Isolation and characterization of lactic acid bacteria from traditional fermented fish product Shidal of India with reference to their probiotic potential

Probiotic and anti-inflammatory properties of Lactiplantibacillus plantarum MKTJ24 isolated from an artisanal fermented fish of North-east India

The study aimed to isolate and characterize lactic acid bacteria from various traditional fermented fish products from North East India, including Xindol, Hentak, and Ngari, which hold significant dietary importance for the indigenous tribes. Additionally, the study sought to examine their untargeted metabolomic profiles. A total of 43 strains of Bacillus, Priestia, Staphylococcus, Pediococcus, and Lactiplantibacillus were isolated, characterized by 16 S rRNA gene and tested for probiotic properties. Five strains passed pH and bile salt tests with strain dependent antimicrobial activity, which exhibited moderate autoaggregation and hydrophobicity properties. Lactiplantibacillus plantarum MKTJ24 exhibited the highest hydrophobicity (42 %), which was further confirmed by adhesion assay in HT-29 cell lines (100 %). Lactiplantibacillus plantarum MKTJ24 treatment in LPS-stimulated HT-29 cells up-regulated expression of mucin genes compared to LPS-treated cells. Treatment of RAW 264.7 cells with Lactiplantibacillus plantarum MKTJ24 decreased LPS-induced reactive oxygen species (ROS) and nitric oxide (NO) productions. Further, genome analysis of Lactiplantibacillus plantarum MKTJ24 revealed the presence of several probiotic markers and immunomodulatory genes. The genome was found to harbor plantaricin operon involved in bacteriocin production. A pangenome analysis using all the publicly available L. plantarum genomes specifically isolated from fermented fish products identified 120 unique genes in Lactiplantibacillus plantarum MKTJ24. Metabolomic analysis indicated dominance of ascorbic acids, pentafluropropionate, cyclopropaneacetic acid, florobenzylamine, and furanone in Xindol. This study suggests that Lactiplantibacillus plantarum MKTJ24 has potential probiotic and immunomodulatory properties that could be used in processing traditional fermented fish products on an industrial scale to improve their quality and enhance functional properties.

Genomic Characterization and Probiotic Properties of Lactiplantibacillus pentosus Isolated from Fermented Rice

The aim of the study was the preliminary genetic and phenotypic characterization of a potential probiotic strain of Lactiplantibacillus pentosus (strain krglsrbmofpi2) obtained from traditionally fermented rice. Genome sequencing revealed that the strain has a 3.7-Mb genome with a GC content of 46 and a total of 3192 protein-coding sequences. Using bioinformatic methods, we have successfully identified phage genes, plasmids, pathogenicity, antibiotic resistance and a variety of bacteriocins. Through comprehensive biochemical and biophysical analyses, we have gained valuable insights into its auto-aggregation, co-aggregation, antibiotic resistance, hydrophobicity, antioxidant activity and tolerance to simulated gastrointestinal conditions. The safety evaluation of the isolated L. pentosus was performed on the basis of its haemolytic activity. Our studies have shown that this strain has a strong antagonistic activity against the priority pathogens identified by the World Health Organization such as Vibrio cholerae, Clostridium perfringens, Salmonella enterica subsp. enterica ser. Typhi, Escherichia coli, Listeria monocytogenes and Staphylococcus aureus. It is essential to fully understand the genetic and functional properties of the L. pentosus strain before considering its use as a useful probiotic in the food industry.

Genome mining and physiological analyses uncover adaptation strategies and biotechnological potential of Virgibacillus dokdonensis T4.6 isolated from high-salt shrimp paste

