Identification and phylogenetic characterization of novel Lactobacillus plantarum species and their metabolite profiles in grass silage

Characterization of halotolerant microalga isolated from waterlogged habitats: Deciphering the biochemical profiling and unraveling the molecular identity

The primary objective of this study was to comprehensively explore the biochemical profile of the novel halotolerant microalgae strain, biogas laboratory scenedesmus (BGLRS), previously isolated from waterlogged regions in the southwest zone of Punjab, India. To achieve this, three distinct drying methods viz. freeze-drying, oven-drying, and shade-drying were employed and biochemical composition and antioxidant analyses on the microalgal biomass were conducted. Utilizing advanced analytical techniques, including high-performance liquid chromatography (HPLC), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and gas chromatography-mass spectroscopy (GC-MS) on freeze-dried biomass, its carbohydrate profile, micronutrient composition, and presence of bioactive compounds with potential therapeutic and nutraceutical significance were sought to unravel. Among the drying methods evaluated, freeze-drying exhibited the most promising experimental results, prompting its selection for further investigation. Notably, ICP-AES unveiled elevated concentrations of essential elements such as calcium, iron, magnesium, and phosphorus in BGLRS, with negligible traces of heavy metals, underscoring its safety for human consumption. GC-MS analysis further divulged the existence of numerous biologically active compounds, indicating potential applications in medical and nutraceutical fields. Through molecular identification using sequencing of the internal transcribed spacer (ITS) region, a close taxonomic resemblance between BGLRS and Scenedesmus sp. MKB was established, solidifying its unique position within the microalgal taxonomy. The deposition of ITS sequences into the NCBI GenBank, obtaining accession number MN796425, attests to the rigor and transparency of this research. Overall, these findings strongly suggest that microalgae BGLRS possesses high-quality biochemical attributes of significant therapeutic and nutraceutical importance.

Unraveling the antimicrobial potential of Lactiplantibacillus plantarum strains TE0907 and TE1809 sourced from Bufo gargarizans: advancing the frontier of probiotic-based therapeutics

Introduction

In an era increasingly defined by the challenge of antibiotic resistance, this study offers groundbreaking insights into the antibacterial properties of two distinct Lactiplantibacillus plantarum strains, TE0907 and TE1809, hailing from the unique ecosystem of Bufo gargarizans. It uniquely focuses on elucidating the intricate components and mechanisms that empower these strains with their notable antibacterial capabilities.

Methods

The research employs a multi-omics approach, including agar diffusion tests to assess antibacterial efficacy and adhesion assays with HT-29 cells to understand the preliminary mechanisms. Additionally, gas chromatography-mass spectrometry (GC-MS) is employed to analyze the production of organic acids, notably acetic acid, and whole-genome sequencing is utilized to identify genes linked to the biosynthesis of antibiotics and bacteriocin-coding domains.

Results

The comparative analysis highlighted the exceptional antibacterial efficacy of strains TE0907 and TE1809, with mean inhibitory zones measured at 14.97 and 15.98 mm, respectively. A pivotal discovery was the significant synthesis of acetic acid in both strains, demonstrated by a robust correlation coefficient (cor ≥ 0.943), linking its abundance to their antimicrobial efficiency. Genomic exploration uncovered a diverse range of elements involved in the biosynthesis of antibiotics similar to tetracycline and vancomycin and potential regions encoding bacteriocins, including Enterolysin and Plantaricin.

Conclusion

This research illuminates the remarkable antibacterial efficacy and mechanisms intrinsic to L. plantarum strains TE0907 and TE1809, sourced from B. gargarizans. The findings underscore the strains' extensive biochemical and enzymatic armamentarium, offering valuable insights into their role in antagonizing enteric pathogens. These results lay down a comprehensive analytical foundation for the potential clinical deployment of these strains in safeguarding animal gut health, thereby enriching our understanding of the role of probiotic bacteria in the realm of antimicrobial interventions.

