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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]

The present study investigated the antiallergic and anti-inflammatory effects of 10-hydroxy-cis-12-octadecenoic acid (HYA), a novel gut microbial metabolite of linoleic acid, in NC/Nga mice, a model of atopic dermatitis (AD). Feeding HYA decreased the plasma immunoglobulin E level and skin infiltration of mast cells with a concomitant decrease in dermatitis score. HYA feeding decreased TNF-α and increased claudin-1, a tight junction protein, levels in the mouse skin. Cytokine expression levels in the skin and intestinal Peyer's patches cells suggested that HYA improved the Th1/Th2 balance in mice. Immunoglobulin A concentration in the feces of the HYA-fed mice was approximately four times higher than that in the control mice. Finally, denaturing gradient gel electrophoresis of the PCR-amplified 16 S rRNA gene of fecal microbes indicated the modification of microbiota by HYA. Taken together, the alterations in the intestinal microbiota might be, at least in part, associated with the antiallergic effect of HYA. [ABSTRACT FROM AUTHOR]

Lactobacillus plantarum AKU 1009a effectively transforms linoleic acid to conjugated linoleic acids of cis-9, trans-11-octadecadienoic acid (18:2) and trans-9, trans-11–18:2. The transformation of various polyunsaturated fatty acids by washed cells of L. plantarum AKU 1009a was investigated. Besides linoleic acid, α-linolenic acid [ cis-9, cis-12, cis-15-octadecatrienoic acid (18:3)], γ-linolenic acid ( cis-6, cis-9, cis-12–18:3), columbinic acid ( trans-5, cis-9, cis-12–18:3), and stearidonic acid [ cis-6, cis-9, cis-12, cis-15-octadecatetraenoic acid (18:4)] were found to be transformed. The fatty acids transformed by the strain had the common structure of a C18 fatty acid with the cis-9, cis-12 diene system. Three major fatty acids were produced from α-linolenic acid, which were identified as cis-9, trans-11, cis-15–18:3, trans-9, trans-11, cis-15–18:3, and trans-10, cis-15–18:2. Four major fatty acids were produced from γ-linolenic acid, which were identified as cis-6, cis-9, trans-11–18:3, cis-6, trans-9, trans-11–18:3, cis-6, trans-10–18:2, and trans-10-octadecenoic acid. The strain transformed the cis-9, cis-12 diene system of C18 fatty acids into conjugated diene systems of cis-9, trans-11 and trans-9, trans-11. These conjugated dienes were further saturated into the trans-10 monoene system by the strain. The results provide valuable information for understanding the pathway of biohydrogenation by anaerobic bacteria and for establishing microbial processes for the practical production of conjugated fatty acids, especially those produced from α-linolenic acid and γ-linolenic acid. [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]

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]

Studies have recently revealed the linoleic acid metabolic pathway of Lactobacillus plantarum , the representative gut bacterium in human gastrointestinal tract, and the anti-inflammatory effects of metabolites in this pathway. However, no clinical trials have evaluated the association between these metabolites and revascularization in patients who underwent percutaneous coronary intervention (PCI). We retrospectively reviewed patients who underwent PCI with subsequent revascularization or coronary angiography (CAG) without revascularization. Patients with frozen blood samples at the index PCI and revascularization or follow-up CAG were enrolled. Among 701 consecutive patients who underwent PCI, we enrolled 53 patients who underwent subsequent revascularization and 161 patients who underwent follow-up CAG without revascularization. Patients who underwent revascularization showed significantly lower plasma 10-oxo-octadecanoic acid (KetoB) levels (720.5 [551.6–876.5] vs. 818.4 [641.1–1103.6 pg/mL]; p = 0.01) at index PCI. Multivariate logistic regression analysis revealed that decreased plasma KetoB levels at the index PCI were independently associated with subsequent revascularization after PCI (odds ratio; 0.90 per 100 pg/mL increase, 95% confidence interval; 0.82–0.98). Additionally, in vitro experiments showed that the addition of purified KetoB suppressed the mRNA levels of IL-6 and IL-1β in macrophages and IL-1β mRNA in neutrophils. Plasma KetoB level at index PCI was independently associated with subsequent revascularization after PCI, and KetoB could act as an anti-inflammatory lipid mediator in macrophages and neutrophils. The assessment of gut microbiome-derived metabolites may help predict revascularization after PCI. [Display omitted] • KetoB, lipid metabolites generated from linoleic and oleic acid by gut microbiome. • Lower plasma KetoB level was associated with subsequent revascularization after PCI. • KetoB suppressed the mRNA expression of IL-1β and IL-6 in macrophages. • KetoB suppressed the mRNA expression of IL-1β in neutrophils. [ABSTRACT FROM AUTHOR]

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]

Oxidative stress is a well-known cause of multiple diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway plays a central role in cellular antioxidative responses. In this study, we investigated the effects of novel fatty acid metabolite derivatives of linoleic acid generated by the gut lactic acid bacteria Lactobacillus plantarum on the Nrf2-ARE pathway. 10-Oxo- trans -11-octadecenoic acid (KetoC) protected HepG2 cells from cytotoxicity induced by hydrogen peroxide. KetoC also significantly increased cellular Nrf2 protein levels, ARE-dependent transcription, and the gene expression of antioxidative enzymes such as heme oxygenase-1 (HO-1), glutamate-cysteine ligase modifier subunit (GCLM), and NAD(P)H:quinone oxidoreductase 1 (NQO1) in HepG2 cells. Additionally, a single oral dose administration of KetoC also increased antioxidative gene expression and protein levels of Nrf2 and HO-1 in mouse organs. Since other fatty acid metabolites and linoleic acid did not affect cellular antioxidative responses, the cytoprotective effect of KetoC may be because of its α,β-unsaturated carbonyl moiety. Collectively, our data suggested that KetoC activated the Nrf2-ARE pathway to enhance cellular antioxidative responses in vitro and in vivo , which further suggests that KetoC may prevent multiple diseases induced by oxidative stress. [ABSTRACT FROM AUTHOR]

Our previous study has shown that gut lactic acid bacteria generate various kinds of fatty acids from polyunsaturated fatty acids such as linoleic acid (LA). In this study, we investigated the effects of LA and LA-derived fatty acids on the activation of peroxisome proliferator-activated receptors (PPARs) which regulate whole-body energy metabolism. None of the fatty acids activated PPARδ, whereas almost all activated PPARα in luciferase assays. Two fatty acids potently activated PPARγ, a master regulator of adipocyte differentiation, with 10-oxo-12( Z )-octadecenoic acid (KetoA) having the most potency. In 3T3-L1 cells, KetoA induced adipocyte differentiation via the activation of PPARγ, and increased adiponectin production and insulin-stimulated glucose uptake. These findings suggest that fatty acids, including KetoA, generated in gut by lactic acid bacteria may be involved in the regulation of host energy metabolism. [ABSTRACT FROM AUTHOR]