Virgibacillus spp. stand out as a potent starter culture for accelerating the fermention of fish sauces and shrimp pastes. However, the underlying molecular mechanisms responsible for their adaptation and biotechnological potential remain elusive. Therefore, the present study focuses on phenotypic and genomic analyses of a halophilic bacterium Virgibacillus dokdonensis T4.6, derived from Vietnamese high-salt fermented shrimp paste. The draft genome contained 4,096,868 bp with 3780 predicted coding sequences. Genome mining revealed the presence of 143 genes involved in osmotic adaptation explaining its resistant phenotype to 24% (w/v) NaCl. Among them, 37 genes making up the complete ectoine metabolism pathway, confirmed its ability to produce 4.38 ± 0.29 wt% ectoine under 12.5% NaCl stress. A significant finding was the identification of 39 genes responsible for an entire degradation pathway of the toxic biogenic amine histamine, which was in agreement with its histamine degradation rate of 42.7 ± 2.1% in the HA medium containing 5 mM histamine within 10 days at 37 °C. Furthermore, 114 proteolytic and 19 lipolytic genes were detected which might contribute to its survival as well as the nutrient quality and flavor of shrimp paste. Of note, a putative gene vdo2592 was found as a possible novel lipase/esterase due to its unique Glycine-Aspartate-Serine-Leucine (GDSL) sequence motif. This is the first report to reveal the adaptative strategies and related biotechnological potential of Virgibacillus associated with femented foods. Our findings indicated that V. dokdonensis T4.6 is a promising starter culture for the production of fermented shrimp paste products.

Isolation, characterization of Weissella confusa and Lactococcus lactis from different milk sources and determination of probiotic features

This study aimed to investigate the probiotic properties of Lactic Acid Bacteria (LAB) isolates derived from various milk sources. These isolates identified based on their morphological characteristics and 16S rRNA gene sequencing. Four strains of Lactococcus lactis and two strains of Weissella confusa were identified with over 96% 16S rRNA gene similarity according to the NCBI-BLAST results. The survival of the isolates was determined in low pH, pepsin, bile salts, and pancreatin, and their adhesion ability was assessed by in vitro cell adhesion assay, hydrophobicity, auto- and co-aggregation, and safety criteria were determined by hemolytic, gelatinase activities, and DNAse production ability tests. The results showed that the LAB isolates had different levels of resistance to various stress factors. L. lactis subsp. cremoris MH31 showed the highest resistance to bile salt, while the highest pH resistance was observed in L. lactis MH31 at pH 3.0. All the isolates survived in pepsin exposure at pH 3.0 for 3 h. The auto-aggregation test results showed that all strains exhibited auto-aggregation ranging from 84.9 to 91.4%. Co-aggregation percentage ranged from 19 - 54% and 17 - 57% against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213, respectively. The hydrophobicity capacity of the LAB isolated ranged from 35-61%. These isolates showed different adhesion abilities to Caco-2 cells (81.5% to 92.6%). None of the isolates exhibited DNase, gelatinase and hemolytic activity (γ-hemolysis). All results indicate that these LAB strains have the potential to be used as probiotics.

Characterization of Autochthonous Lactic Acid Bacteria Isolated from a Traditional Ethiopian Beverage, Tella

This study aimed to isolate lactic acid bacteria (LAB) from a traditional Ethiopian fermented product, Tella, and evaluate their functional properties. Of forty-three isolates, seven LAB were screened and identified as Pediococcus pentosaceus, Latilactobacillus curvatus, Leuconostoc mesenteroides, and Lactiplantibacillus plantarum species. The isolates were tested for their alcohol tolerance, acid and bile resistance, auto-aggregation, co-aggregation, hydrophobicity, antibacterial activity, and antibiotic susceptibility. LAB isolates, specifically P. pentosaceus TAA01, L. mesenteroides TDB22, and L. plantarum TDM41, showed a higher degree of alcohol tolerance in 8% and 10% (w/v) ethanol concentrations. Additionally, these three isolates displayed survival rates >85% in both acidic pH and bile environments. Among the isolates, L. plantarum TDM41 demonstrated the highest auto-aggregation, co-aggregation, and hydrophobicity with (44.9 ± 1.7)%, (41.4 ± 0.2)%, and (52.1 ± 0.1)% values, respectively. The cell-free supernatant of the isolates exhibited antibacterial activity against foodborne pathogens of Escherichia coli, Salmonella Enteritidis, and Staphylococcus aureus. Each isolate exhibited various levels of resistance and susceptibility to seven antibiotics and resistance was observed against four of the antibiotics tested. After performing a principal component analysis, Pediococcus pentosaceus TAA01, L. mesenteroides TDB22, and L. plantarum TDM41 were selected as the most promising ethanol-tolerant probiotic isolates.

