Enhancing the antioxidant capacity and quality attributes of fermented goat milk through the synergistic action of Limosilactobacillus fermentum WXZ 2-1 with a starter culture.

This study evaluated 75 strains of lactic acid bacteria (LAB) isolated from traditional dairy products in western China for their probiotic properties. Among them, Limosilactobacillus fermentum WXZ 2-1, Lactiplantibacillus plantarum TXZ 2-35, Companilactobacillus crustorum QHS 9, and Companilactobacillus crustorum QHS 10 demonstrated potential probiotic characteristics. The antioxidant capacity of these 4 strains was assessed, revealing that L. fermentum WXZ 2-1 exhibited the highest antioxidant capacity. Furthermore, when cocultured with Streptococcus salivarius ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, L. fermentum WXZ 2-1 demonstrated a synergistic effect in growth medium and goat milk. To explore its effect on goat milk fermentation, different amounts of L. fermentum WXZ 2-1 were added to goat milk, and its physicochemical properties, antioxidant activity, flavor substances, and metabolomics were analyzed. The study found that the incorporation of L. fermentum WXZ 2-1 in goat milk fermentation significantly improved the texture characteristics, antioxidant capacity, and flavor of fermented goat milk. These findings highlight the potential of L. fermentum WXZ 2-1 as a valuable probiotic strain for enhancing the functionality and desirability of fermented goat milk, contributing to the development of novel functional foods with improved health benefits and enhanced quality attributes.

Lactobacillus coryniformis MXJ32 administration ameliorates azoxymethane/dextran sulfate sodium-induced colitis-associated colorectal cancer via reshaping intestinal microenvironment and alleviating inflammatory response.

PURPOSE: Gut microbiota has been reported to contribute to either prevent or promote colorectal cancer (CRC), and treatment with probiotics might be a promising intervention method. The present study aimed to evaluate the potential anti-CRC effects of Lactobacillus coryniformis MXJ32 on a colitis-associated (CA)-CRC mouse model. METHODS: The CA-CRC mouse model was induced by a single intraperitoneal injection of 10 mg/kg azoxymethane and followed by three 7-day cycles of 2% dextran sulfate sodium in drinking water with a 14-day recovery period. Mice were supplemented with L. coryniformis MXJ32 by oral gavage (1 × 109 CFU/day/mouse). The CA-CRC attenuating effects of this probiotic were assessed via intestinal barrier integrity, inflammation, and gut microenvironment. RESULTS: Treatment with L. coryniformis MXJ32 could significantly inhibit the total number of tumors and the average tumor diameter. This probiotic administration prevented the damage of intestinal barrier function by enhancing the expression of tight junction proteins (Occludin, Claudin-1, and ZO-1) and recovering the loss of goblet cells. Moreover, L. coryniformis MXJ32 alleviated intestinal inflammation via down-regulating the expression of inflammatory cytokines (TNF-α, IL-1ß, IL-6, IL-γ, and IL-17a) and chemokines (Cxcl1, Cxcl2, Cxcl3, Cxcl5, and Ccl7). In addition, L. coryniformis MXJ32 supplementation increased the abundance of some beneficial bacteria (such as SCFAs-producing bacteria, Lactobacillus, Bifidobacterium, Akkermansia, and Faecalibaculum) and decreased the abundance of some harmful bacteria (such as pro-inflammatory bacteria, Desulfovibrio and Helicobacter), which in turn attenuated the overexpression of inflammation. CONCLUSION: Lactobacillus coryniformis MXJ32 could effectively ameliorate CA-CRC via regulating intestinal microenvironment, alleviating inflammation, and intestinal barrier damage, which further suggested that L. coryniformis MXJ32 could be considered as a functional food ingredient for the alleviation of CA-CRC.

Full components conversion of lignocellulose via a closed-circuit biorefinery process on a pilot scale.

