Dual assistance of surfactants in glycerol organosolv pretreatment and enzymatic hydrolysis of lignocellulosic biomass for bioethanol production.

This study investigated an innovative strategy of incorporating surfactants into alkaline-catalyzed glycerol pretreatment and enzymatic hydrolysis to improve lignocellulosic biomass (LCB) conversion efficiency. Results revealed that adding 40 mg/g PEG 4000 to the pretreatment at 195 °C obtained the highest glucose yield (84.6%). This yield was comparable to that achieved without surfactants at a higher temperature (240 °C), indicating a reduction of 18.8% in the required heat input. Subsequently, Triton X-100 addition during enzymatic hydrolysis of PEG 4000-assisted pretreated substrate increased glucose yields to 92.1% at 6 FPU/g enzyme loading. High-solid fed-batch semi-simultaneous saccharification and co-fermentation using this dual surfactant strategy gave 56.4 g/L ethanol and a positive net energy gain of 1.4 MJ/kg. Significantly, dual assistance with surfactants rendered 56.3% enzyme cost savings compared to controls without surfactants. Therefore, the proposed surfactant dual-assisted promising approach opens the gateway to economically viable enzyme-mediated LCB biorefinery.

Bacterial lipopolysaccharide with different administration routes affects intestinal mucosal morphological, immunological, and microbial barrier functions in goslings.

The current study was conducted to evaluate the effects of different administration routes of bacterial lipopolysaccharide (LPS) on intestinal mucosal morphological, immunological, and microbial barrier functions in goslings. First, we compared intestinal villi morphology of goslings under intraperitoneal or oral LPS treatment through hematoxylin and eosin staining. Then, we determined the signatures of the microbiome in the ileum mucosa of goslings subjected to oral LPS treatment at 0, 2, 4, and 8 mg/kg BW by 16S sequencing, and analyzed the changes in intestinal barrier functions and permeability, levels of LPS in the ileum mucosa, plasma, and liver tissue, and the induced inflammatory response of Toll-like receptor 4 (TLR4). As a result, intraperitoneal LPS injection resulted in a thicker intestinal wall in the ileum within a short time, whereas villus height was less affected; in contrast, oral LPS treatment exerted a stronger influence on villus height but not on intestinal wall thickness. We also found that oral LPS treatment affected the structure of the intestinal microbiome, reflected by changes in the clustering of intestinal microbiota. The average abundance of Muribaculaceae showed an increasing trend with increasing LPS levels, and that of the genus Bacteroides decreased, compared with the control group. In addition, oral LPS treatment with 8 mg/kg BW affected the intestinal epithelial morphology, damage the mucosal immune barrier, downregulated the expression of tight junction proteins, increased circulating D-lactate levels, and stimulated the secretion of various inflammatory mediators and activation of the TLR4/MyD88/NFκB pathway. This study presented the injuries of intestinal mucosal barrier function induced by LPS challenges in goslings and provided a scientific model for searching the novel strategies to attenuate the immunological stress and gut injury caused by LPS.

Hydrophobic modification improves the delivery of cell-penetrating peptides to eliminate intracellular pathogens in animals.

