Hydroxytyrosol Alleviates Intestinal Oxidative Stress by Regulating Bile Acid Metabolism in a Piglet Model.

Infants and young animals often suffer from intestinal damage caused by oxidative stress, which may adversely affect their overall health. Hydroxytyrosol, a plant polyphenol, has shown potential in decreasing intestinal oxidative stress, but its application and mechanism of action in infants and young animals are still inadequately documented. This study selected piglets as a model to investigate the alleviating effects of hydroxytyrosol on intestinal oxidative stress induced by diquat and its potential mechanism. Hydroxytyrosol improved intestinal morphology, characterized by higher villus height and villus height/crypt depth. Meanwhile, hydroxytyrosol led to higher expression of Occludin, MUC2, Nrf2, and its downstream genes, and lower expression of cytokines IL-1ß, IL-6, and TNF-α. Both oxidative stress and hydroxytyrosol resulted in a higher abundance of Clostridium_sensu_stricto_1, and a lower abundance of Lactobacillus and Streptococcus, without a significant effect on short-chain fatty acids levels. Oxidative stress also led to disorders in bile acid (BA) metabolism, such as the lower levels of primary BAs, hyocholic acid, hyodeoxycholic acid, and tauroursodeoxycholic acid, which were partially restored by hydroxytyrosol. Correlation analysis revealed a positive correlation between these BA levels and the expression of Nrf2 and its downstream genes. Collectively, hydroxytyrosol may reduce oxidative stress-induced intestinal damage by regulating BA metabolism.

Physiological and Dual Transcriptional Analysis of Microalga Graesiella emersonii-Amoeboaphelidium protococcarum Pathosystem Uncovers Conserved Defense Response and Robust Pathogenicity.

The underlying mechanisms of microalgal host-pathogen interactions remain largely unknown. In this study, we applied physiological and simultaneous dual transcriptomic analysis to characterize the microalga Graesiella emersonii-Amoeboaphelidium protococcarum interaction. Three infection stages were determined according to infection rate and physiological features. Dual RNA-seq results showed that the genes expression of G. emersonii and A. protococcarum were strongly dynamically regulated during the infection. For microalgal hosts, similar to plant defense response, the expression of defense genes involved in the pattern recognition receptors, large heat shock proteins, and reactive oxygen scavenging enzymes (glutathione, ferritin, and catalase) were significantly upregulated during infection. However, some genes encoding resistance proteins (R proteins) with a leucine-rich repeat domain exhibited no significant changes during infection. For endoparasite A. protococcarum, genes for carbohydrate-active enzymes, pathogen-host interactions, and putative effectors were significantly upregulated during infection. Furthermore, the genes in cluster II were significantly enriched in pathways associated with the modulation of vacuole transport, including endocytosis, phagosome, ubiquitin-mediated proteolysis, and SNARE interactions in vesicular transport pathways. These results suggest that G. emersonii has a conserved defense system against pathogen and that endoparasite A. protococcarum possesses a robust pathogenicity to infect the host. Our study characterizes the first transcriptomic profile of microalgae-endoparasite interaction, providing a new promising basis for complete understanding of the algal host defense strategies and parasite pathogenicity.

Construction of Genomic Library and High-Throughput Screening of Pseudomonas aeruginosa Novel Antigens for Potential Vaccines.

Hospital-acquired infections with Pseudomonas aeruginosa have become a great challenge in caring for critically ill and immunocompromised patients. The cause of high mortality is the presence of multi-drug resistant (MDR) strains, which confers a pressing need for vaccines. Although vaccines against P. aeruginosa have been in development for more than several decades, there is no vaccine for patients at present. In this study, we purified genomic DNA of P. aeruginosa from sera of patients affected, constructed genome-wide library with random recombinants, and screened candidate protein antigens by evaluating their protective effects in vivo. After 13-round of screening, 115 reactive recombinants were obtained, among which 13 antigens showed strong immunoreactivity (more than 10% reaction to PcrV, a well-characterized V-antigen of P. aeruginosa). These 13 antigens were: PpiA, PtsP, OprP, CAZ10_34235, HmuU_2, PcaK, CarAd, RecG, YjiR_5, LigD, KinB, RtcA, and PscF. In vivo studies showed that vaccination with PscF protected against lethal P. aeruginosa challenge, and decreased lung inflammation and injury. A genomic library of P. aeruginosa could be constructed in this way for the first time, which could not only screen candidate antigens but also in a high-throughput way. PscF was considered as an ideal promising vaccine candidate for combating P. aeruginosa infection and was supported for further evaluation of its safety and efficacy.

