Addition Of Butyrate Research Articles

Butyrate as a growth factor of Clostridium acetobutylicum

The butyrate biosynthetic pathway not only contributes to electron management and energy generation in butyrate forming bacteria, but also confers evolutionary advantages to the host by inhibiting the growth of surrounding butyrate-sensitive microbes. While high butyrate levels induce toxic stress, effects of non-toxic levels on cell growth, health, metabolism, and sporulation remain unclear. Here, we show that butyrate stimulates cellular processes of Clostridium acetobutylicum, a model butyrate forming Firmicute. First, we deleted the 3-hydroxybutyryl-CoA dehydrogenase gene (hbd) from the C. acetobutylicum chromosome to eliminate the butyrate synthetic pathway and thus butyrate formation. A xylose inducible Cas9 cassette was chromosomally integrated and utilized for the one-step markerless gene deletions. Non-toxic butyrate levels significantly affected growth, health, and sporulation of C. acetobutylicum. Upon deleting spo0A, the gene of the master regulator of sporulation, Spo0A, and followed by butyrate addition experiments, we conclude that butyrate affects cellular metabolism through both Spo0A-dependent and independent mechanisms. We also deleted the hbd gene from the chromosome of the asporogenous C. acetobutylicum M5 strain lacking the pSOL1 plasmid to examine the potential involvement of pSOL1 genes on the observed butyrate effects. Addition of the precursor of butyrate biosynthesis crotonate to the hbd deficient M5 strain was used to probe the role of butyrate biosynthesis pathway in electron and metabolic fluxes. Finally, we found that butyrate addition can enhance the growth of the non-butyrate forming Clostridium saccharolyticum. Our data suggest that butyrate functions as a stimulator of cellular processes, like a growth factor, in C. acetobutylicum and potentially evolutionarily related Clostridium organisms.

Butyrate protects the intestinal barrier by upregulating Fut2 expression via MEK4-JNK signaling pathway activation.

Necrotizing enterocolitis (NEC) is a severe gastrointestinal inflammatory disease in neonates. Fucosyltransferase 2 (Fut2) regulates intestinal epithelial cell fucosylation. In this study, we aimed to investigate butyrate-mediated upregulation of Fut2 expression and the underlying mechanisms. In vivo and in vitro models were established. SP600125 was used to inhibit the MEK4-JNK pathway, and anisomycin was used to activate the MEK4-JNK pathway. Fut2, occludin, and ZO-1 expressions were assessed. Furthermore, intestinal permeability was analyzed by FITC-Dextran. The expression of proteins in the MEK-4-JNK pathway was examined by western blotting. In vivo, the addition of exogenous butyrate notably upregulated Fut2, occludin, and ZO-1 expressions and reduced intestinal permeability in mice with NEC. Butyrate may increase the phosphorylation of MEK4, JNK, and c-jun, which are key components of the MEK4-JNK pathway. Additionally, SP600125 inhibited their phosphorylation, which was reversed by anisomycin treatment. In vitro, butyrate substantially increased occludin and ZO-1 expressions. Butyrate considerably increased Fut2 expression and markedly upregulated p-MEK4, p-JNK, and p-c-jun expressions. SP600125 administration decreased their expressions, while anisomycin administration increased their expressions. Butyrate upregulated Fut2 expression via activation of the MEK4-JNK pathway, improved intestinal barrier integrity, and protected neonatal mice from NEC. We found that exogenous butyrate could improve intestinal barrier integrity and protect against NEC in neonatal mice. Our data showed that exogenous butyrate supplementation upregulated Fut2 expression by activating the MEK4-JNK pathway. Our study provides novel insights into the pathogenesis of NEC, thereby laying an experimental foundation for future clinical research on the use of butyrate in NEC treatment.

Effect of cellulose derivatives on crystallization and mechanical properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

Abstract In this work, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was modified by cellulose derivatives, and the effects of different kinds of cellulose derivatives on the crystallization and mechanical properties of PHBV were investigated. The crystallization and mechanical properties of PHBV/cellulose derivatives composites were measured by means of differential scanning calorimeter, polarizing microscope, and mechanical properties testing instruments. Studies show that cellulose acetate (CA) can promote the crystallization of PHBV, a small amount of CA can significantly increase the crystallization temperature of PHBV. The crystallization rate of PHBV was also accelerated by CA. However, the addition of cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) decreased the crystallization temperature of PHBV and inhibited the nucleation of PHBV. And the degree of inhibition increased with the increase of CAB and CAP content. CAB and CAP have good compatibility with PHBV, CAB, and CAP can be uniformly dispersed in PHBV. Cellulose derivatives with specific component content can enhance the tensile properties of PHBV without losing the impact strength.