This study developed a closed-circuit biorefinery process for full conversion of lignocellulose into ethanol, biogas and organic fertilizer with zero waste on a pilot scale. In the process, subcritical water pretreatment could effectively break the structure of wheat straw (WS), and ethanol was obtained from pretreated wheat straw (PWS) using two batches of simultaneous saccharification and fermentation (SSF). The pretreatment and ethanol fermentation wastes were reused for biogas and organic fertilizer production by anaerobic digestion (AD), whereas the pretreatment and ethanol conversion efficiency were reduced when supernatant after AD was recovered for next batch pretreatment. The yields of ethanol (0.08-0.09 g/g), biogas (0.05-0.10 L/g) and organic fertilizer (0.55-0.79 g/g) were demonstrated through mass balance. Furthermore, the hidden problems were exposed on pilot-scale conversion process, and several strategies were provided for optimizing the biorefinery process in the future.

Purification, characterization, and mode of action of a novel bacteriocin BM173 from Lactobacillus crustorum MN047 and its effect on biofilm formation of Escherichia coli and Staphylococcus aureus.

There is an increasing demand for dairy products, but the presence of food-spoilage bacteria seriously affects the development of the dairy industry. Bacteriocins are considered to be a potential antibacterial or antibiofilm agent that can be applied as a preservative. In this study, bacteriocin BM173 was successfully expressed in the Escherichia coli expression system and purified by a 2-step method. Furthermore, it exhibited a broad-spectrum antibacterial activity, high thermal stability (121°C, 20 min), and broad pH stability (pH 3-11). Moreover, the minimum inhibitory concentration values of BM173 against E. coli ATCC 25922 and Staphylococcus aureus ATCC 25923 were 14.8 µg/mL and 29.6 µg/mL, respectively. Growth and time-kill curves showed that BM173 exhibited antibacterial and bactericidal activity. The results of scanning electron microscopy and transmission electron microscopy demonstrated that BM173 increased membrane permeability, facilitated pore formation, and even promoted cell lysis. The disruption of cell membrane integrity was further verified by propidium iodide uptake and lactic dehydrogenase release. In addition, BM173 exhibited high efficiency in inhibiting biofilm formation. Therefore, BM173 has promising potential as a preservative used in the dairy industry.

Mining, heterologous expression, purification, antibactericidal mechanism, and application of bacteriocins: A review.

Bacteriocins are generally considered as low-molecular-weight ribosomal peptides or proteins synthesized by G+ and G- bacteria that inhibit or kill other related or unrelated microorganisms. However, low yield is an important factor restricting the application of bacteriocins. This paper reviews mining methods, heterologous expression in different systems, the purification technologies applied to bacteriocins, and identification methods, as well as the antibacterial mechanism and applications in three different food systems. Bioinformatics improves the efficiency of bacteriocins mining. Bacteriocins can be heterologously expressed in different expression systems (e.g., Escherichia coli, Lactobacillus, and yeast). Ammonium sulfate precipitation, dialysis membrane, pH-mediated cell adsorption/desorption, solvent extraction, macroporous resin column, and chromatography are always used as purification methods for bacteriocins. The bacteriocins are identified through electrophoresis and mass spectrum. Cell envelope (e.g., cell permeabilization and pore formation) and inhibition of gene expression are common antibacterial mechanisms of bacteriocins. Bacteriocins can be added to protect meat products (e.g., beef and sausages), dairy products (e.g., cheese, milk, and yogurt), and vegetables and fruits (e.g., salad, apple juice, and soybean sprouts). The future research directions are also prospected.

Characterization of plant growth-promoting rhizobacteria from perennial ryegrass and genome mining of novel antimicrobial gene clusters.

