Propionic Acid Concentration Research Articles

The Halophilic Bacterium Paracoccus haeundaensis for the Production of Poly(3-Hydroxybutyrate-co-3-Hydroxyvalerate) from Single Carbon Sources.

The study objective was to evaluate the potential production of polyhydroxyalkanoates (PHAs), a biodegradable plastic material, by Paracoccus haeundaensis for which PHA production has never been reported. To identify the most effective nitrogen-limited culture conditions for PHAs production from this bacterium, batch fermentation using glucose concentrations ranging from 4 g l-1 to 20 g l-1 with a fixed ammonium concentration of 0.5 g l-1 was carried out at 30°C and pH 8.0. A glucose supplement of 12 g l-1 produced the highest PHA concentration (1.6 g l-1) and PHA content (0.63 g g-1) thereby identifying the optimal condition for PHA production from this bacterium. Gas chromatography-mass spectrometry analysis suggests that P. haeundaensis mostly produced copolymer types of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] from glucose concentrations at 12 g l-1 or higher under the nitrogen-limited conditions. When several other single carbon sources were evaluated for the most efficient PHA production, fructose provided the highest biomass (2.8 g l-1), and PHAs (1.29 g l-1) concentrations. Results indicated that this bacterium mostly produced the copolymers P(3HB-co-3HV) from single carbon sources composing a range of 93-98% of 3-hydroxybutyrate and 2-7% of 3-hydroxyvalerate, whereas mannose-supplemented conditions produced the only homopolymer type of P(3HB). However, when propionic acid as a secondary carbon source were supplemented into the media, P. haeundaensis produced the copolymer P(3HB-co-3HV), composed of a 50% maximum monomeric unit of 3-hydroxyvaleric acid (3HV). However, as the concentration of propionic acid increased, cell biomass and PHAs concentrations substantially decreased due to cell toxicity.

A novel strategy for integration of oxidation within advanced thermal hydrolysis of sludge

Due to its environmental impact, the growing production of sewage sludge is a prime concern for wastewater treatment plants. In this study, advanced thermal hydrolysis, the combination of thermal hydrolysis and oxygen, was examined to enhance biogas production and overcome the disadvantages of thermal hydrolysis, including sludge colour, high energy consumption, and high level of ammonia concentration in the treated sludge. A mixture of 55 % primary sludge and 45 % waste activated sludge was pre-treated using advanced thermal hydrolysis at 100, 115, 130, and 145 °C with a processing time varied from 5 to 30 min and oxygen pressure from 10 to 30 bar before anaerobic digestion. Advanced thermal hydrolysis process at 145 °C 15 min 20 bar O₂ is the condition that provided the highest biogas yield (439.6 mL/g VS added). At this treatment condition, the concentration of ammonia nitrogen and propionic acid in the treated sludge was sufficiently low (approximately 302 mg/L and 559.7 mg/L, respectively) to minimise adverse effects on anaerobic digestion.

Metagenomics-Based Analysis of the Effect of Rice Straw Substitution for a Proportion of Whole-Plant Corn Silage on the Rumen Flora Structure and Carbohydrate-Active Enzymes (CAZymes)

The purpose of this study was to investigate the effects of replacing a portion of whole-plant corn silage with straw on the rumen microbial community structure and carbohydrate-active enzyme activity. The experiment employed a single-factor randomized trial design, with eight late-lactation Chinese Holstein dairy cows being randomly divided into two groups of four replicates each. The control group (CS group) was fed a diet consisting of alfalfa silage and a mixture of alfalfa and whole-plant corn silage, while the experimental group (RS group) received a diet in which one-third of the corn silage was replaced with straw while keeping the other components unchanged. The experiment lasted for a total of 21 days, with a pre-feeding period of 14 days and a formal period of 7 days. The rumen fluid collected on day 21 was used for the rumen fermentation parameters and metagenomic analysis. The concentrations of acetic acid, propionic acid, butyric acid, and total volatile fatty acids (TVFA) in the rumen of RS group cows were significantly lower than those in the CS group (p < 0.01). The ratio of acetic acid to propionic acid was significantly higher in the RS group compared to the CS group (p < 0.01). Metagenomic sequencing revealed that at the genus level, compared to the CS group, the abundance of unclassified bacteria, Bacteroides, Alistipes, Butyrivibrio, Chlamydia, Fibrobacter, unclassified Ruminococcaceae, and unclassified Bacteroidetes in the rumen of RS group cows increased, while the abundance of Eubacterium decreased ([LDA > 3.6], p < 0.05). Compared to the CS group, the enzymatic activities of α-L-arabinofuranosidase (EC3.2.1.55), β-xylosidase (EC3.2.1.37), β-glucosidase (EC3.2.1.21), β-glucosylceramidase (EC3.2.1.45), xylanase (EC3.2.1.8), and arabinanase (EC3.2.1.99) in the rumen of RS group cows increased (p < 0.05). According to the correlation analysis, Alistipes, Bacteroides, and Butyrivibrio showed a significant negative correlation with propionic acid (p < 0.05) and a significant positive correlation with the acetic acid-to-propionic acid ratio (p < 0.05). They also showed a significant positive correlation with GH2, GH3, GH20, GH29, GH43, GH78, GH92, CE1, GT4, β-glucosidase (EC3.2.1.21), α-L-arabinofuranosidase (EC 3.2.1.55), β-xylosidase (EC 3.2.1.37), β-glucosylceramidase (EC 3.2.1.45), xylanase (EC 3.2.1.8), and arabinanase (EC 3.2.1.99) (p < 0.05). In summary, straw can not only alter the composition and structure of the rumen microbiota in cows but also affect the relative abundance of CAZymes at different levels within the rumen. Cows may, thus, potentially improve the degradation efficiency of straw diets by increasing the abundance of certain rumen microbiota and enzymes.

