Isolation, characterization and comparative genomics of potentially probiotic Lactiplantibacillus plantarum strains from Indian foods.

Lactiplantibacillus plantarum is one of the most diverse species of lactic acid bacteria found in various habitats. The aim of this work was to perform preliminary phenotypic and genomic characterization of two novel and potentially probiotic L. plantarum strains isolated from Indian foods, viz., dhokla batter and jaggery. Both the strains were bile and acid tolerant, utilized various sugars, adhered to intestinal epithelial cells, produced exopolysaccharides and folate, were susceptible for tetracycline, erythromycin, and chloramphenicol, did not cause hemolysis, and exhibited antimicrobial and plant phenolics metabolizing activities. The genetic determinants of bile tolerance, cell-adhesion, bacteriocins production, riboflavin and folate biosynthesis, plant polyphenols utilization, and exopolysaccharide production were found in both the strains. One of the strains contained a large number of unique genes while the other had a simultaneous presence of glucansucrase and fructansucrase genes which is a rare trait in L. plantarum. Comparative genome analysis of 149 L. plantarum strains highlighted high variation in the cell-adhesion and sugar metabolism genes while the genomic regions for some other properties were relatively conserved. This work highlights the unique properties of our strains along with the probiotic and technically important genomic features of a large number of L. plantarum strains.

Protective Effect of Probiotics Isolated from Traditional Fermented Tea Leaves (Miang) from Northern Thailand and Role of Synbiotics in Ameliorating Experimental Ulcerative Colitis in Mice.

This study aimed to investigate the protective effect of probiotics and synbiotics from traditional Thai fermented tea leaves (Miang) on dextran sulfate sodium (DSS)-induced colitis in mice, in comparison to sulfasalazine. C57BL/6 mice were treated with probiotics L. pentosus A14-6, CMY46 and synbiotics, L. pentosus A14-6 combined with XOS, and L. pentosus CMY46 combined with GOS for 21 days. Colitis was induced with 2% DSS administration for seven days during the last seven days of the experimental period. The positive group was treated with sulfasalazine. At the end of the experiment, clinical symptoms, pathohistological changes, intestinal barrier integrity, and inflammatory markers were analyzed. The probiotics and synbiotics from Miang ameliorated DSS-induced colitis by protecting body weight loss, decreasing disease activity index, restoring the colon length, and reducing pathohistological damages. Furthermore, treatment with probiotics and synbiotics improved intestinal barrier integrity, accompanied by lowing colonic and systemic inflammation. In addition, synbiotics CMY46 combined with GOS remarkedly elevated the expression of IL-10. These results suggested that synbiotics isolated from Miang had more effectiveness than sulfasalazine. Thereby, they could represent a novel potential natural agent against colonic inflammation.

Evaluation of the Anti-Aging Effects of a Probiotic Combination Isolated From Centenarians in a SAMP8 Mouse Model.

Population aging is a prominent global problem in today's society. However, there are currently no good methods to treat or prevent aging, so anti-aging research has crucial implications. In this research, we screened bacteria from centenarians, and finally selected four probiotics (Lactobacillus fermentum SX-0718, L. casei SX-1107, Bifidobacterium longum SX-1326, and B. animalis SX-0582) to form a probiotic combination. By using the senescence accelerated mouse prone 8 (SAMP8) model, the anti-aging effects of the probiotic combination were evaluated by using behavioural testing, neuroinflammation, intestinal inflammation, and intestinal microbiota. The results showed that probiotic combination improved the impaired spatial memory, motor dysfunction, and decreased exploratory behavior in aging mice. The probiotic combination inhibited Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NFκB)-induced neuroinflammation and up-regulated the expression of Sirt 1 to protect hippocampal neurons. At the same time, the probiotic combination regulated the intestinal microbiota, reduced the relative abundance of Alistipes and Prevotella in SAMP8 mice, inhibited TLR4/NFκB-induced intestinal inflammation, and increased the expression of intestinal permeability related proteins zonula occludens-1 (ZO-1) and Occuldin. The anti-aging effects of the probiotic combination may be through the regulating intestinal microbiota and inhibiting TLR4/NFκB-induced inflammation. This research provides the basis and technical support for the future production and application of the probiotic combination.