A new compound, phomaherbarine A, induces cytolytic reactivation in epstein-barr virus-positive B cell lines

Epstein-Barr virus (EBV), the first virus found to induce cancer in humans, has been frequently detected in various types of B cell lymphomas. During its latent phase, EBV expresses a limited set of proteins crucial for its persistence. Induction of the lytic phase of EBV has shown promise in the treatment of EBV-associated malignancies. The present study assessed the ability of phomaherbarine A, a novel compound derived from the endophytic fungus Phoma herbarum DBE-M1, to stimulate lytic replication of EBV in B95-8 cells. Phomaherbarine A was found to efficiently initiate the expression of both early and late EBV lytic genes in B95-8 cells, with this initiation being further heightened by the addition of phorbol myristate acetate and sodium butyrate. Moreover, phomaherbarine A demonstrated notable cytotoxicity against the EBV-associated B cell lymphoma cell lines B95-8 and Raji. Mechanistically, phomaherbarine A induces apoptosis in these cells through the activation of caspase-3/7. When combined with ganciclovir, phomaherbarine A does not interfere with the reduction of viral replication by ganciclovir and sustains its apoptosis induction. In conclusion, these findings indicate that phomaherbarine A may be a promising candidate for therapeutic intervention in patients with EBV-associated B cell lymphomas.

Effects of the diet enrichment with β-glucan, sodium salt of butyric acid and vitamins on growth parameters and the profile of the gut microbiome of juvenile African catfish (Clarias gariepinus)

This study assessed the effect of the addition of active substances, i.e., β-glucan, sodium butyrate and vitamins (C, A, D3, E, K) to the diet of juvenile African catfish (Clarias gariepinus) on growth parameters and the intestinal microbiome. For this purpose, a four-week rearing of juveniles African catfish in a recirculating aquaculture system (RAS) under controlled conditions at 25°C was conducted. The fish were fed commercial feed (control group - C), which was enriched with various levels of sodium butyrate and β-glucan (FQV1 – FQV4). After the experiment, growth parameters such as weight gain (WG; g), length gain (LG; cm), specific growth rate (SGR; % d−1), condition factor (K) survival rate (SR; %) and cannibalism factor (CF; %) were determined. The profile of the intestinal microbiome was also determined using Next-Generation Sequencing (NGS) based on the analysis of the 16 S rRNA subunit. The obtained results indicated that feed supplementation with active substances in appropriate doses had a positive effect on the growth parameters of tested fish. Compared to the control group, statistically significant differences were obtained in WG (C - 7.62 g; FQV3 - FQV1 respectively 12.2–16.65 g), in WL (C - 6.23 cm; FQV3 - FQV1 respectively 7.59–8.74 cm), in SGR (C - 4.7%/d; FQV3 – V1 respectively 12.20 – 16.65 g), in K (C – 0.76; V3 – FQV4 respectively 0.80 – 0.84) (P <0.05). In addition, the control group had the highest value of CF (8.0%) compared to the research groups (P <0.05). The values of α-diversity metrics did not show statistically significant differences. However, the number of unique amplicon sequence variants (ASVs) in research groups confirmed that enriching the diet with the active substances increases the biodiversity of intestinal microbiome (C - 203; FQV4 - 373). In research groups and the control group, Firmicutes and Proteobacteria dominated, additionally, an increased number of beneficial lactic acid bacteria (LAB) of the Lactococcus and Bacillus genus was observed, while the number of potentially pathogenic bacteria of the Candidatus genus was reduced (P <0.05). Principal coordinate analysis (PCoA) determining β-diversity showed that the FQV3 was characterized by varied species composition compared to the other groups. The obtained results showed that a carefully selected composition of active ingredients used in the diet of juvenile African catfish has a beneficial effect on the profile and biodiversity of the intestinal microbiome, which indirectly improves resistance to infections and increases breeding indicators.

