Probiotic bacteria were isolated from different traditional fermented foods as there are several such foods that are not well explored for their probiotic activities. Hence, the present study was ...conducted to find the potential of lactic acid bacteria (LAB) as probiotics that were isolated from the sap extract of the coconut palm inflorescence - Neera, which is a naturally fermented drink consumed in various regions of India. A total of 75 isolates were selected from the Neera samples collected aseptically in the early morning (before sunrise). These isolates were initially screened for cultural, microscopic, and biochemical characteristics. The initial screening yielded 40 Gram-positive, catalase-negative isolates that were further subjected to acid - bile tolerance with resistance to phenol. Among 40 isolates, 16 survived screening using analysis of cell surface hydrophobicity, auto aggregation with adhesion to epithelial cells, and gastric-pancreatic digestion for gastrointestinal colonization. The isolates were also assessed for antimicrobial, antibiotic sensitivity, and anti-oxidative potential. The safety of these isolates was evaluated by their hemolytic and deoxyribonuclease (DNase) activities. Based on these results, seven isolates with the best probiotic attributes were selected and presented in this study. These LAB isolates, with 51.91-70.34% survival at low pH, proved their resistance to gastric conditions. The cell surface hydrophobicity of 50.32-77.8% and auto aggregation of 51.02-78.95% represented the adhesion properties of these isolates. All the seven isolates exhibited good antibacterial and antifungal activity, showing hydroxyl-scavenging activity of 32.86-77.87%. The results proved that LAB isolated from Neera exhibited promising probiotic properties and seem favorable for use in functional fermented foods as preservatives.
In the present study, we aimed to evaluate the single or conjoint effects of Lactococcus lactis (L. lactis) L19 and Enterococcus faecalis (E. faecalis) W24 isolated from the intestine of Channa argus ...(C. argus) on digestive enzyme activity, antioxidant capacity, intestinal microbiota and morphology of C. argus (initial weight, 9.50 ± 0.03 g). The fish were fed for 56 days with a basal diet (CK) or diets supplemented with 1.0 × 108 CFU/g of L. lactis (L19), E. faecalis (W24), L. lactis + E. faecalis (L + W). Results indicated that these three lactic acid bacteria (LAB) supplementary diets especially the L19 produced significant improvement in the digestive enzyme activity (protease, amylase and lipase) in liver, stomach and intestine compared with control (P < .05). LAB supplementations were enhanced the liver and intestine antioxidant status (SOD, CAT, GSH-Px, T-AOC and MDA) in comparison to the control (P < .05). Serum biochemical parameters (ALT and AST) of fish fed with LAB supplemented diets showed significantly decreased compared with control (P < .05). The intestinal morphology showed protection in fish fed both L19 or/and W24. High-throughput sequencing revealed L19 supplementation can effectively increase the generation of probiotic bacteria and decrease the abundance of aquatic pathogens. Therefore, supplementation of L. lactis L19 showed more effective protection than E. faecalis W24 or the mixture of the two for promoting digestive enzyme activity, antioxidant capacity, intestinal microbiota and morphology of C. argus.
•The digestive enzyme activity were enhanced in fish fed both L19 or/and W24.•The antioxidant capacity were enhanced in fish fed both L19 or/and W24.•The liver health and intestine morphology were protected in both L19 or/and W24.•L19-supplemental diets can regulate the intestine microbiota of Channa argus.
Ferments containing lactic acid bacteria (LAB) have been used for decades in agricultural systems to improve soils, control disease and promote plant growth, however, the functional roles of LAB in ...the phytomicrobiome have yet to be discovered. An understanding of the symbiotic relationship between plants and LAB could be exploited to improve agricultural plant production.
Scientific investigations to validate plant growth promoting properties of LAB are increasing in number and scope. LAB isolated from diverse sources have been shown to be effective biofertilizers, biocontrol agents, biostimulants. As biofertilizers, LAB can improve nutrient availability from compost and other organic material. In fermented food, LAB has served as an effective biocontrol agent; recently LAB have been shown to be effective in the control of a wide variety of fungal and bacterial phytopathogens. As biostimulants, LAB can directly promote plant growth or seed germination, as well as alleviating various abiotic stresses.