Alteration in bile acids profile in Large White pigs during chronic heat exposure.

Bile acids (BAs) are critical for cholesterol homeostasis and new roles in metabolism and endocrinology have been demonstrated recently. It remains unknown whether BA metabolism can be affected by heat stress (HS). The objective of this study was to describe the shifts in serum, hepatic and intestinal BA profiles induced by chronic HS. Twenty-seven Large White pigs weighing 40.8 ±â€¯2.7 kg were assigned to one of the three treatments: a control group (CON, 23 °C), a HS group (33 °C), or a pair-fed group (PF, 23 °C and fed the same amount as HS group) for 21 d. The concentrations of taurine-conjugated BAs (TUDCA and THDCA in serum and TCDCA, TUDCA, THDCA and THCA in liver) were decreased in HS and PF pigs. However, in HS pigs, a reduction in taurine-conjugated BAs (TCBA) correlated with decreased liver genes expression of BA synthesis, conjugation and uptake transport. BA regulated-genes (FXR, TGR5 and FGFR4) in HS pigs and TGR5, FGFR4 and KLß in PF pigs were down-regulated in liver. In ileum, total BAs and glycoursodeoxycholic acid concentrations were higher in HS pigs than other groups and PF group, respectively (P < 0.05). TCBA (P = 0.01) and tauroursodeoxycholic acid (P < 0.01) were decreased in PF group. BA transporters (OSTα and MRP3) were up-regulated in HS pigs compared with CON and PF pigs, respectively (P < 0.01). In cecum, ursodeoxycholic acid was higher in HS (P = 0.02) group than CON group. The expression of apical sodium-coupled bile acid transporter (P = 0.04) was lower in HS pigs than CON pigs, while OSTß (P < 0.01) was greater in HS group than PF group. These results suggest that chronic HS suppressed liver activity of synthesis and uptake of TCBA, at least in part, which was independent of reduced feed intake.

Modulation of pectin on intestinal barrier function via changes in microbial functional potential and bile acid metabolism.

Weaning is one of the major factors that cause stress and intestinal infection in infants and in young animals due to an immature intestine and not fully developed immune functions. Pectin (PEC), a prebiotic polysaccharide, has attracted considerable attention in intestinal epithelial signaling and function via modulation of the microbial community. A total of 16 weaned piglets (21-d-old) were randomly assigned into two groups: control group and PEC group. Supplementation of 5% pectin improved intestinal mucosal barrier function by modulating the composition of the bile acid pool in piglets. Specifically, piglets in PEC group had less serum D-lactate content and alkaline phosphatase activity. In the ileum, dietary pectin increased the number of crypt PAS/AB-positive goblet cells and the mRNA expressions of MUC2, ZO-1, and Occludin. Piglets in PEC group displayed a decreased abundance of Enterococcus (2.71 vs. 65.92%), but the abundances of Lactobacillus (30.80 vs. 7.93%), Streptococcus (21.41 vs. 14.81%), and Clostridium_sensu_stricto_1 (28.34 vs. 0.01%) were increased. Elevated concentrations of bile acids especially hyocholic acid species (HCAs) including HCA, HDCA, and THDCA were also observed. Besides, correlation analysis revealed that dietary pectin supplementation may have beneficial effects through stimulation of the crosstalk between gut microbes and bile acid synthesis within the enterohepatic circulation. Thus, dietary pectin supplementation exhibited a further positive effect on the healthy growth and development of weaned piglets. These findings suggest pectin supplementation as the prebiotic is beneficial for gut health and improvement of weaned stress via regulating microbiota and bile acid metabolism.

Role of Mitophagy in Regulating Intestinal Oxidative Damage.

