Fungi with potential probiotic properties isolated from Fuzhuan brick tea

Several of the fungal species associated with Fuzhuan brick tea(FBT)are considered as potential probiotics,but few studies have investigated the probiotic properties of these fungi.Here,we isolated 18 fungal strains from two types of FBT and identified these strains based on internal transcribed spacer(ITS)fragment sequence similarity to reference strains(sequence similarity>98%).Of the 18 strains,10 tolerated simulated human digestive conditions for sufficient periods in vitro:pH 2-3,0.3%-0.5%(m/V)bile salts,and artificial gastrointestinal juices.We then measured the antimicrobial activity of the remaining 10 strains against 5 enteropathogenic bacteria and tested the bacteriostatic effects of the thalli and fermentation broth extracts.Of the 6 strains with strong bacteriostatic effects,we eliminated Eurotium cristatum S-9 due to its low hydrophobicity of(26.12±0.35)%.Finally,2 exhibited good adhesion abilities to human cells(>100%).Notably,2 strains can survive in vivo,because they can be isolated from C57BL/6 mice feces.Thus,2 strains,Aspergillus cristatus H-1 and A.cristatus H-5,are herein identified as promising candidate probiotic strains.It may be put forward a novel research focus on evaluating potential probiotic fungi from FBT.

Probiotic properties of lactic acid bacteria isolated from traditionally fermented Xinjiang cheese

Six lactic acid bacterial （LAB） strains were isolated from traditionally fermented Xinjiang cheese and evaluated for functional and probiotic properties and potentials as starter cultures. The isolated six LAB strains com- prised Lactobacillus rhamnosus （one strain）, Lactobacillus helveticus （one strain）, and Enterococcus hirae （four strains）. All of the six strains were tolerant to acidic and bile salt conditions. Among which, the L. rhamnosus R4 strain showed more desirable antimicrobial, auto-aggregation, and hydrophobic activity. In addition, the strain L. rhamnosus R4 exhibited the highest level of free radical scavenging activity （53.78% of 1,1-dipheny1-2-picrylhydrazyl （DPPH） free radicals and 45.79% of hydroxyl radicals）. L. rhamnosus R4 also demonstrated cholesterol and triglyceride degrada- tion by 50.97% and 28.92%, respectively. To further examine the health-promoting effects of these LAB strains on host lifespan, Caenorhabditis elegans was used as an in vivo model. Worms fed LAB as a food source had significant differences in lifespan compared to those fed Escherichia coil OP50 （as a negative control）. Feeding of L. rhamnosus R4 extended the mean lifespan of C. elegans by up to 36.1% compared to that of the control. The results suggest that the strains isolated from Xinjiang fermented dairy products have high potential as starter cultures in the cheese industry.

Study on the safety and excellent probiotic properties of fermentation strains isolated from traditional dry-cured duck for starter development

The indigenous starter cultures isolated from fermented food can compete with spoilage and pathogenic bacteria and improve the flavor and organoleptic properties of products.The purposes of this work were to screen and assess the safety,potential probiotic,and fermentation properties of indigenous starter cultures isolated from dry-cured ducks.The properties of indigenous starter cultures were investigated by antibiotic resistance,virulence genes,in vivo toxicity,simulated gastrointestinal,adhesion capacity to Caco-2 cells,inoculation fermentation,etc.Overall,six strains were isolated and identified,including Lactobacillus sakei D15,Weissella hellenica D20,Lactobacillus curvatus D2,Staphylococcus simulans D12,Staphylococcus equorum D19,and Staphylococcus edaphicus D17.The obtained strains showed high safety.Additionally,most strains displayed excellent probiotic properties,including tolerance to lower pH,lysozyme,bile salt,and a high survival rate of the simulated gastrointestinal phase.The adhesion ability of strain cells to Caco-2 cells was 9.22%-14.21%.And the probiotic properties of strains can be strengthened by the expression of specific enzymes.The inoculation with the isolated strains(LS-D15,LC-D2 and SS-D12)could contribute to the formation of volatile flavor compounds in samples.Overall,results demonstrated that strains possessed excellent safety and probiotic properties,and can be used as starter cultures to enhance the quality and flavor of the dry-cured duck.

Probiotic properties of Lactobacillus paraplantarum LS-5 and its effect on antioxidant activity of fermented sauerkraut

This study aimed to investigate the safety and probiotic properties of Lactobacillus paraplantarum LS-5 isolated from traditional northeastern sauerkraut,and to assess the antioxidant capacity of different solvent extracts(ethanol,water,and hot water)of L.paraplantarum LS-5-inoculated sauerkraut.L.paraplantarum LS-5 was shown to have various probiotic characteristics,such as good survival ability under artificial gastrointestinal conditions,antagonistic activity of various pathogens,non-biogenic amines,antibiotic susceptibility,and non-hemolytic.The 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonate(ABTS)radical scavenging activity of the L.paraplantarum LS-5-inoculated sauerkraut alcohol extract(71.13%)was significantly higher than water extract(59.59%)(p<0.05).The ferric reducing antioxidant power(FRAP)of sauerkraut alcohol extract(614.93 Troloxμmol L^(-1))exhibited a slightly stronger ability compared to water extract(388.53 Troloxμmol L^(-1))and the heated sauerkraut water extract(383.20 Troloxμmol L^(-1))at extract concentrations of 5.0 mg mL^(-1).Its 1,1-diphenyl1-2-picrylhydrazyl(DPPH)radical scavenging activity was also stronger.It was found by principal component analysis(PCA)and Pearson that the DPPH radical-scavenging activities of sauerkraut extracts were significantly correlated with the content of polyphenols and flavonoids(p<0.05).Unlike kimchi,Northeastern sauerkraut is consumed mainly by heating,so this study could contribute to understanding the antioxidant capacity of different solvent extracts of sauerkraut,and before and after heating water extracts.