Infections induced by intracellular pathogens are difficult to eradicate due to poor penetration of antimicrobials into cell membranes. It is of great importance to develop a new generation of antibacterial agents with dual functions of efficient cell penetration and bacterial inhibition. In this study, the association between hydrophobicity and cell-penetrating peptide delivery efficiency was investigated by fragment interception and hydrophobicity modification of natural porcine antimicrobial peptide PR-39 and the combination of cationic cell-penetrating peptide (R6) with antimicrobial peptide fragments modified with hydrophobic residues. The chimeric peptides P3I7 and P3L7, obtained through biofunctional screening, exhibited potent broad-spectrum antibacterial activity and low cytotoxicity. Moreover, P3I7 and P3L7 can effectively penetrate cells to eliminate intracellular pathogens mainly through endocytosis. The membrane destruction mechanism makes the peptides fast sterilizers and less prone to developing drug resistance. Finally, their good biocompatibility and antibacterial infection effects were verified in mice and piglets. To conclude, the chimeric peptides P3I7 and P3L7 show great potential as affordable and effective antimicrobial agents and may serve as ideal candidates for the treatment of intracellular bacterial infections. STATEMENT OF SIGNIFICANCE: The low permeability of antibacterial drugs makes infections induced by intracellular bacteria extremely difficult to treat. To address this issue, we designed chimeric peptides with dual cell-penetrating and antibacterial functions. The active peptides P3I7 and P3L7, acquired through functional screening have strong broad-spectrum antibacterial activity and powerful bactericidal effects against intracellular Staphylococcus aureus. The membrane permeation mechanism of P3I7 and P3L7 against bacteria endows fast bactericidal activity with low drug resistance. The biosafety and antibacterial activity of P3I7 and P3L7 were also validated by in vivo trials. This study provides an ideal drug candidate against intracellular bacterial infections.

Effects of resveratrol and its derivative pterostilbene on hepatic injury and immunological stress of weaned piglets challenged with lipopolysaccharide.

The present study was to investigate the protective effects of resveratrol (RSV) and its 3,5-dimethylether derivative pterostilbene (PT) against liver injury and immunological stress of weaned piglets upon lipopolysaccharide (LPS) challenge. Seventy-two weaned piglets were divided into the following groups: control group, LPS-challenged group, and LPS-challenged groups pretreated with either RSV or PT for 14 d (n = 6 pens, three pigs per pen). At the end of the feeding trial, piglets were intraperitoneally injected with either LPS or an equivalent amount of sterile saline. After 6 h of sterile saline or LPS injection, plasma and liver samples were collected. LPS stimulation caused massive apoptosis, activated inflammatory responses, and incited severe oxidative stress in the piglet livers while also promoting the nuclear translocation of nuclear factor kappa B (NF-κB) p65 (P < 0.001) and the protein expression of Nod-like receptor pyrin domain containing 3 (NLRP3; P = 0.001) and cleaved caspase 1 (P < 0.001). PT was more effective than RSV in alleviating LPS-induced hepatic damage by decreasing the apoptotic rate of liver cells (P = 0.045), inhibiting the transcriptional expression of interleukin 1 beta (P < 0.001) and interleukin 6 (P = 0.008), and reducing myeloperoxidase activity (P = 0.010). The LPS-induced increase in hepatic lipid peroxidation accumulation was also reversed by PT (P = 0.024). Importantly, inhibiting protein phosphatase 2A (PP2A) activity in a hepatocellular model largely blocked the ability of PT to prevent tumor necrosis factor alpha-induced increases in NF-κB p65 protein phosphorylation (P = 0.043) and its nuclear translocation (P = 0.029). In summary, PT is a promising agent that may alleviate liver injury and immunological stress of weaned piglets via the PP2A/NF-κB/NLRP3 signaling pathway.

Intensive swine production increases the exposure risk of piglets to immunological stress that disrupts hepatic functionality, leading to inferior disease resistance and compromised growth performance. Therefore, it is imperative to seek appropriate nutrients with protective potential to alleviate liver injury of young piglets under the conditions of immunological stress. The objective of this study was to investigate the potential of resveratrol and its derivative pterostilbene (PT) to protect the liver from lipopolysaccharide (LPS)-induced immunological stress and inflammatory damage in weaned piglets. In the animal study, PT exhibited significantly better efficacy than its parent compound in alleviating LPS-induced hepatic damage, probably by inhibiting nuclear factor kappa B (NF-κB) p65 nuclear translocation, Nod-like receptor pyrin domain containing 3 (NLRP3) and cleaved caspase-1 protein expression, and proinflammatory mediator overproduction. Under cell culture condition, inhibiting protein phosphatase 2A (PP2A), a negative regulator of the NF-κB signaling pathway, largely blocked the ability of PT to prevent NF-κB activation, indicating that PT may inhibit NF-κB signals in a PP2A-dependent manner. This study provides novel evidence that PT could serve as a hepatoprotective agent to alleviate hepatic damage and immunological stress in LPS-challenged piglets.

