Potential Of Lactic Acid Bacteria Research Articles

Selection Of Lactic Acid Bacteria as Starter Culture for Cocoa Fermentation (Theobroma Cacao L.)

This research aims to select the potential lactic acid bacteria (LAB) for starter culture for cocoa beans fermentation. The bio-control activity against mycotoxigenic fungi were also evaluated. The indigenous LAB was analized from Sukabumi cocoa beans fermentation by spontaneous method for four days (96 hours). The preliminary screening of LAB were observed by clear zone forming, morphology characterization and catalase activity. The LAB were screened for their ability to resist acidity, ethanol, and heat, and their ability to produce high acid and antifungal. The antifungal capability was antagonistic assays to Aspergillus ochraceus IPBCC 88.033 on Potato Dextrose Agar (PDA) medium. The result showed that the selected acid bacteria isolate, H 2.34, were antifungal-producing strains, and resist acidity, ethanol and heat, which was suitable property for starter culture and biopreservation agent. The study demonstrated the selection of local Indonesian LAB from Sukabumi fermented cocoa bean to observe the potential of isolate as a starter culture and biopreservation agent

Bioprotective potential of lactic acid bacteria for Salmonella biocontrol in vitro.

Lactic acid bacteria (LAB) are an important option for Salmonella control in animal production, resulting in lower antibiotic use. The objective of this research was to isolate LAB from meat products and from commercial probiotics sold as nutritional supplements for in vitro verification of their bioprotective potential. Eleven bacteria were identified as Pediococcus acidilactici, two as Lacticaseibacillus rhamnosus, one as Lacticaseibacillus paracasei paracasei, one as Limosilactobacillus fermentum, and one as a consortium of Lactobacillus delbrueckii bulgaricus and L. fermentum. All bacteria showed inhibitory activity against Salmonella, with emphasis on the inhibition of P. acidilactici PUCPR 011 against Salmonella Enteritidis 33SUSUP, S. Enteritidis 9SUSP, S. Enteritidis 56301, S. Enteritidis CRIFS 1016, Salmonella Typhimurium ATCC™ 14,028®, and Salmonella Gallinarum AL 1138, with inhibition halos of 7.3 ± 0.5mm, 7.7 ± 1.0mm, 9.0 ± 1.8mm, 7.3 ± 0.5mm, 7.7 ± 1.0mm, and 7.3 ± 0.5, respectively. The isolates P. acidilactici PUCPR 011, P. acidilactici PUCPR 012, P. acidilactici PUCPR 014, L. fermentum PUCPR 005, L. paracasei paracasei PUCPR 013, and L. rhamnosus PUCPR 010 showed inhibition greater than 2mm against at least 3 Salmonella and were used for encapsulation and in vitro digestion. The encapsulation efficiency ranged from 76.89 ± 1.54 to 116.48 ± 2.23%, and the population after 12months of storage was from 5.31 ± 0.17 to 9.46 ± 0.09 log CFU/g. When simulating swine and chicken digestion, there was a large reduction in bacterial viability, stabilizing at concentrations close to 2.5 log CFU/mL after the analyses. The analyzed bacteria showed strong in vitro bioprotective potential; further analyses are required to determine in vivo effectiveness.

Antimicrobial Activities and Biopreservation Potential of Lactic Acid Bacteria (LAB) from Raw Buffalo (Bubalus bubalis) Milk.

