Plantarum Species Research Articles

Potential probiotic Lactiplantibacillus plantarum DS1800 extends lifespan and enhances stress resistance in Caenorhabditis elegans model.

Probiotics are live microorganisms that provide health benefits when administered in appropriate amounts by improving or restoring the balance of intestinal microbiota. Various functional probiotic products have been developed due to the growing interest in the health-promoting and anti-aging effects of enhancing the gut microbiome. Lactiplantibacillus plantarum species are known for their potential to extend lifespan. However, this activity is strain or isolation source specific, necessitating the identification of individual strain functionalities. This study used the C. elegans model to screen probiotics for life-extension effects and analyze their functions. The 43 lactic-acid bacteria strains isolated from fermented foods, breast milk, and human feces were subjected to longevity assays, and L. plantarum DS1800 was selected to demonstrate the most effective lifespan extension. The average lifespan of Caenorhabditis elegans fed DS1800 increased by 17.36% compared with those fed Escherichia coli OP50. Further analysis of the expression of key genes related to longevity revealed the high expression of the skinhead-1 (skn-1), antibacterial, and heat stress resistance genes via the p38 MAPK pathway. These expression patterns suggest that DS1800 extends the lifespan of C. elegans by enhancing its stress resistance and protecting it against pathogens. Additionally, DS1800 exhibited excellent intestinal adhesion, with 7.56% adhesion to HT-29 cells. Therefore, L. plantarum DS1800 is effective in extending the lifespan of C. elegans and can be used as a functional probiotic.

Characterization and Identification of Potential Lactic Acid Bacteria as Biological Control Agent against Ralstonia syzygii subsp. celebesensis of the Banana Blood Disease

Banana is one of the primary fruits cultivated in Malaysia and currently decimated by the emergence of a disease, known as banana blood disease (BBD) which caused by Ralstonia syzygii subsp. celebesensis (Rsc). The BBD has significantly affected the yield and profits of the worldwide banana industry. To date, various approaches including chemical and biological controls have been attempted to manage this disease but none of them succeed in controlling the disease. The uses of lactic acid bacteria (LAB) in managing plant diseases have been reported earlier but little information is available. Therefore, this project is designed to identify and investigate potential plant-associated LAB as biological control agent (BCA) against Rsc by using agar well diffusion method. The inhibition zones of each well were observed after 72h and the isolated LAB that showed inhibition zones were proceed for molecular characterization using PCR amplification followed by gel electrophoresis. The sequences were used for phylogenetic analysis. In addition, each of the potential LAB were used to identify their morphological characterizations and biochemical testing. Throughout the study, the highest inhibition zones of LAB from kimchi and fermented milk achieved a diameter of 21.30 mm and 28.70 mm, respectively. Kimchi isolates showed the highest similarity which is 97% as Lactiplantibacillus plantarum species. Among the fermented milk isolates, the highest similarity which is 98% identified as Lacticaseibacillus paracasei.

Development of Sourdough Bread Made with Probiotic Lactiplantibacillus plantarum Bacteria Addition

Bread is a staple in the diet of people around the world. A new solution is the addition of selected strains of bacteria to the sourdough to increase the quality of the obtained bread. In the presented research, seven bread samples were baked and analysed, which differed by the selected strain of bacteria of the Lactiplantibacillus plantarum species used in sourdough preparation. The bread was subjected to a 3-day ageing test. The structure of the products was analysed using the texture profile analysis (TPA) method on days 1 and 3 of storage. It was observed that the samples with the addition of selected L. plantarum bacterial strains underwent the process of staling much slower than the control sample. The analysis of the viability of lactic acid bacteria (LAB) in products after 1 and 3 days of storage was also performed. The obtained results indicate the highest survival rate of LAB in the control sample, i.e., the native microflora of baker’s starters, which was at 3.07 log CFU after one-day storage after baking. In the case of other samples, the viability of the bacteria was below 2.74 log CFU, which confirms a certain degree of thermostability of selected bacterial strains. The belonging of the isolated bacteria to the species L. plantarum was proven via genetic identification using the PCR method. A sensory analysis using the quantitative descriptive profile (QDP) method was also performed on the bread immediately after it was baked and cooled down. The analysis showed that the use of L. plantarum strains as starters did not significantly affect the aromatic and taste profiles of the samples compared to the control sample. The overall quality of the bread samples was high, above 6 units, with the control sample having the highest sensory quality of 7.5 units (on a scale of 0–10 units). The presented research suggests that it is possible to produce bread with bacteria that have health-promoting properties and good sensory quality, which enhances the textural features of the final product. Future research will focus on attempting to microencapsulate selected thermostable probiotic bacteria.