Fermented fish and fermented fish-based products, an ever-growing source of microbial diversity: A literature review

Fermented fish and fermented fish-based products are part of the diet of many countries all over the world. Their popularity is not only due to the unique flavor, the distinct texture, and the good nutritional quality, but also to the easiness of the production process, that is commonly based on empirical traditional methods. Fish fermentation techniques ususally rely on the combination of some key steps, including salting, addition of spices or additives, and maintenance of anaerobic conditions, thus selecting for the multiplication of some pro-technological microorganisms. The objective of the present review was to provide an overview of the current knowledge of the microbial communities occurring in fermented fish and fish-based products. Specific information was collected from scientific publications published from 2000 to 2022 with the aim of generating a comprehensive database. The production of fermented fish and fish-based foods was mostly localized in West African countries, Northern European countries, and Southeast Asian countries. Based on the available literature, the microbial composition of fermented fish and fish-based products was delineated by using viable counting combined with identification of isolates, and culture-independent techniques. The data obtained from viable counting highlighted the occurrence of microbial groups usually associated with food fermentation, namely lactic acid bacteria, staphylococci, Bacillus spp., and yeasts. The identification of isolates combined with culture-independent methods showed that the fermentative process of fish-based products was generally guided by lactobacilli (Lactiplantibacillus plantarum, Latilactobacillus sakei, and Latilactobacillus curvatus) or Tetragenococcus spp. depending on the salt concentration. Among lactic acid bacteria populations, Lactococcus spp., Pediococcus spp., Leuconostoc spp., Weissella spp., Enterococcus spp., Streptococcus spp., and Vagococcus spp. were frequently identified. Staphylococcus spp. and Bacillus spp. confirmed a great adaptation to fermented fish-based products. Other noteworthy bacterial taxa included Micrococcus spp., Pseudomonas spp., Psychrobacter spp., Halanaerobium spp., and Halomonas spp. Among human pathogenic bacteria, the occurrence of Clostridium spp. and Vibrio spp. was documented. As for yeast populations, the predominance of Candida spp., Debaryomyces spp., and Saccharomyces spp. was evidenced. The present literature review could serve as comprehensive database for the scientific community, and as a reference for the food industry in order to formulate tailored starter or adjunctive cultures for product improvement.

Isolation and characterization of bioprotective lactic acid bacteria from Moroccan fish and seafood

The microbiota of aquatic animals is heavily influenced by their environment, offering a potential source for biotechnologically relevant microorganisms. In this investigation, bacterial strains from fish and fish products were investigated to determine their antimicrobial effects against fish and food pathogens. Twelve strains, including five Lactococcus, two Enterococcus hirae, two Enterococcus mundtii, and three Latilactobacillus sakei were selected as producing bacteriocin-like substances with antimicrobial properties that were active against a broad spectrum of bacteria, such as Listeria monocytogenes, Staphylococcus aureus, and Pseudomonas aeruginosa. Selected strains were identified via 16S rRNA sequencing. Most strains exhibited sensitivity to eight types of antibiotics (erythromycin, tetracycline, chloramphenicol, vancomycin, fosfomycin, gentamicin, ampicillin, and netilmicin), lacked hemolysin and gelatinase virulence factors, and did not produce histamine. These findings suggest that marine fish may be a promising source of lactic acid bacteria strains with antimicrobial potential for use as biopreservatives in the food industry.