An appraisal of the gut health modulatory effects of a calf faecal-origin probiotic Lactobacillus salivarius CPN60 using Wistar rats with dextran sulfate sodium-induced colitis.

BACKGROUND: Probiotics of varied origins are being developed for augmenting the gut health of human and animals. The present study aimed to evaluate the effect of a calf-origin probiotic supplement on the gut health of Wistar rats for both healthy and colitis conditions. RESULTS: Forty-eight rats were randomly distributed into four equal groups. The 42-day study involved feeding basal diet alone (CON) or diet supplemented with the calf-origin Lactobacillus salivarius strain CPN60 (PRO). The third (CONc) and fourth (PROc) groups of rats also received the same dietary treatments (CON and PRO, respectively) but were subjected to dextran sulfate sodium (DSS)-induced colitis after 32 days of feeding. The results of a digestion trial conducted after 5 days of DSS administration revealed no influence of probiotic on the digestibility of nutrients. However, the reduced digestibility of protein and fat seen in the CONc rats was improved in the PROc group. The concentrations of lactate and acetate, propionate and butyrate, as well as total short-chain fatty acids (SCFA), were increased (P < 0.05) in the caecal and colonic digesta upon probiotic supplementation, together with significantly reduced colonic ammonia levels. Furthermore, there were reductions (P < 0.05) in acetate, butyrate and total SCFA levels in the caecal contents as a result of colitis. Probiotic supplementation increased (P < 0.05) lactobacilli and bifidobacteria counts in the colon, whereas clostridia and coliform counts were reduced (P < 0.05). These were reversed by the probiotic supplementation. CONCLUSION: Dietary supplementation of L. salivarius CPN60 had a positive effect with respect to improving the overall gut health of healthy rats, as well as that of rats exposed to experimental colitis. © 2020 Society of Chemical Industry.

Lactobacillus commensals autochthonous to human milk have the hallmarks of potent probiotics.

Maternal milk is an important source of essential nutrients for the optimal growth of infants. Breastfeeding provides a continuous supply of beneficial bacteria to colonize the infant gastrointestinal tract (GIT) and offers health benefits for disease prevention and immunity. The purpose of this study was to isolate novel probiotic strains from the breast milk of native Pakistani mothers and to evaluate their probiotic potential. We isolated 21 strains of bacteria from the colostrum and mature milk of 20 healthy mothers, who had vaginal deliveries and were not taking antibiotics. After phenotypic and genotypic characterization, these isolates were tested for survival in the GIT using in vitro acid and bile tests. Nine strains showing good acid tolerance were assessed for their growth rate, bile resistance and ability to hydrolyze bile salts. Out of the four Lactobacillus isolates adjudged to be most promising as probiotics, three were Lactobacillus fermentum strains and one was a strain of Lactobacillus oris. This study demonstrates that human milk is a viable source of commensal bacteria beneficial to both adults and babies.

Characterization of potentially probiotic lactic acid bacteria and bifidobacteria isolated from human colostrum.

Breast milk is the main source of nutrition for infants; it contains considerable microflora that can be transmitted to the infant endogenously or by breastfeeding, and it plays an important role in the maturation and development of the immune system. In this study, we isolated and identified lactic acid bacteria (LAB) from human colostrum, and screened 2 strains with probiotic potential. The LAB isolated from 40 human colostrum samples belonged to 5 genera: Lactobacillus, Bifidobacterium, Streptococcus, Enterococcus, and Staphylococcus. We also isolated Propionibacterium and Actinomyces. We identified a total of 197 strains of LAB derived from human colostrum based on their morphology and 16S rRNA sequence, among them 8 strains of Bifidobacterium and 10 strains of Lactobacillus, including 3 Bifidobacterium species and 4 Lactobacillus species. The physiological and biochemical characteristics of strains with good probiotic characteristics were evaluated. The tolerances of some of the Bifidobacterium and Lactobacillus strains to gastrointestinal fluid and bile salts were evaluated in vitro, using the probiotic strains Bifidobacterium lactis BB12 and Lactobacillus rhamnosus GG as controls. Among them, B. lactis Probio-M8 and L. rhamnosus Probio-M9 showed survival rates of 97.25 and 78.33% after digestion for 11 h in artificial gastrointestinal juice, and they exhibited growth delays of 0.95 and 1.87 h, respectively, in 0.3% bile salts. These two strains have the potential for application as probiotics and will facilitate functional studies of probiotics in breast milk and the development of human milk-derived probiotics.