PSVII-28 Effects of Adding Either Fibrolytic Enzymes Or Sodium Butyrate to Feedlot Diets on Rumen Parameters of Angus Cattle

Abstract This study conducted at São Paulo State University feedlot, Dracena campus, Brazil, was designed to evaluate the addition of either sodium butyrate (BUT) or exogenous fibrolytic enzymes (ENZ) on dry matter intake (DMI), ruminal pH, short-chain fatty acids (SCFA), and rumen disappearance rate of Angus cattle. Three Angus steers, cannulated in the rumen (+ 690 kg), were used in a replicated 3 x 3 Latin square, resulting in 6 experimental periods, in a total of 203 days of study. Each experimental period lasted 28 days; 14 days of adaptation diets, and 14 days of the finishing diet containing 85% concentrate (71% finely-ground corn). Cattle were given a 7-day washout interval between periods, where they were allowed to graze. The experimental diets fed to the animals were different only with respect to the feed additives used, according to the treatments: Control (CTL; no feed additives added), ENZ [0.01% of diet dry matter (DM)], and BUT (0.3% and 0.1% of diet DM during adaptation and finishing phases, respectively). The DMI was measured daily, and rumen pH and temperature were measured by data loggers on days 25 and 26 of each experimental period. The rumen fluid samples were collected at 0, 4, 8, and 12 hours after feeding on day 26 of each period to determine the molar proportion of SCFA. The rumen of the animals was emptied on day 27 at 1100 h (3 hours after feeding) and day 28 at 0800 h (before feeding) in each experimental period. The rumen contents were separated into solid and liquid fractions and then weighed. Based on the solid and liquid mass values obtained, as well as the DM intake, the rumen disappearance rate was calculated and expressed in %/h. Data were analyzed by PROC MIXED of SAS (2003), using Tukey's test to compare means when appropriate, considering P ≤ 0.05 as significant. The DMI was not affected (P &amp;gt; 0.76) by treatments in this study. Likewise, no treatment effect was observed on minimum, maximum, and mean ruminal pH (P &amp;gt; 0.23). The pH time below 6.2, 5.6, and 5.2 was not affected by treatments (P &amp;gt; 0.45), as well as pH area under 6.2, 5.6, and 5.2 (P &amp;gt; 0.55). Rumen temperature was lower in cattle fed ENZ when compared with those fed CON and BUT (39.63°C vs. 40.12°C and 40.02°C, respectively; P = 0.04). Furthermore, the molar proportions of SCFA were not affected by treatments (P &amp;gt; 0.71). Cattle consuming ENZ increased ruminal disappearance rate (%/h) when compared with CTL-fed cattle (8.61 vs 6.36; P = 0.05). Thus, the addition of BUT to feedlot diets did not cause any impact on ruminal fermentation parameters; however, the use of ENZ promoted small benefits that deserve further investigation.

Dietary supplementation of sodium butyrate enhances lactation performance by promoting nutrient digestion and mammary gland development in dairy cows

This experiment was to evaluate the influence of sodium butyrate (SB) addition on milk production, ruminal fermentation, nutrient digestion, and the development and metabolism regulation of the mammary gland in dairy cows. Forty Holstein dairy cows averaging 710 ± 18.5 kg body weight, 72.8 ± 3.66 d in milk (DIM), and 41.4 ± 1.42 kg/d milk production were divided into four treatments blocked by DIM and milk production. Treatments were control group, low SB, medium SB, and high SB with 0, 100, 200 and 300 g/d of SB addition per cow, respectively. The study lasted for 105 d. Production of milk, milk protein and lactose quadratically increased (P < 0.05), while fat-corrected milk, energy-corrected milk and milk fat yields linearly increased (P < 0.05) with increasing SB addition. The digestibility of dietary dry matter, organic matter, and crude protein linearly increased (P < 0.05), whereas the digestibility of ether extract, neutral detergent fibre, and acid detergent fibre quadratically increased (P < 0.05). Ruminal pH quadratically decreased (P = 0.04), while total volatile fatty acids (VFA) quadratically increased (P = 0.03) with increasing SB addition. The acetic acid to propionic acid ratio increased (P = 0.03) linearly due to the unaltered acetic acid molar percentage and a linear decrease in propionic acid molar percentage. Ruminal enzymatic activity of carboxymethyl-cellulase and α-amylase, populations of total bacteria, total anaerobic fungi, total protozoa, Ruminococcus albus, R. flavefaciens, Butyrivibrio fibrisolvens, Fibrobacter succinogenes, and Ruminobacter amylophilus linearly increased (P < 0.05). Blood glucose, urea nitrogen, and non-esterified fatty acids linearly decreased (P < 0.05), while total protein concentration linearly increased (P = 0.04). Moreover, the addition of SB at 200 g/d promoted (P < 0.05) mRNA and protein expression of PPARγ, SREBF1, ACACA, FASN, SCD, CCNA2, CCND1, PCNA, Bcl-2, GPR41, and the ratios of p-Akt/Akt and p-mTOR/mTOR, but decreased (P < 0.05) mRNA and protein expressions of Bax, caspase-3, and caspase-9. The results suggest that milk production and milk fat synthesis increased with SB addition by stimulating rumen fermentation, nutrient digestion, gene and protein expressions concerned with milk fat synthesis and mammary gland development.

