Fatty Acid Content Research Articles

Effects of Key Rumen Bacteria and Microbial Metabolites on Fatty Acid Deposition in Goat Muscle

In this study, the fatty acid composition in the muscles of Hechuan white goats was correlated with the metabolome and metagenome of their rumen contents, and potential effects of the metabolites and microorganisms in the rumen on host muscle fatty acid deposition were analyzed. The results of the correlation analysis between the rumen content’s metabolome and muscle fatty acid content showed that vitamin-B-related metabolites were significantly correlated with fatty acid content (p < 0.05). Most of these metabolites were positively correlated with stearic acid and negatively correlated with palmitic acid. In accordance with the level of fatty acid content, significant differences were found in the microbial species and abundance among groups at the species level. An abundance of Bacteroides, Ruminococcaceae P7, Eubacterium ruminant, and Prevotella in the rumen was significantly correlated with fatty acid content. These results provide data support for the development of targeted feeding management strategies to improve the quality of goat meat.

Analysis of the nutritional composition of Bahraini breed camel (Camelus dromedarius) milk: fatty acid, mineral, phenolic, and antioxidant content

Camels live under extremely arid conditions, yet they can produce more milk than any other animal in the desert ecosystem. They also have a longer lactation duration as well as low nutrition requirements. This study aims to determine the fatty acids profile, minerals, antioxidant activity and total phenols/flavonoids content, in camel milk of the species Camelus dromedarius in Bahrain. Gas chromatography was employed to analyze the fatty acid methyl esters obtained after the extraction of fatty acids. Mineral concentrations were measured by an Inductively Coupled Plasma Optical Emission Spectrometer. Antioxidant measurements included total phenolic content by the Folin-Ciocalteu method, total flavonoid contents by AlCl3 colorimetric method, and total antioxidant activity by the ferric reducing antioxidant power assay. The fatty acids analysis (median(interquartile range) %) showed that the most predominant fatty acids were unsaturated fatty acids (50.40(6.76) %), which were slightly higher than saturated fatty acids (49.60(12.17) %). The most abundant saturated fatty acids were C16:0 (26.73(6.73) %), C18:0 (12.32(4.28) %), and C14:0 (10.55(2.86)%). Monounsaturated fatty acid 18:1n9 was 31.5(5.66) %, and 16:1n7 was 12.75(2.19)%, while the major omega-3 was C18:3n3 (3.91(0.71) %). The main omega-6 were C18:2n6 and C18:3n6, accounting for 1.30(0.35) % and 0.94(0.21) %, respectively. The mineral content of camel milk varied, with the presence of macro minerals such as calcium (699.60 mg/L), sodium (855.18 mg/L), magnesium (9.33 mg/L) and potassium (87.09 mg/L). The results showed that camel milk has considerable values of total antioxidant activity (4.75(1.71) mmol/g), total phenolic contents (20.24(11.18) mg GAE/L) and total flavonoid contents (31.74(20.72) mg CE/L). In conclusion, although the (poly)phenol content in camel milk is relatively lower compared to certain plant-based sources, it can represent a good source of antioxidants, in addition to a significant content in unsaturated fatty acids and minerals, further enhancing its nutritional value for human health.

Dietary supplementation with citrus peel extract in transition period improves rumen microbial composition and ameliorates energy metabolism and lactation performance of dairy cows