BACKGROUND: Plant growth-promoting rhizobacteria (PGPR) are good alternatives for chemical fertilizers and pesticides, which cause severe environmental problems worldwide. Even though many studies focus on PGPR, most of them are limited in plant-microbe interaction studies and neglect the pathogens affecting ruminants that consume plants. In this study, we expand the view to the food chain of grass-ruminant-human. We aimed to find biocontrol strains that can antagonize grass pathogens and mammalian pathogens originated from grass, thus protecting this food chain. Furthermore, we deeply mined into bacterial genomes for novel biosynthetic gene clusters (BGCs) that can contribute to biocontrol. RESULTS: We screened 90 bacterial strains from the rhizosphere of healthy Dutch perennial ryegrass and characterized seven strains (B. subtilis subsp. subtilis MG27, B. velezensis MG33 and MG43, B. pumilus MG52 and MG84, B. altitudinis MG75, and B. laterosporus MG64) that showed a stimulatory effect on grass growth and pathogen antagonism on both phytopathogens and mammalian pathogens. Genome-mining of the seven strains discovered abundant BGCs, with some known, but also several potential novel ones. Further analysis revealed potential intact and novel BGCs, including two NRPSs, four NRPS-PKS hybrids, and five bacteriocins. CONCLUSION: Abundant potential novel BGCs were discovered in functional protective isolates, especially in B. pumilus, B. altitudinis and Brevibacillus strains, indicating their great potential for the production of novel secondary metabolites. Our report serves as a basis to further identify and characterize these compounds and study their antagonistic effects against plant and mammalian pathogens.

Exploring the role of Luman/CREB3 in regulating decidualization of mice endometrial stromal cells by comparative transcriptomics.

BACKGROUND: Luman is a member of CREB3 (cAMP responsive element-binding) subfamily of the basic leucine-zipper (bZIP) transcription factors. It may play an important regulatory role during the decidualization process since Luman was highly expressed in the decidual cells. However, the exact molecular mechanisms of how Luman regulating decidualization is unknown. RESULTS: Using an in vitro model, we prove that Luman knockdown significantly affects the decidualization process of mice endometrial stromal cells (ESCs) as the expression of two decidual markers PRL8a2 and PRL3c1 were repressed. We employed massively parallel RNA sequencing (RNA-Seq) to understand the changes in the transcriptional landscape associated with knockdown of Luman in ESCs during in vitro decidualization. We found significant dysregulation of genes related to protein processing in the endoplasmic reticulum (ER). Several genes involved in decidualization including bone morphogenetic proteins (e.g. BMP1, BMP4, BMP8A, BMP2, and BMP8B), growth factor-related genes (e.g. VEGFB, FGF10, and FGFR2), and transcription factors (IF4E, IF4A2, WNT4, WNT9A, ETS1, NOTCH1, IRX1, IDB1, IDB2, and IDB3), show altered expression. We also found that the knockdown of Luman is associated with increased expression of cell cycle-related genes including cycA1, cycB1, cycB2, CDK1, CDK2, and PLPK1, which resulted in an increased proportion of ESCs in the G1 phase. Differentially expressed genes (DEGs) were highly enriched on ECM-receptor interaction signaling, endoplasmic reticulum protein processing, focal adhesion, and PI3K-Akt signaling pathways. CONCLUSIONS: Luman knockdown results in widespread gene dysregulation during decidualization of ESCs. Genes involved in protein processing in ER, bone morphogenetic protein, growth factor, and cell cycle progression were identified as particularly important for explaining the decidual deficiency observed in this in vitro model. Therefore, this study provides clues as to the underlying mechanisms that may expand our understanding of gene regulation during decidualization.

Screening of cellulolytic bacteria from rotten wood of Qinling (China) for biomass degradation and cloning of cellulases from Bacillus methylotrophicus.