The aim of this study was to investigate the antimicrobial and biopreservation potential of lactic acid bacteria. The potential probiotic culture inhibited the growth of gram-positive and gram-negative foodborne pathogens in agar spot assay with inhibition zones ranging from 10 to 21 mm in diameter. The strains showed coaggregation capabilities ranging from 7 to 71% with tested food pathogens including Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica subsp. enterica serovar Typhimurium. The effect of cell-free supernatants on the release of 260 nm absorbing material, especially nucleic acids, was evaluated and indicated the antagonistic activity on foodborne pathogens, the highest being Lactobacillus paraplantarum against E. coli (3.77) and S. aureus (3.86) after 60 min. The effect of cell-free supernatant (CFS) on the growth of pathogens showed that Lactobacillus paraplantarum 11 and L. pentosus 93 had the highest inhibitory activity against tested strains. The biopreservation assay indicated that the potential probiotic strains Lactobacillus paraplantarum 11 (BT), Lactiplantibacillus plantarum 19, Lactobacillus pentosus 42, Limosilactobacillus fermentum 60, Lactobacillus pentosus 93, and Limosilactobacillus reuteri 112 were effective in reducing the Listeria monocytogenes population in raw buffalo milk. Complete Listeria monocytogenes inhibition was observed after 6-8 days. This study showed that probiotic LAB from buffalo milk have antimicrobial and biopreservation potential; these strains have the potential to be utilized as biopreservative agents in food products.

Probiotic Potentiality of Lactic Acid Bacteria Isolated from “Theki Dahi” around Various Places of Pokhara Valley

This research is undertaken to study the probiotic potential of lactic acid bacteria (LAB) isolated from theki dahi of Pokhara valley. A total of 48 samples were collected, pooled together, and examined. From characterization, three types of Lactobacilli (Lb A, LbB, and LbC), two types of Leuconostoc (Leu A and LeuB), two types of Bifidobacterium (Bif A and Bif B), one Streptococcus and three types of Lactococci (Lc A, LcB, and LcC) were identified. Also, the probiotic strain of Lactobacillus casei sub sp. Shirota was isolated from the yakult sample. All were then subjected to further examination.In terms of acid resistance, all were found to be resistant to low pH 2 and 4 for 2 h. Similarly, all were resistant to bile salt (0.3% and 0.4% w/v) and able to hydrolyze it. With regards to antibiotic resistance, all were sensitive to penicillin G, ampicillin, and amoxicillin but only Lactobacilli and Bifidobacterium showed resistance to ciprofloxacin. Also, the isolates adhered to hexane. This study implies that theki dahi comprises various LAB with probiotic properties. Majorly, Lb A and Bif A demonstrated similar probiotic properties to control organism. Thus, they can be considered as potential probiotic candidates in theki dahi. Keywords: Theki dahi , probiotic potentiality, LAB, isolation, identification, characterization DOI: 10.7176/JNSR/14-4-04 Publication date: February 28 th 2023

Characterization of Short-chain fatty acid-producing and cholesterol assimilation potential probiotic Lactic acid bacteria from Chinese fermented rice

Probiotic strains are phrased as beneficial for life because this bacterial association has substantial effects on human and animal health when administrated orally, among which bio-active metabolite short-chain fatty acids production and cholesterol assimilation are most significant. All the short-chain fatty acids, mainly acetate, propionate, and butyrate reveal valuable effects on human health. In this research, the ability of 9 the potential lactic acid bacteria food-isolated probiotics was investigated to produce bio-active metabolite short-chain fatty acids directly or indirectly, and cholesterol-lowering ability through various mechanisms. Their 16S rRNA gene sequences were analyzed. short-chain fatty acids were quantified by gas chromatography, while cholesterol assimilation was measured using the o-phthalaldehyde method with slight modifications. All isolated strains through this study have the ability to optimize cholesterol content in the culture broth, short-chain fatty acid production, and survival in extreme alkaline and acidic conditions. The highest resistance to bile salt concentrations, γ-hemolysis, and strong antibacterial activity against pathogenic indicators, especially Escherichia coliATCC25922. The highest Lipid accumulation inhibitory effect was noticed in Lentilactobacillus hilgardii LMG 07934 as a potential probiotic isolate on the basis of cholesterol assimilation capacity (i.e., 91.4%), along with the ability to produce abundant i.e., butyric acid, propionic acid, and acetic acid, followed by Lacticaseibacillus paracasei ATCC 334 which has 85.3% cholesterol assimilation ability. These findings demonstrated that these isolated strains from Chinese fermented rice can be used as a potential probiotic and alternate therapeutic supplement because of their ability to produce short-chain fatty acids and their cholesterol-lowering ability.

Identification and characterization of probiotics isolated from indigenous chicken (Gallus domesticus) of Nepal.