Topical ozone therapy restores microbiome diversity in atopic dermatitis.

BACKGROUND: Staphylococcus aureus (S. aureus) accounts for 90% of the microbiome in atopic dermatitis (AD) lesions and plays a role in disease flare-ups and worsens disease outcome. Ozone treatment can improve AD conditions by its bactericidal effect on S. aureus. OBJECTIVE: To study the effects of topical ozone therapy on microbiome diversity in AD lesions and explore potential probiotic pathogens correlated with AD progression. METHODS: Patients with moderate to severe bilateral skin lesions in AD were recruited. Randomized split sides were performed. One side was treated with ozone hydrotherapy followed by ozonated oil; while the contralateral side with tap water and basal oil. Patients' SCORAD scores and modified EASI were recorded before and after treatments. The microbiological compositions in targeting sites were determined using 16S rDNA sequencing. RESULTS: After three-day ozone therapy, patients showed a significant decrease in SCORAD scores and inflammatory cell infiltration in AD lesions. The micro-ecological diversity was higher in the non-lesional as compared with lesional areas (p < 0.05), which was also negatively correlated with the severity of AD (r = -0.499, p < 0.05). The proportion of S. aureus in AD lesions was positively correlated with the severity of AD (r = 0.564, p = 0.010), which was decreased after ozone treatment (p = 0.07). Ozone therapy showed an increase in microbiological diversity with a significant increase in the proportion of Acinetobacter (p < 0.05). CONCLUSION: Topical ozone therapy is highly effective for treatment for AD. It can change the proportional ratio of Staphylococcus and Acinetobacter, thereby restoring the microbiological diversity in AD lesions.

Autochthonous vs allochthonous probiotic strains to Rhamdia quelen.

The aim of this study was to obtain an autochthonous probiotic candidate strain from the silver catfish (Rhamdia quelen) intestinal tract, comparing its in vivo performance with an allochthonous probiotic isolated from another fish, Nile tilapia (Oreochromis niloticus), in a growth performance assay. The study was divided in two parts: in vitro and in vivo assay followed by challenge with A. hydrophila. In the in vitro assay, the species-specific isolated strain Lactococcus lactis presented characteristics such as: absence of hemolysis, antagonism to bacterial pathogens isolated from freshwater fish, and considerable speed of duplication. In the in vivo trial, both fish supplemented with autochthonous or allochthonous strains presented an increase the final concentration of lactic acid bacteria in the intestinal tract of the fish after 60 days of dietary supplementation reaching concentrations of 1 × 107 CFU g-1 and 4 × 107 UFC.g-1, respectively. In addition, the autochthonous strain increased the mean corpuscular hemoglobin (MCH) of the treated animals, but no significant differences were observed in the other hemato-immunological and zootechnical parameters between treatments. After challenge with Aeromonas hydrophila, only animals that received autochthonous probiotic supplementation showed an increase in the serum total immunoglobulin concentration, but not enough to observe a significant difference in the survival rate between the treatments. Dietary supplementation of the probiotic allochthonous strain did not demonstrate any effects superior to those of the isolated autochthonous strain. Although the autochthonous strain did not present significant improvements in the other parameters evaluated in this study, it was able to inhibit bacterial pathogens in vitro, to increase the final concentration of LAB's and the amount of immunoglobulin after experimental challenge, demonstrating probiotic potential. This study demonstrated for the first time the isolation and in vivo use of an autochthonous probiotic strain isolated from silver catfish, as well as its comparative evaluation with the performance of allochthonous probiotic.

Safety Evaluation and Whole-Genome Annotation of Lactobacillus plantarum Strains from Different Sources with Special Focus on Isolates from Green Tea.