Excessive Mitochondrial Fission Suppresses Mucosal Repair by Impairing Butyrate Metabolism in Colonocytes.

Mucosal healing is one of the principal therapeutic targets for ulcerative colitis (UC). Mitochondria are dynamic organelles that undergo constant fusion and fission; however, the process that is most conducive to mucosal healing remains unclear. This study investigated the role of mitochondrial fission in mucosal healing in UC patients. Quantitative polymerase chain reaction, Western blotting, and immunostaining were used to detect mitochondrial fission in UC patients and a dextran sulfate sodium-induced colitis model. Colonic organoids were used to investigate the role of mitochondrial fission in butyrate metabolism. Enzyme activity assays were performed to identify the key proteins involved in this mechanism. It was found that inhibition of mitochondrial fission promoted mucosal healing in mice and that there was an increase in mitochondrial fission in colonic epithelial cells of UC patients. Excessive fission inhibits stem cell proliferation by impairing butyrate metabolism in colonic organoids. The mitochondrial fission antagonist P110 failed to promote mucosal healing in antibiotic-treated mice, and the addition of exogenous butyrate reversed this effect. Increased butyrate exposure in the colonic stem cell niche has also been observed in UC patients. Mechanistically, enzyme activity assays on colonic organoids revealed that excessive fission inhibits mitochondrial acetoacetyl-CoA thiolase activity via reactive oxygen species. Collectively, these data indicate that excessive mitochondrial fission suppresses mucosal repair by inhibiting butyrate metabolism and provides a potential target for mucosal healing in patients with ulcerative colitis.

Epigenetic Induction of Secondary Metabolites Production in Endophytic Fungi Penicillium chrysogenum and GC-MS Analysis of Crude Metabolites with Anti-HIV-1 Activity.

The continuous burden of human immunodeficiency virus-1 in Sub-Saharan Africa, coupled with the inability of antiretroviral agents to eradicate HIV-1 from viral reservoirs, the potential risks of drug resistance development, and the development of adverse effects, emphasizes the need to develop a new class of HIV-1 inhibitors. Here, we cultivated four endophytic fungal isolates from a medicinal plant, Albizia adianthifolia with the addition of small epigenetic modifiers, sodium butyrate, and valproic acid, to induce the expression of biosynthetic gene clusters encoding active secondary metabolites with probable anti-HIV activities. We identified a non-toxic crude extract of the endophytic fungus Penicillium chrysogenum treated with sodium butyrate to possess significantly greater anti-HIV activity than the untreated extracts. Penicillium chrysogenum P03MB2 showed anti-HIV activity with an IC50 of 0.6024 µg/mL compared to untreated fungal crude extract (IC50 5.053 µg/mL) when treated with sodium butyrate. The profile of secondary metabolite compounds from the bioactive, partially purified extracts were identified by gas chromatography-mass spectrometry (GC-MS), and more bioactive compounds were detected in treated P. chrysogenum P03MB2 fractions than in untreated fractions. Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro (13.64%), cyclotrisiloxane, hexamethyl (8.18%), cyclotetrasiloxane, octamethyl (7.23%), cyclopentasiloxane, decamethyl (6.36%), quinoline, 1,2-dihydro-2,24-trimethyl (5.45%), propanenitrile (4.55%), deca-6,9-diene (4.55%), dibutyl phthalate (4.55%), and silane[1,1-dimethyl-2-propenyl)oxy]dimethyl (2.73%) were the most abundant compounds. These results indicate that treatment of endophytic fungi with small epigenetic modifiers enhances the secretion of secondary metabolites with stronger anti-HIV-1 properties, acknowledging the feasibility of epigenetic modification as an innovative approach for the discovery of cryptic fungal metabolites which can be developed into therapeutic compounds.