The effects of dietary protein and fiber levels on growth performance, gout occurrence, intestinal microbial communities, and immunoregulation in the gut-kidney axis of goslings.

The current study evaluated the effects of dietary protein and fiber levels on growth performance, gout occurrence, intestinal microbial communities, and immunoregulation in the gut-kidney axis of goslings. A completely randomized 2 × 3 factorial design was adopted with 2 CP levels (180 [18CP] and 220 [22CP] g/kg) and 3 crude fiber (CF) levels (30 [low CF], 50 [mid CF], and 70 [high CF] g/kg). The high CP or low CF diets predisposed the goslings to gout. The high protein diets worsened renal function; serum concentrations of UA and Cr as well as XOD activity in 9-day-old goslings fed 22% CP diets were significantly increased. Although CF levels from 3 to 7% did not directly affect kidney health, increasing CF levels might accelerate the increase of probiotics in the cecum of goslings and withhold maleficent bacteria, alleviating the gut dysbiosis caused by high protein diets. An analysis of the cecal microbiota via 16Sr RNA sequencing revealed that the abundance of Enterococcus in the 22CP group was higher than that in the 18CP group but decreased with increasing CF levels on d 9. The abundance of Lactobacillus increased with increasing CF levels. Additionally, higher serum LPS and proinflammatory cytokine concentrations and upregulated mRNA expression levels in the cecal, tonsil, and kidney tissues indicated that high-protein diets could activate the TLR4/MyD88/NFκB pathway and induce both intestinal and renal inflammation in young goslings. Serum LPS concentrations on d 9 were found to decrease with increasing CF, although altering dietary CF levels did not directly affect the serum immune indices of goslings. In conclusion, the high CP diet exerted a negative effect on gout occurrence, microbial communities, and immunoregulation in the gut-kidney axis of goslings, while appropriately increased dietary fiber levels helped maintain intestinal balance and reduced serum LPS concentration. We propose a diet of 18% CP paired with a 5% CF as the optimal combination for gosling feed.

Fermented Feed Supplement Relieves Caecal Microbiota Dysbiosis and Kidney Injury Caused by High-Protein Diet in the Development of Gosling Gout.

Firstly, forty-eight 1-day-old goslings were randomly allocated to four groups and were fed diets containing crude protein (CP) at different concentrations: 160, 180, 200, and 220 g/kg in Experiment One. We found a dose-dependent relationship between the dietary protein levels and morbidity of gosling gout. The concentration of serum uric acid (UA), creatinine (Cr), and urea nitrogen (UN), and the activity of xanthine oxidase in the 220CP groups were significantly higher than those in the low-protein diet groups. Beneficial microbes, including Akkermansia, Lactococcus, and Butyricicoccus were enriched in the ceca of healthy goslings, while the microbes Enterococcus, Enterobacteriaceae, and Bacteroides were enriched in those with gout. Then, we explored the effects of fermented feed on gosling gout caused by high-protein diets in Experiment Two. A total of 720 1-day-old goslings were randomly allotted to four experimental groups: CN (162.9 g/kg CP), CNF (167.5 g/kg CP, replacing 50 g/kg of the basal diet with fermented feed), HP (229.7 g/kg CP, a high-protein diet), and HPF (230.7 g/kg CP, replacing 50 g/kg of the high-protein diet with fermented feed). We found that the cumulative incidence of gout increased in the HP group compared with that in the control, but decreased in the HPF group compared to that in the HP group. Similarly, the concentration of serum UA in the HP group was higher than that in the CN group, but decreased in the HPF group. Meanwhile, compared with the HP group, using fermented feed in diets decreased the abundance of Enterococcus in the ceca of goslings, while increasing the abundance of Lactobacillus. These results suggest that appropriate dietary protein levels and the fermented feed supplement might relieve the kidney injury and gut microbiota dysbiosis caused by high-protein diets in the development of gosling gout.