A Multi-Sensor Mini-Bioreactor to Preselect Silage Inoculants by Tracking Metabolic Activity in situ During Fermentation

The microbiome in silage may vary substantially from the onset to the completion of fermentation. Improved additives and inoculants are being developed to accelerate the ensiling process, to enhance fermentation quality, and to delay spoilage during feed-out. However, current methods for preselecting and characterizing these amendments are time-consuming and costly. Here, we have developed a multi-sensor mini-bioreactor (MSMB) to track microbial fermentation in situ and additionally presented a mathematical model for the optimal assessment among candidate inoculants based on the Bolza equation, a fundamental formula in optimal control theory. Three sensors [pH, CO₂, and ethanol (EtOH)] provided data for assessment, with four additional sensors (O₂, gas pressure, temperature, and atmospheric pressure) to monitor/control the fermentation environment. This advanced MSMB is demonstrated with an experimental method for evaluating three typical species of lactic acid bacteria (LAB), Lentilactobacillus buchneri (LB) alone, and LB mixed with Lactiplantibacillus plantarum (LBLP) or with Enterococcus faecium (LBEF), all cultured in De Man, Rogosa, and Sharpe (MRS) broth. The fermentation process was monitored in situ over 48 h with these candidate microbial strains using the MSMB. The experimental results combine acidification characteristics with production of CO₂ and EtOH, optimal assessment of the microbes, analysis of the metabolic sensitivity to pH, and partitioning of the contribution of each species to fermentation. These new data demonstrate that the MSMB associated with the novel rapid data-processing method may expedite development of microbial amendments for silage additives.

Effects of fermentation treatments on Polygonatum odoratum flavones' antioxidant activities

The main aim of this study is to analyze antioxidant properties of Polygonatum odoratum fermented with bacteria, fungi and yeast. Antioxidant activities (1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, hydroxyl radical scavenging, and anti-lipid peroxidation abilities) were assessed in samples of flavones isolated from fermented P. odoratum (Mill.) druce samples. Fermentations using Lactobacillus, yeast and Aspergillus were investigated. Results showed that the antioxidant ability of Polygonatum odoratum flavones was decreased by the fermentation of Lactobacillus and yeast. Aspergillus niger fermentation improved the antioxidant ability of P. odoratum flavones. In this study, effective antioxidant activity was achieved in flavones fermented with Aspergillus niger than yeast and Lactobacillus species.

Probiotic characteristics of Lactobacillus strains isolated from cheese and their antibacterial properties against gastrointestinal tract pathogens

In the present study, four Lactobacillus strains from the cheese were analyzed for its probiotic potential against enteropathogenic bacteria. The probiotic properties of the selected strains were also analyzed and the selected bacterial strains showed high tolerance in bile salts and organic acid. The strain L. plantarum LP049 showed maximum survival rate (92 ± 4.2% and 93.3 ± 2%) after 3 h of treatment at 0.25% (w/v) bile salts and 0.25% (w/v) organic acid concentrations. The ability of the Lactobacillus strains to adhere to human epithelial cells (HT-29 cell lines) was evaluated and L. plantarum LP049 showed maximum adhesion property (19.2 ± 1.1%) than other tested strains. The Lactobacillus strains produced lactic acid at various concentrations. Compared with other strains, maximum level of lactic acid (3.1 g/L), hydrogen peroxide (4.31 mM) and bacteriocin (31 AU/mg) was detected in LB049. The inhibitory activity of culture supernatant against various bacterial pathogens was observed. The zone of inhibition ranged between 6 ± 2 mm and 23 ± 2 mm. The cell free extract showed activity against, Escherichia coli (ATCC 10536), Salmonella enteritidis (ATCC 13076), Shigella flexneri (ATCC 29903), and Enterococcus faecium (ATCC 8459). Consequently, L. plantarum LP049 may be considered as a potential candidate for the production of novel bioactive metabolites for therapeutic and bio-protective applications.

