Conjugated Linoleic Acid Production Research Articles

Conjugated linoleic acid metabolite impact in colorectal cancer: a potential microbiome-based precision nutrition approach.

Colorectal cancer (CRC) is the second most deadly and the third most diagnosed cancer in both sexes worldwide. CRC pathogenesis is associated with risk factors such as genetics, alcohol, smoking, sedentariness, obesity, unbalanced diets, and gut microbiota dysbiosis. The gut microbiota is the microbial community living in symbiosis in the intestine, in a dynamic balance vital for health. Increasing evidence underscores the influence of specific gut microbiota bacterial species on CRC incidence and pathogenesis. In this regard, conjugated linoleic acid (CLA) metabolites produced by certain gut microbiota have demonstrated an anticarcinogenic effect in CRC, influencing pathways for inflammation, proliferation, and apoptosis. CLA production occurs naturally in the rumen, and human bioavailability is through the consumption of food derived from ruminants. In recent years, biotechnological attempts to increase CLA bioavailability in humans have been unfruitful. Therefore, the conversion of essential dietary linoleic acid to CLA metabolite by specific intestinal bacteria has become a promising process. This article reviews the evidence regarding CLA and CLA-producing bacteria as therapeutic agents against CRC and investigates the best strategy for increasing the yield and bioavailability of CLA. Given the potential and limitations of the present strategies, a new microbiome-based precision nutrition approach based on endogenous CLA production by human gut bacteria is proposed. A literature search in the PubMed and PubMed Central databases identified 794 papers on human gut bacteria associated with CLA production. Of these, 51 studies exploring association consistency were selected. After excluding 19 papers, due to health concerns or discrepancies between studies, 32 papers were selected for analysis, encompassing data for 38 CLA-producing bacteria, such as Bifidobacterium and Lactobacillus species. The information was analyzed by a bioinformatics food recommendation system patented by our research group, Phymofood (EP22382095). This paper presents a new microbiome-based precision nutrition approach targeting CLA-producing gut bacterial species to maximize the anticarcinogenic effect of CLA in CRC.

Production of Conjugated Linoleic Acid from Safflower Oil as Precursor by Probiotic Cultures

Four potentially probiotic strains of lactobacillus and Bifidobacterium were evaluated for their ability to produce conjugated linoleic acid (CLA) from safflower oil in vitro. All the four strains were found to be capable of converting linoleic acid to CLA when using lipolysed safflower oil as a precursor for free linoleic acid. Production of CLA by four probiotics bacterial strains increases in presence 0.6% lipolysed safflower oil as maximum level for 48 h at 37°C and Lb. plantartum has higher CLA content in MRS broth media than Lb. acidophilus, Lb. casei and B. lactis. Also, Supplementation with amounts higher than 0.6% lipolysed safflower oil reduced the CLA content. The research on the ability of converting CLA of probiotics cultures could be basis for the future research and development of fermented dairy products.

Production of Conjugated Linoleic Acid (CLA) by Lactiplantibacillus plantarum: A Review with Emphasis on Fermented Foods.

The term Conjugated Linoleic Acid (CLA) refers generically to a class of positional and geometric conjugated dienoic isomers of linoleic acid. Among the isomers of linoleic acid cis9, trans11-CLA (c9, t11-CLA) and trans10, cis12-CLA (t10, c12-CLA) are found to be biologically active isomers, and they occur naturally in milk, dairy products and meat from ruminants. In addition, some vegetables and some seafoods have also been reported to contain CLA. Although the CLA levels in these natural sources are insufficient to confer the essential health benefits, anti-carcinogenic or anti-cancer effects are of current interest. In the rumen, CLA is an intermediate of isomerization and the biohydrogenation process of linoleic acid to stearic acid conducted by ruminal microorganisms. In addition to rumen bacteria, some other bacteria, such as Propionibacterium, Bifidobacterium and some lactic acid bacteria (LAB) are also capable of producing CLA. In this regard, Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) has demonstrated the ability to produce CLA isomers from linoleic acid by multiple enzymatic activities, including hydration, dehydration, and isomerization. L. plantarum is one of the most versatile species of LAB and the bacterium is widely used in the food industry as a microbial food culture. Thus, in this review we critically analyzed the literature produced in the last ten years with the aim to highlight the potentiality as well as the optimal conditions for CLA production by L. plantarum. Evidence was provided suggesting that the use of appropriate strains of L. plantarum, as a starter or additional culture in the production of some fermented foods, can be considered a critical factor in the design of new CLA-enriched functional foods.