Probiotic potential of Lactobacillus sakei L-7 in regulating gut microbiota and metabolism

A growing body of research suggests that gut microbiota is inextricably linked to host health and disease，so we are committed to finding more probiotic resources that are beneficial to human health. This study evaluated the probiotic properties of Lactobacillus sakei L-7 isolated from home-made sausages. The basic probiotic properties of L. sakei L-7 were evaluated through in vitro tests. The strain showed 89% viability after 7 h of digestion in simulating gastric and intestinal fluid. The hydrophobicity, self-aggregation and co-aggregation of L. sakei L-7 showed it had a strong adhesion ability. C57BL/6 J mice were fed L. sakei L-7 for 4 weeks. 16 S rRNA gene analysis indicated that intake of L. sakei L-7 increased the richness of gut microbiota and abundance of beneficial bacteria Akkermansia, Allobaculum and Parabacteroides. Metabonomics analysis revealed that beneficial metabolite gamma-aminobutyric acid and docosahexaenoic acid increased significantly. While the level of metabolite sphingosine and arachidonic acid significantly decreased. In addition, serum levels of inflammatory cytokines interleukin (IL)- 6 and tumor necrosis factor (TNF)-α were significantly decreased. The results suggested that L. sakei L-7 may promote gut health and reduce the occurrence of inflammatory response, it has the potential to become a probiotic.

In-vitro evaluation of the probiotic potential and the fermentation profile of Pediococcus and Enterococcus strains isolated from Moroccan camel milk

The promotion of human health through natural approaches like functional foods and probiotics is in high demand. The medicinal plants are the major feed of Moroccan dromedary, which improves the functional properties of their milk. A few studies have reported the probiotic and functional aptitudes of lactic acid bacteria (LAB) of this milk. In this context, our study aimed to identify LAB isolated from Moroccan raw camel milk and investigate their probiotic features and their fermentation profile. The molecular identification of twelve isolates indicated that they belong to Pediococcus pentosaceus, Enterococcus faecium, and Enterococcus durans. All LAB strains displayed high tolerance to gastrointestinal conditions (survival rate of 31.85-96.52% in pH 2.5, 35.23-99.05% in 0.3 bile salts, and 26.9-90.96% in pepsin), strong attachment abilities (auto-aggregation and hydrophobicity ranged from 28.75 to 95.9% and from 80.47 to 96.37%, respectively), and high co-aggregation ability with pathogenic bacteria. Importantly, they did not present antibiotic resistance or hemolytic activity. Our LAB strains demonstrated antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, and Salmonella enterica. Moreover, they could acidify cow milk (ΔpH of 2.55 after 24 h) and improve its antioxidant ability (inhibition of 36.77% of DPPH). Based on the multivariate analysis, Pediococcus pentosaceus Pd24, Pd29, Pd38, Enterococcus faecium Ef18, and Enterococcus durans Ed22 were selected as the most promising probiotics. Therefore, we propose that Pediococcus pentosaceus isolated from camel milk could be used as potential probiotic strains and/or starter cultures in functional milk fermentation.

Effect of Salt Concentration on Flavor Characteristics and Physicochemical Quality of Pickled Brassica napus

This study aimed to elaborate on the role of salt concentration on pickled Brassica napus leaf and stem (BLS); it also contributed to the development of low-salt and healthy Brassica napus products in the harvest period. Five sets of pickled BLS samples were prepared, and the physicochemical parameters, free amino acids (FAAs), and the volatile flavor components (VFCs) were analyzed after fermentation. Results showed that some antioxidants, FAAs, and VFCs underwent dynamic changes during fermentation. Nitrite increased with an increase in the salt concentration used for fermentation. Pickled BLS contained a wide range of FAAs; a total of 23 were detected, which might be used as a source of amino acid supplementation. The VFCs were analyzed via headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography and mass spectrometry (GC-MS). A total of 51 VFCs were tentatively identified. The contribution to flavor could be expressed by the relative odor activity value (ROAV). Salt is one of the important factors affecting the quality of vegetable fermentation. Therefore, for large-scale pickled BLS production, a key issue is to balance the low salt concentration and high fermentation quality. Under the action of salt and microorganisms, the fresh BLS fermented via dry pickling, which not only improved its FAAs and VFCs, endowed the production with a unique flavor, but also prolonged the shelf life.