BACKGROUND: Cellulosic biomass degradation still needs to be paid more attentions as bioenergy is the most likely to replace fossil energy in the future, and more evaluable cellulolytic bacteria isolation will lay a foundation for this filed. Qinling Mountains have unique biodiversity, acting as promising source of cellulose-degrading bacteria exhibiting noteworthy properties. Therefore, the aim of this work was to find potential cellulolytic bacteria and verify the possibility of the cloning of cellulases from the selected powerful bacteria. RESULTS: In present study, 55 potential cellulolytic bacteria were screened and identified from the rotten wood of Qinling Mountains. Based on the investigation of cellulase activities and degradation effect on different cellulose substrates, Bacillus methylotrophicus 1EJ7, Bacillus subtilis 1AJ3 and Bacillus subtilis 3BJ4 were further applied to hydrolyze wheat straw, corn stover and switchgrass, and the results suggested that B. methylotrophicus 1EJ7 was the most preponderant bacterium, and which also indicated that Bacillus was the main cellulolytic bacteria in rotten wood. Furthermore, scanning electron microscopy (SEM) and X-ray diffraction analysis of micromorphology and crystallinity of wheat straw also verified the significant hydrolyzation. With ascertaining the target sequence of cellulase ß-glucosidase (243 aa) and endoglucanase (499 aa) were successfully heterogeneously cloned and expressed from B. methylotrophicus 1EJ7, and which performed a good effect on cellulose degradation with enzyme activity of 1670.15 ± 18.94 U/mL and 0.130 ± 0.002 U/mL, respectively. In addition, based on analysis of amino acid sequence, it found that ß-glucosidase were belonged to GH16 family, and endoglucanase was composed of GH5 family catalytic domain and a carbohydrate-binding module of CBM3 family. CONCLUSIONS: Based on the screening, identification and cellulose degradation effect evaluation of cellulolytic bacteria from rotten wood of Qinling Mountains, it found that Bacillus were the predominant species among the isolated strains, and B. methylotrophicus 1EJ7 performed best on cellulose degradation. Meanwhile, the ß-glucosidase and endoglucanase were successfully cloned and expressed from B. methylotrophicus for the first time, which provided new materials of both strain and the recombinant enzymes for the study of cellulose degradation and its application in industry.

Anti-obesity effect of Lactobacillus rhamnosus LS-8 and Lactobacillus crustorum MN047 on high-fat and high-fructose diet mice base on inflammatory response alleviation and gut microbiota regulation.

PURPOSE: The objective of the study was to evaluate the anti-obesity effect of Lactobacillus rhamnosus LS-8 and Lactobacillus crustorum MN047, and illustrate the potential functional mechanism about the alleviation of high fat and high fructose diet (HFFD) induced obesity and related metabolic abnormalities. METHODS: C57BL/6J mice were subjected to a standard or HFFD with or without supplementation of L. rhamnosus LS-8 and L. crustorum MN047 for 10 weeks. Obesity related metabolic indices including glucose tolerance, insulin resistance, serum lipid, liver function, hormones and inflammatory cytokines were assessed by standard protocols. For the monitoring of inflammatory response and lipid metabolism, transcriptional levels were profiled in liver and/or adipose tissues. Furthermore, gut microbiota composition analyses in the fecal samples were performed using 16S rRNA gene sequencing, and gut microbial metabolites, including lipopolysaccharide (LPS) and short-chain fatty acids (SCFAs), were also tested for the assessment of the relationship between gut microbiota variation and inflammatory response. RESULTS: Administration with L. rhamnosus LS-8 and L. crustorum MN047 significantly mitigated body weight gain and insulin resistance, and inflammatory response (TNF-α, IL-1ß and IL-6 levels in serum and corresponding mRNA levels in adipose tissues) was significantly inhibited in these two strains-treated mice. Moreover, L. rhamnosus LS-8 and L. crustorum MN047 could partially normalized mRNA expression levels involved in lipid metabolism including Pparγ, Srebp-1c, CD36, Fabp2 and FAS. In addition, these two strains manipulated gut microbiota by decreasing the abundance of Bacteroides and Desulfovibrio and increasing that of Lactobacillus and Bifidobacterium, which in turn raised the levels of feces SCFAs and lowered the levels of circulating LPS. CONCLUSION: These results indicated that L. rhamnosus LS-8 and L. crustorum MN047 supplementation possessed the anti-obesity effect on the HFFD fed mice by alleviating inflammatory response and regulating gut microbiota, which further suggested that these two probiotics can be considered as an alternative dietary supplement in combination with the preventive and therapeutic strategies against obesity and related complications.

Fermentation optimization and kinetic model for high cell density culture of a probiotic microorganism: Lactobacillus rhamnosus LS-8.