Excessive and irrational use of antibiotics as growth promoters in poultry has been one of key factors contributing to increased emergence of antibiotics resistant bacteria. Several alternatives for antibiotic growth promoters are being sought, and the search for effective probiotics to be used as feed additives is amongst the promising ones. Our study aimed to isolate and test potential probiotics bacteria from cloacal swabs of various indigenous chicken (Gallus domesticus) breeds from rural outskirts of the Kathmandu valley (Nepal). Selective isolation of probiotics was conducted by micro-aerophilic enrichment of sample in MRS Broth at 37°C, followed by culturing on MRS agar supplemented with 5 g/L of CaCO3. Isolated bacterial colonies producing transparent halo were selected as potential lactic acid bacteria (LAB), and tested for their antibacterial activity, phenotypic and biochemical characteristics, acidic yield, and tolerance to acid and bile. A total of 90 potential LAB were isolated from cloacal samples collected from 41 free-ranging chickens of indigenous breeds. Of these, 52 LAB isolates (57%) showed variable antibacterial activity to at least one bacterial pathogen. Of 52 LAB, 46 isolates fulfilled phenotypic and biochemical criteria of Lactobacillus spp. Of these, 37 isolates produced varying percentage yields of lactic acid, 27 isolates showed survival at pH 3.0, and 17 isolates showed survival tolerances in the presence of 0.3% and 0.5% bile salts for 24 hours. Phylogenetic analysis of 16S rDNA sequencing of LAB isolates fulfilling in vitro probiotics properties showed that 3 isolates had genetic identity of 99.38% with Lactobacillus plantarum, while one isolate was genetically similar (99.85%) with the clade of L. reuteri, L. antri and L. panis. Our study identified four Lactobacillus spp. strains having potential probiotics properties. Further investigations are needed to evaluate these isolates to be used as poultry probiotics feed supplement.

The potential of lactic acid bacteria in mediating the control of plant diseases and plant growth stimulation in crop production - A mini review.

The microbial diseases cause significant damage in agriculture, resulting in major yield and quality losses. To control microbiological damage and promote plant growth, a number of chemical control agents such as pesticides, herbicides, and insecticides are available. However, the rising prevalence of chemical control agents has led to unintended consequences for agricultural quality, environmental devastation, and human health. Chemical agents are not naturally broken down by microbes and can be found in the soil and environment long after natural decomposition has occurred. As an alternative to chemical agents, biocontrol agents are employed to manage phytopathogens. Interest in lactic acid bacteria (LAB) research as another class of potentially useful bacteria against phytopathogens has increased in recent years. Due to the high level of biosafety, they possess and the processes they employ to stimulate plant growth, LAB is increasingly being recognized as a viable option. This paper will review the available information on the antagonistic and plant-promoting capabilities of LAB and its mechanisms of action as well as its limitation as BCA. This review aimed at underlining the benefits and inputs from LAB as potential alternatives to chemical usage in sustaining crop productivity.

Probiotic evaluation of lactic acid bacteria isolated from the intestinal tract of labeo rohita (rohu)

Probiotics, defined as live microorganisms conferring health benefits, have gained global popularity for their role in promoting host well-being. Lactic acid bacteria, known inhabitants of the gastrointestinal tract, are investigated for their probiotic properties, including acid and bile salt tolerance. Numerous researchers have documented the potential probiotic properties of lactic acid bacteria, attributing them to their ability to enhance the host animal's immune system and promote microbial equilibrium in the gastrointestinal tract. This study aimed to assess the probiotic potential of lactic acid bacteria obtained from the intestinal tract of the freshwater fish, Labeo rohita (Rohu). The isolated lactic acid bacteria underwent thorough characterization and identification, employing morphological, cultural, and biochemical analyses. Subsequently, their probiotic potential was evaluated through acid tolerance and bile salt tolerance studies. This investigation revealed that two Lactobacillus species isolated from the gut of Labeo rohita met the essential criteria for probiotics, demonstrating resilience to high acidity within the pH range of 3 to 5 and tolerating bile salt concentrations up to 0.3%.