BackgroundDuring the transition period, excessive negative energy balance (NEB) lead to metabolic disorders and reduced milk yield. Rumen microbes are responsible for resolving plant material and producing volatile fatty acids (VFA), which are the primary energy source for cows. In this study, we aimed to investigate the effect of citrus peel extract (CPE) supplementation on rumen microbiota composition, energy metabolism and milk performance of peripartum dairy cows.MethodsDairy cows were fed either a basal diet (CON group) or the same basal diet supplemented with CPE via intragastric administration (4 g/d, CPE group) for 6 weeks (3 weeks before and 3 weeks after calving; n = 15 per group). Samples of serum, milk, rumen fluid, adipose tissue, and liver were collected to assess the effects of CPE on rumen microbiota composition, rumen fermentation parameters, milk performance, and energy metabolic status of dairy cows.ResultsCPE supplementation led to an increase in milk yield, milk protein and lactose contents, and serum glucose levels, while reduced serum concentrations of non-esterified fatty acid, β-hydroxybutyric acid, insulin, aspartate aminotransferase, alanine aminotransferase, and haptoglobin during the first month of lactation. CPE supplementation also increased the content of ruminal VFA. Compared to the CON group, the abundance of Prevotellaceae, Methanobacteriaceae, Bacteroidales_RF16_group, and Selenomonadaceae was found increased, while the abundance of Oscillospiraceae, F082, Ruminococcaceae, Christensenellaceae, Muribaculaceae UCG-011, Saccharimonadaceae, Hungateiclostridiaceae, and Spirochaetaceae in the CPE group was found decreased. In adipose tissue, CPE supplementation decreased lipolysis, and inflammatory response, while increased insulin sensitivity. In the liver, CPE supplementation decreased lipid accumulation, increased insulin sensitivity, and upregulated expression of genes involved in gluconeogenesis.ConclusionsOur findings suggest that CPE supplementation during the peripartum period altered rumen microbiota composition and increased ruminal VFA contents, which further improved NEB and lactation performance, alleviated lipolysis and inflammatory response in adipose tissue, reduced lipid accumulation and promoted gluconeogenesis in liver. Thus, CPE might contribute to improve energy metabolism and consequently lactation performance of dairy cows during the transition period.

Deciphering the inhibitory effects of trimetazidine on pulmonary hypertension development via decreasing fatty acid oxidation and promoting glucose oxidation

Pulmonary hypertension (PH) is a devastating disease characterized by vascular remodeling, resulting in right ventricular failure and death. Dysregulation of energy metabolism is linked to PH pathogenesis. Trimetazidine (TMZ), a selective long-chain 3-ketoacyl coenzyme A thiolase inhibitor, is critical in maintaining energy metabolism. Despite the indicated TMZ’s inhibitory effect on pulmonary vascular remodeling in PH development, the integrated evaluation of the changes in biomolecules, such as metabolites and transcripts, that TMZ induces in the lung and heart tissues is largely unknown in vivo. For an improved understanding of the molecular mechanism involving the effects of TMZ on PH development, we performed a comprehensive analysis of the changes in cardiac metabolites and pulmonary transcripts of SU5416-Hypoxia (Su/Hx) rats treated with TMZ. Metabolomic analysis of the Su/Hx-induced PH hearts demonstrated that TMZ reduced the long-chain fatty acid concentration. Additionally, TMZ alleviated PH degree and excessive strain on the right heart functions in rats with Su/Hx-induced PH. We identified the candidate target genes for TMZ treatment during PH development. Interestingly, the mRNA levels of the fatty acid transporters were substantially downregulated by TMZ administration in the lungs with Su/Hx-induced PH. Notably, TMZ suppressed excessive proliferation of human pulmonary artery smooth muscle cells under hypoxic conditions. Our study suggests that TMZ ameliorates PH development by involving energy metabolism in the lungs and heart.

Preventive potential of chitosan self-assembled coconut residue dietary fiber in hyperlipidemia: Mechanistic insights into gut microbiota and short-chain fatty acids.

Hyperlipidemia is a metabolic disorder resulted from unhealthy dietary and lifestyle habits. Its pathogenesis is possibly linked to gut microbiota dysbiosis. This study investigates the preventive effects of chitosan self-assembled coconut residue dietary fiber (CRFSC) on hyperlipidemia induced by a high-fat diet (HFD) and gut microbiota. CRFSC resulted in a significant weight loss of 7.9% in HFD rats and had a preventive effect on all four lipid parameter abnormalities. HFD supplemented with oat group resulted in a weight loss of 3.8% in HFD rats and had no preventive effect on low-density lipoprotein cholesterol (LDL-C) abnormalities. Prevention was achieved not only through the modulation of gut microbiota composition and the increase of short-chain fatty acids (SCFAs) levels, but also through the activation of superoxide dismutase enzyme and the inhibition of malondialdehyde accumulation, all of which are the factors leading to the controlling of lipid abnormalities and oxidative damage. The prevention of lipid parameters by chitosan self-assembled coconut residue dietary fiber (CRFSC) may be attributed to its richness in chitosan and insoluble dietary fiber, as well as its ability to enrich beneficial bacteria such as Akkermansia, Roseburia, and Ruminococcus. Correlation analysis demonstrated that key bacterial species producing SCFAs, which are rich in the CRFSC diet, had a positive impact on controlling hyperlipidemia. Hence, consumption of a CRFSC diet could serve as an effective strategy for preventing and controlling the development of hyperlipidemia due to its potential ability to regulate gut microbiota and SCFAs. PRACTICAL APPLICATION: This study showed that dietary fiber from coconut residue after chitosan self-assembly had preventive effects on overweight, dyslipidemia, and oxidative damage in rats. In addition, CRFSC also increased the content of short-chain fatty acids in the gut. And improve gut health by affecting gut microbiota. This finding suggests that CRFSC can be used as a dietary strategy to prevent hyperlipidemia and has practical significance in developing new healthy foods.