A novel approach to Lactiplantibacillus plantarum: From probiotic properties to the omics insights

Lactiplantibacillus plantarum (previously known as Lactobacillus plantarum) strains are one of the lactic acid bacteria (LAB) commonly used in fermentation and their probiotic and functional properties along with their health-promoting roles come to the fore. Food-derived L. plantarum strains have shown good resistance and adhesion in the gastrointestinal tract (GI) and excellent antioxidant and antimicrobial properties. Furthermore, many strains of L. plantarum can produce bacteriocins with interesting antimicrobial activity. This probiotic properties of L. plantarum and existing in different niches give a great potential to have beneficial effects on health. It is also has been shown that L. plantarum can regulate the intestinal microbiota composition in a good way. Recently, omics approaches such as metabolomics, secretomics, proteomics, transcriptomics and genomics try to understand the roles and mechanisms of L. plantarum that are related to its functional characteristics. This review provides an overview of the probiotic properties, including the specific interactions between microbiota and host, and omics insights of L. plantarum.

A Comprehensive Review with Future Insights on the Processing and Safety of Fermented Fish and the Associated Changes

As an easily spoiled source of valuable proteins and lipids, fish is preserved by fermentation in many cultures. Over time, diverse types of products have been produced from fish fermentation aside from whole fish, such as fermented fish paste and sauces. The consumption of fermented fish products has been shown to improve both physical and mental health due to the composition of the products. Fermented fish products can be dried prior to the fermentation process and include various additives to enhance the flavours and aid in fermentation. At the same time, the fermentation process and its conditions play a major role in determining the quality and safety of the product as the compositions change biochemically throughout fermentation. Additionally, the necessity of certain microorganisms and challenges in avoiding harmful microbes are reviewed to further optimise fermentation conditions in the future. Although several advanced technologies have emerged to produce better quality products and easier processes, the diversity of processes, ingredients, and products of fermented fish warrants further study, especially for the sake of the consumers' health and safety. In this review, the nutritional, microbial, and sensory characteristics of fermented fish are explored to better understand the health benefits along with the safety challenges introduced by fermented fish products. An exploratory approach of the published literature was conducted to achieve the purpose of this review using numerous books and online databases, including Google Scholar, Web of Science, Scopus, ScienceDirect, and PubMed Central, with the goal of obtaining, compiling, and reconstructing information on a variety of fundamental aspects of fish fermentation. This review explores significant information from all available library databases from 1950 to 2022. This review can assist food industries involved in fermented fish commercialization to efficiently ferment and produce better quality products by easing the fermentation process without risking the health and safety of consumers.

Integrated genome based evaluation of safety and probiotic characteristics of Lactiplantibacillus plantarum YW11 isolated from Tibetan kefir

The comparative genomic analysis of Lactiplantibacillus plantarum YW11 (L. plantarum YW11) isolated from Tibetan kefir involves comparison of the complete genome sequences of the isolated strain with other closely related L. plantarum strains. This type of analysis can be used to identify the genetic diversity among strains and to explore the genetic characteristics of the YW11 strain. The genome of L. plantarum YW11 was found to be composed of a circular single chromosome of 4,597,470 bp with a G + C content of 43.2%. A total of 4,278 open reading frames (ORFs) were identified in the genome and the coding density was found to be 87.8%. A comparative genomic analysis was conducted using two other L. plantarum strains, L. plantarum C11 and L. plantarum LMG21703. Genomic comparison revealed that L. plantarum YW11 shared 72.7 and 75.2% of gene content with L. plantarum C11 and L. plantarum LMG21703, respectively. Most of the genes shared between the three L. plantarum strains were involved in carbohydrate metabolism, energy production and conversion, amino acid metabolism, and transcription. In this analysis, 10 previously sequenced entire genomes of the species were compared using an in-silico technique to discover genomic divergence in genes linked with carbohydrate intake and their potential adaptations to distinct human intestinal environments. The subspecies pan-genome was open, which correlated with its extraordinary capacity to colonize several environments. Phylogenetic analysis revealed that the novel genomes were homogenously grouped among subspecies of l Lactiplantibacillus. L. plantarum was resistant to cefoxitin, erythromycin, and metronidazole, inhibited pathogens including Listeria monocytogenes, Clostridium difficile, Vibrio cholera, and others, and had excellent aerotolerance, which is useful for industrial operations. The comparative genomic analysis of L. plantarum YW11 isolated from Tibetan kefir can provide insights into the genetic characteristics of the strain, which can be used to further understand its role in the production of kefir.