Characterization of probiotic potential of lactic acid bacteria isolated from aquaculture objects of Uzbekistan

Lactic acid bacteria have a high potency to combat infections in the body. The range of lactic acid bacteria isolated from aquaculture in Uzbekistan has been described in this article. We found that Lactobacillus delbrueckii, L. plantarum, L. sakei, L. brevis, Lactococcus lactis, Pediococcus acidilactici, P. pentosaceus, Enterococcus faecium, E. hirae, E. mundii, E.faecalis, Leuconostoc citreum, and Weisella sibaria strains are represented in hydrobionts. Among them isolates Lactobacillus delbrueckii R1, Lactobacillus plantarum Kr5, Pediococcus acidilactici B, Enterococcus faecium R2, Lactobacillus plantarum R3, Pediococcus pentosaceus R1 showed high antagonistic activity against aquaculture pathogens. Four strains: Lactobacillus plantarum Kr5, Pediococcus acidilactici B, Enterococcus faecium R2, and Pediococcus pentosaceus R1, meet all the criteria for probiotics and can be recommended as part of probiotic feed additives.

Random UV-Mutagenesis of Lactobacillus Species for the Generation of a Mutant with Better Probiotic Potential

Antibiotic resistance has reduced the value of synthetic drugs, offering up possibilities for the development of new substitutes with significant potential to benefit their host. Probiotics are living microbes that restore the microbiome in the gut. The main purpose of this research is to explore the probiotic potential of Lactic Acid Bacteria and its mutant strains. LAB was isolated from a variety of fermented foods. They were first examined for cultural, microscopic, and biochemical properties. The four probiotic LAB isolates were identified to the strain level using 16S rRNA gene sequence comparisons. The tolerance of these strains to pH, NaCl, and phenol was used to establish their safety. In vitro testing for probiotic potential comprised survival under simulated GI tract conditions and antimicrobial activity. Lastly exposure to U.V. for varied periods for strain improvement. The isolates were screened as Limosilactobacillus fermentum (LAB01), Lactobacillus acidophilus (LAB02), Lactobacillus paracasei (LAB03) and Lactobacillus delbrueckii subsp bulgaricus (LAB04). Mutated strains were resistant to a wide spectrum of antibiotics, whereas most strains were only tolerant to limited antibiotics. The correlation between gut flora and health is exciting since it opens new avenues for research. Based on these findings, it can be concluded that LAB is a potent probiotic

Probiotic Potentials of Lactic Acid Bacteria and Yeasts from Raw Goat Milk in Nigeria.

Probiotic microorganisms are incorporated in foods due to their numerous health benefits. We investigated lactic acid bacteria (LAB) and yeasts isolated from goat milk in Nigeria for novel probiotic strains. In this study, a total of 27 LAB and 23 yeast strains were assessed for their probiotic potentials. Only six LAB strains (Weissella cibaria GM 93m3, Weissella confusa GM 92m1, Pediococcus acidilactici GM 18a, Pediococcus pentosaceus GM 23d, Lactiplantibacillus pentosus GM 102s4, Limosilactobacillus fermentum GM 30m1) and four yeast strains (Candida tropicalis 12a, C. tropicalis 33d, Diutina rugosa 53b, and D. rugosa 77a) identified using partial 16S and 26S rDNA sequencing, respectively, showed survival at pH 2.5, 0.3% bile salt, and simulated gastrointestinal conditions and possessed auto-aggregative and hydrophobic properties, thus satisfying key in vitro criteria as probiotics. All LAB strains showed coaggregation properties and antimicrobial activities against pathogens. Pediococcus pentosaceus GM 23d recorded the strongest coaggregation percentage (34-94%) against 14 pathogens, while W. cibaria GM 93m3 showed the least (6-57%) against eight of the 14 pathogens. The whole cell and extracellular extracts of LAB and yeast strains, with the exception of D. rugosa 77a, had either 2,2-diphenyl-1-picryl-hydrazyl and/or hydroxyl radical scavenging activity. In conclusion, all six LAB and four yeast strains are important probiotic candidates that can be further investigated for use as functional starter cultures.