Preparation and characterization of Tobacco polysaccharides and its modulation on hyperlipidemia in high-fat-diet-induced mice.

This study aimed to investigate the structural properties of tobacco polysaccharide (TP) and its mechanism of modulating hyperlipidemia in high-fat diet-induced mice. The structural properties of TP were characterized by FT-IR, 1HNMR, SEM, AFM and thermogravimetric analysis. And the regulatory mechanism of TP on lipid metabolism was investigated in hyperlipidemia mice. These results showed that TP had a high composition of reducing monosaccharide and the glycosidic bond type was α-glycosidic bond. The intervention by TP resulted in a significant reduction of body weight and improvement in lipid accumulation. And the modulation mechanism by which TP ameliorated the abnormalities of lipid metabolism was associated with the expression levels of lipid metabolism-related genes and serum exosomes miRNA-128-3p, as well as the modulation of structure and abundance of the gut microbiota in mice. In addition, TP treatment significantly increased the content of short-chain fatty acids (SCFAs) in mice feces. The results of molecular docking and dual-luciferase assay exhibited a good interaction between propionic acid and PPAR-α, and it was hypothesized that the interaction might further ameliorate the hyperlipidemia. Therefore, TP can regulate the expression levels of lipid metabolism-related genes through miRNAs from serum exosomes and SCFAs from gut microbiota.

Effects of Dietary Fiber and Copper on the Performance and Gut Microbiota of Finishing Pigs

This study aimed to investigate the effects of dietary fiber (DF) levels and copper concentrations on the production performance and cecal microbial diversity of finishing pigs. A 2 × 2 factorial experimental design was used, with different levels of dietary fiber (low [23% DF]: L and high [30% DF]: H) and copper concentrations (normal [25 mg/kg]: N and supplemented [45 mg/kg]: S) resulting in four diets (LN, LS, HN, and HS). Forty-eight hybrid barrows (Duroc × Landrace × Yorkshire), with an initial body weight of 76 kg ± 1.5 kg, were randomly assigned to four groups: LN, LS, HN, and HS, with 12 replicates per group and one pig per replicate. There was a 7-day adaptation period followed by a 56-day feeding trial, after which all pigs were slaughtered for sampling. Results indicated that in finishing pigs, the low dietary fiber group exhibited a higher final weight, a higher average daily gain, and a lower feed-to-gain ratio compared to the high fiber group (p < 0.05). The LS group showed higher digestibility of dry matter, crude protein, crude fiber, ash, neutral detergent fiber, and DF than the HN and HS groups (p < 0.05). Blood total protein levels were higher in the high fiber group, whereas blood Cu levels were higher in the supplemented copper group (p < 0.05). High dietary fiber increased the activities of colonic carboxymethylcellulase and β-glucanase (p < 0.05). Concentrations of acetic acid, propionic acid, and total volatile fatty acids were elevated in the high fiber group (p < 0.05). Microbial α-diversity indices (observed species, Chao 1, and Shannon indices) increased with fiber but decreased with copper supplementation (p < 0.05). The Firmicutes/Bacteroidetes ratio increased with fiber levels, with a higher relative abundance of Lactobacillus in the LS group. In conclusion, appropriate copper supplementation in diets can mitigate the negative effects of high fiber levels on finishing pig production performance by enhancing nutrient digestibility, fiber-degrading enzyme activity, regulating the microbial community, and its metabolic products.