The choice of probiotics affects the rheological, structural, and sensory attributes of lupin-oat-based yoghurt

Plant-based yoghurt (PBY) presents an alternative for vegetarians, flexitarians, and individuals with dairy allergies. However, how the bacterial (culture) variations can impact the properties are not yet well investigated. This study aims to investigate the physicochemical attributes, encompassing texture, rheological properties, microstructure, and sensory characteristics, of yoghurt formulated with a lupin-oat base as affected by the addition of commercial probiotics including Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, Lactobacillus rhamnosus, L. casei 431 (Lactobacillus paracasei), Lactobacillus plantarum, BB12 (Bifidobacterium sps) during storage at 4 °C for 28-day. Significantly, lupin-oat yoghurt fermented with a combination of Lactobacillus plantarum, and Bifidobacterium species exhibited rapid metabolic activity, leading to a notable reduction in fermentation time compared to other probiotic strains. Furthermore, this combination conferred similar water-holding capacity, firmness, and consistency with dairy yoghurt (control). Different probiotic strains induced variations in particle size and led to shear-thinning behaviour across all yoghurt samples. Over the refrigerated storage, a decline in apparent viscosity was observed and lupin-oat yoghurt exhibited greater rigidity compared to dairy yoghurt. Changes in the yoghurt microstructure during storage, notably the presence of increased serum pores were associated with its functional attributes. Confocal and scanning electron microscopy revealed distinctive microstructural features in yoghurt fermented with Lactobacillus plantarum and Bifidobacterium species compared to other probiotic combinations. Notably, this combination garnered higher sensory ratings for appearance, taste, flavour, texture, and overall acceptability, positioning it as a suitable dairy yoghurt alternative. These findings provide insights into enhancing the structural and sensory attributes of lupin-oat-based yoghurt.

Alleviating Pentatrichomonas hominis-induced damage in IPEC-J2 cells: the beneficial influence of porcine-derived lactobacilli.

Pentatrichomonas hominis is a common intestinal parasitic protozoan that causes abdominal pain and diarrhea, and poses a zoonotic risk. Probiotics, known for enhancing immunity and pathogen resistance, hold promise in combating parasitic infections. This study aimed to evaluate two porcine-derived probiotics, Lactobacillus reuteri LR1 and Lactobacillus plantarum LP1, against P. hominis infections in pigs. Taxonomic identity was confirmed through 16S rRNA gene sequencing, with L. reuteri LR1 belonging to L. reuteri species and L. plantarum LP1 belonging to L. plantarum species. Both probiotics exhibited robust in vitro growth performance. Co-culturing intestinal porcine epithelial cell line (IPEC-J2) with these probiotics significantly improved cell viability compared with the control group. Pre-incubation probiotics significantly enhanced the mRNA expression of anti-oxidative response genes in IPEC-J2 cells compared with the PHGD group, with L. reuteri LR1 and L. plantarum LP1 significantly up-regulating CuZn-SOD、CAT and Mn-SOD genes expression (p < 0.05). The anti-oxidative stress effect of L. reuteri LR1 was significantly better than that of L. plantarum LP1 (p < 0.05). Furthermore, pre-incubation with the probiotics alleviated the P. hominis-induced inflammatory response. L. reuteri LR1 and L. plantarum LP1 significantly down-regulated IL-6、IL-8 and TNF-α gene expression(p < 0.05) compared with the PHGD group. The probiotics also mitigated P. hominis-induced apoptosis. L. reuteri LR1 and L. plantarum LP1 significantly down-regulated Caspase3 and Bax gene expression (p < 0.05), significantly up-regulated Bcl-2 gene expression (p < 0.05) compared with the PHGD group. Among them, L. plantarum LP1 showed better anti-apoptotic effect. These findings highlight the probiotics for mitigating P. hominis infections in pigs. Their ability to enhance anti-oxidative responses, alleviate inflammation, and inhibit apoptosis holds promise for therapeutic applications. Simultaneously, probiotics can actively contribute to inhibiting trichomonal infections, offering a novel approach for preventing and treating diseases such as P. hominis. Further in vivo studies are required to validate these results and explore their potential in animal and human health.