Interactions among Relevant Non-Saccharomyces, Saccharomyces, and Lactic Acid Bacteria Species of the Wine Microbial Consortium: Towards Advances in Antagonistic Phenomena and Biocontrol Potential

The topic of microbial interactions is of notable relevance in oenology, being connected with their impact on microbial biodiversity and wine quality. The interactions among different couples of microorganisms, in particular yeasts and lactic acid bacteria representative of the must/wine microbial consortium, have been tested in this study. This interaction’s screening has been implemented by means of plate assays, using culture medium, grape juice, and wine agar as substrates. Different antagonistic phenomena have been detected, belonging to the following interaction categories: yeast-yeast, yeast-bacteria, bacteria-yeast, and bacteria-bacteria. In general, the inhibitory activity has been observed in all three media agar used as substrates, resulting in more frequent on culture medium, followed by grape juice and, finally, wine. Specifically, the work is one of the first reports demonstrating the reciprocal interactions between non-Saccharomyces yeasts (NSY) and malolactic bacteria. The findings shed new light on the co-inoculation of the yeast starter culture with malolactic bacteria, as well as the biocontrol potential of Lactic Acid Bacteria (LAB) strains. Highlighted microbial interactions are relevant for the management of alcoholic fermentation, malolactic fermentation, and the development of distinctive aroma profiles, control of spoilage yeasts, and the selection of tailored mixed starter cultures. In addition, the plate assay method could be a fast, cheap, and suitable method to exclude negative interactions among Saccharomyces spp., NSY, and malolactic bacteria during trials from regional spontaneous fermentations with the aim to select tailored mixed starter cultures.

In vitro Evaluation of Biocontrol Potential of Lactic Acid Bacteria Isolated from Natural Ecosystem against Plant Pathogenic Fungi

Lactic acid bacteria (LAB) are ubiquitous, Gram-positive, fermentative bacteria, which are regarded as safe for both humans and the environment. The present study aimed to evaluate the biocontrol efficiency of LAB isolated from different natural ecosystems against fungal pathogens. A total of 30 LAB was isolated from rhizosphere soil and phyllosphere sample of Solanaceous crop viz., Brinjal, Capsicum, Chilli, Tomato, whey, and sauerkraut out of them 14, 9, 4 and 3 lactic acid bacteria (LAB) were isolated from rhizosphere soil & phyllosphere sample of Solanaceous crops, whey and Sauerkraut respectively. The biocontrol ability of LAB isolates were tested against fungal plant pathogens such as Fusarium oxysporum, Pythium aphanidermatum, Sclerotium rolfsi, Rhizoctonia solani, Alternaria sp. agar well diffusion assay and mycelial growth inhibition in liquid culture. The results indicated that the isolates LAB 4, LAB 10, LAB 22, LAB 24 and LAB 29 were prominent in inhibiting the growth of most of the pathogens. Molecular characterization of selected LAB isolates revealed that LAB 4, LAB 10, LAB 22, LAB 24 belongs to Lactobacillus plantarum and LAB 29 belong to Leuconostoc mesentroides.

Selection of potential lactic acid bacteria from fish intestine of mackerel (Rastrelliger kanagurta) from Lembata Regency, East Nusa Tenggara, Indonesia

Selection of potential lactic acid bacteria from fish intestine of mackerel (Rastrelliger kanagurta) from Lembata Regency, East Nusa Tenggara, Indonesia

Probiotic Properties and Physicochemical Potential of Lactic Acid Bacteria Isolated from Moroccan Table Olives