Optimization of Conjugated Linoleic Acid and Eicosapentaenoic Acid Production from Sesame Waste by Response Surface Methodology

Conjugated linoleic acid (CLA) and eicosapentaenoic acid (EPA) have been recognized for their physiological functions and potential as dietary supplements. This study is aimed at investigating the production and enhancing the efficiency of these two acids from Lactiplantibacillus plantarum using sesame waste as a natural, cost-effective, and readily available culture medium. Response surface methodology (RSM) was employed to optimize the production of CLA and EPA in a solid bed system using sesame waste paste as the fermentation substrate. The main processing parameters, including three humidity levels (60%, 70%, and 80%), three inoculum percentages (2%, 4%, and 6% v/v), and three fermentation temperatures (30°C, 37°C, and 44°C), were optimized. An experiment was conducted to validate the determined conditions, and a strong correlation was observed between the experimental results and the predictions made by the software. The optimal conditions for CLA and EPA production were determined to be an inoculation level of 6% with 80% humidity and at 37°C. Gas chromatography analysis of the fermented sesame waste medium revealed that the highest yields of CLAc9t11 and CLAt10c12, as well as eicosapentaenoic acid, were obtained in the medium fermented with 80% humidity and 6% inoculation at 37°C. The respective percentages of these fatty acids in the total fatty acid composition were found to be 0.351% (w/v) and 0.1% (w/v) for CLA and 0.139% (w/v) for EPA under the optimized conditions. These findings contribute to the understanding of CLA and EPA production and highlight the potential of L. plantarum and sesame waste as a fermentation substrate for their efficient production.

Levels of lipid-derived gut microbial metabolites differ among plant matrices in an in vitro model of colon fermentation

This study explored differences in microbial lipid metabolites among sunflower seeds, soybeans, and walnuts. The matrices were subjected to in vitro digestion and colonic fermentation. Defatted digested materials and fiber/phenolics extracted therefrom were added to sunflower oil (SO) and also fermented. Targeted and untargeted lipidomics were employed to monitor and tentatively identify linoleic acid (LA) metabolites. Walnut fermentation produced the highest free fatty acids (FFAs), LA, and conjugated LAs (CLAs). Defatted digested walnuts added to SO boosted FFAs and CLAs production; the addition of fibre boosted CLAs, whereas the addition of phenolics only increased 9e,11z-CLA and 10e,12z-CLA. Several di-/tri-hydroxy-C18-FAs, reported as microbial LA metabolites for the first time, were annotated. Permutational multivariate analysis of variance indicated significant impacts of food matrix presence and type on lipidomics and C18-FAs. Our findings highlight how the food matrices affect CLA production from dietary lipids, emphasizing the role of food context in microbial lipid metabolism.

Partial purification of linoleic acid isomerase enzyme from Lactobacillus paracasei bacteria isolated from milk.

Conjugated Linoleic Acid (CLA) has attracted the attention of many researchers, especially that of microbial origin due to its biological importance to the consumer. The current study aims to extract LA Isomerase enzyme from Lactobacillus paracasei bacteria from milk and to use the enzyme in the production of CLA. Selective media, including MRS and MRS-Dagatose, were used in isolating local strains. The selected bacterial isolates were tested for their ability to produce LA-Isomerase enzyme. The isolate with high enzymatic activity was selected. After extraction and partial purification of the enzyme, the optimal conditions for the production of conjugated fatty acid were studied, and the reaction products were diagnosed using GC-MS technology. It was found that 11 isolates have the ability to produce CLA at different concentrations, H1 isolate showed the highest production of conjugated fatty acid at a concentration of 120.45 g.ml-1, this isolate was selected as the source for enzyme extraction. The enzymatic activity of the crude extract and partially purified with ammonium sulfate was estimated using color methods at wavelength of 233 nm. The effect of the optimum conditions (pH, temperature, linoleic acid concentration and enzyme concentration) on the CLA product was studied using the partially purified LA Isomerase enzyme, the optimum conditions for production were 6.5, 45 °C, 100 μg.ml-1 and 0.7 ml, respectively. The GC-MS technique showed the presence of a number of reaction products that are isomers of conjugated linoleic acid (C9T11, T9T12, T10C12) with different concentrations.