Dietary Coated Sodium Butyrate Ameliorates Hepatic Lipid Accumulation and Inflammation via Enhancing Antioxidative Function in Post-Peaking Laying Hens.

During the aging process of laying hens, hepatic oxidative stress damage and lipid accumulation are prone to occur, leading to the deterioration of egg quality and a decline in production properties. This research was designed to explore the effects of different levels of coated sodium butyrate (CSB) addition on oxidation resistance, inflammatory reaction, lipid metabolism and hepatic oxidative damage-related gene expression in aged laying hens. A total of 720 healthy 52 weeks old Huafeng laying hens were arbitrarily divided into 5 groups of 6 replicates with 24 birds each and fed a basal diet supplemented with 0, 250, 500, 750 and 1000 mg/kg CSB for 8 weeks, respectively. The CSB quadratically upgraded GSH-Px activities and downgraded MDA content in the liver and serum. The LDL-C, NEFA and TG contents decreased quadratically in CSB groups and significantly reduced the fatty vacuoles as well as the formation of fat granules in the liver (p < 0.05). Meanwhile, the CSB quadratically upregulated the gene expression of IL-10, Nrf2 and HO1, but downregulated the gene expression of IFN-γ, TNF-α and Keap1 in a quadratic manner (p < 0.05). Moreover, the CSB quadratically degraded the mRNA level of fatty acid synthesis but increased the gene level of key enzymes of fatty acid catabolism (p < 0.05). In conclusion, dietary CSB supplementation has a favorable effect in protecting against liver injury and alleviating lipid accumulation and inflammation by enhancing hepatic antioxidative function in aged laying hens.

Zootechnical performance, immune response, and resistance to hypoxia stress and Vibrio harveyi infection in Pacific white shrimp (Litopeneaus vannamei) fed different fishmeal diets with and without addition of sodium butyrate

The dietary effect of a chemically protected sodium butyrate, Butirex®C4 (BU), on growth performance, digestive enzymes activity, immunity, gut microflora, and resistance against hypoxia stress and infectious disease were studied in Pacific white shrimp fed different levels of fishmeal (FM) diets in earthen outdoor ponds. Nine isonitrogenous and isolipidic experimental diets were formulated to contain different levels of FM (45 %, 30 %, and 15 %) and enriched with the incremental levels of BU (0, 0.3%, and 0.6%). After 60 days, the shrimp fed diets containing 45% and 30 % FM along with 0.3 % and 0.6 % BU, respectively, showed higher levels of final weight and weight gain, while, the group fed diet with 15 % FM free from BU showed the highest level of feed conversion ratio. The levels of protease and trypsin activity significantly decreased in the group fed 15 % FM without BU, while the administration of BU improved the digestive enzymes activity in low FM diets. The total hemocyte count, phenoloxidase, and lysozyme were negatively affected by decreasing levels of FM in the diets, but BU-supplemented diets improved these parameters. The dietary administration of BU increased lactic acid bacteria and decreased total Vibrio sp. counts in the intestine of shrimp fed different levels of FM. Although the diets with low levels of FM had no significant effect on the hypoxia stress tolerance, the cumulative mortality was decreased in the low FM groups fed with different BU levels. The mortality of shrimp against Vibrio harveyi infection was notably decreased in BU-added groups compared to the groups that did not receive BU in their diets. Overall, dietary BU administration at 0.6 % mitigates the adverse impacts of the diets with the lowest FM (15 %) on overall performance and immunity in Pacific white shrimp.