191 Apparent Total Tract Digestibility, Fecal Metabolites, and Feces Quality of Pulse-Based Vegan Dog Foods with Or Without Added Enzymes in Adult Dogs and Comparison to Digestibility from a Pig Model

Abstract Consumer demand for vegetarian and vegan dog foods is increasing. These specialty diets may rely on alternative plant-based protein sources such as pulses and pulse protein concentrates instead of animal protein to meet amino acid (AA) requirements. Pulses such as field pea and lentil contain more protein than cereal grains, but also contain anti-nutritional factors (ANF) such as phytate and insoluble dietary fiber (IDF) that have the potential to reduce nutrient digestibility. The objectives were 1) to determine if the addition of enzymes before or after extrusion would increase apparent total tract digestibility (ATTD) of pulse-based extruded vegan dog foods; and 2) to compare ATTD of nutrients and gross energy (GE) between dogs and growing pigs fed the same diets. Two formulations were created: low protein (Low) containing 24% crude protein (CP) including 35% field pea flour and 15% lentil flour, and high protein (High) containing 43% CP including 50% pea protein concentrate and 20% lentil protein concentrate. Each formulation was used to prepare 3 diets: control without enzymes (Con), with enzymes added before extrusion (P; X-115 single screw; Wenger, Sabetha, KS) or enzymes added after extrusion (A) for a total of 6 diets. The enzyme blend contained cellulase (480,000 or 510,000 U/kg of diet), xylanase (360,000 or 680,000 U/kg), protease (960,000 or 1,360,000 U/kg), and phytase (12,000 or 17,000 U/kg) for Low and High diets, respectively. Following extrusion, kibbles were ground and 0.5% TiO2 was added to diets. Ten mix breed adult dogs (1.5 - 2yrs; 21-29 kg BW) were fed in a 6 × 6 replicated incomplete Latin square with 10-d periods. Feces were collected during the last 4-d of each period. The ATTD of organic matter (OM) and CP ranged from 77.7 to 86.3% and 74.6 to 87.8%, respectively. The ATTD of OM, CP, crude fat, GE, and ash did not differ between A and Con diets. Feces concentrations of glucose, xylose, acetic and propionic acid was greater (P < 0.05) for A than Con diets, indicating that enzymes hydrolyzed some IDF that was subsequently fermented by gut microbes. Addition of enzymes after extrusion increased (P < 0.05) feces moisture by 1.5% causing loose stools. Addition of enzymes before extrusion reduced (P < 0.05) ATTD of CP due to overheating during drying after wet enzyme processing. The ATTD of nutrients was greater (P < 0.05) for pigs than dogs; Nevertheless, could be a good predictor (R2 = 0.74 - 0.87) for ATTD of OM, CP, and GE. In conclusion, enzyme addition after extrusion did not increase ATTD for the dogs but did impact feces metabolites and fecal quality. Finally, pigs are a good translational model for testing ATTD of dog foods.

PSII-26 Feeding Behavior and Feed Conversion in Roughage-Lacking Diets Containing Ionized Amino Acids as Antibiotic Alternative