To develop a practical food-grade medium and optimal fermentation process for the cost-effective fermentation of Lactobacillus rhamnosus LS-8, both culture medium and conditions were optimized by combining single-factor experimental design, Plackett-Burman design and Box-Behnken design. The medium was simplified to five ingredients (g/L): whey powder (62.5), maltose syrup (50), corn steep liquor (55), NaCl (1) and lysine (0.05), and the optimal culture conditions were initial pH (6.28), constant fermentation pH (4.7), neutralizing agent (NaOH), aeration rate (0.2 v/v/min) and stirrer speed (200 rpm). After culturing in this optimized medium and conditions, the cell density of L. rhamnosus LS-8 was improved to 4.5 × 109 CFU/mL, which was elevated about 9 times higher than that obtained in MRS medium. Moreover, cell growth and substrate consumption kinetic constants were determined by the logistic equation and Luedeking-Piret model, and the R2 values from the model equation were 0.9900 and 0.9971, respectively, indicating that these models were able to simulate the growth and substrate consumption of L. rhamnosus LS-8 accurately. In addition, a high-efficient production process of L. rhamnosus LS-8 was developed by repeated-batch operation, which was verified by five cycles of fermentation with good stability and repeatability. In conclusion, the efficiency of L. rhamnosus LS-8 fermentation was greatly improved as well as the reduction of the cost using the medium and process developed in the present study.

Exploring plant-microbe interactions of the rhizobacteria Bacillus subtilis and Bacillus mycoides by use of the CRISPR-Cas9 system.

Bacillus subtilis HS3 and Bacillus mycoides EC18 are two rhizosphere-associated bacteria with plant growth-promoting activity. The CRISPR-Cas9 system was implemented to study various aspects of plant-microbe interaction mechanisms of these two environmental isolates. The results show that fengycin and surfactin are involved in the antifungal activity of B. subtilis HS3. Moreover, this strain emits several other volatile organic compounds than 2,3-butanediol, contributing to plant growth promotion. Confocal laser scanning microscopy observations of the GFP-labelled strain showed that HS3 selectively colonizes root hairs of grass (Lolium perenne) in a hydroponic system. For B. mycoides EC18, we found that the wild-type EC18 strain and a ΔasbA (petropectin-deficient) mutant, but not the ΔdhbB (bacillibactin-deficient) and ADKO (asbA and dhbB double knockout) mutants, can increase the plant biomass and total chlorophyll. All the mutant strains have a reduced colonization capability on Chinese cabbage (Brassica rapa) roots, at the root tip and root hair region compared with the wild-type strain. These results indicate that the siderophore, bacillibactin, is involved in the plant growth promoting activity and could affect the root colonization of B. mycoides. Collectively, the CRISPR-Cas9 system we developed for environmental isolates is broadly applicable and will facilitate deciphering the mechanisms of Bacillus-plant interactions. © 2018 The Authors.

Probiotic potential of Bacillus velezensis JW: Antimicrobial activity against fish pathogenic bacteria and immune enhancement effects on Carassius auratus.