Organic matter contributions to nitrous oxide emissions following nitrate addition are not proportional to substrate-induced soil carbon priming

The addition of carbon (C) substrate often modifies the rate of soil organic matter (SOM) decomposition. This is known as the priming effect. Nitrous oxide (N2O) emissions from soil are also linked to C substrate dynamics; however, the relationship between the priming effect and N2O emissions from soil is not understood. This study aimed to investigate the effects of C and N substrate addition on the linkages between SOM priming and N2O emissions. We applied 13C-labelled substrates (acetate, butyrate, glucose; 80 μg C g−1), with water as a control, and 15N-labelled N (300 μg N g−1 soil, potassium nitrate) to three different soils, and, after 3 days, we measured the effects on the priming of SOM and sources of N2O emission. Carbon substrate addition increased both CO2- and SOM-derived N2O emissions in the presence of exogenous N. Emissions of CO2 and N2O from soils with added glucose (mean ± standard deviation, 0.73 ± 0.13 μmol m−2 s−1 and 21.4 ± 12.1 mg N m−2 h−1) were higher (p < 0.05) than those from soils treated with acetate (0.64 ± 0.11 μmol m−2 s−1 and 10.9 ± 6.5 mg N m−2 h−1) or butyrate (0.61 ± 0.11 μmol m−2 s−1 and 11.0 ± 6.6 mg N m−2 h−1), respectively. Acetate addition induced a stronger (p < 0.05) priming effect on soil C (0.07 ± 0.09 μmol C m−2 s−1) than that for glucose (0.02 ± 0.10 μmol C m−2 s−1), while butyrate addition resulted in negative priming (−0.09 ± 0.05 μmol C m−2 s−1). SOM-derived N2O emissions were relatively low from soils with butyrate addition (1.4 ± 1.5 mg N m−2 h−1) compared with acetate (2.9 ± 2.3 mg N m−2 h−1) or glucose (9.2 ± 4.5 mg N m−2 h−1). There was no clear relationship between the priming effect and SOM-derived N2O emissions. The observed priming effect related to the potential electron donor supply of the C substrates was not observed. There is a need to further examine the role of soil priming in relation to soil N2O emissions.

Dietary Protected Butyrate Supplementation of Broilers Modulates Intestinal Tight Junction Proteins and Stimulates Endogenous Production of Short Chain Fatty Acids in the Caecum.

Simple SummaryThe aim of this study was to evaluate the effect of protected butyrate supplementation in broiler nutrition. Two experiments were conducted: (i) a performance study (1–35 days of age) and (ii) a study on the gut integrity and microbiome (1–21 days of age). The growth performance of birds, abundance of intestinal tight junction proteins, the quantitative characteristics of caecal microbiome and intestinal short chain fatty acid (SCFA) concentrations were investigated in these studies. Based on the results, it could be concluded that the addition of protected butyrate to broiler diets improved growth performance and intestinal integrity in accordance with the modulation of the caecal microbiome and the stimulated endogenous production of SCFA in the caecum. These findings provide important information that increases the understanding of the complex effects of the biologically most active SCFA, butyrate, on the overall health status and metabolism of the chicken.Short chain fatty acid (SCFA) butyrate has various beneficial effects on the gut microbiota as well as on the overall health status and metabolism of the host organism. The modulatory role of butyrate on gut barrier integrity reflected by tight junction protein expression has been already described in mammalian species. However, there is limited information available regarding chickens. Therefore, the main aim of this study was to monitor the effects of protected butyrate on claudin barrier protein and monocarboxylate transporter 1 abundance in different gastrointestinal segments of chickens as well as the growth performance of broiler chickens. The effect of protected butyrate on the caecal microbiota was monitored by quantifying the concentrations of total eubacteria and key enzymes of butyrate production. Furthermore, intestinal SCFA concentrations were also measured. Based on the data obtained, protected butyrate increased the overall performance as well as the barrier integrity of various gut segments. Protected butyrate also positively affected the SCFA concentration and composition. These findings provide valuable insight into the complex effects of protected butyrate on broiler gut health, highlighting the beneficial effects in improving intestinal barrier integrity and performance parameters.