Isolation and characterization of potential Lactobacillus acidophilus strains isolated from pig feces

The aim of this study was to isolate and characterize Lactic Acid Bacteria (LAB) from 16 feces samples of pig farm, and to evaluate the probiotic potential of these isolates as potential oral probiotic candidates. The selection process was based on the isolation, identification, and a series of experiments for the selection of appropriate candidates with beneficial properties. The results demonstrated that most of LAB showed relatively strong resistance to pH 2.5 and high bile salts (1%), and had good survival in simulated gastric and intestinal juice. 9 isolates displayed antimicrobial activities against Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa and Enterobacter sakazakii. Almost all isolates were sensitive to ampicillin, chloramphenicol, vancomycin and amoxicillin, and most of isolates exhibited resistance against tetracycline and vancomycin. The adhesion rates of LAB varied greatly. The results of the study suggested that the Lactobacillus acidophilus NCUA065001 have the important functional property of probiotic candidates to enhance gut integrity and could considered to be the potential antibiotic alternatives in the pig feed industry.

Functional Annotation of Lactiplantibacillus plantarum 13-3 as a Potential Starter Probiotic Involved in the Food Safety of Fermented Products

The important role of Lactiplantibacillus plantarum strains in improving the human mucosal and systemic immunity, preventing non-steroidal anti-provocative drug-induced reduction in T-regulatory cells, and as probiotic starter cultures in food processing has motivated in-depth molecular and genomic research of these strains. The current study, building on this research concept, reveals the importance of Lactiplantibacillus plantarum 13-3 as a potential probiotic and bacteriocin-producing strain that helps in improving the condition of the human digestive system and thus enhances the immunity of the living beings via various extracellular proteins and exopolysaccharides. We have assessed the stability and quality of the L. plantarum 13-3 genome through de novo assembly and annotation through FAST-QC and RAST, respectively. The probiotic-producing components, secondary metabolites, phage prediction sites, pathogenicity and carbohydrate-producing enzymes in the genome of L. plantarum 13-3 have also been analyzed computationally. This study reveals that L. plantarum 13-3 is nonpathogenic with 218 subsystems and 32,918 qualities and five classes of sugars with several important functions. Two phage hit sites have been identified in the strain. Cyclic lactone autoinducer, terpenes, T3PKS, and RiPP-like gene clusters have also been identified in the strain evidencing its role in food processing. Combined, the non-pathogenicity and the food-processing ability of this strain have rendered this strain industrially important. The subsystem and qualities characterization provides a starting point to investigate the strain’s healthcare-related applications as well.

Evaluation of probiotic potential of autochthonous lactobacilli strains isolated from Zabuli yellow kashk, an Iranian dairy product

AIMS

The aim of this study was evaluating the probiotic potential and anti-biofilm activity of five lactobacilli strains which isolated and identified from an Iranian product.

METHODS AND RESULTS

Five lactobacilli strains which were isolated from Zabuli yellow kashk, were evaluated for the presence of probiotic properties, such as resistance to low pH, resistance to simulated gastrointestinal conditions, bile salt tolerance, hydrophobicity, auto- and co-aggregation. In addition, antimicrobial susceptibility, adherence to Caco-2 cells (human colon cancer cell line), anti-adhesion activity, ability against biofilm formation, and biofilm degradation of mentioned strains against Pseudomonas aeruginosa PTCC 1707 were assessed. All the strains tested showed acceptable characteristics, but Lactiplantibacillus plantarum TW57-4 appeared of particular interest. Some probiotic properties of this strain were similar and in some cases higher than the commercial probiotic strain Lacticaseibacillus rhamnosus GG (standard sample). Cholesterol assimilation and radical-scavenging activity of Lpb. plantarum TW57-4 were70.2 % and 62.3 %, respectively. The adhesion degree of Lpb. plantarum TW57-4 was 10.6 %. Applying competition and inhibition assay, this strain showed 55.3 % and 62.3 % of competition and inhibition activity in adhesion of P. aeruginosa PTCC 1707 to the intestinal cells, respectively.