This study evaluated the probiotic potential of B. velezensis JW through experimental and genomic analysis approaches. Strain JW showed antimicrobial activity against a broad range of fish pathogenic bacteria including Aeromonas hydrophila, Aeromonas salmonicida, Lactococcus garvieae, Streptococcus agalactiae, and Vibrio Parahemolyticus. Fish (Carassius auratus) were fed with the diets containing 0 (control), 107, and 109 cfu/g of B. velezensis JW for 4 weeks. Various immune parameters were examined at 1, 2, 3, and 4 weeks of post-feeding. Results showed that JW supplemented diets significantly increased acid phosphatase (ACP), alkaline phosphatase (AKP), and glutathione peroxidase (GSH-PX) activity. The mRNA expression of immune-related genes in the head kidney of C. auratus was measured. Among them, the interferon gamma gene (IFN- γ) and tumor necrosis factor-α (TNF-α) showed higher expression after 3 and 4 weeks of feeding (P < 0.05). The expression of interleukin-1 (IL-1) only being significantly upregulated by 109 cfu/g of JW after 1 week of feeding (P < 0.05). The upregulation of interleukin-4 (IL-4) increased over time from 1st to 4th week. The expression of interleukin-10 (IL-10) and interleukin-12 (IL-12) showed an opposite expression pattern with IL-10 significantly upregulated and IL-12 significantly downregulated by JW containing diets at 2, 3, and 4 weeks of post-feeding (P < 0.05). Moreover, fish fed with JW supplemented diets showed significantly improved survival rate after A. hydrophila infection. The analysis of the genome of JW revealed several features aiding host health and being relevant to the GIT adaptation. Four bacteriocins, three Polyketide Synthetase (PKS), and five Nonribosomal Peptide-Synthetase (NRPS) gene clusters were identified in the genome. In summary, the above results clearly proved that B. velezensis JW has the potential to be developed as a probiotic agent in aquaculture.

Endoplasmic reticulum stress is involved in the T-2 toxin-induced apoptosis in goat endometrium epithelial cells.

T-2 toxin is one of the trichothecene mycotoxins commonly found in animal feed and agricultural products. Ingestion of T-2 toxin by animals results in acute and chronic diseases, as well as reproductive failure. This study aimed at investigating the role of endoplasmic reticulum (ER) stress in T-2 toxin-induced apoptosis in goat endometrium epithelial cells. Flow cytometry and cell viability assay showed that T-2 toxin significantly induced cell apoptosis, which was accompanied with increased expression of cleaved-caspase-3. The altered expression of two ER stress markers CHOP and GRP78 proved that ER stress is involved in the T-2 toxin-induced apoptosis. 4-phenylbutyrate pretreatment was applied to relieve the ER stress, pretreated endometrium epithelial cells showed a decreased apoptosis level and the expression pattern of CHOP and GRP78 was reversed. The key genes involved in signaling pathways of ER stress-associated apoptosis were examined, which showed that the IRE1-JNK and PERK-ATF4-CHOP signal transduction pathways are both activated. Moreover, the level of cytokines including interleukin (IL)-1ß, IL-6, IL-10 and tumor necrosis factor-α decreased in the T-2 toxin-treated cells. While the 4-phenylbutyrate pretreatment elevates the cytokine levels after T-2 treatment. Collectively, these results suggest that ER stress contributes to the T-2 toxin-induced apoptosis and decreased cytokine levels in goat endometrium epithelial cells. This study offers new insight into the molecular mechanisms of T-2 toxicity on reproductive cells.

Screening of plant extracts for anthelmintic activity against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus).

With the aim of finding natural anthelmintic agents against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus), 26 plants were screened for antiparasitic properties using in vivo anthelmintic efficacy assay. The results showed that Caesalpinia sappan, Lysima chiachristinae, Cuscuta chinensis, Artemisia argyi, and Eupatorium fortunei were found to have 100% anthelmintic efficacy at 125, 150, 225, 300, and 500 mg L(-1) after 48 h of exposure. Crude extract of the five plants were further partitioned with petroleum ether, chloroform, ethyl acetate, methanol, and water to obtain anthelmintically active fractions with various polarity. Among these fractions tested, the ethyl acetate extract of L. chiachristinae was found to be the most effective with a 50% effective concentration (EC50) value of 5.1 mg/L after 48 h of exposure. This was followed by ethyl acetate extract of C. chinensis (48 h-EC50 = 8.5 mg L(-1)), chloroform extracts of C. sappan (48 h-EC50 = 15.6 mg L(-1)), methanol extract of C. chinensis (48 h-EC50 = 15.9 mg L(-1)), and chloroform and petroleum ether extract of L. chiachristinae (EC50 values of 17.2 and 21.1 mg/L, respectively), suggesting that these plants, as well as the active fractions, provide potential sources of botanic drugs for the control of D. intermedius in aquaculture.