Populational and metabolic shifts induced by acetate, butyrate and lactate in dark fermentation

Dark fermentation is subject to inhibition by end products. In this study, the effects of acetate, butyrate and lactate on fermentation routes of glucose were investigated for concentrations ranging from 25 to 400 mM. Whatever the acid considered, an inhibition threshold of hydrogen production was observed at acid concentration as low as 50 mM. 300 mM of acetate, 200 mM of butyrate and 400 mM of lactate were critical concentrations resulting exclusively in lactate production. At these high concentrations, bacterial communities shifted from Clostridiaceae to Lactobacillaceae family after acetate or lactate addition, and to Bacillaceae after butyrate addition. At lower acid concentrations, the nature and the concentration of the added acid shaped metabolic and populational changes. Specifically, Clostridium butyricum was able to grow up to 250 mM, 150 mM and 300 mM of acetate, butyrate and lactate respectively, but was suspected to shift its metabolism towards lactate production.

Pengaruh suplementasi kalsium butirat dalam ransum terhadap kecernaan nutrien, performa produksi dan kualitas telur ayam umur 75 minggu

Objective: To determine the digestibility of laying hens ration supplemented with calcium butyrate, and its effect on the production and quality of the eggs produced. Methods: This study used a completely randomized design (CRD) with 4 treatments and each treatment consisted of 5 replicates. The treatment method was dietary calcium butyrate supplementation, specifically: R0 = Without calcium butyrate supplement (control), R1 = supplemented of 0.175 g/kg calcium butyrate on diet, R2 = supplemented of 0.350 g/kg calcium butyrate on diet, and R3 = supplemented of 0.525 g/kg calcium butyrate on diet. The observed parameters include the digestibility of substances in the feed; crude protein and crude fiber digestibility, production performance including ration consumption, egg production and feed conversion. Then measure egg quality including egg weight, egg white weight, egg yolk weight, Haugh unit value, weight eggshell and eggshell thickness. Results: The results showed that calcium butyrate supplementation in the ration of laying hens in the third production phase had no significant effect (P&gt;0.05) on nutrient digestibility, egg production performance, but significantly (P&lt;0.05) on eggshell quality. Conclusions: The conclusion of the study was that calcium butyrate supplementation up to 0.525 g/kg in the ration of laying hens had not been able to increase the digestibility of crude protein and digestibility of crude fiber in the ration, and had not been able to increase egg production and feed efficiency, but could improve the quality of the eggshell produced. Egg shell thickness increased by 21.21% compared to without the addition of calcium butyrate in the ration.

Sodium butyrate reduces ammonia emissions through glutamate metabolic pathways in cecal microorganisms of laying hens

Ammonia emission is an important problem that needs to be solved in laying hen industries. Sodium butyrate (SB) is considered to have potential for reducing ammonia production because of its ability to improve nitrogen metabolism. In this in vitro fermentation study, we presented a correlation analysis of the metatranscriptome and metaproteome of lay hen cecal microorganisms, in order to identify important proteins and pathways involved in ammonia production reduction due to sodium butyrate supplementation. The results showed that sodium butyrate supplement decreased the production of ammonia by 26.22% as compared with the non-sodium butyrate supplementation (CK) group. The SB group exhibited a lower concentration of ammonium nitrogen (NH4+-N) and a decreased pH. Sodium butyrate promoted the uric acid concentration and lowered the uricase activity in the fermentation broth of laying hens cecal content. Notably, the ‘alanine, aspartate and glutamate metabolism’ category was more abundant in the SB group. The addition of sodium butyrate increased the expression of glutamate dehydrogenase (GDH) gene in cecal microbiota (e.g., Ruminococcus sp. and Bacteroides sp.) in vitro. The metaproteome analysis results showed that the expression of GDH with NADPH as coenzyme (NADPH-GDH) was up-regulated in cecal microbiota by sodium butyrate supplement. Our results indicate that sodium butyrate can affect glutamate metabolism through regulating the expression of glutamate dehydrogenase in cecal microorganisms, thereby reducing ammonia production. This study reveals that glutamate dehydrogenase-mediated glutamate metabolism play a key role in ammonia emission reduction in laying hen and provide theoretical basis for further developing ammonia production reduction approach.