Mitigation of Oxidized Oil Effects on Production Performances and Meat Quality of Broilers by Dietary Supplementation of Allicin

The objective of this study was to evaluate the effects of dietary oxidized oil and allicin (two different dietary sources) as natural antioxidants on the growth performance and meat quality of broilers. A total of 200 one-day-old Ross 308 broilers were randomly divided into four dietary groups (50 birds/group). The experimental groups (OO—oxidized oil; OOA—oxidized oil and allicin; OOG—oxidized oil and garlic leaves) differed from the control one by the presence of oxidized oil in their dietary structure (peroxide value 9.07 (OO, OOA and OOG groups) vs. 1.70 (C group) meq active oxygen/kg). The diets given to the experimental groups differed from each other by the presence of allicin (100 mg/kg inclusion rate as extract (OOA) and 0.5% as garlic leaf powder (OOG)). At the end of the experiment, six animals/group were slaughtered, meat samples (breast and thigh) were collected, and nutritional value was established. The results showed that the allicin included in the experimental diet did not influence the proximate composition of breast meat (crude protein, fat, ash, and dry matter). The fatty acid profile was determined for each group of samples; a significant decrease in omega 3 FAs was noticed between the C group and the E groups (3.27% vs. 1.46%, 1.60%, and 1.56%) in breast meat samples, and a corresponding increase was noticed in saturated fatty acid (SFA) concentrations. Health indices with implications for atheroma and thrombus formation and cholesterol level were negatively affected by the presence of oxidized oil in the experimental diets, but the allicin extract supplement appeared to mitigate its influence. A positive influence of the dietary supplement was noticed on antioxidant capacity and polyphenol concentrations determined in breast and thigh samples under allicin supplement influence. The results of the current study revealed that the use of low oxidized oil in broilers diets did not affect productive performance. The nutritional quality of meat (breast and thigh) was negatively influenced by the presence of oxidized oil, but allicin supplements (extract or garlic leaves) improved lipid quality indices and antioxidant potential.

Microwave-Assisted Enzymatic Green Solvent Technology for the Extraction and Characterization of Sesame Seed Oil

Traditional methods of extracting oil with organic solvents raise issues related to health, safety, and the environment. Microwave-assisted enzymatic green solvent extraction (MAEGSE) technology is environment friendly because it involves less hazardous chemical synthesis, utilizes renewable feedstock, and decreases the chemical load and emissions produced by organic solvents. The solvents methanol, ethanol, and various cell wall degrading enzymes such as hemicellulose, viscozyme L, pectinase, xylanase, and cellulase were used in this study. The MAEGSE process of sesame oil was conducted, and the results indicated that, unlike the controlled group, no enzymes were used during the process. Among all the combinations a higher oil extraction efficiency was obtained with combination of pectinase and ethanol (37.27%) followed by the xylanase with ethanol (36.75%) from sesame seed without compromising the quality of oil. Among the enzymes tested, pectinase resulted in the highest oil extraction efficiency, followed by xylanase. Use of pectinase improved the oil extraction efficiency in both ethanol and methanol mediums. The outcomes suggested that the application of pectinase enzymes plays a significant role in increasing the oil yield in comparison with the control without compromising quality of oil. Oil extracted without the use of enzyme (control) had a lower free fatty acid (FFA) concentration than the oils extracted with MAEGSE. Even though the specific gravity (SG) and refractive index (RI) of extracted oils were not significantly different in the solvents, the saponification value (SV), peroxide value (PV), iodine value (IV), and free fatty acid (FFA) were found to have minor differences among the extraction techniques.

Influence of Silicate Concentrations on Growth, Carotenoid, and Fatty Acid Profiles of the Marine Diatom Conticribra weissflogii

Enhancing microalgal growth and bioactive compound production is becoming a duty for improving photosynthetic microorganisms. In this study, the growth, carotenoid, and fatty acid profiles of Conticribra weissflogii were studied under four different silicate concentrations and silicate-deficient conditions in an f/2 medium with continuous aeration, light intensity (30 ± 2 µmol m−2 s−1), salinity (25 ± 2‰), pH (8), and temperature (25 ± 2 °C). At the end of the experiment, we observed that a silicate concentration of 120 mg L−1 produced the maximum biomass dry weight (0.86 g L−1), carotenoid content (1.63 µg mL−1), and fucoxanthin content (1.23 mg g−1) in C. weissflogii. The eicosapentaenoic acid (EPA) (11,354.37 µg g−1), docosahexaenoic acid (DHA) (2516.16 µg g−1), gamma-linolenic acid (C18:3n6) (533.51 µg g−1), and arachidonic acid (C20:4n6) (1261.83 µg g−1) contents were significantly higher at Si 120 mg L−1. The results further showed the maximum fatty acid content in C. weissflogii at Si 120 mg L−1. However, the silicate-deficient conditions (Si 0 mg L−1) resulted in higher levels of saturated fatty acids (38,038.62 µg g−1). This study presents a practical approach for the large-scale optimization of biomass, carotenoid, fucoxanthin, and fatty acid production in C. weissflogii for commercial purposes.