The mitochondrion is also a major site for maintaining redox homeostasis between reactive oxygen species (ROS) generation and scavenging. The quantity, quality, and functional integrity of mitochondria are crucial for regulating intracellular homeostasis and maintaining the normal physiological function of cells. The role of oxidative stress in human disease is well established, particularly in inflammatory bowel disease and gastrointestinal mucosal diseases. Oxidative stress could result from an imbalance between ROS and the antioxidative system. Mitochondria are both the main sites of production and the main target of ROS. It is a vicious cycle in which initial ROS-induced mitochondrial damage enhanced ROS production that, in turn, leads to further mitochondrial damage and eventually massive intestinal cell death. Oxidative damage can be significantly mitigated by mitophagy, which clears damaged mitochondria. In this review, we aimed to review the molecular mechanisms involved in the regulation of mitophagy and oxidative stress and their relationship in some intestinal diseases. We believe the reviews can provide new ideas and a scientific basis for researching antioxidants and preventing diseases related to oxidative damage.

Caffeic acid supplementation ameliorates intestinal injury by modulating intestinal microbiota in LPS-challenged piglets.

During weaning, piglets are susceptible to intestinal injuries caused by a range of infections, which result in serious economic losses for pig producers. Caffeic acid (CA) is a plant-derived phenolic acid that exhibits potential as a dietary supplement for enhancing intestinal health. There is, however, limited information available about the potential benefits of CA supplementation on intestinal injury and growth performance in piglets. A 28-day study was conducted to examine the effectiveness of CA supplementation in protecting against intestinal injury induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS) in piglets. Twenty-four piglets (7.43 ± 0.79 kg body weight; Duroc × Landrace × Large White; barrows) were randomly divided into 4 groups: the control group, the LPS group, the LPS + CA group, and the CA group. Piglets were administered with LPS or saline on d21 and d28 of the experiment. Supplementation with CA improved intestinal barrier function in LPS-challenged piglets by enhancing intestinal morphology and integrity, as well as increasing the expression of Claudin-1 and ZO-1. Meanwhile, CA supplementation improved the systemic and colonic inflammation responses, oxidative stress, and apoptosis induced by LPS. CA supplementation improved the alpha diversity and structure of the intestinal microbiota by increasing the abundance of beneficial microbiota. Additionally, it was found that it improves metabolic disorders of colonic bile acids (BAs) and short-chain fatty acids (SCFAs) in LPS-challenged piglets, including an increase in primary BAs and isovalerate. In conclusion, CA supplementation could enhance intestinal integrity and barrier function by modifying intestinal microbiota and its metabolites, which could lead to a reduction in inflammatory responses and oxidative stress and ultimately enhanced growth performance in piglets.

Optimization of Heterotrophic Culture Conditions for the Algae Graesiella emersonii WBG-1 to Produce Proteins.

The aim of this study was to improve the protein content and yield of heterotrophic microalgal cultivation and establish a simple, economical, and efficient method for microalgal protein production using the novel green alga, Graesiella emersonii WBG-1, which has not been previously reported for heterotrophic cultivation. Through batch heterotrophic cultivation of this alga, we observed that glucose was the optimal carbon source, while it could not use sucrose as a carbon source. Biomass production and protein content were significantly reduced when sodium acetate was used as the carbon source. Compared with nitrate, protein content increased by 93% when urea was used as the nitrogen source. Cultivation temperature had a significant impact on biomass production and protein content. The optimal conditions were glucose as the carbon source at an initial concentration of 10 g/L, urea as the nitrogen source at an initial concentration of 1.62 g/L, and a culture temperature of 35 °C. On the second day of batch cultivation, the highest protein content (66.14%) was achieved, which was significantly higher than that reported in heterotrophic cultures of Chlorella and much higher than that reported for specially established technologies aimed at increasing the protein content, such as two-stage heterotrophic, heterotrophy-dilution-photoinduction, and mixotrophic processes. These results demonstrate the great potential of the heterotrophic cultivation of G. emersonii WBG-1 for protein production.

Aptamer-based kinetically controlled DNA reactions coupled with metal-organic framework nanoprobes for sensitive detection of SARS-CoV-2 spike protein.