Effect of Lactiplantibacillus plantarum on the Conversion of Linoleic Acid of Vegetable Oil to Conjugated Linoleic Acid, Lipolysis, and Sensory Properties of Cheddar Cheese.

Conjugated linoleic acid (CLA) is perceived to protect the body from metabolic diseases. This study was conducted to determine the effect of Lactiplantibacillus plantarum (Lp. plantarum) on CLA production and sensory characteristics of cheddar cheese. Lp. plantarum can convert linoleic acid (LA) to CLA. To increase CLA in cheddar cheese and monitor the conversion of LA to CLA by Lp. plantarum, the LA content of cheese milk (3.4% fat) was increased by partially replacing fat with safflower oil (85% LA of oil) at 0, 3, 6, and 9% concentrations (T1, T2, T3, and T4). Furthermore, Lp. plantarum 108 colony-forming units (CFU)/mL (8 log CFU mL-1) was added in all treatments along with traditional cheddar cheese culture (Lactococcus lactis ssp. lactis and L. lactis ssp. cremoris). After 30 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.75, 6.72, 6.65, and 6.55 log CFU g-1. After 60 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.35, 6.27, 6.19, and 6.32 log CFU g-1. After 60 days of ripening, Lp. plantarum in T1, T2, T3, and T4 was 6.41, 6.25, 6.69, and 6.65 log CFU g-1. GC-MS analysis showed that concentrations of CLA in the 90 days' control, T1, T2, T3, and T4 were 1.18, 2.73, 4.44, 6.24, and 9.57 mg/100 g, respectively. HPLC analysis revealed that treatments containing Lp. plantarum and LA presented higher concentrations of organic acids than the control sample. The addition of safflower oil at all concentrations did not affect cheese composition, free fatty acids (FFA), and the peroxide value (POV) of cheddar cheese. Color flavor and texture scores of experimental cheeses were not different from the control cheese. It was concluded that Lp. plantarum and safflower oil can be used to increase CLA production in cheddar cheese.

Probiotics from the bovine raw milk of Lahaul valley showed cis-9, trans-11 conjugated linoleic acid isomer and antioxidant activity with food formulation ability

Dairy foods, especially of bovine origin, are the most common carriers of probiotics and conjugated linoleic acid (CLA)-producing microorganisms. The present study isolated probiotic strains from raw cow milk of the Lahaul valley capable of producing cis-9, trans-11 CLA isomer, besides exhibiting antioxidant properties with food formulation abilities. After preliminary probiotic screening, 34 strains were obtained, with 21 qualifying all the probiotic attributes and passing safety analysis. The seven most statistically promising probiotics were further explored for CLA production (16.87–28.01 μg/mL), and showed cis-9, trans-11 CLA isomer production as confirmed by GC-MS. To establish genomic evidence for safety analysis, whole genome sequencing was conducted for Enterococcus faecalis LJM:05, resulting in the deduction of antibiotic-resistance and virulence genes (lower identity scores). Based on the superior probiotic attributes, antioxidant, and CLA-producing properties, the strain Latilactobacillus curvatus LGM:16 was used to develop the curdled milk, with a legal, viable count (7.55 log10 CFU/mL) under pH ∼4.15 for 28 days of storage periods (4 °C). Scanning electron microscopic examination revealed microstructural changes after fermentation in the curdled milk compared to the control. The findings highlighted the role of indigenous probiotic strains with superior probiotic features, antioxidant activity, and CLA-producing ability in functional food formulation.

Development of a whey-based beverage with enhanced levels of conjugated linoleic acid (CLA) as facilitated by endogenous walnut lipase

In this study, optimization of fermentation conditions, and applying endogenous walnut lipase were investigated for the manufacture of a fermented, whey-based beverage containing conjugated linoleic acid (CLA). Among different commercial starter and probiotic cultures, the culture containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus showed high potency for CLA synthesis. The fermentation time and the type of walnut oil (lipolyzed or non-lipolyzed) had significant effects on CLA production, as the highest CLA content (36 mg/g fat) was synthesized in the sample containing 1 % lipolyzed walnut oil fermented at 42 °C for 24 h. Moreover, fermentation time had the highest contribution on viable cell counts, proteolysis, DPPH scavenging activity, and final pH. A significant and positive correlation between cell counts and CLA content was also observed (r = +0.823, p < 0.05). This study establishes a cost effective approach for converting cheese whey to a value added beverage enriched with CLA.