Background: Lactic Acid Bacteria are a group of Gram-positive bacteria which are widely used in the food industry as organic ferments called starter cultures. In this study, Enterococcus faecium, Leuconostoc mesenteroides, Lactococcus lactis, Weissella paramesenteroides, and Lactiplantibacillus plantarumisolated from Moroccan table olives were tested for their acquisition of probiotic and technological properties.
 Methods: The 5 strains were previously isolated from table olives in 2017. Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometer (MALDI-TOF MS) and intergenic space sequencing were used for molecular identification. Following that, probiotic and physicochemical properties were evaluated, including growth at different pH levels (2, 3, and 10), temperatures (7, 45, and 50 °C), and sodium chloride (NaCl) concentrations (6.5 and 18% m/v). Antibacterial activity was tested out against Gram-positive and Gram-negatives bacteria.
 Results: The 5 strains (E. faecium 168, L. lactis 9, L. plantarum 11, L. mesenteroides 62, and W. paramesenteroides36) showed an ability to grow at low temperatures (7 °C). L. lactis 9 and L. plantarum 11 showed higher acid (pH 2) and salt (18% NaCl) tolerances. In addition, L. lactis 9 and L. plantarum 11 exhibited the highest level of free radical scavenging activity after 48 h of incubation, respectively). L. plantarum 11 and E. faecium 168 showed the highest antibacterial capacity. However, E. faecium 168 and W. paramesenteroides 36 demonstrated better and more rapid acid production capabilities.
 Conclusion: L. plantarum 11, E. faecium 168, and W. paramesenteroides 36 were considered the best candidates as probiotic cultures for further in vivo studies and functional food product development.

Correlation between metabolites of lactic acid bacteria isolated from dairy traditional fermented Tunisian products and antifungal and antioxidant activities.

The objective of this study is to identify and investigate the antifungal and antioxidant potential of lactic acid bacteria (LAB) isolated from traditional fermented products. In this work, a collection of LAB was isolated from traditional fermented products collected in four Tunisian regions. After first screening using the overlay method, seven bacterial strains were retained due to their high antifungal effect. Four strains of Limosilactobacillus fermentum were identified, one strain of Lacticaseibacillus paracasei, one strain of Lacticaseibacillus rhamnosus and one strain of Enterococcus faecium. The antifungal and the antioxidant potential of these bacteria were then evaluated. Bacterial strains were effective against six fungal strains with minimum inhibitory concentrations ranging from 25 to 100 mg/ml and minimum fungicidal concentrations ranging from 50 to 200 mg/ml. Cell-free supernatants of LAB were analysed by HPLC-DAD and LC-MS-qTOF-MS analysis. Results showed significant production of organic acids as well as several phenolic compounds. Correlation analysis confirmed that PLA and 1,2-dihydroxybenzene were positively correlated with antifungal potential. The results of the antioxidant activity highlighted an ABTS radical cation scavenging activity ranging from 49% to 57% and a DPPH trapping percentage ranging from 80% to 97%. Therefore, due to these characteristics, identified lactic acid bacteria strains have shown their effectiveness to perform as antifungal and antioxidant agents. Since microbial contamination is at the root of extensive losses in the food sector, the identified strains or their metabolites can potentially be used as additives to limit micro-organism spoilage in food products and increase their shelf life.

In Vitro Evaluation of the Broad-Spectrum Antimicrobial Potential of Lactic Acid Bacteria Isolated from Milk Whey and Nunu for Veterinary Applications

Background Information One of the characteristic of bacteria zoonoses diseases is their tendency to re-emerge, as such they said to be responsible for a very high proportion of morbidity and mortality. Many documented zoonotic diseases and reported to be resistant to some conventional antibiotics. Similarly challenging is the fact that most of the antibiotics currently being used against these diseases are reported not to be completely metabolized and are often released in unmetabolized forms which when they find their ways into the food chain becomes health issue. Metabolites from some Lactic Acid Bacteria are being harnessed as a bio-active compounds for the novel unconventional control of these diseases which this research seeks to make contribution. Abstract Zoonoses incidences continue to play significant roles in both human and veterinary medicine and their eradication especially in the developing country like Nigeria, is difficult. Zoonotic food-borne infections caused by Gram-positive and Gram-negative bacteria are re-emerging. Several findings indicated that the cell-free supernatant derived from some Lactic Acid Bacteria have some antibacterial effects when applied directly or added to food during packaging. The aim of this study was to investigate the in vitro antagonistic effect of cell-free supernatant derived from some LAB species isolated from whey and Nunu (obtained from a locally fermented milk product) against some zoonotic bacteria pathogens (Escherichia coli, Salmonella sp. and Staphylococcus aureus. Streptococcus sp. and Salmonella sp. Four (4) LAB isolates were isolated, identified using basic morphological and biochemical characterization and screened on the basis of functional and technological characterization. The Cell-free supernatant from these strains, Lactobacillus casei LB01, Lactobacillus sp. LB02, Lactobacillus acidophilus LB03 and Lactobacillus plantarum LB04 were prepared by centrifugation at 10,000 rpm for 5 minutes and used against the indicator organisms at 107 CFU/ml using agar well diffusion method. The cell-free supernatant inhibited the growth of both Gram- positive and Gram-negative bacteria strains of veterinary origins. Our findings suggest that the LAB strains have the potential for antibiotic alternatives for the control of several zoonotic diseases. This holds a great advantage in the current efforts to tackling and reducing the prevalence and spread of zoonotic diseases which are re-emerging in Nigeria