CONCLUSIONS

According to the obtained results, it can be concluded that Lpb. plantarum TW57-4 strain can be used as a promising candidate for in-vivo studies with the aim of developing new probiotic starter cultures.

SIGNIFICANCE AND IMPACT OF STUDY

The present study furthers our understanding of lactobacilli strains behavior after consumption to establish their beneficial effects.

Probiotic potential characterization and clustering using unsupervised algorithms of lactic acid bacteria from saltwater fish samples

This research aimed to isolate lactic acid bacteria from the bowel of saltwater fish to assess their potential probiotic properties. Nineteen isolates of LAB including Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Lactobacillus acidophilus, Levilactobacillus brevis, Pediococcus pentosaceus, and Pediococcus acidilactici were recognized using molecular tools. All the isolates survived in the simulated conditions of the GI tract. Auto-aggregation ranged from 01.3 ± 0.5 to 82.6 ± 1.4% and hydrophobicity with toluene ranged from 3.7 ± 1.6 to 69.4 ± 1.3%, while the range of hydrophobicity with xylene was from 02.2 ± 1.6 to 56.4 ± 2.1%. All the isolates of lactobacilli, pediococci, enterococci, and lactococci indicated variable sensitivity and resistance towards clinical antibiotics. Non-neutralized cell free supernatant of isolates F12 and F15 showed antimicrobial activity against all the 8 evaluated enteric pathogens. Cluster analysis of identified potential probiotic bacteria based on heat-map and PCA methods also highlighted the priority of isolates F3, F7, F12, and F15 as bio-control agents in fishery industry. The findings of this study may essentially contribute to the understanding of the probiotic potential of LAB in saltwater fish, in order to access their probiotic characterization for use as biocontrol in fishery.

Probiotic and Antioxidant Potential of the Lactobacillus Spp. Isolated from Artisanal Fermented Pickles

The present study was based on bacterial isolation with probiotic potential from artisanal fermented pickles. A total of 36 bacterial strains were isolated from 50 different artisanal fermented pickle samples. Nine isolates with promising probiotic potential (PCR99, PCR100, PCR118, PCR119, PCR121, PCR125, PCR137, PCR140 and PCR141) were selected. The strains showed varied protease, amylase, lipase and cellulase patterns. The isolated strains displayed varied responses towards various antibiotic classes, i.e., PCR140 showed resistance to penicillin G, polymyxin B, Metronidazole and Streptomycin. PCR140 showed highest resistance to bile salt concentrations (0.3% and 0.5%) and acidic conditions (pH 3 and pH 4) when exposed to mimicked gastrointestinal conditions. The cell viability against enzymes produced in stomach and intestines showed different patterns as pepsin was in the range of 94.32–91.22%, pancreatic resistance 97.32–93.11% and lysozyme resistance was detected at 99.12–92.55%. Furthermore, the auto-aggregation capability of isolated strains was in the range of 46.11–33.33% and cell surface hydrophobicity was in the range of 36.55–31.33%. PCR 140 showed maximum antioxidant activity in lyophilized cells as well as probiotic potential. A phylogenetic analysis based on 16S rRNA gene sequencing confirmed that PCR140 (NMCC91) with higher in vitro probiotic and antioxidant potential belongs to the genus Lactobacillus with 97% similarity with Lacticaseibacillus paracasei. This work demonstrated that the isolate PCR 140 (NMCC91) is suitable for use in food and medical industries.