Abstract To improve animal performance there has been an increase of starch amounts in the ruminant diets; however, feeding high-grain diets can induce metabolic disturbs, needs to include antibiotics in the diet to avoid acidosis and control the growth of lactic acid producing microorganism. In this study was used ionized amino acids to replace monensin and withdraw all forage of diet. Twenty-four Nellore young bulls were allocated into two groups. The first group was fed with high-grain diet containing Brachiaria brizantha hay (15% of DM) and sodium monensim (120 mg/d). The second group was fed with high-grain diet without forage and without antibiotics, containing 82 mg/kg of ionized amino acids (no-forage diet, MJ Nutricao Animal). The feeding lasted 100 d before slaughter, at the end of period l rumen fluid was collected for VFA and lactic acid measurements. The Penn State Particle Separator has been used to monitor feeding sorting, the dry matter intake (DMI) was monitored daily in GrowSafe system and body weight (BW) was measured monthly. A completely randomized design was used. In the forage plus monensin diet the animals sorted larger particle (7.8 to 19 and > 19 mm), the proportion of larger particles decrease after feeding, the proportion of particles from 1.7 to 7.8 mm increased and there was no effect on smaller particles (< 1.7 mm). The animals feeding with no-forage diet avoided the whole cottonseed, the proportion of particles from 1.7 to 7.8 mm decreased and smaller particles (< 1.7 mm) did not change, before or after feeding (Table 2). The feeding behavior was changed; there were visits in the Growsafe feeder, the visits were faster and there was greater consumption per visit, in no-forage diet (Table 1). However, there were greater concentrations of propionic acid (50.9 vs 16.0 mM), smaller acetic:propionic ratio (1.1 vs 3.4), a trend to increased lactic acid (0.3 vs 0.2 mM), and the pH decreased in no-forage diet (6.29 vs 6.68), reducing the DMI (2 vs 2.5% of BW). There was a trend to reduce the BWG (1.7 vs 2.0 kg/d) in no-forage diet. There was no difference in feed conversion (6.43 in forage diet vs 6.08 no forage diet). In conclusion, the faster starch consumption of no-forage diet can induce greater propionic acid concentration, reducing DMI, on the other hand, the no-forage diet representing advantage to become the management of feedlot diets easier, allowing supply concentrate with less frequency, reducing dependence of forage production on farm, with the same feed conversion, without use of antibiotics. We hypothesize that fast passage rate reduces the hind gut starch digestibility, thus, further investigation can include supplies to improve alfa-amylase, to achieve even better feed conversion.

In vitro digestion and fecal fermentation of encapsulated starch constructed via layer-by-layer coating of calcium alginate

This research prepared functional-resistant starch capsules by constructing multiple calcium alginate shells around calcium alginate/starch beads. Scanning electron microscopy revealed a dense structure for each layer of the calcium alginate shell, tightly encapsulating the calcium alginate/starch beads. The rapidly digestive starch content of three-layer calcium alginate shelled starch capsules decreased to 0.50 ± 1.14%, while the resistant starch content increased to 78.25 ± 1.55%. The estimated glycemic index (eGI) experiment suggested that the two-layer shell capsules (eGI: 59.91) and Three-layer shell capsules (eGI: 47.75) were classified as low-glycemic index foods. Furthermore, calcium alginate/corn starch multilayer capsules showed reduced microbial gas production and increased concentrations of propionic acid, isobutyric acid, and valeric acid compared to lactulose in vitro fecal fermentation experiment. Moreover, three-layer capsules and beads promoted a relative abundance of Bacteroidetes but inhibited the reproduction of Proteobacteria and Actinobacteria compared with lactulose and corn starch. These results suggest that constructing multi-layered sodium alginate shells for starch beads can effectively increase the digestive resistance of starch within the capsules and control its fermentation in the colon. This study will have a profound impact on the development of RS1-type resistant starch and be beneficial in the design and production of functional foods for prevention and assistance in the treatment of chronic diseases such as diabetes and obesity.

Dietary NDF/Starch Ratio Modulates Colonic Microbiota and Metabolites in Lambs before and after Weaning

The neutral detergent fiber (NDF)/starch ratio is a key determinant of the carbohydrate composition in ruminant diets, which affects the development of the gastrointestinal tract and animal growth. In this study, we used a combination of 16S amplicon sequencing and metabolomics technologies to reveal changes in the microbiota and their metabolites associated with digestive matter in the colon of lambs between different starter NDF/starch ratios and before and after weaning. A total of 40 male lambs of Hu sheep with a newborn weight of 3.14 ± 0.05 kg were selected for the experiment and fed with breast milk until 10 days of age, and were randomly divided into 2 groups, which were fed ad libitum with a starter of NDF/starch of 0.5 (A) or 1.0 (B) for a period of 56 days, and then weaned off the milk powder at 35 days of age. Six lambs with weights close to the average weight of the group were selected for slaughter in each of the two groups before (35 days of age) and after weaning (56 days of age), and were accordingly named A35, A56, B35 and B56. The results showed that, before weaning, the concentrations of acetic acid, propionic acid, butyric acid and total volatile fatty acids (TVFA) in group B35 were significantly higher than those in group A35 (p < 0.05), while the concentrations of isobutyric acid, valeric acid and isovaleric acid were significantly lower than those in group A35 (p < 0.05). After weaning, the concentrations of all volatile acids and total acids in group B56 were significantly lower than those in group A56 (p < 0.01). At the phylum level, the dominant phyla identified were Firmicutes and Bacteroidetes; the relative abundances of Firmicutes and Desulfobacterota were significantly higher and lower in group B35 than in group A35, respectively (p < 0.05); the relative abundances of Euryarchaeota and Desulfobacterota were significantly higher and lower in group A56 than in group A35 (p < 0.05); and, at the genus level, the relative abundance of Lachnospiraceae_FCS020_group and Eubacterium nodatum group had higher relative abundance in group B35 before weaning (p < 0.05). Metabolomic results showed that feeding 1.0 NDF/starch ratio starter before weaning significantly up-regulated (p < 0.05) the concentrations of several anti-inflammatory-related metabolites such as lithocholic acid, oleanolic acid and LysoP. After weaning, the number of differential microorganisms and anti-inflammatory-related metabolites decreased between the two ratios. In summary, feeding a 1.0 NDF/starch ratio starter may be more effective in regulating microbial fermentation, leading to an increase in beneficial microbiota and metabolites, thus improving colonic environmental homeostasis in lambs before and after weaning.