Evaluation of Lactiplantibacillus plantarum KAU007 against Low-Pathogenic Avian Influenza Virus (H9N2).

Avian influenza A viruses (AIVs) pose a persistent threat to humans owing to their reassortment and antigenic drift properties. Among them is H9N2, a low-pathogenic avian influenza virus first discovered in the non-human host and later found infective to humans with huge pandemic potential. In recent years, antiviral resistance has become an increasing threat to public health. Additionally, vaccination against AIVs is becoming increasingly challenging with little success due to antigenic drift. This has resulted in a growing demand for products that can replace the presently in-use medications and the development of innovative antiviral therapies. In this study, we systematically investigate the antiviral potential of lactic acid bacteria against H9N2. Bacteria that produce lactic acid are commonly used in food processing. In addition, these bacteria are considered more affordable, effective, and safe "nutraceuticals" than other alternative medicines. We tested Lactiplantibacillus plantarum KAU007 against the low-pathogenic avian influenza virus (H9N2). As confirmed by the hemagglutination assay, KAU007 showed potent antiviral activity against H9N2 and vigorous antioxidant activity. The CFCS showed a dose-dependent reduction in the levels of IL-6 and IFN-γ. Thus, KAU007 might be considered a potential H9N2 target-based probiotic.

In Vitro Evaluation of the Broad-Spectrum Antimicrobial Potential of Lactic Acid Bacteria Isolated from Milk Whey and Nunu for Veterinary Applications

In Vitro Evaluation of the Broad-Spectrum Antimicrobial Potential of Lactic Acid Bacteria Isolated from Milk Whey and Nunu for Veterinary Applications

In Vitro Characterisation of Potential Probiotic Bacteria Isolated from a Naturally Fermented Carrot and Ginger Brine

Unhealthy dietary patterns have been associated with an increase in mortality rate as well as the high occurrence of nontransmissible chronic degenerative diseases. Subsequently, the development of new functional foods has been proposed to reduce the incidence of nontransmissible chronic degenerative diseases. Probiotics represent a group of functional foods, defined as live microbial feeds, which provide the host with intestinal health benefits. The present study focused on the identification and characterisation of the probiotic potential of lactic acid bacteria isolated from a fermented carrot and ginger brine. Sixteen isolates were identified as Leuconostoc mesenteroides subsp. mesenteroides species, following preliminary screening based on 16S rDNA gene sequencing, and were further characterised for probiotic candidature. The probiotic properties tested included resistance towards gastrointestinal conditions (bile, acid, lysozyme tolerance), cell surface hydrophobicity, antioxidant activity, and antagonistic activity against intestinal pathogens. In general, all the isolated Leuconostoc mesenteroides subsp. mesenteroides strains exhibited high acid, bile, and lysozyme tolerance. They also showed strong antibacterial activity against common intestinal pathogens, i.e., Staphylococcus aureus and Escherichia coli, as well as antioxidant activity such as hydroxyl radical-scavenging ability and hydrogen peroxide resistance. Overall, Leuconostoc mesenteroides subsp. mesenteroides possesses a great potential as a beneficial strain for functional food.