Since the outbreak in 2019, COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become the deadliest infectious disease worldwide for people of all ages, from children to older adults. As a main structural protein of SARS-CoV-2, spike protein is reported to play a key role in the entry of the virus into host cells and is considered as an effective antigenic marker for COVID-19 diagnosis. Herein, we develop a new aptamer-based fluorescence method for SARS-CoV-2 spike protein detection based on using kinetically controlled DNA reactions and metal-organic framework nanoprobes. Specifically, the binding of SARS-CoV-2 spike protein to its aptamer is designed to precisely control the kinetics of a DNA displacement reaction, leading to the release of free signaling probes. By reasonable integration of magnetic enrichment and exonuclease-fuelled recycling, the released probes efficiently disrupt the interaction within metal-organic framework nanoprobes, thereby generating a remarkable fluorescent response. Experimental results show that the method not only exhibits a wide linear range and a low detection limit of 7.8 fg mL-1 for SARS-CoV-2 spike protein detection but also demonstrates desirable specificity and utility in complex samples. Therefore, the method may provide a valuable tool for the detection of SARS-CoV-2 spike protein, and has bright prospects in the rapid diagnosis of COVID-19, which is of great significance for guiding rational treatment during a pandemic of respiratory infectious diseases and reducing the occurrence of severe disease in children.

Pectin modulates intestinal immunity in a pig model via regulating the gut microbiota-derived tryptophan metabolite-AhR-IL22 pathway.

BACKGROUND: Pectin is a heteropolysaccharide that acts as an intestinal immunomodulator, promoting intestinal development and regulating intestinal flora in the gut. However, the relevant mechanisms remain obscure. In this study, pigs were fed a corn-soybean meal-based diet supplemented with either 5% microcrystalline cellulose (MCC) or 5% pectin for 3 weeks, to investigate the metabolites and anti-inflammatory properties of the jejunum. RESULT: The results showed that dietary pectin supplementation improved intestinal integrity (Claudin-1, Occludin) and inflammatory response [interleukin (IL)-10], and the expression of proinflammatory cytokines (IL-1ß, IL-6, IL-8, TNF-α) was down-regulated in the jejunum. Moreover, pectin supplementation altered the jejunal microbiome and tryptophan-related metabolites in piglets. Pectin specifically increased the abundance of Lactococcus, Enterococcus, and the microbiota-derived metabolites (skatole (ST), 3-indoleacetic acid (IAA), 3-indolepropionic acid (IPA), 5-hydroxyindole-3-acetic acid (HIAA), and tryptamine (Tpm)), which activated the aryl hydrocarbon receptor (AhR) pathway. AhR activation modulates IL-22 and its downstream pathways. Correlation analysis revealed the potential relationship between metabolites and intestinal morphology, intestinal gene expression, and cytokine levels. CONCLUSION: In conclusion, these results indicated that pectin inhibits the inflammatory response by enhancing the AhR-IL22-signal transducer and activator of transcription 3 signaling pathway, which is activated through tryptophan metabolites.

Hydroxytyrosol attenuates diquat-induced oxidative stress by activating Nrf2 pathway and modulating colonic microbiota in mice.

This study was conducted to investigate the antioxidant effects of hydroxytyrosol (HT) administration in diquat (DQ)-challenged mice. The results showed that HT treatment markedly alleviated DQ-induced oxidative stress, which was indicated by the enhanced total antioxidant capacity (T-AOC), increased activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase and decreased malondialdehyde (MDA) concentration in serum. Additionally, HT increased the mRNA expression levels of NF-E2-related factor 2 (Nrf2) and its downstream genes, including NADPH quinone oxidoreductase 1 (NQO1) and catalase (CAT) in the small intestine of DQ-challenged mice. 16S rRNA gene sequencing results showed that HT treatment increased the relative abundance of Firmicutes and Lactobacillus and decreased the relative abundance of Bacteroidetes. Interestingly, Pearson correlation analysis showed that there were strong association between colonic Firmicutes, Lactobacillus, and Bacteroidetes and the activities of serum antioxidant enzymes. Meanwhile, HT significantly enhanced the colonic butyrate concentration in DQ-challenged mice. Additionally, HT treatment decreased the serum metabolites involving in glycerophospholipid metabolism, pentose, and glucuronate interconversions, which were associated with alleviated oxidative stress. These results indicate that oral administration of 100 mg/kg body weight HT alleviates oxidative stress in DQ-challenged mice, which may involve Nrf2 signaling pathways via modulation of colonic microbiota.

Current Situation and Utilization of Velvet Deer Germplasm Resources in China.

Velvet deer are not only a representative special economic animal but also an important part of livestock. With the increasing awareness of international competition for germplasm resources in China, more and more attention has been paid to the protection and utilization of germplasm resources. However, there is poor understanding about velvet deer resources. Therefore, we are providing a comprehensive introduction of Chinese velvet deer germplasm resources from the aspects of ecological distribution, domestication and breeding.