Microbiological survey and physicochemical analysis of Moroccan durum, soft and red wheat landraces

Morocco possesses a significant genetic diversity of wheat cultivars in the form of landraces conserved by local farmers in several regions. This study aimed to evaluate the microbiological quality of refined flour and bran derived from 75 samples of Moroccan durum, soft, and red wheat landraces and to estimate their microbiological stability for controlling and preventing undesirable microbial proliferation. Various microbial and physicochemical parameters were evaluated according to ISO and AOAC standards, and results were interpreted based on Codex Alimentarius Commission regulation. Compliance of the analyzed refined flour and bran samples with current regulatory limits and satisfactory microbiological quality were observed. The phenotypic characterization revealed the identification of 16 yeast species belonging to the genera Trichosporon, Candida, Cryptococcus, Rhodotorula, and Saccharomyces, which had not been previously explored. Furthermore, the biodiversity of lactic acid bacteria is notably characterized by the predominance of Pediococcus acidilactici and Lactobacillus plantarum species. The analysis of moisture content and water activity exhibited values falling below the maximum limits defined by international standards, demonstrating the effectiveness of the implemented processing and storage practices. The neutral pH recorded confirms the absence of excessive proliferation of the assessed microbial contaminants. The abundant availability of carbohydrates, lipids, proteins, and minerals creates a favorable non-competitive environment essential for maintaining their functional stability in the analyzed samples. These findings hold significant implications for the agricultural and food industries, providing insights into preserving indigenous wheat varieties and producing safe wheat-based products with high nutritional quality.

Impact of indigenous Oenococcus oeni and Lactiplantibacillus plantarum species co-culture on Cabernet Sauvignon wine malolactic fermentation: Kinetic parameters, color and aroma

Malolactic fermentation (MLF) is a crucial process to enhance wine quality, and the utilization of indigenous microorganisms has the potential to enhance wine characteristics distinct to a region. Here, the MLF performance of five indigenous Oenococcus oeni strains and six synthetic microbial communities (SynComs), were comparatively evaluated in Cabernet Sauvignon wine. In terms of malate metabolism rate and wine aroma diversity, the strain of O. oeni Oe114–46 demonstrated comparable MLF performance to the commercial strain of O. oeni Oe450 PreAc. Furthermore, the corresponding SynComs (Oe144–46/LpXJ25) exhibited improved fermentation properties, leading to increased viable cell counts of both species, more rapid and thorough MLF, and increased concentrations of important aroma compounds, such as linalool, 4-terpinenol, α-terpineol, diethyl succinate, and ethyl lactate. These findings highlight the remarkable MLF performance of indigenous O. oeni and O. oeni-L. plantarum microbial communities, emphasizing their immense potential in improving MLF efficiency and wine quality.

Identification of Lactic Acid Bacteria Strains Isolated from Sourdoughs Prepared with Different Flour Types