Improving the biodiesel production in the marine diatom Thalassiosira pseudonana cultivated in nutrient deficiency and sewage water.

The use of microalgae as a feedstock in biofuel production is highly encouraging. The marine diatom in this study, Thalassiosira pseudonana, was used as a test organism to evaluate the impact of nitrogen or phosphorus limitation and sewage water on improving biodiesel production. The growth rate is more affected in cultures without phosphorus by 41.8% lower than in control and the highest dry weight estimated in control. The cellular dry weight significantly increased in cultures treated with mix1 and mix2 wastewater compared to the control cultures. Chlorophyll a content decreased in the absence of nitrogen and phosphorous and in sewage water cultures. Lipid content in algal cultures without nitrogen or phosphorus and in sewage water accumulated nearly twice as much lipid content in synthetic medium. T. pseudonana showed high FAME contents; the two most abundant fatty acids, stearic acid (C18:0) and palmitoleic acid (C16:1), in the algal extracts revealed that T. pseudonana was predominantly composed of these fatty acids. T. pseudonana grown in nitrogen or phosphorus-deficient conditions exhibited an extreme percentage of saturated fatty acids (SFAs) by 87.38% and 85.47%, respectively, of the total fatty acids (TFAs). More importantly, the low polyunsaturated fatty acid content in oils indicates a high cetane number, low iodine value, and low corrosion for biodiesel quality indicators. Producing biodiesel that closely meets worldwide biodiesel requirements (ASTM D6751 and EN 14214) is the goal of this work, which shows that growing T. pseudonana under nutrient limitations leads to algal metabolism in that direction.

Extracts of Drynariae Rhizoma Promote Bone Formation in OVX Rats through Modulating the Gut Microbiota.

Drynariae Rhizoma (DR) has been commonly used as a preventive and therapeutic agent for bone diseases. However, its pharmacological mechanisms have not been fully elucidated. Here, we aimed to investigate the effects of DR in a bilateral ovariectomized (OVX) rat model and explore the correlation with the gut microbiome. We established an OVX rat model and treated with different doses of DR (DR-L, 0.27 g/kg/day; DR-M, 0.81 g/kg/day; DR-H, 2.43 g/kg/day) through intragastric administration for 12 weeks. Results showed that DR alleviated body weight, moderated bone microstructure, and promoted the expression of bone formation related factors in OVX rats, in which DR-H behaved the most significant effects among the three doses. Furthermore, the effects of DR on promoting bone formation were correlated to the changes in microbial richness and the restorations of several genera, among which Ruminiclostridium and Ruminococcaceae_UCG_007 were positively correlated with the bone formation related factors, and both of them enriched in DR-H group as biomarker. Moreover, CMP-legionaminate biosynthesis I might be a crucial pathway of DR regulates gut microbiota, and the content of serum short-chain fatty acids in OVX rats were regulated by DR. Our results demonstrated that DR promoted bone formation in OVX rats, and it was related to the regulation of the gut microbiota structure.

Metabolic abnormalities and reprogramming in cats with naturally occurring hypertrophic cardiomyopathy.