Low-Carbohydrate Tolerant LAB Strains Identified from Rumen Fluid: Investigation of Probiotic Activity and Legume Silage Fermentation

The objective of this study was to isolate and characterize lactic acid bacteria (LAB) with low carbohydrate tolerance from rumen fluid and to elucidate their probiotic properties and the quality of fermentation of Medicago sativa L. and Trifolium incarnatum L. silage in vitro. We isolated 39 LAB strains and screened for growth in MRS broth and a low-carbohydrate supplemented medium; among them, two strains, Lactiplantibacillus plantarum (Lactobacillus plantarum) RJ1 and Pediococcus pentosaceus S22, were able to grow faster in the low-carbohydrate medium. Both strains have promising probiotic characteristics including antagonistic activity against P. aeruginosa, E. coli, S. aureus, and E. faecalis; the ability to survive in simulated gastric-intestinal fluid; tolerance to bile salts; and proteolytic activity. Furthermore, an in vitro silage fermentation study revealed that alfalfa and crimson clover silage inoculated with RJ1 and S22 showed significantly decreased pH and an increased LAB population at the end of fermentation. Also, the highest lactic acid production was noted (p < 0.05) in LAB-inoculated silage vs. non-inoculated legume silage at high moisture. Overall, the data suggest that RJ1 and S22 could be effective strains for fermentation of legume silage.

Probiotic Characteristics and Antifungal Activity of Lactobacillus plantarum and Its Impact on Fermentation of Italian Ryegrass at Low Moisture

The study aimed to investigate probiotic characteristics, and low moisture silage fermentation capability of selected lactic acid bacteria (LAB) isolated from Alfalfa (Medicago sativa L). Morphological and physiological properties, carbohydrates fermentation, enzymes, and organic acids production, anti-fungal activity, antibiotic sensitivity patterns, and probiotic characteristics (acidic and bile salt tolerances, hydrophobicity and aggregations natures) of LAB were examined. 16SrRNA sequencing was carried out to identify isolated strains. The identified strains Lactobacillus plantarum (KCC-37) and Lactobacillus plantarum (KCC-38) showed intense antifungal activity, survival tolerant in acidic and bile salt environments, cell surface and auto aggregations ability, enzymes and organic acids productions. At ensiled condition, KCC-37 and KCC-38 enhanced acidification of Italian ryegrass silages by producing a higher amount of lactic acid, a key acid for indicating silage quality with less extent to acetic acid and succinic acid at low moisture level than non-inoculated silages. Notably, the addition of mixed strains of KCC-37 and KCC-38 more potentially enhanced acidification of silage and organic acid productions than the single-culture inoculation. The overall data suggested that these strains could be used as an additive for improving the quality of the fermentation process in low moisture silage with significant probiotic characteristics.

Spirulina consumption effectively reduces anti-inflammatory and pain related infectious diseases

BACKGROUND

Inflammation and pain triggers several pathological illnesses. Synthetic drugs used for the controlling of inflammatory conditions convey significant toxic effects. Global scientific community continually attempt to improve effective, economic and harmless naturally derived remedies against inflammation and pain. The present study aimed to quantify the phytochemical constituents of the freshly cultivated Spirulina and targeted to examining the anti-inflammatory and analgesic activity of Spirulina extract (SE) derived from Arthrospira platensis.

METHODS

The anti-inflammatory effect of SE was evaluated in animal models including carrageenan-induced rat hind paw oedema, and cotton pellet-induced granuloma formation. Analgesic effects of SE were evaluated by acetic acid induced writhing response and hot plate test.

RESULTS

Phytochemical quantification guided to identify seven carbohydrates, thirteen amino acids, eleven fatty acids and polyphenolic compounds respectively. The results indicated that SE significantly attenuated carrageenan-induced hind paw oedema, and cotton pellet-induced granuloma. Preliminary molecular mechanistic studies established that SE decreased the productions of TNF-α, IL-1β, IL-6, PGE2 and NO, and suppressed the activities of COX-2 and iNOS.

CONCLUSION

These results provide a strong scientific foundation for the anti-inflammatory and analgesic activities of SE against different studies in animal models.