Antiprotozoal screening of traditional medicinal plants: evaluation of crude extract of Psoralea corylifolia against Ichthyophthirius multifiliis in goldfish.

Ichthyophthirius multifiliis (also called "ich") is an external protozoan parasite that may infest almost all freshwater fish species and caused significant economic damage to the aquaculture industry. Since the use of malachite green was banned, there have been relatively few effective alternative strategies for controlling I. multifiliis infections. The present study was designed to screen potential antiparasitic medicinal plants based on our previous studies, and comprehensively evaluate in vitro and in vivo anti-ich activity of selected plant extracts. The screening results showed that the methanol extract of Psoralea corylifolia had the highest activity against I. multifiliis theronts. In vivo theront trials demonstrated that 1.25 mg/L or more concentrations of P. corylifolia methanol extract caused 100 % mortality during the 4-h exposure period, and the subsequent in vitro trials indicated that the minimum concentration of P. corylifolia methanol extract that prevented the initial infestation was 2.50 mg/L. Protomonts and encysted tomonts surviving trials suggested that encysted tomonts were less susceptible to P. corylifolia methanol extract than protomonts, and the methanol extract of P. corylifolia at a concentration of 5.00 mg/L could kill 100 % of protomonts and 88.89 % of encysted tomonts. It was also observed that after 12-h exposure of protomonts or encysted tomonts to 2.50 mg/L of P. corylifolia methanol extract, the theronts emerged from encysted tomonts led to more infection level than the ones in the other groups. The results suggested that whether the protomonts finish encystment is crucial to the survival, reproduction, and theronts infectivity. In addition, our results showed that long duration (24 h) and high concentration (5.00 mg/L) significantly reduced the survival and reproduction of I. multifiliis tomont exited from the fish after in-bath treatment, and it is indicated that P. corylifolia methanol extract had a potential detrimental effect on I. multifiliis trophont in situ.

Antiprotozoal activity of medicinal plants against Ichthyophthirius multifiliis in goldfish (Carassius auratus).

Ichthyophthiriasis is a widespread disease in aquaculture and causes mass mortalities of fish. The development of new antiprotozoal agents for the treatment of Ichthyophthirius multifiliis infections is of increasing interest. The aim of the present study was to investigate the efficacy of 30 medicinal plants against I. multifiliis. The results showed that the methanol extracts of Magnolia officinalis and Sophora alopecuroides displayed the highest antiprotozoal activity against theronts, with 4-h LC(50) values estimated to be 2.45 and 3.43 mg L(-1), respectively. Concentrations of 2.5, 5.0, 10.0, and 20.0 mg L(-1) of M. officinalis extracts resulted in tomont mortality of 9.7, 43.7, 91.3, and 100% at 20 h, respectively. From 40 to 320 mg L(-1) of S. alopecuroides extracts, tomont mortality increased from 29.7 to 100%. Antiprotozoal efficacy against settled tomonts (2 and 10 h) was also applied; the results indicated that encysted I. multifiliis tomonts were less susceptible to these plant extract treatments. In vivo experiments demonstrated that high concentrations of M. officinalis and S. alopecuroides extracts could kill tomonts, and M. officinalis significantly reduced its reproduction (P < 0.05). These results suggested that the methanol extracts of M. officinalis and S. alopecuroides have the potential to be used as an eco-friendly approach for the control of I. multifiliis.

Roles of intestinal Parabacteroides in human health and diseases.

The stability of gut microbiota is essential for the host's health. Parabacteroides spp., core members of the human gut microbiota, have an average abundance of 1.27% in humans of 12 populations. Parabacteroides have recently been reported to have a close relationship with host health (e.g. metabolic syndrome, inflammatory bowel disease and obesity). Parabacteroides have the physiological characteristics of carbohydrate metabolism and secreting short chain fatty acids. However, antimicrobial resistance of Parabacteroides to antibiotics (such as clindamycin, moxifloxacin and cefoxitin) should not be ignored. In this review, we primarily focus on Parabacteroides distasonis, Parabacteroides goldsteinii, Parabacteroides johnsonii and Parabacteroides merdae and discuss their relationships with host disease, diet and the prevention or induction of diseases. Pa. distasonis and Pa. goldsteinii may be viewed as potential next generation probiotic candidates due to their protective effects on inflammation and obesity in mice. We also discuss the potential therapeutic application of Parabacteroides spp. in maintaining host-intestine homeostasis.