The heart is a metabolic organ rich in mitochondria. The failing heart reprograms to utilize different energy substrates, which increase its oxygen consumption. These adaptive changes contribute to increased oxidative stress. Hypertrophic cardiomyopathy (HCM) is a common heart condition, affecting approximately 15% of the general cat population. Feline HCM shares phenotypical and genotypical similarities with human HCM, but the disease mechanisms for both species are incompletely understood. Our goal was to characterize global changes in metabolome between healthy control cats and cats with different stages of HCM. Serum samples from 83 cats, the majority (70/83) of which were domestic shorthair and included 23 healthy control cats, 31 and 12 preclinical cats with American College of Veterinary Internal Medicine (ACVIM) stages B1 and B2, respectively, and 17 cats with history of clinical heart failure or arterial thromboembolism (ACVIM stage C), were collected for untargeted metabolomic analysis. Multiple linear regression adjusted for age, sex and body weight was applied to compare between control and across HCM groups. Our study identified 1253 metabolites, of which 983 metabolites had known identities. Statistical analysis identified 167 metabolites that were significantly different among groups (adjusted P<0.1). About half of the differentially identified metabolites were lipids, including glycerophospholipids, sphingolipids and cholesterol. Serum concentrations of free fatty acids, 3-hydroxy fatty acids and acylcarnitines were increased in HCM groups compared with control group. The levels of creatine phosphate and multiple Krebs cycle intermediates, including succinate, aconitate and α-ketoglutarate, also accumulated in the circulation of HCM cats. In addition, serum levels of nicotinamide and tryptophan, precursors for de novo NAD+ biosynthesis, were reduced in HCM groups versus control group. Glutathione metabolism was altered. Serum levels of cystine, the oxidized form of cysteine and cysteine-glutathione disulfide, were elevated in the HCM groups, indicative of heightened oxidative stress. Further, the level of ophthalmate, an endogenous glutathione analog and competitive inhibitor, was increased by more than twofold in HCM groups versus control group. Finally, several uremic toxins, including guanidino compounds and protein bound putrescine, accumulated in the circulation of HCM cats. Our study provided evidence of deranged energy metabolism, altered glutathione homeostasis and impaired renal uremic toxin excretion. Altered lipid metabolism suggested perturbed structure and function of cardiac sarcolemma membrane and lipid signalling.

Green energy using oscillatory baffled reactors: advances in biodiesel production from high free fatty acid karanja oil

Abstract The global demand for sustainable and ecologically friendly energy sources has spurred biodiesel research. Civilization, urbanization, and population growth have drastically boosted transportation energy consumption. Energy demand is causing fossil fuel crises. Replace petroleum diesel to solve energy and environmental problems. Biofuels have very vast scope in the area of energy sector. Karanja oil, derived from the seeds of the Karanja tree (Pongamia pinnata), is a promising biodiesel feedstock due to its high Free Fatty Acid content. This study uses Oscillatory Baffled Reactor (OBR) to produce biodiesel from Karanja oil. The feedstock is high-FFA Karanja oil trans-esterified in two steps. In OBR, reaction time is only 15 min, whereas in conventional reactor it takes 1–2 h to produce biodiesel. Optimizing biodiesel synthesis involved varying H2SO4 concentrations from 1 vol% to 5 vol% and 0.3 to1.0 wt% of NaOH concentration for first and second step respectively. Oil-to-alcohol molar ratios 1:6, 1:9 and 1:12. Optimization occurs at 1:12 oil-to-alcohol ratio, 1 vol% H2SO4 catalyst, and 0.6 wt% NaOH catalyst. Studies have also examined how catalyst concentration and oil: alcohol molar ratio affect biodiesel conversion and physical qualities such kinetic viscosity, specific gravity, and acid value. This study shows that OBR can increase biodiesel production from high-FFA Karanja oil, which further opens up opportunities for additional study and improvement.

REGULATOR OF FATTY ACID SYNTHESIS proteins regulate de novo fatty acid synthesis by modulating hetACCase distribution.

In plants, heteromeric acetyl-CoA carboxylase (hetACCase) initiates de novo fatty acid synthesis (FAS) by generating malonyl-CoA in the first committed step of this process. hetACCase activity is precisely regulated to meet the cellular demand for acyl chains during the plant life cycle. In this study, we performed a systematic co-expression analysis of hetACCase and its regulators in Arabidopsis (Arabidopsis thaliana) to better understand the regulatory mechanism of hetACCase. Our analysis uncovered REGULATOR OF FATTY ACID SYNTHESIS 1 (RFS1), whose expression is positively correlated with that of other regulators of hetACCase. The RFS gene family encodes two plastid inner envelope membrane proteins with undiscovered roles. Further analysis revealed that RFS1 co-localizes and directly interacts with CARBOXYLTRANSFERASE INTERACTOR 1 (CTI1). CRISPR/Cas9-mediated knockouts of RFSs exhibit enhanced hetACCase activity, higher FAS rates, and increased fatty acid contents, with particularly marked accumulation of absolute triacylglycerol levels in leaves, similar to cti mutants. The mutations of rfs and cti alter the plastid membrane distribution pattern of α-carboxyltransferase, leading to reduced hetACCase activity on the membrane, which could potentially be the original mechanism through which RFSs restrain hetACCase activity. Thus, we reveal a unique regulatory module that regulates de novo FAS and a genetic locus that may contribute to breeding of improved oil crops.