In this review, we discuss the history and ecology of plants and LAB, appraise the available information on the use of LAB in improving plant production, and consider the limitations and potential new directions for the use of LAB in plant agriculture.
•Lactic acid bacteria (LAB) have been used for decades to improve plant growth.•The plant - LAB relationship has yet to be fully characterized.•LAB can serve as biofertilizers, biocontrols, biostimulants, and bioelicitors.
In the wake of continual foodborne disease outbreaks in recent years, it is critical to focus on strategies that protect public health and reduce the incidence of foodborne pathogens and spoilage ...microorganisms. Currently, there are limitations associated with conventional microbial control methods, such as the use of chemical preservatives and heat treatments. For example, such conventional treatments adversely impact the sensorial properties of food, resulting in undesirable organoleptic characteristics. Moreover, the growing consumer advocacy for safe and healthy food products, and the resultant paradigm shift toward clean labels, have caused an increased interest in natural and effective antimicrobial alternatives. For instance, natural antimicrobial elements synthesized by lactic acid bacteria (LAB) are generally inhibitory to pathogens and significantly impede the action of food spoilage organisms. Bacteriocins and other LAB metabolites have been commercially exploited for their antimicrobial properties and used in many applications in the dairy industry to prevent the growth of undesirable microorganisms. In this review, we summarized the natural antimicrobial compounds produced by LAB, with a specific focus on the mechanisms of action and applications for microbial food spoilage prevention and disease control. In addition, we provide support in the review for our recommendation for the application of LAB as a potential alternative antimicrobial strategy for addressing the challenges posed by antibiotic resistance among pathogens.
The present study was aimed at investigating the bacterial community in lactic acid bacteria (LAB) suspensions prepared from whole-plant corn silage (LAB suspension-CS) and
silage (LAB suspension-ES) ...and the bacterial community succession of whole-plant corn silages inoculated with LAB suspension-CS or LAB suspension-ES during initial aerobic phase, intense fermentation phase, and stable phase. The LAB suspensions were cultured in sterile Man, Rogosa, Sharpe broth at 37°C for 24 h and used as inoculants for ensiling. The chopped whole-plant corn was treated with distilled water (CK), LAB suspension-CS (CSL), or LAB suspension-ES (ESL) and then ensiled in vacuum-sealed plastic bags containing 500 g of fresh forage. Silages were sampled at 0 h, anaerobic state (A), 3 h, 5 h, 10 h, 24 h, 2 days, 3 days, 10 days, 30 days, and 60 days of ensiling with four replicates for each treatment. The results showed that
,
, and
_5 dominated the bacterial community in LAB suspension-CS;
was the most predominant bacterial genus in LAB suspension-ES. During the initial aerobic phase (from 0 h to A) of whole-plant corn silage, the pH and the abundances of
,
,
,
, and
increased. During the intense fermentation phase (from A to 3 days), the pH decreased rapidly, and the microbial counts increased exponentially; the most predominant bacterial genus shifted from
to
, and then to
; inoculating LAB suspensions promoted the bacterial succession and the fermentation process, and LAB suspension-CS was more effective than LAB suspension-ES. During the stable phase (from 3 to 60 days), the pH and the microbial counts decreased, and
dominated the bacterial community with a little decrease. The results also confirmed the existence of LAB fermentation relay during fermentation process, which was reflected by
,
, and
in the first 5 h;
,
,
,
, and
between 5 and 24 h; and
from 24 h to 60 days.
Consumer interest in healthy lifestyle and health-promoting natural products is a major driving force for the increasing global demand of biofunctional dairy foods. A number of commercial sources ...sell synthetic formulations of bioactive substances for use as dietary supplements. However, the bioactive-enrichment of health-oriented foods by naturally occurring microorganisms during dairy fermentation is in increased demand. While participating in milk fermentation, lactic acid bacteria can be exploited
as microbial sources for naturally enriching dairy products with a broad range of bioactive components that may cover different health aspects. Several of these bioactive metabolites are industrially and economically important, as they are claimed to exert diverse health-promoting activities on the consumer, such as anti-hypertensive, anti-inflammatory, and anti-diabetic, anti-oxidative, immune-modulatory, anti-cholesterolemic, or microbiome modulation. This review aims at discussing the potential of these health-supporting bacteria as starter or adjunct cultures for the elaboration of dairy foods with a broad spectrum of new functional properties and added value.