Production and Optimization of Conjugated Linoleic and Eicosapentaenoic Acids by Bifidobacterium lactis in Cold-Pressed Soybean Cake.

Background and PurposeIn regard to the biosynthesis of conjugated linoleic acid (CLA) and eicosapentaenoic acid (EPA) by some bacteria, the objective of this study was to evaluate the efficiency of solid-state fermentation based on soybean pressed cake (SPC) to produce CLA and EPA by Bifidobacterium lactis. The objective of this study was to evaluate the efficiency of solid-state fermentation based on SPC to produce CLA and EPA by B. lactis.MethodsProcess conditions including humidity, inoculation level, and temperature parameters were optimized by adopting the response surface methodology (RSM) method (response surface method) and the design expert software. Accordingly, a homogeneous SPC paste substrate at 60, 70, and 80% humidity was prepared with different inoculation levels at 30, 37, and 44°C to assess the strain behavior. The introduced SPC consisted of 60% humidity, 2% inoculation level at 37°C, and 60% humidity, and 4% inoculation level at 30 and 44°C; it also included 6% inoculation level at 37°C, 70% humidity at 2% inoculation level, at 30 and 44°C, and 4% inoculation level at 37°C. Also, SPC with 80% humidity at 2% and 4% inoculation levels, and at 30 and 44°C was obtained. To confirm the accuracy of the conditions, an experiment was conducted according to the defined requirements.ResultsThe results were compared with the predicted data, which showed a significant difference. Under optimized conditions, with an inoculation level of 4% on the SPC medium with 70% humidity and at 37°C, B. lactis strains could yield 9cis-, 11 trans-linoleic and eicosapentaenoic at 0.18 and 0.39% of the total fatty acids.ConclusionSo, the potential benefits of using SPC as an inexpensive substrate for the commercial production of CLA and EPA should be noted.

Valorization of waste chicken skin for conjugated linoleic acid (CLA) production: optimization using response surface methodology.

The valorization of waste chicken skin fat (WCSF) for conjugated linoleic acid (CLA) production was performed by photoisomerization and optimized the process conditions for high CLA production by response surface methodology. The fat extraction yield from waste chicken skin was approximately 52%. The linoleic acid content of the fat obtained from waste chicken skin was increased by the fractionation process approximately 2 times, up to 52%. Optimum iodine amount and processing time for predicted maximum total CLA amount were determined as 0.87% and 116.36h, respectively. The maximum total CLA amount was predicted and produced experimentally as 32.14% and 29.01%, respectively. Additionally, iodine amount, processing time, and their interaction significantly affected the amount and variety of produced CLA isomers. The results indicated that dominant isomers produced by photoisomerization of WCSF were trans, trans isomers. However, the amount of cis 9, trans 11 and trans 10, cis 12 CLA isomers could be more increased by optimizing the production parameters. The present study indicated that waste chicken skin could be valorized in CLA production by photoisomerization and obtained high value-added product, and also a more economical and faster CLA production could be realized.

Bio-Molecular analysis of selected food derived Lactiplantibacillus strains for CLA production reveals possibly a complex mechanism

Lactiplantibacillus is among the most extensively studied bacterial specie belonging to the genus Lactobacillus with proven probiotic and health promoting effects. These beneficial effects are generally strains specific but the underlying molecular mechanisms are still not fully understood. Dissecting the determinants behind probiotic topographies of this bacterium is of particular interest since it would help select strains that stand the best chance of success in clinical trials and potential industrial applications. In the current study, we have compared the oleate hydratase phylogeny of seven selected strains of L. plantarum on the basis of their sequence, physiochemical properties and 3D structures. All the strains were assessed on molecular level visualization to find out the active site residues which take part in binding with linoleic acid (LA) at the time of interactions. From the whole genome sequences, the genes responsible for conjugated linoleic acid (CLA) production were identified by Venn diagrams. Identified genes were further compared phylogenetically by MEGA X and physiochemical parameters were analyzed by utilizing ExPaSy-Protparam. The genes were further analyzed for the secondary structures using PSIPRED and tertiary structure was generated by trRosseta and SWISS-MODEL. For the analysis of molecular interactions, LA was used as a ligand and the docking was performed using AutoDock Vina. The phylogenetic analysis showed a close phylogeny of the strains with publicly available genomes. The best interaction energy with LA was observed as −6.7 kcal/mol. The bacteria perform an important role in the CLA production through LA metabolism. Oleate hydratase genes are involved in the complex mechanism of the saturated conversion of LA in to CLA. The current study provides further insights for CLA production by different strains of L. plantarum. There is an excellent opportunity for future studies to investigate different CLA production mechanisms in different bacterial strains.