Cold isostatic pressing-study on methane production and microbial communities in anaerobic digestion of wheat straw with high-solids

In this study, the effect of cold isostatic pressing (CIP) pretreatment on the physicochemical properties and subsequent anaerobic digestion (AD) performance of wheat straw (WS) was explored, which did not have additional chemical reagent over the whole process. The WS was subjected to CIP pretreatment by pressures from 350 to 700 MPa, respectively, while AD was carried out at mesophilic temperature with total solids (TS) 7% and 14%. The mapping indicated that the CIP pretreatment promoted the hydrolysis of WS by destroying the dense structure. The CIP pretreatment changed pH and volatile fatty acids (VFAs) in the AD system. Compared with the control group, the cumulative methane production of CIP pretreatment group with TS 14% increased by 22.07%–56.18%. The acetic acid concentration peaked on 4th day and 14th day with 3943.23 mg/L and 3815.21 mg/L, respectively, in H600, and propionic acid concentration also reached two peaks at the same time with 2014.92 mg/L and 2405.20 mg/L, respectively. It was also observed that the CIP pretreatment maintained the pH in the range of 6.44–7.40, maintaining the stability of the overall system. It was also found that CIP pretreatment increased 9 species of hydrolysis and acidogenic bacteria, and methanogen Methanosarcina, thereby facilitating the hydrolysis and methanogenic stages. Predictive functional profiling comfirmed that CIP pretreatment could promote glycolysis/gluconeogenesis, fatty acid metabolism, and fatty acid degradation, whose relative abundance increased from 1.10% to 1.13%, 0.60%–0.62%, and 0.19%–0.23%. Methanogenic capacity of the system was improved because of CIP pretreatment enhancing the accessibility of microorganisms by disrupting the microstructure of WS. The energy conversion analysis showed that this method without chemical reagent addition is feasible for high-solids anaerobic digestion.

Effects of the Oat Hay Feeding Method and Compound Probiotic Supplementation on the Growth, Antioxidant Capacity, Immunity, and Rumen Bacteria Community of Dairy Calves.

This study aimed to investigate the effects of the oat hay feeding method and compound probiotics (CMP) on the growth, health, serum antioxidant and immune indicators, rumen fermentation, and bacteria community of dairy calves from 3 to 5 months of age. Forty-eight female Holstein calves (80 ± 7 days of age, 93.71 ± 5.33 kg BW) were selected and randomly divided into four groups. A 2 × 2 factorial design was adopted for the experiment, with the factors of the oat hay feeding method (fed as free-choice or 16.7% in the diet) and compound probiotics (CMP) inclusion (0.15% or 0%) in the pelleted starter. The results showed that, compared with giving oat hay as free-choice, feeding a diet of 16.7% oat hay increased the pelleted starter intake at 1-84 d (p < 0.05), with an average daily gain (ADG) at 61-84 d (p = 0.02); adding CMP to the pelleted starter did not significantly affect body weight, and reduced the fecal index (p < 0.05). Feeding 16.7% oat hay increased the concentration of IgA, IgG, and IgM (p < 0.01), while adding CMP increased the catalase (p < 0.01) and decreased the concentration of malondialdehyde (p < 0.01) in serum. Feeding 16.7% oat hay increased the ruminal concentration of propionic acid (p < 0.05) and isobutyric acid (p = 0.08), and decreased the ruminal pH (p = 0.08), the concentration of acetic acid (p < 0.05), and the ratio of acetic acid to propionic acid (p < 0.01). Feeding 16.7% oat hay reduced the relative abundance of ruminal Firmicutes, Unidentified-Bacteria, Actinobacteria, Prevotella, NK4A214-group, Olsenella, and Actinobacteriota (p < 0.05); adding CMP increased the relative abundance of ruminal Prevotella, Rikenellaceae-RC9-gut-group, Ruminococcus, NK4A214-group, and Ruminococcus (p < 0.05), and decreased the abundance of Desulfobacterora, Prevotella-7, and Erysipelotricaceae-UCG-002 (p < 0.05). In conclusion, feeding a diet of 16.7% oat hay increased the pelleted starter intake and average daily gain, while slightly reducing the ruminal pH values; adding CMP to the pelleted starter resulted in reduced diarrhea incidence, increased serum antioxidant capacity and immunity, as well as ruminal richness and diversity of microorganisms in dairy calves from 3 to 5 months of age.

Effects of three different plant-derived polysaccharides on growth performance, immunity, antioxidant function, and cecal microbiota of broilers.