Species identification is the first step in the examination of newly isolated microorganism strains, including the cases when they are intended for application in the development of probiotic preparations or starters for different food products. The thorough identification process of newly isolated strains combines the application of different physiological, biochemical, and molecular genetic methods. The aim of the present study was to identify the species-level lactic acid bacteria (LAB) strains isolated from spontaneously fermented sourdoughs prepared from different flour types: Khorosan wheat, wheat, barley, buckwheat, spelled, spelt, and corn. Both classical phenotypic (cellular morphology characterization, and API 50 CHL) and molecular genetic methods (RAPD, ARDRA-analysis, 16S rDNA sequencing, and species-specific PCR) were applied. It was found that cultures with a short-rod morphology predominated among the 30 sourdough isolates. According to the RAPD profiles obtained, the isolates were divided into nine genotypes corresponding to nine genetically distinct strains. It was determined that individual sourdoughs made with different flour types shared cultures with a common genotype. The analysis of the physiological and biochemical profiles of the LAB isolates performed with the API 50 CHL system divided them into two groups according to their identification: Lactiplantibacillus plantarum (Lp. plantarum) 1 and Levilactobacillus brevis (Lv. brevis) 3. According to the 16S rDNA restriction profile, the LAB isolates showed two profiles corresponding to the Lp. plantarum and Lv. brevis groups. 16S rDNA sequencing and a comparison of the partially read 16S rDNA sequences of the studied isolates confirmed that some of them belonged to the Lv. Brevis species, but did not provide sufficient evidence that the rest of the cultures belonged to the Lp. Plantarum species. The species-specific PCR clearly separated the isolates from the Lp. plantarum group into two groups: isolates of the Lp. plantarum species and isolates of the Lp. paraplantarum species. The summary of the results of the conducted polyphasic taxonomic study determined the investigated LAB strains isolated from spontaneously fermented sourdoughs as representatives of the Lv. brevis, Lp. plantarum ssp. paraplantarum, and Lp. paraplantarum species.

Phenotypic and molecular differentiation of lactic acid bacteria in fonio millet ogi fermentation and their potential as starter cultures

This study focused on the phenotypic and 16S rRNA characterization of lactic acid bacteria (LAB) isolated from spontaneously fermented fonio ogi and evaluation of their starter cultures potentials. The isolates were screened for biochemical characteristics, acidification, organic acid production and growth kinetics. Phenotypically, LABs (n = 28) were identified to be inclusive of Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Limosilactobacillus fermentum and Pediococcus species. However, genotypic typing revealed the strains as Lactiplantibacillus plantarum, Levilactobacillus brevis, and Pediococcus pentosaceus well as presence of non lactobacillus strains. Suitability for starter cultures revealed higher acidification and organic acid production for strains of Lactiplantibacillus plantarum and Pediococcus pentosaceus to between 3.20–3.65 (pH); 4.67- 6.67 total titratable acidity (TTA); 46.4 − 57.4 mg/g (lactic acid), 0.27–0.36 h (maximum specific growth rate). The selected LABs were shown to be strain specific and strains with rapid rate of acidification, high organic acid production and low pH exhibited significant potential for starter culture.

Characterization of Lactic Acid Bacteria Isolated From Rotting Oranges and Use of Agropastoral Processing By-products as Carbon and Nitrogen Sources Alternative for Lactic Acid Production.

This study investigated the ability of lactic acid bacteria (LAB) isolated from oranges to use fish by-products (FB) and chicken by-products (CB) as nitrogen sources alternative to yeast extract for lactic acid (LA) production in a papaya by-product medium as a carbon source. Once the fermentation agents had been isolated, they were subjected to biochemical and molecular characterization. Inexpensive nitrogen sources, precisely CB and FB, were prepared, freeze-dried, and yield evaluated. Also, before to the fermentation experiments, the Total Kjehdahl Nitrogen (TKN) of these by-products and that of the yeast extract were determined. Then, three production media differing in terms of nitrogen source were formulated from these nitrogen sources. From the 22 LAB isolated from orange, two isolates of interest (NGO25 and NGO23) were obtained; all belonging to the Lactiplantibacillus plantarum species based on 16S rRNA gene sequencing. Furthermore, the production yield powder obtained after lyophilization of 1 L of CB and FB surpernatant were, respectively, 16.6 g and 12.933 g. The TKN of different nitrogen sources powder were 71.4 ± 0.000% DM (FB), 86.145 ± 0.001% DM (CB), and 87.5 ± 0.99% DM (yeast extract). The best kinetic parameters of LA production (LA (g/L): 31.945 ± 0.078; volumetric productivity (g/L.h): 1.331 ± 0.003; LA yield (mg/g) 63.89 ± 0.156; biomass (g/L) 7.925 ± 0.035; cell growth rate (g/L.h): 0.330 ± 0.001) were recorded by Lactiplantibacillus plantarum NGO25 after 24 h of fermentation. The latter data were obtained in the production medium containing CB as nitrogen sources. In addition, this production medium cost only $0.152 to formulate, compared to yeast extract which required $1.692 to formulate. Thus, freeze-dried CB can be used as an alternative to yeast extract in large-scale production of LA.