Lactobacillus plantarum shows high intraspecies diversity species, and has one of the largest genome sizes among the lactobacilli. It is adapted to diverse environments and provides a promising potential for various applications. The aim of the study was to investigate the safety and probiotic properties of 18 L. plantarum strains isolated from fermented food products, green tea, and insects. For preliminary safety evaluation the L. plantarum strains were tested for their ability to produce hemolysin and biogenic amines and for their antibiotic resistance. Based on preliminary safety screening, four strains isolated from green tea showed antibiotic resistance below the cut-off MIC values suggested by EFSA, and were selected out of the 18 strains for more detailed studies. Initial selection of strains with putative probiotic potential was determined by their capacity to survive in the human GIT using an in vitro simulation model, and for their adhesion to human Caco-2/TC-7 cell line. Under simulated GIT conditions, all four L. plantarum strains isolated from green tea showed higher survival rates than the control (L. plantarum subsp. plantarum ATCC 14917). All studied strains were genetically identified by 16S rRNA gene sequencing and confirmed to be L. plantarum. In addition, whole-genome sequence analysis of L. plantarum strains APsulloc 331261 and APsulloc 331263 from green tea was performed, and the outcome was compared with the genome of L. plantarum strain WCFS1. The genome was also annotated, and genes related to virulence factors were searched for. The results suggest that L. plantarum strains APsulloc 331261 and APsulloc 331263 can be considered as potential beneficial strains for human and animal applications.

A High Throughput Isolation Method for Phosphate-Accumulating Organisms.

Hyperphosphatemia is a secondary issue associated with chronic kidney disorder. Use of phosphate binders and dialysis are the treatments for hyperphosphatemia, albeit with harmful side effects and high cost, respectively. A safer and healthier approach is attempted to administer phosphate-accumulating organisms (PAOs) from probiotics to prevent hyperphosphatemia. However, screening and isolation of PAOs are limited by inefficient enrichment of relevant metabolism and contamination. Therefore, we devised a novel strategy to isolate elite PAOs from Lactobacillus casei JCM 1134 and Bifidobacterium adolescentis JCM 1275 (previously reported PAOs). PAOs were first enriched for phosphate uptake and incubated in low-pH phosphate-free media to dormant non-PAOs, and then purified using Percoll density gradient centrifugation. Subsequently, elite PAOs were isolated from centrifuged pellet on a toluidine blue O-supplemented agar-based media. Using this technique, elite PAOs could not only be isolated, but also semi-quantitatively scored for their phosphate accumulation capabilities. Additionally, these scores correlated well with their accumulated phosphate values. The elite PAOs isolated from L. casei and B. adolescentis showed 0.81 and 0.70 [mg-phosphate/mg-dry cell], respectively (23- and 4.34-fold increase, respectively). Thus, our method can be used to successfully isolate elite PAOs, which might be of use to prevent hyperphosphatemia at early stages.

Toward rational selection criteria for selection of probiotics in pigs.

An accurate understanding of properties of probiotics is a prerequisite for selecting probiotic organisms for use in swine production. This review aims to review selection criteria for probiotic organism in swine. The systematically investigated ecological history rather than the source of isolates should be regarded as the natural origin of probiotic strains, which helps to correct the inconsistencies arising from incorrect identification of the source. Moreover, in vivo studies are suggested as follow-up assessment to validate the characteristics of probiotic predicted by in vitro experiments. In addition, the intended probiotic effect depends on the age of the animal and disease prevention in young animals may require different probiotic strains when compared to growth promotion in older animals. With adequate selection criteria, the inclusion of probiotic in feed supplementation is a promising way to exert positive effects on sows, newborns, weanling animals and grower-finisher pigs. Both host-adapted probiotics and nomadic probiotics can be applied for pathogen inhibition but host adapted organisms appear to have a different mode of action. Host-adapted probiotic strains are likely to be associated with exclusive colonization while the nomadic or environmental strain exert better immune stimulating functions. Strains with potent enzymatic activity are fitter for grower pigs favoring feed digestion and enhancing growth performance.

Combined Amelioration of Ginsenoside (Rg1, Rb1, and Rg3)-enriched Korean Red Ginseng and Probiotic Lactobacillus on Non-alcoholic Fatty Liver Disease.