This study investigated the effects of dietary plant polysaccharides on growth performance, immune status and intestinal health in broilers. We randomly divided 960 one-day-old Arbor Acres broiler chicks into 4 groups. The control (CON) group was fed a basal diet, and the remaining groups were fed a basal diet supplemented with 1,000 mg/kg ginseng polysaccharide (GPS), astragalus polysaccharides (APS), or Salvia miltiorrhiza polysaccharide (SMP) for 42 d. Dietary supplementation with SMP significantly increased BW at 21 and 42 days of age, ADG and ADFI during the starter and whole experimental period, decreased the concentrations of IL-1β, TNF-α and MDA, increased the levels of IL-4 and IL-10 and CAT activity in the serum (P < 0.05). GPS, APS, and SMP supplementation increased serum levels of immunoglobulins, activities of GSH-Px, T-SOD and T-AOC, and cecal concentrations of acetic acid and propionic acid of broilers (P < 0.05). Furthermore, high-throughput sequencing results showed that the relative abundance of Firmicutes was decreased while the relative abundance of Bacteroidota, Alistipes, and Prevotellaceae_NK3B31_group were increased (P < 0.05) in the GPS, APS, and GMP groups compared with the CON group. Dietary GPS, APS, and SMP supplementation could improve growth performance, enhance immune function by increasing serum immunoglobulin and regulating cytokines, improve antioxidant function by increasing serum antioxidant enzyme activity, increase volatile fatty acid levels and improve the microbial composition in the cecum of broilers. Dietary SMP supplementation had the optimal effect in this study. This article is protected by copyright. All rights reserved.

Propionic Acid Driven by the Lactobacillus johnsonii Culture Supernatant Alleviates Colitis by Inhibiting M1 Macrophage Polarization by Modulating the MAPK Pathway in Mice.

In this study, we investigated the effects of Lactobacillus johnsonii on the mouse colitis model. The results showed that the supernatant of the L. johnsonii culture alleviated colitis and remodeled gut microbiota, represented by an increased abundance of bacteria producing short-chain fatty acids, leading to an increased concentration of propionic acid in the intestine. Further studies revealed that propionic acid inhibited activation of the MAPK signaling pathway and polarization of M1 macrophages. Macrophage clearance assays confirmed that macrophages are indispensable for alleviating colitis through propionic acid. In vitro experiments showed that propionic acid directly inhibited the MAPK signaling pathway in macrophages and reduced M1 macrophage polarization, thereby inhibiting the secretion of pro-inflammatory cytokines. These findings improve our understanding of how L. johnsonii attenuates inflammatory bowel disease (IBD) and provide valuable insights for identifying molecular targets for IBD treatment in the future.

Encapsulation of probiotics with poly-γ-glutamic acid alters gut microbiota and short-chain fatty acid content by maintaining cell viability in the gastrointestinal tract

The viability of most probiotics is generally reduced by gastric and bile acids during passage through the host's gastrointestinal tract. Therefore, we investigated the effect of encapsulation with poly-γ-glutamic acid (γ-PGA) on the viability and function of probiotics. The protective effect of γ-PGA encapsulation at different γ-PGA concentrations (0.25, 0.5, 0.75, and 1.0%) and simulated gastric juice (SGJ) exposure times (1, 2, and 3 h) was assessed. The viability of all probiotics was either completely lost or significantly reduced within 3 h of exposure to SGJ under non-encapsulation conditions. In contrast, γ-PGA encapsulation at a concentration of 0.25–1.00% maintained the viability of all SGJ-exposed strains. In an in vitro gastrointestinal digestion experiment simulating the oral, gastric, and duodenal phases, encapsulation resulted in a higher survival rate than that associated with non-encapsulation. In vivo experiments involving oral administration of encapsulated Limosilactobacillus reuteri to mice showed that encapsulation increased the abundance of the genus Lactobacillus in the gut microbiota and increased propionic acid content among the short-chain fatty acids (SCFAs) analyzed. In addition, live probiotic cell concentrations in mouse feces were found to be significantly higher in the encapsulated probiotic-fed group than in the non-encapsulation group. The present findings demonstrate that γ-PGA encapsulation maintains the viability of probiotics in the gastrointestinal tract of the host, while providing beneficial effects on changes in the gut microbiota and SCFA content.