Deciphering the mechanisms of Limosilactobacillus fermentum L1 involved in conjugated linoleic acid regulated by luxS/AI-2 quorum sensing

Conjugated linoleic acid (CLA) is an unsaturated fatty acid with many active functions. Here, we demonstrate quorum sensing (QS) to study mechanisms involved in CLA production of L. fermentum L1. Addition of linoleic acid (LA) with increased concentration results in promising CLA production of 2.22–10.36 mg/mL, cell density and autoinducer-2 (AI-2) involved in QS of L1. Further, proteomics analysis quantified up-expression of 185 differentially expressed proteins (DEPs) upon addition substrate of 8% LA, including myosin cross-reactive antigen protein, enolase (eno), and S-ribosylhomocysteine lyase (luxS), while 174 DEPs were down-regulated. Furthermore, S-Adenosyl-l-methionine metabolic pathway involved in luxS/AI-2 QS system was up-regulated. Additionally, protein-protein interaction network leverage key proteins, luxS and eno responsible for CLA production. Finally, furanone inhibitor block luxS/AI-2 QS system to allow AI-2 content, CLA, and cell density of L1 to decrease level. Western blot analysis confirmed, furanone successfully inhibited expression of luxS and eno. Whereas, luxS/AI-2 QS system was activated with LA results in increase expression of eno and production of CLA. Collectively, this study provides a new mechanism of CLA production by lactic acid bacteria.

Linoleic Acid Triggered a Metabolomic Stress Condition in Three Species of Bifidobacteria Characterized by Different Conjugated Linoleic Acid-Producing Abilities

Abundant conjugated linoleic acid (CLA) producers exist among Bifidobacterium species. This CLA production is related to the mitigation of LA toxicity. However, there is still a lack of information on the metabolic response underlying this detoxification strategy. In this study, six bifidobacteria strains belonging to three different species were used to characterize growth and CLA accumulation in the presence of LA. A combination of non-targeted metabolomics techniques and biochemical indicators were used to explore metabolic profile changes in response to LA and the expression of important factors driving CLA production in Bifidobacterium species. The results suggested that free LA had growth inhibitory effects on bifidobacteria, resulting in a global metabolic stress response that caused metabolic reprogramming on all tested strains and promoted malondialdehyde production, inducing a redox imbalance. In particular, a strong decrease in reduced glutathione level was observed in Bifidobacterium breve CCFM683 [log2(FC) = -3.29]. Furthermore, LA-induced oxidative stress is an important factor driving high CLA production in certain strains.

Reasons for the differences in biotransformation of conjugated linoleic acid by Lactobacillus plantarum

Conjugated linoleic acid (CLA) has attracted a great deal of attention for its functions in weight loss, regulation of metabolism, and antioxidant capabilities. Many microorganisms, including rumen bacteria, propionic acid bacilli, and Lactobacillus, have CLA biotransformation ability. The CLA production capability of different species is different, as are those different strains of the same species. However, the reasons for this discrepancy remain unclear. In this study, 14 strains of Lactobacillus plantarum were found, through gas chromatography-mass spectrometry analysis, to be capable of converting linoleic acid to CLA. The transcriptional levels of CLA-related genes in the high- (AR195, WCFS1, and AR488) and low-yield strains (AR176, AR269, and AR611) were analyzed using real-time quantitative PCR. The transcriptional levels of cla-hy, cla-dh, and cla-dc in AR195 were the lowest in the exponential phase, but it had the highest CLA yield. Correlation analysis showed no correlation between CLA yield and the transcription level of these genes in the exponential phase. The results showed that a high transcriptional level in the exponential phase of cla-hy, cla-dh, and cla-dc did not necessarily lead to high CLA production. Investigation of the transcription level in different growth phases showed that the CLA biotransformation abilities of Lactobacillus plantarum strains significantly depended on the transcriptional maintenance of cla-hy, cla-dh, and cla-dc. We observed a correlation between CLA production and increased levels of cla-hy transcription, but a prerequisite is needed: the transcription of cla-dh and cla-dc should be upregulated and maintained a high transcriptional level during the platform period. This study provides a new strategy for screening high CLA-producing strains. It also lays a theoretical foundation for regulating CLA biotransformation and increasing the yield of CLA.