Improving the Thermal and Oxidative Stability of Food-Grade Phycocyanin from Arthrospira platensis by Addition of Saccharides and Sugar Alcohols.

The water-soluble pigment protein phycocyanin (C-PC) from cyanobacteria Arthrospira sp. is an excellent natural food colorant and nutritional supplement with a brilliant blue color. However, C-PC is highly unstable, especially at high temperatures and when exposed to oxidative stress. The lack of simple and economical methods for improving the stability of C-PC greatly limits the application of this functional protein in the food industry. This study investigated the effect of adding saccharides (glucose, mannose, galactose, and maltose) and sugar alcohols (mannitol and maltitol) on the stability of food-grade C-PC extracted from Arthrospira platensis; the relevant reaction kinetics were also analyzed. The results revealed that glucose, mannose, mannitol, galactose, and maltose could effectively improve the thermal stability of C-PC. This improvement was positively correlated with the concentration of the additives and decreased sharply when the temperature exceeded 60 °C. Furthermore, the results also revealed the instability of C-PC when subjected to oxidative stress and the effectiveness of glucose, mannose, mannitol, and maltose in preventing the oxidative degradation of C-PC. In general, this study demonstrates that glucose, mannose, mannitol, and maltose are promising compounds for promoting the thermal and oxidative stability of C-PC, providing an economical and effective method for C-PC preservation.

Heat stress-induced mucosal barrier dysfunction is potentially associated with gut microbiota dysbiosis in pigs.

Heat stress (HS) can be detrimental to the gut health of swine. Many negative outcomes induced by HS are increasingly recognized as including modulation of intestinal microbiota. In turn, the intestinal microbiota is a unique ecosystem playing a critical role in mediating the host stress response. Therefore, we aimed to characterize gut microbiota of pigs' exposure to short-term HS, to explore a possible link between the intestinal microbiota and HS-related changes, including serum cytokines, oxidation status, and intestinal epithelial barrier function. Our findings showed that HS led to intestinal morphological and integrity changes (villus height, serum diamine oxidase [DAO], serum D-lactate and the relative expressions of tight junction proteins), reduction of serum cytokines (interleukin [IL]-8, IL-12, interferon-gamma [IFN-γ]), and antioxidant activity (higher glutathione [GSH] and malondialdehyde [MDA] content, and lower superoxide dismutase [SOD]). Also, 16S rRNA sequencing analysis revealed that although there was no difference in microbial α-diversity, some HS-associated composition differences were revealed in the ileum and cecum, which partly led to an imbalance in the production of short-chain fatty acids including propionate acid and valerate acid. Relevance networks revealed that HS-derived changes in bacterial genera and microbial metabolites, such as Chlamydia, Lactobacillus, Succinivibrio, Bifidobacterium, Lachnoclostridium, and propionic acid, were correlated with oxidative stress, intestinal barrier dysfunction, and inflammation in pigs. Collectively, our observations suggest that intestinal damage induced by HS is probably partly related to the gut microbiota dysbiosis, though the underlying mechanism remains to be fully elucidated.

Pectin supplementation ameliorates intestinal epithelial barrier function damage by modulating intestinal microbiota in lipopolysaccharide-challenged piglets.

During weaning, infants and young animals are susceptible to severe enteric infections, thus inducing intestinal microbiota dysbiosis, intestinal inflammation, and impaired intestinal barrier function. Pectin (PEC), a prebiotic polysaccharide, enhances intestinal health with the potential for a therapeutic effect on intestinal diseases. One 21-d study was conducted to investigate the protective effect of pectin against intestinal injury induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS) in a piglet model. A total of 24 piglets (6.77±0.92 kg BW; Duroc × Landrace × Large White; barrows; 21 d of age) were randomly assigned into three groups: control group, LPS-challenged group, and PEC + LPS group. Piglets were administrated with LPS or saline on d14 and d21 of the experiment. All piglets were slaughtered and intestinal samples were collected after 3 h administration on d21. Pectin supplementation ameliorated the LPS-induced inflammation response and damage to the ileal morphology. Meanwhile, pectin also improved intestinal mucin barrier function, increased the mRNA expression of MUC2, and improved intestinal mucus glycosylation. LPS challenge reduced the diversity of intestinal microbiota and enriched the relative abundance of Helicobacter. Pectin restored alpha diversity and improved the structure of the gut microbiota by enriching anti-inflammatory bacteria and short-chain fatty acids (SCFAs)-producing bacteria, and increased the concentrations of acetate. In addition, Spearman rank correlation analysis also revealed the potential relationship between intestinal microbiota and intestinal morphology, intestinal inflammation, and intestinal glycosylation in piglets. Taken together, these results indicate that pectin enhances intestinal integrity and barrier function by altering intestinal microbiota composition and their metabolites, which subsequently alleviates intestinal injury and finally improves the growth performance of piglets.