Protective Effects of Fucoidan against Hydrogen Peroxide-Induced Oxidative Damage in Porcine Intestinal Epithelial Cells.

This study was conducted to evaluate the effectiveness of fucoidan in ameliorating hydrogen peroxide (H2O2)-induced oxidative stress to porcine intestinal epithelial cell line (IPEC-1). The cell viability test was initially performed to screen out appropriate concentrations of H2O2 and fucoidan. After that, cells were exposed to H2O2 in the presence or absence of pre-incubation with fucoidan. Hydrogen peroxide increased the apoptotic and necrotic rate, boosted reactive oxygen species (ROS) generation, and disturbed the transcriptional expression of genes associated with antioxidant defense and apoptosis in IPEC-1 cells. Pre-incubation with fucoidan inhibited the increases in necrosis and ROS accumulation induced by H2O2. Consistently, in the H2O2-treated IPEC-1 cells, fucoidan normalized the content of reduced glutathione as well as the mRNA abundance of NAD(P)H quinone dehydrogenase 1 and superoxide dismutase 1 while it prevented the overproduction of malondialdehyde. Moreover, H2O2 stimulated the translocation of nuclear factor-erythroid 2-related factor-2 to the nucleus of IPEC-1 cells, but this increase was further promoted by fucoidan pre-treatment. The results suggest that fucoidan is effective in protecting IPEC-1 cells against oxidative damage induced by H2O2, which may help in developing appropriate strategies for maintaining the intestinal health of young piglets.

Gut microbiota dysbiosis increases the risk of visceral gout in goslings through translocation of gut-derived lipopolysaccharide.

We investigated the gut-kidney interaction in goslings with gout and tried to decipher the probable mechanisms through which gut dysbiosis leads to the progression of renal injury and inflammation. A total of 15 goslings (Anser cygnoides), with typical visceral gout symptoms, were screened and compared with 15 healthy goslings. We determined the signatures of the microbiome in the cecum chyme of goslings in the 2 groups by 16S sequencing, and analyzed the changes in intestinal permeability, levels of serum lipopolysaccharide (LPS), and the induced inflammatory response of Toll-like receptors (TLRs). We found the existence of gut dysbiosis in goslings with gout as a result of interactions among the multitude of bacteria present in the gut, and the proliferation of a specific pathogenic genus, Proteobacteria, played a decisive role in this process. Moreover, the permeability increased not only in the intestinal epithelium but also in the renal endothelium, providing possibilities for gut-derived LPS to enter the blood circulation and damage the kidneys. The systemic LPS concentration was increased in the gout group and exhibited a positive correlation with the degree of renal injury. In addition, we also found that inflammatory disorders concurrently existed in the gut and kidney of goslings with gout, and the LPS/TLR4/MyD88 (Myeloid differentiation primary response gene 88) inflammatory signaling was activated. These results indicate that the loss of intestinal barrier as a result of gut dysbiosis causes the translocation of gut-derived LPS, which can play an important role in the development of gout in goslings through interference with kidney functions.

Fermented feed regulates growth performance and the cecal microbiota community in geese.

This study was designed to investigate the effects of fermented feed diets on the growth performance and cecal microbial community in geese, and to examine associations between the gut microbiota and growth performance. A total of 720 healthy, 1-day-old male SanHua geese were used for the 55-D experiment. Geese were randomly divided into 4 groups, each with 6 replicates of 30 geese. Groups were fed a basal diet supplemented with 0.0, 2.5, 5.0, or 7.5% fermented feed. The results showed that 7.5% fermented feed had an increasing trend in the body weight and average daily gain of the geese; however, there was no significant response to increasing dietary fermented feed level with regards to ADFI and FCR. In addition, compared with the control group, there was a higher abundance of bacteria in the phylum Bacteroidetes in the cecal samples of geese in the 7.5% fermented feed group (53.18% vs. 41.77%, P < 0.05), whereas the abundance of Firmicutes was lower in the 7.5% fermented feed group (36.30% vs. 44.13%, P > 0.05). At the genus level, the abundance of Bacteroides was increased by adding fermented feed to geese diets, whereas the abundances of Desulfovibrio, Phascolarctobacterium, Lachnospiraceae_uncultured, Ruminiclostridium, and Oscillospira were decreased. These results indicate that fermented feeds have an important effect on the cecal microflora composition of geese, and may affect host growth, nutritional status, and intestinal health.