Structure analysis and in vitro evaluation of probiotic properties for polysaccharides from Phellinus baumii extracted with phosphotungstic acid assistance

Heteropolysaccharides were extracted from Phellinus baumii using hot water assisted by phosphotungstic acid, and their physicochemical properties and structures were analyzed. Two isolated components (SPB and SPC) were composed of fucose, galactose, glucose and mannose, with molecule weight of 12.6 kDa and 9.4 kDa, respectively. Structural analysis showed that →6)-Galp-(1→ and →4)-Glcp-(1→ were the main 2D structural fragments in SPB, while →6)-Galp-(1→ and →6)-Glcp-(1→ predominated in SPC. After 48 h of in vitro fermentation with human fecal inoculum, the concentration of propionic acid was extensively boosted (166.3–538.0 μg/mL) by SPB. In addition, the heteropolysaccharides could promote the abundance and diversity of gut microbiota. SPB markedly promoted proliferation of Limosilactobacillus, Megamonas and Bifidobacterium. KEGG-based functional gene prediction implied that biosynthesis of antibiotics, secondary metabolites and ribosome were promoted by SPB component, indicating a stronger probiotic proliferative ability compared to SPA. Overall, these findings emphasized the potential of these heteropolysaccharides possess to maintain the gut health as a potential prebiotic supplemented in foods and nutraceuticals.

Enhancing Acetic Acid Production in In Vitro Rumen Cultures by Addition of a Homoacetogenic Consortia from a Kangaroo: Unravelling the Impact of Inhibition of Methanogens and Effect of Almond Biochar on Rumen Fermentations

A homoacetogenic consortium was cultivated from feces from a nursing joey red kangaroo and inoculated into an in vitro ruminal culture. The in vitro ruminal culture was treated with methanogenic inhibitor 2-bromoethanesulfonate (BES), followed by two different homoacetogenic inoculation strategies. Initial observations showed inhibitory effects of BES, with stabilization of the acetic acid concentrations without any increase in concentration, even with the homoacetogenic inoculation. When homoacetogenic bacterial culture was added after the BES addition had ceased, acetic acid production was increased 2.5-fold. Next-generation sequencing showed an increased population of Bacteroidetes after inoculation with the homoacetogenic consortia, along with a slight decrease in diversity. An Almond Shell biochar (AS) addition resulted in a 28% increase in acetic acid concentration if tested directly on the homoacetogenic kangaroo consortia. However, when applied to the rumen culture, it did not enhance acetate production but further promoted other reductive pathways such as methanogenesis and propiogenesis, resulting in increased concentrations of methane and propionic acid, respectively. These findings demonstrate that bioaugmentation with homoacetogenic bacteria can improve acetic acid production of an in vitro rumen culture when methanogenesis has been eliminated. Such advancements can potentially contribute to the optimization of rumen fermentation processes and may have practical implications for improved livestock feed efficiency and methane mitigation strategies.

Effect of moxibustion of acupoints for both lung and intestine disorders on lung inflammation and intestinal short-chain fatty acids in asthmatic model rats

To explore the mechanism of moxibustion in the treatment of asthmatic inflammation from the point of short-chain fatty acids (SCFAs) in rats with asthma. A total of 48 SD rats (half male and half female) were randomly divided into 4 groups： normal, model, lung treatment and joint-treatment of lung and intestine (joint-treatment), with 12 rats in each group. The asthma model was made by subcutaneous (bilateral back and inguinal regions) and intraperitoneal injection of mixture solution of ovalbumin and aluminium hydroxide gel (on day 1 and 8) and followed by inhalation of atomized 1% ovalbumin (20 min from day 15, once daily for one week). Moxibustion was applied to bilateral "Feishu" (BL13) for rats of the lung treatment group or bilateral "Feishu" (BL13) and "Tianshu" (ST25) for rats of the joint treatment group. One hour after the intervention, the rats in the later three groups were separately given atomized 1% ovalbumin solution inhalation for 20 min. The treatment was conducted for 30 min, once daily for 14 consecutive days. At the end of the intervention, the percentage of inflammatory cells in blood was detected by biochemical method and histopathological changes of the lung were observed after H.E. staining. The inflammatory cells in the bronchoalveolar lavage fluid (BALF) were counted after Wright-Giemsa staining. The mRNA expressions of interleukin (IL)-4, IL-5, IL-13, IL-17, IL-33, leukotriene (LT), thymic stromal lymphopoietin (TSLP) and prostaglandin D2 (PGD2) were detected by real-time PCR, and the contents of SCFAs in rats' feces were detected by gas chromatography-mass spectrometry. Relevant to the normal group, the model group had an obvious increase in the percentages of neutrophils, lymphocytes and eosinophils in the blood, the percentages of neutrophils and eosinophils in the BALF, and in the expression levels of PGD2, TSLP, LT, IL-4, IL-5, IL-13, IL-17 and IL-33 mRNAs in the lung tissues (P<0.01, P<0.05), and a marked decrease in the contents of acetic acid, propionic acid, isobutyric acid, butyric acid and valeric acid in feces (P<0.05, P<0.01). After the treatment, the percentages of neutrophils and lymphocytes in the peripheral blood, eosinophils in the BALF, and the expression levels of PGD2, TSLP, LT, IL-4, IL-17, IL-33 mRNAs in the lung tissues in both the lung treatment and joint treatment groups, as well as neutrophils of BALF, and expression of IL-5 and IL-13 mRNAs in the joint treatment group were significantly down-regulated (P<0.01, P<0.05), while the contents of acetic acid, propionic acid and valerate in the lung treatment group, and acetic acid, propionic acid, isobutyric acid, butyric acid and valeric acid in the joint treatment group were all strikingly increased (P<0.05, P<0.01). The effect of the joint treatment was superior to that of lung treatment in down-regulating the expressions of LT and IL-5 mRNAs (P<0.05, P<0.01) and up-requlating the content of propionic acid (P<0.05). Results of H.E. staining showed thickened alveolar wall, infiltration of a large number of inflammatory cells and interstitial fibrous tissue hyperplasia around the bronchus and scattered arrangement of cells of the lung tissue in the model group, which was relatively milder in both lung treatment and joint treatment groups, particularly the later. Joint treatment of asthma from the lung and intestine can better regulate the contents of intestinal SCFAs and alleviate the inflammatory response of asthmatic model rats, thus, intestinal SCFAs may be involved in the process of moxibustion in improving inflammatory response.