Chronic heat stress induces the disorder of gut transport and immune function associated with endoplasmic reticulum stress in growing pigs.

Although high temperatures influence gut health, data on underlying mechanisms remains scant. Using a pig model, this study performed a global analysis on how chronic heat stress affects the transport and immune function of the gut through transcriptome, proteome, microbial diversity and flow cytometry. A total of 27 pigs with similar body weights were assigned into 3 groups, control (Con) group (23 °C), chronic heat stressed (HS) group (33 °C), and pair-fed (PF) group, in a controlled environment for 21 days. Our results showed that pigs in the HS group had reduced growth performance and diminished height of ileal villi (P < 0.01). Transcriptome and proteome analyses demonstrated notable modification of expression of nutrients and ion transport-related transporters and gut mechanical barrier-related genes by chronic heart stress (P < 0.05), suggesting damage of transport functions and the gut barrier. Chronic heat stress-induced endoplasmic reticulum stress also increased the synthesis of misfolded proteins, leading to upregulation of misfolded protein degradation and synthesis, as well as vesicle transport disorder (P < 0.05). Energy supply processes were enhanced in the mitochondrion (P < 0.05) to maintain biological processes with high energy demands. Furthermore, chronic heat stress activated complement cascade response-related genes and proteins in the gut mucosa (P < 0.05). Our flow cytometry assays showed that the proportion of gut lymphocytes (CD4+ T cells, T cells, B cells in Peyer's patch lymphocytes and CD4+ CD25+ T cells in intraepithelial lymphocytes) were significantly altered in the HS group pigs (P < 0.05). In addition, the occurrence of gut microbial dysbiosis in the HS group pigs was characterized by increased potential pathogens (e.g., Asteroleplasma, Shuttleworthia, Mycoplasma) and suppression of beneficial bacteria (e.g., Coprococcus and Aeriscardovia), which are associated with gut immune function. Altogether, our data demonstrated that chronic heat stress induced gut transport and immune function disorder associated with endoplasmic reticulum stress in growing pigs.

Gut microbiota mediates the effects of inulin on enhancing sulfomucin production and mucosal barrier function in a pig model.

Dietary fibers (DFs) have many beneficial effects on intestinal health by ameliorating intestinal inflammation and modulating the microbial community composition, thereby affecting the barrier function. This study aims to characterize the gut microbiota of pigs fed with DFs, revealing a link between the intestinal microbiota and mucin chemotypes. Pigs (six per group) were randomly allotted to consume one of the following diets: control (CON) or a diet supplemented with 5% microcrystalline cellulose (MCC) or inulin (INU) for 72 days. We found that INU but not MCC enhanced the colonic barrier function by promoting the expression of ZO-1, Occludin and MUC2 and reducing the colonic crypt depth. INU increased sulfomucin production and mRNA levels of sulfotransferases Gal3ST1 and Gal3ST2. Goblet cells in the ileum were found to contain predominantly sialomucins while colonic goblet cells were dominated by sulfomucins with sialomucins absent. DF consumption increased the concentrations of short-chain fatty acids (SCFAs) of the ileum and colon compared to the CON diet. Moreover, the results of 16S rRNA gene sequencing analysis revealed that DFs significantly altered the composition of ileal and colonic mucosal microbiota. Network analysis indicated that INU-induced changes in bacterial genera and SCFAs, such as Akkermansia and butyrate, were significantly related with sulfomucins and the mucosal barrier function-gene in pigs. Collectively, these findings suggest that the intestinal mucosal microbiota and SCFAs induced by INU play a crucial role in modulating the chemotypes of mucin and the barrier function.