Evaluation of probiotic Lactobacillus plantarum against foodborne pathogens and its fermentation potential in improving Lolium multiflorum silage quality

The objective of this study was to isolate the lactic acid bacteria from fermented silage sample and analyze their antibacterial activities, probiotic properties, and fermentation potential in silage. Eleven lactic acid bacteria (LAB) were selected based on distinct morphologies and preliminary studies. Cell-free supernatant (CFS) was then prepared from the selected strains for antibacterial analysis. L-30 strain and its CFS showed highest inhibition (> 10 mm) against tested foodborne pathogens as compared to other strains. Hereafter, the strain L-30 was named as KCC-30 and used for further studies. KCC-30 can survive in the harsh conditions of GIT such as low pH ( 2) and bile salt environment (oxgal) than standard L. plantarum KACC-91016 (pH 2: 27.2% vs 20.5%; oxgal: 72.3% vs 57.7%, both p < 0.05). In addition, KCC-30 exhibited strong auto-aggregation (68.3% vs 51.5%) and co-aggregation (33% vs 23.9%) properties. For silage experiment, KCC-30 treatment did not alter the nutrient profiles of silage. At the same time, KCC-30 treatment increased the lactic acid content of silage as compared to untreated silage (5.55 DM% vs 3.11 DM%). An increase of lactic acid content in the silage is due to higher lactic acid bacteria population in KCC-30 treated silage (15.33 × 10⁷ CFU/g vs 7.66 × 10⁷ CFU/g) than untreated silage (p < 0.05). Overall data suggested that KCC-30 exhibited strong probiotic potential and improved the quality of Lolium multiflorum silage by increasing the lactic acid level. Therefore, KCC-30 could be considered as potential strain to improve the fermentation quality of L. multiflorum silage.

Isolation and characterization of a new fructophilic Lactobacillus plantarum FPL strain from honeydew

In the present study, a Lactobacillus plantarum FPL strain exhibiting fructophilic behavior has been isolated for the first time from honeydew. It is a probably syntrophic bacterium inhabiting the gastrointestinal tract of Coccus hesperidum L. and taking part in sugar metabolism. The promising growth characteristics and biochemical properties of Lb. plantarum FPL indicate that this may be a facultatively fructophilic species, whose properties are not associated with the loss of the alcohol/acetaldehyde dehydrogenase gene. The article attempts to classify the peculiar behavior of this strain by means of tests that are characteristic for FLAB as well as through a classic identification approach. In this study, we used a reference strain Lb. plantarum NRRL B-4496, which showed no fructophilic properties. With the FLAB group, the new strain shares the habit, such as a fructose-rich environment, the preference of this sugar for growth, and similar growth curves. However, it exceeds FLAB in terms of osmotolerance to high sugar content. The fructophilic Lb. plantarum FPL strain can proliferate and grow on a medium wherein the sugar concentration is 45 and 50% (w/v). Our findings indicate that honeydew can be a promising source of new fructophilic lactic acid bacteria.

Quantification of Phytochemicals from Commercial Spirulina Products and Their Antioxidant Activities

The present study aimed to profile the polyunsaturated fatty acids, sugars, free amino acids, and polyphenols in 37 varieties of Spirulina commonly available in the market using gas chromatography and high performance liquid chromatography. In addition, the biological potentials of the Spirulina samples were evaluated by analysing the in vitro antioxidant activities using various analytical techniques. The analyses revealed the presence of 13 polyunsaturated fatty acids, 18 amino acids, 7 sugars, and polyphenols. The polyunsaturated fatty acids contents were varied between Spirulina samples. The total polyunsaturated fatty acids amount was 4.25 mg/100 g, and the average among of sapienic acid detected was 2.25 mg/100 g, which was followed by linoleic acid (16.7%) and γ-linolenic acid (14%). Among the 7 sugars, the hexose levels were the highest (73.85%). The total amino acids contents ranged from 11.49 to 56.14 mg/100 g, and the individual essential amino acids accounted for 17% to 39.18%. The “natural” tablets exhibited the highest polyphenols levels (24 mg/g). All of the Spirulina samples expressed dose-dependent antioxidant activities. The polyunsaturated fatty acids, sugars, free amino acids, and polyphenols contents varied widely, and the variations in these compounds between the Spirulina samples were significant.