Effects of exogenous inosine monophosphate on growth performance, flavor compounds, enzyme activity, and gene expression of muscle tissues in chicken.

The goal of this experiment was to examine effects of diets supplemented with exogenous inosine monophosphate (IMP) on the growth performance, flavor compounds, enzyme activity and gene expression of chicken. A total of 1,500 healthy, 1-day-old male 3-yellow chickens were used for a 52-d experimental period. Individuals were randomly divided into 5 groups (group I, II, III, IV, V) with 6 replicates per group, and fed a basal diet supplemented with 0.0, 0.05, 0.1, 0.2, and 0.3% IMP, respectively. There was no significant response to the increasing dietary IMP level in average daily feed intake (ADFI), average daily gain (ADG), and feed:gain ratio (F/G) (P ≥ 0.05). IMP content of the breast and thigh muscle showed an exponential and linear response to the increasing dietary IMP level (P < 0.05), the highest IMP content was obtained when the diet with 0.3% and 0.2% exogenous IMP was fed. There were significant effects of IMP level in diet on free amino acids (FAA) (exponential, linear and quadratic effect, P < 0.05) and delicious amino acids (DAA) (quadratic effect, P < 0.01) content in breast muscle. FAA and DAA content in thigh muscle showed an exponential and linear response (P < 0.05), and quadratic response (P < 0.01) to the increasing dietary IMP level, the highest FAA and DAA content was obtained when the diet with 0.2% exogenous IMP was fed. Dietary IMP supplementation had a quadratic effect on 5΄-NT and the alkaline phosphatase (ALP) enzyme activity in the breast muscle (P < 0.05), and the adenosine triphosphate (ATP) enzyme activity in the thigh muscles increased exponentially and linearly with increasing IMP level in diet (exponential effect, P = 0.061; linear effect, P = 0.059). Cyclohydrolase (ATIC) gene expression in thigh muscle had a quadratic response to the increasing dietary IMP level (P < 0.05), 0.2% exogenous IMP group had the highest (AMPD1) gene expression of the breast muscle and ATIC gene expression of the thigh muscle. These results indicate that dietary IMP did not affect the growth performance of chicken, the diet with 0.2 to 0.3% exogenous IMP is optimal to improve the meat flavor quality in chicken.

The identification, characterization, and function of two TREMs genes in Chinese Yangzhou goose (Anas cygnoides).

Triggering receptor expressed on myeloid cells (TREM) is a cell-surface receptor primarily expressed on macrophages. Here, two novel TREM genes, AcTREM1 and AcTREM2, were identified from Anas cygnoides. AcTREM1 cDNA contained a putative signal peptide, two IG domains, and a transmembrane domain. The deduced AcTREM2 sequence also contained a signal peptide, an IG domain, and a transmembrane domain. qRT-PCR, fluorescence in situ hybridization, and immunofluorescence experiments showed that AcTREM1 and AcTREM2 were mainly expressed in the liver and spleen, and both genes and proteins were mainly distributed in cytoplasm. AcTREM1 expression in the liver and spleen was significantly upregulated following lipopolysaccharide (LPS) challenge at an early stage of infection and then decreased at a later stage. Changes in AcTREM2 expression were reciprocal to those of AcTREM1 in the liver and spleen after LPS challenge. Our results indicate that AcTREM1 and AcTREM2 participate in the antibacterial immunity of A. cygnoides.