Linoleate Isomerase Complex Contributes to Metabolism and Remission of DSS-Induced Colitis in Mice of Lactobacillus plantarum ZS2058.

A linoleate isomerase complex including myosin-cross-reactive antigen, short-chain dehydrogenase/oxidoreductase, and acetoacetate decarboxylase has been confirmed as the pivotal factor for conjugated linoleic acid (CLA) production in Lactobacillus plantarum. However, its role in the metabolism and health-associated benefits of Lactobacillus remain unclear. In the current study, the mild type, knockout, and complemented mutants of the linoleate isomerase complex of L. plantarum ZS2058 were used to investigate those putative effects. The metabonomic results showed that a linoleate isomerase complex could significantly influence the glycol-metabolism, lipid metabolism, and antioxidant compounds. Especially, with the stress of linoleic acid, linoleate isomerase complex knockout mutants induced the increase of several antioxidant compounds, such as glutamic acid, glycine, l-cysteine, glycerol, and l-sorbosone. Moreover, the linoleate isomerase complex played a pivotal role in ameliorating DSS-induced colitis. The knockout mutants showed effects similar to those in the DSS group, whereas complementation of the corresponding gene in the knockout mutants could restore the anti-inflammatory activity, wherein the integrity of a mucus layer was repaired, the level of pro-inflammatory cytokines decreased, and the amount of anti-inflammatory cytokines increased significantly. All the results indicated that the linoleate isomerase complex plays a key role in CLA production and metabolism as well as the health-associated benefits of L. plantarum ZS2058. These results are conducive to promote clinical trials and product development of probiotics for colitis.

Co-production of parabiotic metabolites by Lactobacillus acidophilus LA5 and Bifidobacterium animalis subsp. lactis BB12 in dairy effluents

In this study, the effects of initial pH (5 − 7), temperature (30 − 38 ◦C) and incubation time (12 − 48 h), as well as yeast extract and free linoleic acid concentrations, respectively (0 – 4 %) and (0 − 400 µL), on the co-production of conjugated linoleic acid (CLA), exopolysaccharides (EPSs) and bacteriocins (BACs) by Lactobacillus acidophilus LA5 and Bifidobacterium animalis subsp. lactis BB12 and their biomass in cheese whey and milk permeate were evaluated. The results showed that biomass, CLA, EPSs and BACs activity ranged Log 0.80 - Log 8.67 g.L-1, 3.08-107.95 µg.mL-1, 107.75-351.92 mg.L-1 and 9.29-14.62 mm, respectively. Yeast extract concentration was the only factor with the positive significant effect on biomass and parabiotic metabolites i.e. its increasing caused to an increase in both of them (p <0.05). The temperature significantly affected the production of biomass and CLA; its increasing resulted in increasing both (p <0.05). The initial pH had significant, but different, effects on EPSs and BACs production (p <0.05) i.e. EPSs and BACs production decreased and increased, respectively, as a result of increased initial pH. Increasing free linoleic acid concentration from 0 up to 400 µL led to increased CLA biosynthesis. Higher biomass, EPSs and BACs are produced in cheese whey, compared with milk permeate, but CLA produced in milk permeate was higher than that obtained in cheese whey. B. animalis BB12 produced more biomass, CLA and EPSs in comparison to L. acidophilus LA5. However, these probiotics had no statistical difference in terms of producing BACs. This work successfully demonstrated the co-production potential of CLA, EPSs and BACs by two commercial probiotics in dairy effluents.