Separation and Preliminary Identification of Intestinal Probiotics of Laying Hens

[Objective] The paper was to isolate and identify probiotics in the intestine of laying hens. [Method] The intestinal probiotics in laying hens at peak period were isolated using conventional separation methods; the physical and chemical properties of target strains and in vitro antibacterial effects were measured. Moreover, the safety test of chicks was conducted. [Result] Four strains of lactobacillus were isolated from the jejunum of laying hens, including Lactobacillus plantarum, Bacillus acidophilus, L. delbrueckii subsp. Delbrueckii and L. delbrueckii subsp. Lactis, and their inhibition zone diameters were 18.30, 16.07, 11.45, 17.26 mm, respectively. One strain of Lactobacillus, L. brevis, was isolated from the cecum, with the inhibition zone diameter of 10.26 mm. Three strains of bacillus were isolated from the cecum, including Bacillus subtilis, B. cereus and B. licheniformis, and their inhibition zone diameters were 9.25, 8.46 and 8.37 mm, respectively. Daily drinking 2 billion units of viable bacteria was the safe dosage for chicks. [Conclusion] Eight strains of probiotics had certain inhibitory effect on Escherichia coli O;, and had no toxic side effects to chicks. Lactobacillus had strong antibacterial effect on E. coli O;, while the antibacterial effect of bacillus was relatively weak.

Three lactic acid bacteria with anti-obesity properties:In vitro screening and probiotic assessment

The worldwide obesity epidemic has imposed human being a huge burden and attention had been drawn to manipulating the lactic acid bacteria (LAB) to improve obesity symptoms.In this study,a more comprehensive and reliable in vitro method was established to screen LAB with greater potential against obesity.Firstly,twenty-eight human feces-derived LAB strains were selected by assessing bile salt-acid tolerance and cholesterol lowering capacity.Subsequently,the triglyceride lowering capacity,bile salt hydrolase (BSH) activity,α-glucosidase activity inhibition capacity and Enterobacter cloacae (E.cloacae) growth inhibition capacity were tested for further evaluating the anti-obesity properties of LAB strains.Principal component analysis (PCA) of these results indicated that Limosilactobacillus reuteri (L.reuteri) NCUH003,Lactiplantibacillus plantarum (L.plantarum) NCUH046 and Limosilactobacillus fermentum (L.fermentum) NCUH068 exhibited favorable anti-obesity properties.Besides,the LAB displayed good gastrointestinal adaptability and antioxidant activity but no hemolytic activity,and they were sensitive to various antibiotics.These results indicated that L.reuteri NCUH003,L.plantarum NCUH046 and L.fermentum NCUH068 are potential for application in obesity treatment.

Evaluation of novel isolates of Lacticaseibacillus rhamnosus Probio-M9 derived through space mutagenesis

This study evaluated the growth and probiotic properties of Probio-M9 after exposure to the environment of space.Probio-M9 has excellent probiotic properties.As a rapidly developed new cutting-edge technology,space mutagenesis can confer potentially desirable properties to novel isolates.In this study,three novel isolates(HA-R7970-29,HG-R7970-18,HG-R7970-29)mutated from Probio-M9 in space,had significantly higher growth characteristics than the original Probio-M9.Antibacterial properties,auto aggregation ability,cell surface hydrophobicity and antioxidant activity of the three mutagenic isolates were evaluated.The results showed that Probio-M9 remained stable after mutagenesis,and the mutant strains could effectively inhibit the growth of six common pathogenic bacteria.The mutated isolates showed strong auto aggregation ability(49.3%-76.5%,24h)and cell surface hydrophobicity(25.7%-43.0%);HA-R7970-29 showed significantly higher auto aggregation ability and cell surface hydrophobicity than HG-R7970-18 and HG-R7970-29(P<0.05).In addition,the supernatants and bacterial suspensions of the three mutated isolates had strong antioxidant activities.Genomic analysis identified genes associated with bacteriocin,adhesion properties and antioxidant activity and probiotic features at the genetic level.Mutated isolates not only had good growth characteristics but also exhibited excellent probiotic properties indicating their potential as probiotics.

Lactic acid bacteria with anti-hyperuricemia ability: Screening in vitro and evaluating in mice

Hyperuricemia has become the increasing public health burden,which is a risk factor for gout,chronic kidney,cardiovascular diseases and diabetes.Lactic acid bacteria have been attracting considerable interest for the safe and effective treatment of hyperuricemia in recent years.In this study,Limosilactobacillus fermentum NCUH003018,Limosilactobacillus reuteri NCUH064056 and Lactobacillus gasseri NCUH066006 were preliminarily selected from sixty strains of lactic acid bacteria isolated from infant feces and fermented vegetables,and showed the ability of efficient degradation of inosine and guanosine,inhibition of xanthine oxidase activity,the tolerance to acid and bile salt,adhesion to epithelium cells,antibacterial activity,and antibiotic susceptibility in vitro.Then hyperuricemia mice model was established by high-yeast diet and intraperitoneal injection of potassium oxonate to analyze the uric acid-lowering effect of the three Lactobacillus in vivo.The results showed that Limosilactobacillus fermentum NCU003018 was the most effective in lowering uric acid level in mice,which prompted the decrease of serum uric acid by 30.77%compared with hyperuricemia model group.Therefore,the Limosilactobacillus fermentum NCU003018 is considered as a probiotic with anti-hyperuricemia ability,which could be used as a promising candidate in preventing and treating hyperuricemia,and the uric-acid lowering mechanism merits further investigation.