Euglena Attenuates High-Fat-Diet-Induced Obesity and Especially Glucose Intolerance

Background: Obesity, a global disease, can lead to different chronic diseases and a series of social health problems. Lifestyle changes, especially dietary changes, are the most effective way to treat obesity. Euglena, a novel food, has attracted much attention. Previous studies have shown that Euglena is an important modulator of the host immune response. In this study, the effects of Euglena as a nutritional intervention in high-fat-diet-induced obese C57BL/6J mice were investigated regarding adipose tissue accumulation and lipid and glucose metabolism by gavage at the dose of 100 mg/kg bodyweight for 9 weeks. This study is one of the few to investigate, in detail, the preventive effects of dietary Euglena on obesity. Methods: Five-week-old male C57BL/6J mice were fed with a high-fat diet (HFD) to induce obesity. An obesity model was created by feeding the high-fat diet for a period of 10 weeks. Obese mice were randomized into 2 groups with the same mean body weight, and no significant differences were observed between the groups: (1) the mice in the HEG group were maintained on a high-fat diet and daily gavaged with Euglena (100 mg/kg body weight) dissolved in saline (n = 7); and (2) the mice in the HFD group were maintained on a high-fat diet and daily gavaged with saline with the same volume (n = 7). The experiment finished after a nine-week period. Results: The results showed that Euglena could reduce the accumulation of white body fat, including subcutaneous fat and visceral fat, and mainly targeted subcutaneous fat. Euglena also reduced adipocyte particle size expansion, promoted lipolysis in adipose (adipose triglyceride lipase and hormone-sensitive triglyceride lipase) and liver tissue (reduced non-esterified fatty acid content), and improved obesity-induced ectopic fat deposition and glucose tolerance. Conclusions: Our findings suggest that Euglena, as a nutritional intervention in HFDs, efficiently reduces body weight and white adipose tissue deposition. The mechanism of Euglena is mainly though enhancing lipolysis. It is worth noting that Euglena β-glucan recovers the hyperglycemia and accumulation of ectopic fat within the liver induced by HFD. Our study is one of the few studies to report in detail the preventive effects of dietary Euglena on obesity in vivo. This study revealed that Euglena also has an important ameliorative effect on obesity and metabolic disorders, which laid a theoretical foundation for its future application in functional foods.

Enrichment of Methanothrix species via riboflavin-loaded granular activated carbon in anaerobic digestion of high-concentration brewery wastewater amidst continuous inoculation of Methanosarcina barkeri

Effective treatment of high-concentration brewery wastewater through anaerobic digestion (AD) has always been a challenging issue. Enhancing direct interspecies electron transfer (DIET) was demonstrated to increase methane production during AD under high organic loading rate (OLR). Herein, the feasibility of enhancing DIET with the addition of riboflavin-loaded granular activated carbon (RF-GAC) as well as co-addition with Methanosarcina barkeri (Rf-GAC+M.barkeri) was investigated (M.barkeri is well-known to be capable of DIET with electroactive bacteria). During the whole process, the Rf-GAC and the Rf-GAC+M.barkeri group both achieved average COD removal rates above 97 %, which was 14 % higher than that of the control. The average methane production in the Rf-GAC group and the Rf-GAC+M.barkeri group respectively reached 0.334 ± 0.02 L(stp)/g COD and 0.345 ± 0.02 L(stp)/g COD, 1.35 and 1.39 times higher than the 0.247 ± 0.03 L(stp)/g COD reached by the control. The control reactor deteriorated at an OLR of 12 kg COD/(m3·d), whereas the Rf-GAC and the Rf-GAC+M.barkeri group maintained stable as the OLR reached as high as 17.5 kg COD/(m3·d) and the volatile fatty acids concentration was consistently below 10 mM. The RF-GAC performed better than Rf-GAC+M.barkeri in enriching Methanothrix, whose relative abundance was 60.6 % in the former group. Metabolic pathway analysis revealed the addition of RF-GAC upregulated genes related to DIET in Methanothrix species, including hdrA and fpoD. Furthermore, Methanothrix remained the dominant archaea even continuously inoculating pure strains of M.barkeri during the entire operational period. Pure culture experiments proved that GAC inhibited M.barkeri growth. The results of this study can be optimized for practical application of AD treating high-concentration brewery wastewater.