Characterization of the biofilm structure and microbial diversity of sulfate-reducing bacteria from petroleum produced water supplemented by different carbon sources

Colonization by sulfate-reducing bacteria (SRB) in environments associated with oil is mainly dependent on the availability of sulfate and carbon sources. The formation of biofilms by SRB increases the corrosion of pipelines and oil storage tanks, representing great occupational and operational risks and respective economic losses for the oil industry. The aim of this study was to evaluate the influence of the addition of acetate, butyrate, lactate, propionate and oil on the structure of biofilm formed in carbon steel coupons, as well as on the diversity of total bacteria and SRB in the planktonic and sessile communities from petroleum produced water. The biofilm morphology, chemical composition, average roughness and the microbial diversity was analyzed. In all carbon sources, formation of dense biofilm without morphological and/or microbial density differences was detected, with the most of cells observed in the form of individual rods. The diversity and richness indices of bacterial species in the planktonic community was greater than in the biofilm. Geotoga was the most abundant genus, and more than 85% of SRB species were common to all treatments. The functional predicted profile shown that the observed genres in planktonic communities were related to the reduction of sulfate, sulfite, elementary sulfur and other sulfur compounds, but the abundance varied between treatments. For the biofilm, the functions predicted profile for the oil treatment was the one that most varied in relation to the control, while for the planktonic community, the addition of all carbon sources interfered in the predicted functional profile. Thus, although it does not cause changes in the structure and morphology biofilm, the supplementation of produced water with different carbon sources is associated with changes in the SRB taxonomic composition and functional profiles of the biofilm and the planktonic bacterial communities.

Short-chain fatty acids activate acetyltransferase p300

Short-chain fatty acids (SCFAs) acetate, propionate, and butyrate are produced in large quantities by the gut microbiome and contribute to a wide array of physiological processes. While the underlying mechanisms are largely unknown, many effects of SCFAs have been traced to changes in the cell's epigenetic state. Here, we systematically investigate how SCFAs alter the epigenome. Using quantitative proteomics of histone modification states, we identified rapid and sustained increases in histone acetylation after the addition of butyrate or propionate, but not acetate. While decades of prior observations would suggest that hyperacetylation induced by SCFAs are due to inhibition of histone deacetylases (HDACs), we found that propionate and butyrate instead activate the acetyltransferase p300. Propionate and butyrate are rapidly converted to the corresponding acyl-CoAs which are then used by p300 to catalyze auto-acylation of the autoinhibitory loop, activating the enzyme for histone/protein acetylation. This data challenges the long-held belief that SCFAs mainly regulate chromatin by inhibiting HDACs, and instead reveals a previously unknown mechanism of HAT activation that can explain how an influx of low levels of SCFAs alters global chromatin states.

Influence of butyrate on fermentative hydrogen production and microbial community analysis

The effect of butyrate on hydrogen production and the potential mechanism were investigated by adding butyric acid into dark fermentative hydrogen production system at different concentrations at pH range of 5.5–7.0. The results showed that under all the tested pH from 5.5 to 7.0, the addition of butyric acid can inhibit the hydrogen production, and the inhibitory degree (from 10.5% to 100%) increased with the increase of butyric acid concentration and with the decrease of pH values, which suggested that the inhibition effect is highly associated with the concentration of undissociated acids. Substrate utilization rate and VFAs accumulation also decreased with the addition of butyric acid. The microbial community analysis revealed that butyrate addition can decrease the dominant position of hydrogen-producing microorganisms, such as Clostridium, and increase the proportion of other non-hydrogen-producing bacteria, including Pseudomonas, Klebsiella, Acinetobacter, and Bacillus.

One-pot production of butyl butyrate from glucose using a cognate \u201cdiamond-shaped\u201d E. coli consortium

Esters are widely used in plastics, textile fibers, and general petrochemicals. Usually, esters are produced via chemical synthesis or enzymatic processes from the corresponding alcohols and acids. However, the fermentative production of esters from alcohols and/or acids has recently also become feasible. Here we report a cognate microbial consortium capable of producing butyl butyrate. This microbial consortium consists of two engineered butyrate- and butanol-producing E. coli strains with nearly identical genetic background. The pathways for the synthesis of butyrate and butanol from butyryl-CoA in the respective E. coli strains, together with a lipase-catalyzed esterification reaction, created a “diamond-shaped” consortium. The concentration of butyrate and butanol in the fermentation vessel could be altered by adjusting the inoculation ratios of each E. coli strain in the consortium. After optimization, the consortium produced 7.2 g/L butyl butyrate with a yield of 0.12 g/g glucose without the exogenous addition of butanol or butyrate. To our best knowledge, this is the highest titer and yield of butyl butyrate produced by E. coli reported to date. This study thus provides a new way for the biotechnological production of esters.