BACKGROUND: Red ginseng is a traditional medicine that has been used to treat numerous metabolic and inflammatory diseases. Probiotic administration has been established to have beneficial effects in non-alcoholic fatty liver disease (NAFLD). The purpose of this study was to determine whether a combination of Korean red ginseng (KRG) and probiotics could synergistically reduce NAFLD and liver inflammation compared with the effects reported for each individual product. METHOD: db/db and C57BL/6 mice were fed a normal chow diet and high-fat diet (HFD), respectively, and were treated with KRG, probiotics, or both. Samples were examined for lipid content, kinase protein phosphorylation, and gene expression patterns. RESULTS: KRG- and probiotic-treated HFD-fed mice exhibited a reduction in body weight and a decrease in inflammatory cytokine secretion compared with the non-treated control mice. The same treatment was less successful in improving NAFLD parameters in the db/db mice while the combination of both products did not enhance their therapeutic potential. CONCLUSION: The results of this study indicate that KRG and probiotics administration ameliorated NAFLD symptoms in a mouse model of dyslipidemia by reducing weight gain and liver inflammation. Coadministration of both products did not enhance their efficacy, and further research should be conducted to clarify their mechanisms of action.

Characterization and Antibacterial Activity Against Helicobacter pylori of Lactic Acid Bacteria Isolated from Thai Fermented Rice Noodle.

A total of 32 lactic acid bacteria (LAB) were isolated from Khanom-jeen, a Thai traditional fermented rice noodle. They belonged to the genus Leuconostoc (Ln), Lactobacillus (Lb), Enterococcus (E), Lactococcus (Lc), and Weissella (W), based on their phenotypic characteristics and 16S rRNA gene sequence analyses. The strains were identified as Ln. pseudomesenteroides (group 1, two strains), Ln. citreum (group 2, three strains), Ln. lactis (group 3, three strains), Lb. paracasei subsp. tolerans (group 4, two strains), E. faecium (group 5, three strains), Lc. lactis subsp. lactis (group 6, one strain), W. confusa (group 7, six strains), Lb. fermentum (group 8, seven strains), and Lb. plantarum subsp. plantarum and Lb. pentosus (group 9, five strains). Fifteen strains exhibited the inhibitory activity against Helicobacter pylori clinical isolates by spot-on-lawn method. Lb. fermentum P43-01 resisted to bile acids showed the broad spectrum of antimicrobial activity against H. pylori strains MS83 and BK364. These antagonistic effects were associated with proteinaceous compounds which are sensitive to α-chymotrypsin and pepsin. Results indicated that production of bacteriocin-like substances of selected strain might be the significant mechanism that exerted the inhibition on H. pylori. A potential strain could be used as probiotics in alternative or adjunctive therapy for a patient suffering from H. pylori infection.

Preventive Effect of Lactobacillus fermentum CQPC03 on Activated Carbon-Induced Constipation in ICR Mice.

Background and objectives: Paocai (pickled cabbage), which is fermented by lactic acid bacteria, is a traditional Chinese food. The microorganisms of Paocai were isolated and identified, and the constipation inhibition effect of one of the isolated Lactobacillus was investigated. Materials and Methods: The 16S rDNA technology was used for microbial identification. A mouse constipation model was established using activated carbon. After intragastric administration of Lactobacillus (108 CFU/mL), the mice were dissected to prepare pathological sections of the small intestine. Serum indicators were detected using kits, and the expression of small intestine-related mRNAs was detected by qPCR assay. Results: One strain of Lactobacillus was identified and named Lactobacillus fermentum CQPC03 (LF-CQPC03). Body weight and activated carbon propulsion rate were all higher in mice intragastrically administered with LF-CQPC03 compared with the control group, while the time to the first black stool in treated mice was lower than that in the control group. Serum assays showed that gastrin (Gas), endothelin (ET), and acetylcholinesterase (AchE) levels were significantly higher in the LF-CQPC03-treated mice than in the control group, while somatostatin (SS) levels were significantly lower than in the control mice. Mouse small intestine tissue showed that c-Kit, stem cell factor (SCF), and glial cell-derived neurotrophic factor (GDNF) mRNA expression levels were significantly higher in the LF-CQPC03 treated mice than in control mice, while transient receptor potential cation channel subfamily V member 1 (TRPV1) and inducible nitric oxide synthase (iNOS) expression levels were significantly lower in the LF-CQPC03 treated mice than in control mice. Conclusions: There is a better effect with high-dose LF-CQPC03, compared to the lower dose (LF-CQPC03-L), showing good probiotic potential, as well as development and application value.

Isolation and characterization of native probiotics for fish farming.