A new approach to biotransformation and value of kitchen waste oil driven by gut microorganisms in Hermetia illucens

Hermetia illucens larvae are known for their ability to recycle organic waste, but their capacity to recover waste oils and the role of gut microorganisms in this process are not fully understood. To gain further insights, the biological recovery of waste frying oil into valuable lipids and the influence of gut bacteria on this biotransformation were investigated. The larvae efficiently digested and absorbed waste frying oil, demonstrating their potential for converting various oils into insect fat. The presence of different fatty acids in their diet significantly altered gut bacterial communities, enriching certain genera such as Actinomyces, Enterococcus, and Providencia. Redundancy analysis revealed that the composition and structure of these bacterial communities were predictive of their function in the biotransformation of fatty acids and the lipid biosynthesis in the larvae. Specific bacteria, including Corynebacterium_1, Providencia, Actinomyces, Escherichia-Shigella, and others, were identified to play specialized roles in the digestion and absorption of fatty acids, contributing to lipid synthesis and storage. These findings highlight the potential of Hermetia illucens in the biological recovery of waste frying oil and underscore the crucial role of gut microbiota in this process, offering a sustainable approach to waste management and bioenergy production.

Characteristics of volatile flavor development in aged longissimus lumborum post-ultrasound treatment: 4D proteomics combined with phosphoproteomics analysis

The present study aimed to evaluate the impact of ultrasonic treatment on the development of volatile flavor compounds in beef during postmortem aging and its potential mechanism. Results showed that ultrasound treatment may cause an increase in the total content of unsaturated fatty acids, which could lead to lipid oxidation and potentially result in changes in the flavor development. Additionally, it was also found that ultrasound exacerbated protein oxidation. A total of 141 volatile compounds were obtained by SPME–GC–MS analysis, and 18 differential aroma substances (P < 0.05, VIP > 1) were obtained by orthogonal partial least squares discrimination analysis (OPLS-DA). Five key volatile flavor compounds (hexanal, nonanal, octanal, pentanal, and 1-pentanol) originating from lipid oxidation were identified according to odor activity values (OAVs). The concentration of these compounds was significantly higher in the ultrasonic treatment group compared to the non-ultrasonic group that underwent a 3-day aging process. Nine common differentially expressed proteins (DEPs) were identified through the utilization of proteomics and phosphoproteomics analysis. KEGG pathways showed that selenocompound metabolism, tryptophan metabolism and cysteine and methionine metabolism led to flavor formation during wet aging of beef after ultrasound treatment. This study provided proteomic insights into the flavor of beef aged through sonication and suggested potential links between flavor development and biological processes.

Metagenomic analysis of a top-down enriched straw biodegradation synthetic bacterial consortium (StrBsyn) facilitates anaerobic rice straw degradation

Lignocellulose is a complex and recalcitrant component of plant biomass. Traditional sources of lignocellulose-degrading microorganisms are the rumen system of herbivores and soil microorganisms, with limited studies on marine sediments. In this study, we employed a "top-down" approach to construct a straw biodegradation synthetic bacterial consortium (StrBsyn) capable of degrading lignocellulose from offshore marine sediments. It achieved 66.74% cellulose, 63.79% hemicellulose, and 42.85% lignin conversion within 30 days using 0.2% rice straws. Additionally, the maximum concentrations of total organic carbon (TOC) and total volatile fatty acids (TVFA) reached 4.66g/mL and 15.10g/L, respectively, with a significant increase in pH. β-glucosidase, xylanase, laccase, and lignin peroxidase activities were detected in StrBsyn. Metagenomic sequencing revealed a dynamic shift in the community composition and functional genes. The taxonomic assignment of these functional genes suggested the genera Clostridium, Glomeromyces, and Sedimentobacter as major contributors to carbohydrate transport, metabolism, and lignin degradation processes. This study demonstrated the significant potential of harnessing the power of marine sediment microbial communities for sustainable and efficient anaerobic lignocellulose bioconversion.