Effect of Yeast Culture on Reproductive Performance, Gut Microbiota, and Milk Composition in Primiparous Sows.

The objective of this study was to evaluate the effects of yeast culture (YC) on reproductive performance, gut microbiota, and milk composition in primiparous sows. A total of 60 primiparous sows were randomly assigned to the control group (CON) and YC group (0.5% YC during gestation and 0.8% YC during lactation) consisting of 30 replicates, with one sow in each. The results showed that dietary YC supplementation increased the piglet birth weight and backfat thickness at 28 d of lactation (p < 0.05). Dietary YC supplementation increased the apparent total tract digestibility (ATTD) of gross energy and calcium during lactation, the content of acetic acid and propionic acid at 110 d of gestation, and the content of acetic acid and butyric acid at 28 d of lactation in feces (p < 0.05). Furthermore, dietary YC supplementation decreased the abundance of Firmicutes, Lachnospiraceae_XPB1014_group, and Terrisporobacter (p < 0.05), and increased the abundance of Prevotellaceae_NK3B31_group and Rikenellaceae_RC9_gut_group (p < 0.05). Compared to the control group, dietary YC supplementation increased the fat and lactose content of the colostrum (p < 0.05). Metabolomics analysis showed that YC increased 26 different metabolites in the colostrum. Among them were mainly pantothenic acid, proline, isoleucine, phenylalanine, acylcarnitine, and other metabolites. In conclusion, these results suggested that dietary YC supplementation improves reproductive performance and gut health and increases the nutrient content in the colostrum of primiparous sows.

Carbon nano-onions acting as artificial pili enhance chloramphenicol degradation in an anaerobic membrane bioreactor

Carbon-based materials are commonly used to promote methane production and organic degradation by enhancing direct interspecies electron transfer (DIET). Carbon nano-onions (CNOs) were first applied in an anaerobic membrane bioreactor to treat chloramphenicol (CAP) wastewater in this study. Results demonstrate that CAP was almost undetectable in the effluent after 188 days of operation. In Phases 1–3 (days 1 to 152), CAP increase in the influent led to maximum concentrations of 291.1 mg/L for acetic acid and 86.3 mg/L for propionic acid. In Phase 4 (days 153 to 188), the concentrations of acetic acid and propionic acid increased to a maximum of 211.5 mg/L and 342.3 mg/L. During Phase 3, the maximum methane productivity was 0.72 L/d, and the methanogenic lag time was 4.97 days. However, with the addition of CNOs and a higher CAP load, the maximum methane productivity reached 0.71 L/d, accompanied by a reduced methanogenic lag time of 1.22 days. Moreover, it significantly enhanced the abundances of Geobacteraceae, norank o norank c Thermodesulfovibrionia, Syntrophobacteraceae, Methanosaetaceae and Methanobacteriaceae which exhibited much higher specific growth rates in the family level. CNOs with high electrical conductivity acted as artificial pili to enhance DIET between Geobacteraceae and Methanosaetaceae, as well as between Syntrophobacteraceae and Methanobacteriaceae or Methanosaetaceae. Furthermore, CNOs dosing during Phase 4 mitigated membrane contamination, and the maximum filtration resistance was 11% lower than that of Phase 3. These results suggest that CNOs can be used effectively in AnMBR for treating CAP wastewater, particularly for enhancing methanogens.

Evaluation of Associative Effects of In Vitro Gas Production and Fermentation Profile Caused by Variation in Ruminant Diet Constituents

This study aimed to investigate the associative effects caused by changes in the proportions of feed ingredients (forage-to-concentrate ratio) and the forage source in ruminant diets on in vitro gas production and fermentation parameters. The study consisted of two assays conducted in a completely randomized design with a 3 × 10 factorial arrangement consisting of three forages (pineapple crop waste silage [PS], corn silage [CS], and Tifton hay [TH]) associated with concentrate feed (C) (binary mixture) in 11 proportions, with triplicates of each combination. For the first assay, the asymptotic volume of gas did not show any difference among (p = 0.059) CS and PS (p = 0.464) and their proportions. We evaluated the associative effect among forages and their proportions and noticed there was an effect on gas production between the combination of forage and concentrate for the CS (p = 0.003) and PS (p = 0.003). In the second assay, volatile fatty acids (VFA) and ammonia nitrogen (p &lt; 0.05) were affected by the forage source and concentrate inclusion. In conclusion, forages with a high content of soluble carbohydrates presented the lowest gas production, as well as higher concentrations of propionic acid and ammonia nitrogen. The associative effect on in vitro gas production was more pronounced in the first 12 h incubation. The different forage sources and the inclusion of concentrate change fermentation parameters.