Controlling of two destructive zooplanktonic predators in Chlorella mass culture with surfactants.

BACKGROUND: Predatory flagellates and ciliates are two common bio-contaminants which frequently cause biomass losses in Chlorella mass culture. Efficient and targeted ways are required to control these contaminations in Chlorella mass cultivation aiming for biofuel production especially. RESULTS: Five surfactants were tested for its ability to control bio-contaminations in Chlorella culture. All five surfactants were able to eliminate the contaminants at a proper concentration. Particularly the minimal effective concentrations of sodium dodecyl benzene sulfonate (SDBS) to completely eliminate Poterioochromonas sp. and Hemiurosomoida sp. were 8 and 10 mg L-1, respectively, yet the photosynthesis and viability of Chlorella was not significantly affected. These results were further validated in Chlorella mass cultures in 5, 20, and 200 m2 raceway ponds. CONCLUSIONS: A chemical method using 10 mg L-1 SDBS as pesticide to control predatory flagellate or ciliate contamination in Chlorella mass culture was proposed. The method helps for a sustained microalgae biomass production and utilization, especially for biofuel production.

Running Head: Heat Affects Cholesterol and Bile Acid Alterations in Cholesterol and Bile Acids Metabolism in Large White Pigs during Short-Term Heat Exposure.

Heat stress influences lipid metabolism independently of nutrient intake. It is not well understood how cholesterol and bile acid (BA) metabolism are affected by heat stress. To investigate the alterations of cholesterol and bile acids when pigs are exposed to short term heat stress, 24 Large White pigs (63.2 ± 9.5 kg body weight, BW) were distributed into one of three environmental treatments: control conditions (CON, 23 °C with ad libitum intake; n = 8), heat stress conditions (HS, 33 °C with ad libitum intake; n = 8), or pair-fed conditions (PF, 23 °C with the same amount to the feed consumed by the HS; n = 8) for three days. Compared with CON pigs, HS pigs reduced the average daily feed intake and average daily gain by 55% and 124%, respectively, and significantly increased rectal temperatures by 0.9 °C and respiration rates more than three-fold. The serum total cholesterol (TC), low-density lipoprotein-cholesterol, and triglycerides (TG) increased (p < 0.05), while hepatic TC, TG, and mRNA of 3-hydroxy-3-methylglutaryl-CoA reductase were reduced on day 3. Furthermore, liver taurine-conjugated BAs (TCBAs), including taurolithocholic acid, taurochenodeoxycholic acid (TCDCA), tauroursodeoxycholic acid, taurohyodeoxycholic acid, and taurocholic acid were elevated in HS pigs compared to CON and PF pigs (p < 0.05), and the level of chenodeoxycholic acid was more significant in the PF group than in the CON and HS groups. The concentration of ursodeoxycholic acid in the serum was higher in HS pigs than CON and PF pigs (p < 0.05), and TCDCA was increased in HS pigs compared with PF pigs (p < 0.05). Altogether, short-term HS reduced hepatic cholesterol levels by decreasing cholesterol synthesis, promoting cholesterol to TCBAs conversion, and cholesterol release to serum in growing pigs. This independently reduced feed intake might serve as a mechanism to protect cells from damage during the early period.

Application of surfactants for controlling destructive fungus contamination in mass cultivation of Haematococcus pluvialis.

Large-scale cultivation of Haematococcus pluvialis is frequently contaminated by the destructive fungus Paraphysoderma sedebokerense, which can cause huge losses in astaxanthin production. Here, we propose the use of four commercial surfactants to control P. sedebokerense contamination in H. pluvialis cultures. In laboratory experiments, sodium dodecylbenzene sulfonate, sodium dodecyl sulfate and primary alcohol ethoxylate treatments showed inhibitory effects on fungal contamination. Moreover, sodium dodecylbenzene sulfonate was the most promising because treatment at 7 mg L-1 was effective against fungal infection without negatively affecting the growth or astaxanthin contents of H. pluvialis. This could be ascribed to their different cell coverings and structures. Additionally, applying sodium dodecylbenzene sulfonate to open raceway ponds prevented fungal contamination, and astaxanthin production reached 1.82 g m-2. Therefore, sodium dodecylbenzene sulfonate can be used as an effective and economical control agent for commercial production of astaxanthin fromH. pluvialis.