BACKGROUND: Innovations in fish nutrition act as drivers for the sustainable development of the rapidly expanding aquaculture sector. Probiotic dietary supplements are able to improve health and nutrition of livestock, but respective bacteria have mainly been isolated from terrestrial, warm-blooded hosts, limiting an efficient application in fish. Native probiotics adapted to the gastrointestinal tract of the respective fish species will establish within the original host more efficiently. RESULTS: Here, 248 autochthonous isolates were cultured from the digestive system of three temperate flatfish species. Upon 16S rRNA gene sequencing of 195 isolates, 89.7% (n = 175) Gram-negatives belonging to the Alpha- (1.0%), Beta- (4.1%) and Gammaproteobacteria (84.6%) were identified. Candidate probiotics were further characterized using in vitro assays addressing 1) inhibition of pathogens, 2) degradation of plant derived anti-nutrient (saponin) and 3) the content of essential fatty acids (FA) and their precursors. Twelve isolates revealed an inhibition towards the common fish pathogen Tenacibaculum maritimum, seven were able to metabolize saponin as sole carbon and energy source and two isolates 012 Psychrobacter sp. and 047 Paracoccus sp. revealed remarkably high contents of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Furthermore, a rapid and cost-effective method to coat feed pellets revealed high viability of the supplemented probiotics over 54 d of storage at 4°C. CONCLUSIONS: Here, a strategy for the isolation and characterization of native probiotic candidates is presented that can easily be adapted to other farmed fish species. The simple coating procedure assures viability of probiotics and can thus be applied for the evaluation of probiotic candidates in the future.

Lactobacillus curvatus KFP419 and Leuconostoc mesenteroides subsp. mesenteroides KDK411 Isolated from Kimchi Ameliorate Hypercholesterolemia in Rats.

Western-style diets increase the risk for cardiovascular diseases. It is suggested that the risk could be prevented by lowering cholesterol concentrations in blood. In the present study, hypocholesterolemic effects of the probiotics isolated from kimchi (Lactobacillus curvatus KFP419, Leuconostoc paramesenteroides KJP421, and Leuconostoc mesenteroide subsp. mesenteroides KDK411) were investigated in hypercholesterolemia-induced rats. There was no difference in growth performance between the rats fed high cholesterol diet (HCD) and normal diet (ND). However, blood total cholesterol, low-density lipoprotein cholesterol, and hepatic cholesterol were elevated by the HCD compared to ND, and those concentrations were decreased by dietary supplementation of KFP419 and KDK411. It was concomitant with an increase in fecal excretion of neutral sterols (cholesterol, coprostanol, and coprostanone) in the rats fed HCD compared to ND and was even greater with KDK411 supplementation. These findings indicate that probiotics L. curvatus KFP419 and L. mesenteroide subsp. mesenteroides KDK411 isolated from kimchi ameliorate hypercholesterolemia in rats by assimilating and excreting cholesterol in feces.

In Vitro Evaluation of the Probiotic and Safety Properties of Bacteriocinogenic and Non-Bacteriocinogenic Lactic Acid Bacteria from the Intestines of Nile Tilapia and Common Carp for Their Use as Probiotics in Aquaculture.

In this study, seven bacteriocinogenic and non-bacteriocinogenic LAB strains previously isolated from the intestines of Nile tilapia and common carp and that showed potent antibacterial activity against host-derived and non-host-derived fish pathogens were assayed for their probiotic and safety properties so as to select promising candidates for in vivo application as probiotic in aquaculture. All the strains were investigated for acid and bile tolerances, transit tolerance in simulated gastrointestinal conditions, for cell surface characteristics including hydrophobicity, co-aggregation and auto-aggregation, and for bile salt hydrolase activity. Moreover, haemolytic, gelatinase and biogenic amine-producing abilities were investigated for safety assessment. The strains were found to be tolerant at low pH (two strains at pH 2.0 and all the strains at pH 3.0). All of them could also survive in the presence of bile salts (0.3% oxgall) and in simulated gastric and intestinal juices conditions. Besides, three of them were found to harbour the gtf gene involved in pH and bile salt survival. The strains also showed remarkable cell surface characteristics, and 57.14% exhibited the ability to deconjugate bile salts. When assayed for their safety properties, the strains prove to be free from haemolytic activity, gelatinase activity and they could neither produce biogenic amines nor harbour the hdc gene. They did not also show antibiotic resistance, thus confirming to be safe for application as probiotics. Among them, Lactobacillus brevis 1BT and Lactobacillus plantarum 1KMT exhibited the best probiotic potentials, making them the most promising candidates.