From the perspective of rumen microbiome and host metabolome, revealing the effects of feeding strategies on Jersey Cows on the Tibetan Plateau.

Previous studies have discussed the effects of grazing and house feeding on yaks during the cold season when forage is in short supply, but there is limited information on the effects of these feeding strategies on Jersey cows introduced to the Tibetan Plateau. The objective of this study was to use genomics and metabolomics analyses to examine changes in rumen microbiology and organism metabolism of Jersey cows with different feeding strategies. We selected 12 Jersey cows with similar body conditions and kept them for 60 days under grazing (n=6) and house-feeding (n=6) conditions. At the end of the experiment, samples of rumen fluid and serum were collected from Jersey cows that had been fed using different feeding strategies. The samples were analyzed for rumen fermentation parameters, rumen bacterial communities, serum antioxidant and immunological indices, and serum metabolomics. The results of the study were examined to find appropriate feeding strategies for Jersey cows during the cold season on the Tibetan plateau. The results of rumen fermentation parameters showed that concentrations of acetic acid, propionic acid, and ammonia nitrogen in the house-feeding group (Group B) were significantly higher than in the grazing group (Group G) (P<0.05). In terms of the rumen bacterial community 16S rRNA gene, the Chao1 index was significantly higher in Group G than in Group B (P=0.038), while observed species, Shannon and Simpson indices were not significantly different from the above-mentioned groups (P>0.05). Beta diversity analysis revealed no significant differences in the composition of the rumen microbiota between the two groups. Analysis of serum antioxidant and immune indices showed no significant differences in total antioxidant capacity between Group G and Group B (P>0.05), while IL-6, Ig-M , and TNF-α were significantly higher in Group G than in Group B (P<0.05). LC-MS metabolomics analysis of serum showed that a total of 149 major serum differential metabolites were found in Group G and Group B. The differential metabolites were enriched in the metabolic pathways of biosynthesis of amino acids, protein digestion and absorption, ABC transporters, aminoacyl-tRNA biosynthesis, mineral absorption, and biosynthesis of unsaturated fatty acids. These data suggest that the house-feeding strategy is more beneficial to improve the physiological state of Jersey cows on the Tibetan Plateau during the cold season when forages are in short supply.

Diet medication and beta-glucanase affect ileal digesta soluble beta-glucan molecular weight, carbohydrate fermentation, and performance of coccidiosis vaccinated broiler chickens given wheat-based diets

Exogenous enzymes as alternatives to feed antibiotics in poultry has become an emerging research area with the emergence of antibiotic resistance. The objective was to evaluate the effects of diet medication (antibiotics) and β-glucanase (BGase) on digesta soluble β-glucan depolymerization, carbohydrate fermentation, and performance of coccidiosis-vaccinated broiler chickens fed wheat-based diets. A total of 1,782 broilers were raised on litter floor pens, and each treatment was assigned to 1 pen in each of the 9 rooms. The 3 dietary treatments were based on wheat as the sole grain (control, control + medication and control + 0.1% BGase), and the birds were fed the respective treatments ad libitum from 0 to 33 d. Treatments were arranged in a randomized complete block design and analyzed as a one-way ANOVA. Beta-glucanase reduced the peak molecular weight, weight average molecular weight (Mw) and maximum molecular weight for the smallest 10% β-glucan molecules (MW-10%) in ileal digesta at d 11 and 33, whereas diet medication reduced Mw and MW-10% at d 33 compared to the control (P < 0.01). Beta-glucanase and medication reduced the ileal viscosity at d 11 compared to the control (P = 0.010). Ileal propionic acid concentration at d 11 and caecal total SCFA, acetic, and butyric acid concentrations at d 33 were lower in the BGase-supplemented diet than in the control (P < 0.05). The BGase-added diet had higher duodenal pH compared to the control at d 33 (P = 0.026). The effect of medication on carbohydrate fermentation was minimal. Diet medication increased weight gain after d 11, whereas BGase increased the gain for the total trial period compared to the control (P < 0.001). Feed intake was not affected by the dietary treatment. Medication and BGase improved feed efficiency after d 11 compared to the control (P < 0.001). The response to diet medication was larger than BGase, considering weight gain and feed efficiency after d 11 (P < 0.001). In conclusion, diet medication and BGase depolymerized high molecular weight ileal soluble β-glucan and increased overall bird performance. Dietary BGase may benefit bird health in broilers fed wheat-based diets without medication.