Mechanistic Target of Rapamycin Complex 1: From a Nutrient Sensor to a Key Regulator of Metabolism and Health.

Mechanistic target of rapamycin complex 1 (mTORC1) is a multi-protein complex widely found in eukaryotes. It serves as a central signaling node to coordinate cell growth and metabolism by sensing diverse extracellular and intracellular inputs, including amino acid-, growth factor-, glucose-, and nucleotide-related signals. It is well documented that mTORC1 is recruited to the lysosomal surface, where it is activated and, accordingly, modulates downstream effectors involved in regulating protein, lipid, and glucose metabolism. mTORC1 is thus the central node for coordinating the storage and mobilization of nutrients and energy across various tissues. However, emerging evidence indicated that the overactivation of mTORC1 induced by nutritional disorders leads to the occurrence of a variety of metabolic diseases, including obesity and type 2 diabetes, as well as cancer, neurodegenerative disorders, and aging. That the mTORC1 pathway plays a crucial role in regulating the occurrence of metabolic diseases renders it a prime target for the development of effective therapeutic strategies. Here, we focus on recent advances in our understanding of the regulatory mechanisms underlying how mTORC1 integrates metabolic inputs as well as the role of mTORC1 in the regulation of nutritional and metabolic diseases.

Antibiofilm Effects of Bacteriocin BMP32r on Listeria monocytogenes.

Listeria monocytogenes is a well-known foodborne pathogen that usually lives as biofilm to cope with unfavorable surroundings. Bacteriocins have been reported as antimicrobial compounds, and their bactericidal actions have been extensively studied, but their antibiofilm actions have rarely been studied. Previous study indicated that bacteriocin BMP32r has a broad-spectrum antibacterial activity. In this study, the efficacy of BMP32r against the planktonic bacteria, inhibition of forming biofilm, destruction of mature biofilm, and kill persisters of L. monocytogenes ATCC 15,313 was determined. BMP32r exhibited the bactericidal effect on L. monocytogenes planktonic bacteria. Crystal violet staining showed that sub-minimum inhibitory concentrations (SICs) of BMP32r (1/32 × MIC and 1/16 × MIC) significantly (p < 0.001) inhibit the biofilm formation. In addition, the results of CCK-8, plate count, ruthenium red staining, scanning electron microscopy, and real-time quantitative PCR assay showed that SICs of BMP32r reduced cell adhesion, exopolysaccharide production, quorum sensing, and virulence genes expression in biofilm formation. Moreover, higher concentrations of BMP32r (2 × MIC and 4 × MIC) disrupt the mature biofilm by killing the bacteria in the biofilm and kill L. monocytogenes persisters bacteria effectively. Therefore, BMP32r has promising potential as an antibiofilm agent to combat L. monocytogenes.

Systematic evaluation of a series of pectic polysaccharides extracted from apple pomace by regulation of subcritical water conditions.

To investigate the influences of different subcritical water conditions on apple pomace pectic polysaccharides (APP) extraction, 20 samples were successfully prepared and systematically analyzed. At low temperature region (100-120 °C), extraction effect was predominant and extracted APP was high molecular weight, esterification degree and galacturonic acid content as well as light color. At middle temperature region (140 °C), the balance of extraction and degradation effects was reached and led to the highest APP yield (14.89%). At high temperature region (160-180 °C), degradation effect was predominant and led to serious degradation of APP and more extraction of co-extracts, which endowed the APP with low viscosity and good antioxidant activities in vitro. Overall, the relationship between different subcritical water conditions and APP properties are preliminarily illuminated, which not only provides a promising way for directed extraction of specific APP, but also promotes the potential application of subcritical water to commercial pectin.