Effect of Dietary Supplementation of Novel Probiotic Bacteria Bacillus vireti 01 on Antioxidant Defence System of Freshwater Prawn Challenged with Pseudomonas aeruginosa.

The aim of the present work was to isolate probiotic bacteria from the intestinal tract of healthy freshwater prawn Macrobrachium rosenbergii and to examine the effect of the isolated probiotic Bacillus vireti 01 in controlling Pseudomonas aeruginosa infection. This is probably the first report on the isolation of probiotic B. vireti 01 from the intestine of M. rosenbergii. The compounds present in B. vireti 01 were identified using GC-MS analysis. The effect of B. vireti 01-incorporated diet on survival and antioxidant enzymes was studied in M. rosenbergii for 2 weeks. Decreased mortality was observed in M. rosenbergii which were administered with the probiotic diet compared to control diet. The antioxidant defence enzymes activities such as SOD, catalase and GSH were analysed in various organs of M. rosenbergii probiotic-treated and control groups. Antioxidant enzyme activities were considerably lowered (p < 0.01) in the muscles, hepatopancreas and gills of prawns infected by P. aeruginosa when compared to that of prawns fed with the probiotic-supplemented diet. The histopathological results suggest that the hepatopancreas, gills and muscles infected with P. aeruginosa were altered structurally. The result of the present work demonstrates that the probiotic B. vireti 01 could be used as a substitute to antibiotics for treating P. aeruginosa infection in prawns.

A novel probiotic Bacillus siamensis B44v isolated from Thai pickled vegetables (Phak-dong) for potential use as a feed supplement in aquaculture.

The use of probiotic bacteria to control bacterial infection in farmed fish is of clear practical interest. The aims of this study were to isolate and select a probiotic Bacillus sp. and to evaluate the effects of its supplementation on the growth and disease resistance of hybrid catfish. Bacillus siamensis strain B44v, selectively isolated from Thai pickled vegetables (Phak-dong), displayed a high potential as a probiotic in catfish culture. This bacterium produced a bacteriocin-like substance and exhibited a broad-spectrum antibacterial activity inhibiting both Gram-positive and Gram-negative bacteria, especially the fish pathogens Aeromonas hydrophila and Streptococcus agalactiae. The susceptibility to all 14 antibiotics tested implies its less possibility to be the antibiotic-resistant bacterium. Bacillus siamensis strain B44v possessed interesting adhesion properties, as shown by its high percentages of hydrophobicity (64.8%), auto-agglutination (73.8%), co-aggregation (67.2% with A. hydrophila FW52 and 63.5% with S. agalactiae F3S), and mucin binding (88.7%). The strain B44v survived simulated gastrointestinal conditions and produced protease and cellulase enzymes. Hybrid catfish (C. macrocephalus × C. gariepinus) were employed in the feed-trial experiments. Fish fed diet containing strain B44v (107 CFU/g feed) displayed not only no mortality but also growth improvement. At the end of the feed trial, fish were challenged by an intraperitoneal injection of Aeromonas hydrophila FW52. The Bacillus siamensis strain B44v fed fish survived (75.0%; p < 0.05) better than the controls (36.7%; p < 0.05) after a two week challenge. These collective results present for the first time the potential of Bacillus siamensis strain B44v for use as a bacterial probiotic in aquaculture.

Probiotics production and alternative encapsulation methodologies to improve their viabilities under adverse environmental conditions.

Probiotic products are dietary supplements containing live microorganisms producing beneficial health effects on the host by improving intestinal balance and nutrient absorption. Among probiotic microorganisms, those classified as lactic acid bacteria are of major importance to the food and feed industries. Probiotic cells can be produced using alternative carbon and nitrogen sources, such as agroindustrial residues, at the same time contributing to reduce process costs. On the other hand, the survival of probiotic cells in formulated food products, as well as in the host gut, is an essential nutritional aspect concerning health benefits. Therefore, several cell microencapsulation techniques have been investigated as a way to improve cell viability and survival under adverse environmental conditions, such as the gastrointestinal milieu of hosts. In this review, different aspects of probiotic cells and technologies of their related products are discussed, including formulation of culture media, and aspects of cell microencapsulation techniques required to improve their survival in the host.