Probiotic bacteria from 10 different traditional Iranian cheeses: Isolation, characterization, and investigation of probiotic potential

In this study, 10 different traditional Iranian cheeses, which are still consumed by people in rural areas of Iran, were examined to isolate new strains of probiotic bacteria. Isolated bacteria were identified by 16s rRNA gene amplification and subjected to series of in vitro tests to find out their probiotic potential. A total of 2345 colonies were collected and 465 of them were confirmed as lactic acid bacteria (LAB), of which Lactiplantibacillus plantarum, Lactobacillus bulgaricus, and Lacticaseibacillus casei were the top three isolated bacteria. Among the different species of LAB isolated in this study, Lactip. plantarum was the most isolated species, and seven isolates had the significant criteria for being a probiotic strain than other isolates indicating the most adaptable properties of this species. Lactiplantibacillus plantarum was the most resistant bacteria in the bile resistance test and was also the most durable bacteria in gastrointestinal conditions, for example, acidic environment (pH = 2.5) and trypsin. In contrast, Lacticaseibacillus casei was the most susceptible bacterial strain. Lactobacillus rhamnosus showed the most antibacterial effect against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. This study showed that probiotic strains isolated from local cheeses could be considered as suitable biopreservatives and used as specific starter cultures for the production of functional cheeses.

Starter inoculums assisted fermentation of Puntius sp. - role of Lactiplantibacillus plantarum and Staphylococcus piscifermentans to reduce fermentation time while increasing safety

AIMS

To evaluate the role of starter inoculums to reduce total fermentation time as well as improve safety and quality of Sheedal, a fermented fish-product of India.

METHODS AND RESULTS

Lactiplantibacillus plantarum and Staphylococcus piscifermentans were isolated from the Sheedal and used as starter inoculums. To justify fermenting and probiotic properties of the starter inoculums, characteristics like proteolytic and lipolytic activity, cell-surface hydrophobicity, cell auto-aggregation and co-aggregation, antibiotic susceptibility and antimicrobial assay were performed. Changes of the count of lactic acid bacteria, staphylococci and Enterobacteriaceae were studied periodically.

CONCLUSIONS

Higher increase of α-amino nitrogen and TCA-soluble peptides during fermentation was observed in treatment which was inoculated with both L. plantarum and S. piscifermentans. Poor competitiveness of staphylococci in presence of LAB was found. Inoculation of both L. plantarum and S. piscifermentans as starter showed positive effect to reduce significantly the fermentation period from usual 4-5 months to 75 days, whereas, same was achieved after 105^th and 120^th by the use of either L. plantarum or S. piscifermentans, respectively.

SIGNIFICANCE AND IMPACT OF STUDY

Reduction of the total fermentation period is considered as an additional advantage in Sheedal technology in addition to the safety of the product as evidenced by low pH and high titratable acidity.

Rice flour powder carrying mixed starter culture of Lactiplantibacillus plantarum KU-LM173 and Pediococcus acidilactici KU-LM145 for fermented mussel, Perna viridis Linnaeus 1758

AIMS

To develop a dried rice flour powder (DP) formulation to contain a lactic acid bacterial starter culture for fermenting mussel meat (FM).

METHODS AND RESULTS

Lactiplantibacillus plantarum KU-LM173 (LP), Enterococcus hirae KU-LM174 and Pediococcus acidilactici KU-LM145 (PA) were selected from commercial FMs and identified to have high acid and protease production. Mixed culture between LP, for high acid production, and PA, for the flavour, was the best for DP and had greater organoleptic properties than a single starter fermentation. The best ratio of DP for production was 1% of the mussel weight, while the highest numeric scoring of the organoleptic test between 3% and 6%. The starter culture fermentation accelerated over the natural (wild) fermentation and ended at day 3. The shelf life of the product was at least 30 days at 30-35°C with no pathogens detected. The shelf life of DP at 4°C was 10 weeks.

CONCLUSIONS

DP with the best strains and long shelf life promoted safety of FM and reduced the processing time. High consumer acceptance, protease and acid production and flavour were unique product characteristics.

SIGNIFICANCE AND IMPACT OF STUDY

Accelerated commercial FMs with effective DP formulation for the industrial sector may be plausible.