutagen, accumulates Mead acid (20:3ω9) instead of 20:4ω6. p -Anisidine was found to be a Δ6 desaturation inhibitor in this study. The concentration of 0.1 mg/ml of p -anisidine had an inhibitory effect on the growth of M. alpina JT-180. The addition of p -anisidine to the medium caused M. alpina JT-180 to produce only monoenoic acids such as oleic acid (18:1ω9) and eicosenoic acid (20:1ω9) as unsaturated fatty acids. The effects of exogenous fatty acids were investigated when M. alpina JT-180 was cultivated in medium containing p -anisidine. The addition of linoleic acid (18:2ω6) and 6 Z ,9 Z -octadecadienoic acid (18:2ω9) restored the growth of M. alpina JT-180 cultivated on the medium containing p -anisidine, but palmitic acid (16:0), 18:1ω9, and vaccenic acid (18:1ω7) had no effect. For the growth of oleaginous fungus M. alpina , 18-carbon length fatty acids with more than two double bonds are considered to be essential. [ABSTRACT FROM AUTHOR]

The fatty acid desaturation and elongation reactions catalyzed by Trichoderma sp. 1-OH-2-3 were investigated. This strain converted palmitic acid (16:0) mainly to stearic acid (18:0), and further to oleic acid ( c9-18:1), linoleic acid ( c9, c12-18:2), and α-linolenic acid ( c9, c12, c15-18:3) through elongation, and Δ9, Δ12, and Δ15 desaturation reactions, respectively. Palmitoleic acid ( c9-16:1) and cis-9, cis-12-hexadecadienoic acid were also produced from 16:0 by the strain. This strain converted n-tridecanoic acid (13:0) to cis-9-heptadecenoic acid and further to cis-9, cis-12-heptadecadienoic acid through elongation, and Δ9 and Δ12 desaturation reactions, respectively. trans-Vaccenic acid ( t11-18:1) and trans-12-octadecenoic acid ( t12-18:1) were desaturated by the strain through Δ9 desaturation. The products derived from t11-18:1 were identified as the conjugated linoleic acids (CLAs) of cis-9, trans-11-octadecadienoic acid and trans-9, trans-11-octadecadienoic acid. The product derived from t12-18:1 was identified as cis-9, trans-12-octadecadienoic acid. cis-6, cis-9-Octadecadienoic acid was desaturated to cis-6, cis-9, cis-12-octadecatrienoic acid by this strain through Δ12 desaturation. The broad substrate specificity of the elongation, and Δ9 and Δ12 desaturation reactions of the strain is useful for fatty acid biotransformation. [ABSTRACT FROM AUTHOR]

The conditions for conjugated linoleic acid (CLA) production from castor oil, in which the main fatty acid component is ricinoleic acid, were investigated using washed cells of Lactobacillus plantarum JCM 1551 as the catalyst. In the presence of lipase, castor oil became an effective substrate for CLA production by the bacterium. Lipase M “Amano” 10 supported CLA production most effectively among the lipases tested. The addition of a detergent, especially Lubrol PX, enhanced the CLA production. The CLA produced comprised a mixture of two isomers, i.e. cis-9,trans-11-octadecadienoic acid (CLA1) and trans-9,trans-11-octadecadienoic acid (CLA2). Under the optimum conditions (1.0 M sodium citrate buffer, pH 6.0, 37 °C) with castor oil as the substrate and washed cells of L. plantarum (12%, wet cell w/v) as the catalyst, 2.7 mg/ml CLA was produced from 5.0 mg/ml castor oil in 99 h (productivity, 0.027 mg/ml/h), and 7.5 mg/ml CLA from 30 mg/ml castor oil in 171 h (productivity, 0.044 mg/ml/h). In the former case, the CLA produced accounted for 45.5% of the total fatty acids obtained, and consisted of CLA1 (26%) and CLA2 (74%). [Copyright &y& Elsevier]

Conjugated fatty acids have attracted much attention as a novel type of biologically beneficial functional lipid. Some isomers of conjugated linoleic acid (CLA) reduce carcinogenesis, atherosclerosis, and body fat. Considering the use of CLA for medicinal and nutraceutical purposes, a safe isomer-selective process is required. The introduction of biological reactions for CLA production could be an answer. We screened microbial reactions useful for CLA production, and found several unique reactions in lactic acid bacteria. Lactic acid bacteria produced CLA from linoleic acid. The produced CLA comprised a mixture of cis-9,trans-11-octadecadienoic acid (18:2) and trans-9,trans-11-18:2. Lactobacillus plantarum AKU 1009a was selected as a potential CLA producer. Using washed cells of L. plantarum AKU 1009a as a catalyst, CLA production from linoleic acid reached 40 mg/ml under the optimized conditions. The CLA-producing reaction was found to consist of two successive reactions, i.e., hydration of linoleic acid to 10-hydroxy-12-octadecenoic acid and dehydrating isomerization of the hydroxy fatty acid to CLA. On the basis of these results, the transformation of hydroxy fatty acids by lactic acid bacteria was investigated. Lactic acid bacteria transformed ricinoleic acid (12-hydroxy-cis-9-octadecenoic acid) to CLA (a mixture of cis-9,trans-11-18:2 and trans-9,trans-11-18:2). Castor oil, which is rich in the triacylglycerol form of ricinoleic acid, was also found to act as a substrate for CLA production by lactic acid bacteria with the aid of lipase-catalyzed triacylglycerol hydrolysis. L. plantarum AKU 1009a produced conjugated trienoic fatty acids from α- and γ-linolenic acid. The trienoic fatty acids produced from α-linolenic acid were identified as cis-9,trans-11,cis-15-octadecatrienoic acid (18:3) and trans-9,trans-11,cis-15-18:3. Those produced from γ-linolenic were cis-6,cis-9,trans-11-18:3 and cis-6,trans-9,trans-11-18:3. The conjugated trienoic fatty acids produced from α- and γ-linolenic acid were further saturated by L. plantarum AKU 1009a to trans-10,cis-15-18:2 and cis-6,trans-10-18:2, respectively. [Copyright &y& Elsevier]

The aim of this work was to study the molecular breeding of oleaginous filamentous Mortierella alpina for high production of linoleic (LA) or oleic acid (OA). Heterologous expression of the Δ12-desaturase (DS) gene derived from Coprinopsis cinerea in the Δ6DS activity-defective mutant of M. alpina increased the LA production rate as to total fatty acid to 5 times that in the wild strain. By suppressing the endogenous Δ6I gene expression by RNAi in the Δ12DS activity-defective mutant of M. alpina , the OA accumulation rate as to total fatty acid reached 68.0%. The production of LA and OA in these transformants reached 1.44 and 2.76 g/L, respectively, on the 5th day. The Δ6I transcriptional levels of the RNAi-treated strains were suppressed to 1/10th that in the parent strain. The amount of Δ6II RNA in the Δ6I RNAi-treated strain increased to 8 times that in the wild strain. [ABSTRACT FROM AUTHOR]