Fermentation Optimization for Co-production of Postbiotics by Bifidobacterium lactis BB12 in Cheese Whey

Bioactive molecules, with health-beneficial effects and functional activity on the human, are called “postbiotics”, produced by probiotic bacteria. In this study, co-production of conjugated linoleic acid (CLA), exopolysaccharides (EPSs), and bacteriocins (BACs) by Bifidobacterium lactis BB12 in supplemented cheese whey was optimized using Box–Behnken design. Yeast extract concentration had a significant effect on all responses except EPSs. The temperature significantly affected the production of CLA and the inhibition zone (p < 0.05). The incubation time had significant effects on CLA, EPSs, and BACs production (p < 0.05). Desirability functions performed to the optimization of multiple responses by maximization of CLA, EPSs and inhibition zone. Optimum conditions of CLA, EPSs, and BACs co-production were as follows: incubation temperature 38 °C, incubation time 28 h, and yeast extract concentration 2.5%. Fourier transform infrared spectroscopy was used to analyze functional groups of postbiotics. Gas chromatography, thin-layer chromatography, and SDS-PAGE were used to analyze CLA isomers, EPSs monosaccharides composition, and BACs molecular weight, respectively. Co-production of CLA, EPSs, and BACs by B. lactis BB12 in dairy effluent, as a cultivation medium, optimized successfully in this study.

Bacterial conjugated linoleic acid bio-fortification of synbiotic yogurts using Propionibacterium freudenreichii as adjunct culture

In this study, Propionibacterium freudenreichii was used for in situ production of conjugated linoleic acid (CLA) in yogurt. Firstly, effects of process variables, including strain type, percentage of milk fat, percentage of inoculum, quantity of sunflower oil, concentration of inulin, temperature of fermentation and time of storage at 4°C, on production of CLA by Propionibacterium freudenreichii were investigated using screening method of the Plackett–Burman design. Then optimisation of CLA production process was conducted using three major factors of milk fat percentage, inulin concentration and storage time at 4°C using central composite design. Analysis of variance established that the models were highly significant (P ? 0.05). The model demonstrated that the production of CLA was affected by these three factors. Optimised CLA production by Propionibacterium freudenreichii ssp. shermanii in yogurts was achieved after 17 days of storage at 4°C in skim-milk containing 1.75% (w/w) fat and 2.25% (w/v) inulin as prebiotic. Reconfirmation test established that at the highlighted optimum conditions, the highest concentration of produced CLA was 6.4 mg g–1 lipid in yogurt, which is a 256% increase in total CLA production, compared with control samples. Results demonstrated that Propionibacterium freudenreichii ssp. shermanii not only leads to production of synbiotic yogurts containing inulin but also increases CLA production in yogurts.

Linoleic acid isomerization ability of Lactobacillus spp. isolated from Vietnamese human intestinal origins

Conjugated linoleic acid (CLA) have been shown to exert numerous health benefits, including anti-carcinogenic, anti-atherogenic, anti-diabetic, antiobesity, cholesterol reducing, antioxidant, anti-microbial, immune system modulator and growth-stimulating properties. In human, CLA is produced from Linoleic acid (LA) by gut bacteria. In this study, nineteen Lactobacillus (Lac.) strains isolated from human feces were studied to determine their ability to metabolize LA. The bacteria were grown in the liquid form of anaerobic MRS medium supplemented with 0.5 mg/mL LA. The linoleate isomerase activity in bacteria grown on MRS medium was determined by Gas chromatograpy. The results indicated that 4 out of 19 strains, including strains Lac.02, Lac.05, Lac.14 and Lac.16 are capable of producing about 40-50 μg/mL CLA from LA. Among them, the highest ability to produce CLA from LA is Lac.02 strain. In the production of CLA from LA, enzymes involved in this metabolism in Lactobacillus act as catalysts of hydration/dehydration (CLA-HY), oxidation of hydroxy groups/reduction of oxo groups (CLA-DH), migration of carbon-carbon double bonds (CLA-DC), and saturation of carbon-carbon double bonds (CLA-ER). The cla-dh, cla-dc, cla-hy and cla-er genes that encode enzymes CLA-DH, CLA-DC, and CLA-ER had been found in all Lac.02, Lac.05, Lac.14 and Lac.16 strains. Gas chromatography traces indicated that these strains produced the same compounds, which was subsequently identified as cis-9, trans-11, and trans-10, cis-12 CLA. In the next study, we will optimize the conditions such as substrate concentrations, pH values, temperature and culture time of each strain to obtain the best rerults.