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•LABs (Weissella, Lactobacillus, and Pediococcus) were dominant bacteria around day 2.•Thermotolerant/thermophilic taxa exhibited the highest proportion after day 6.•A metabolic ...network of core microbes involved in flavor development was constructed.•Potential populations responsible for the production of lytic enzymes were revealed.•Lactic acid and bio-heat produced by microbes could promote the microbiota shift.
As a widely used Asian starter culture, the quality of daqu can significantly affect the organoleptic characteristics of the final products, yet the microbial metabolic network involved in flavor development remains unclear. This study aims to investigate that network based on the dynamics of physicochemical properties, microbial community, and volatile compounds in medium-temperature daqu (MT-daqu) during spontaneous fermentation. Analyses using the metagenomic data set facilitated the gene repertoire overview of this ecosystem, indicating that Lactobacillales (mainly Weissella, Lactobacillus, and Pediococcus), Mucorales (mainly Lichtheimia), and Eurotiales (mainly Aspergillus, Rasamsonia and Byssochlamys) were the potential predominant populations successively responsible for the production of lytic enzymes and flavor precursors/compounds in MT-daqu. Flavor-relevant pathways were found to exist in multiple species, but only bacteria showed the potential to participate in butane-2,3-diol (e.g. Weissella, Lactobacillus, and Staphylococcus) and butanoate (Thermoactinomyces) metabolism, and only fungi were potentially involved in biosynthesis of guaiacol (Byssochlamys) and 4-vinylguaiacol (Aspergillus). Furthermore, a combined analysis revealed that the acidic thermal environment present in early phases was mainly due to the catabolic activities of Lactobacillales and Lichtheimia, which could contribute to the effective self-domestication of microbiota. The study helps elucidate the different metabolic roles of microorganisms and disclose the formation mechanism of daqu’s partial functions, namely providing various aromatic substances/precursors and enzymes.
Lactic acid is an industrially important product with a large and rapidly expanding market due to its attractive and valuable multi-function properties. The economics of lactic acid production by ...fermentation is dependent on many factors, of which the cost of the raw materials is very significant. It is very expensive when sugars, e.g., glucose, sucrose, starch, etc., are used as the feedstock for lactic acid production. Therefore, lignocellulosic biomass is a promising feedstock for lactic acid production considering its great availability, sustainability, and low cost compared to refined sugars. Despite these advantages, the commercial use of lignocellulose for lactic acid production is still problematic. This review describes the “conventional” processes for producing lactic acid from lignocellulosic materials with lactic acid bacteria. These processes include: pretreatment of the biomass, enzyme hydrolysis to obtain fermentable sugars, fermentation technologies, and separation and purification of lactic acid. In addition, the difficulties associated with using this biomass for lactic acid production are especially introduced and several key properties that should be targeted for low-cost and advanced fermentation processes are pointed out. We also discuss the metabolism of lignocellulose-derived sugars by lactic acid bacteria.
Patulin, a secondary metabolite produced by fungi, such as Aspergillus, Penicillium, and Byssochlamys, is highly toxic to bacteria and plants and exerts serious threat to human and animal health. The ...use of beneficial microbes shows good effect and application prospects in removing mycotoxins. As a widely used biological control agent, lactic acid bacteria (LAB) can remove mycotoxins from foodstuff. In this research, a LAB strain that can degrade patulin, namely, Lactobacillus casei YZU01, was screened. The physiological mechanism of patulin degradation by L. casei YZU01 was investigated. L. casei YZU01 mainly degraded patulin by secreting extracellular metabolites, and its cell wall also absorbed patulin. Furthermore, L. casei YZU01 was applied for the removal of patulin in raw apple juice (RAJ) or raw pear juice (RPJ). Patulin (10 μg/mL) in RAJ or RPJ was completely degraded by L. casei YZU01 after 36 h of incubation, and patulin in commercialized apple or pear juice products was degraded after 48 h of incubation after treatment with L. casei YZU01. Results indicated the potential of L. casei YZU01 in dealing with patulin contamination in food industries.
•Lactobacillus casei YZU01 can degrade patulin.•L. casei YZU01 degrade patulin by secreting extracellular metabolites.•L. casei YZU01 shows good effect to remove patulin from foodstuff.
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