Screening of lactobacilli strains isolated from artisanal Poro de Tabasco cheese for their ability to biosynthesise conjugated linoleic acid under simulated gastrointestinal conditions

SummaryConjugated linoleic acid (CLA) is a mixture of linoleic acid isomers which have been shown to provide beneficial health effects; particularly, the isomers cis‐9, trans‐11 (c9‐t11) and trans‐10, cis‐12 (t10‐c12) are those with proven biological activity. Some lactic acid bacteria (LAB) have demonstrated the ability to synthesise CLA in culture media or in fermented milk, however, few studies have considered the possibility that LAB can continue to produce CLA in the human gut. Therefore, the objective of this study was to screen lactobacilli strains isolated from artisanal Poro de Tabasco cheese for their ability to biosynthesise CLA under simulated gastrointestinal digestion (SGD) and to evaluate their survival and gut colonisation capacity under these conditions. First of all, LAB strains were identified molecularly and their CLA biosynthesis capacity in culture media and under simulated gastrointestinal conditions were evaluated. Besides, bacterial survival to the gastrointestinal conditions and gut colonisation capacity by their adhesion and autoaggregation properties were assessed. Sixteen LAB strains were phenotypically and genotypically identified and were classified within the Lactiplantibacillus pentosus, Lactiplantibacillus plantarum, Limosilactobacillus fermentum and Companilactobacillus farciminis species. Nine strains were able to synthesise CLA in culture media supplemented with linoleic acid (7.19–18.78 μg mL−1; with a conversion rate of 0.43–1.13%) and seven of them achieved it under simulated gastrointestinal conditions (4.28–47.67 μg mL−1; with a conversion rate of 0.51–5.75%), with an outstanding performance of Lactiplantibacillus pentosus LC12. In addition, the viable counts demonstrated that all the study strains achieved to survive under gastric conditions with a high population survival rate of 94.5%, except for LC19 (67%); however, all the nine strains recovered their viability with a high capacity to colonise the gut. Therefore, they may be considered as potential probiotic CLA‐producing strains, mainly Lactiplantibacillus pentosus LC12 since it was able to produce the closest CLA concentration to Limosilactobacillus reuteri ATCC 55739 (positive control). Thus, these strains can be used as starter cultures for designing promising functional foods with beneficial claims associated to the CLA content in the food matrix or produced after consumed.

Depiction of the In Vitro and Genomic Basis of Resistance to Hop and High Hydrostatic Pressure of Lactiplantibacillus plantarum Isolated from Spoiled Beer.

Among the beer-spoiling microorganisms, the dominant ones belong to the genera Lactobacillus, Leuconostoc, Oenococcus, and Pediococcus. It is assumed that resistance to hop bitters correlates with resistance to other factors and can significantly impact the brewing industry. Beer preservation with high hydrostatic pressure eliminates the spoiling microorganisms while preserving all desired properties of the beer. Here, we present comprehensive in vitro and genomic analysis of the beer-spoiling Lactiplantibacillus plantarum KKP 3573 capacity to resist hop and high hydrostatic pressure. Lp. plantarum KKP 3573 is a strain isolated from spoiled beer. Our finding suggests that the growth rate of the strain depends on the medium variant, where a small concentration of beer (5 IBU) stimulates the growth, suggesting that the limited concentration has a positive effect on cell growth. At the same time, increased concentrations of 20 IBU, 30 IBU, and pure beer 43.6 IBU decreased the growth rate of the KKP 3573 strain. We observed that higher extract content in the pressurized beer increased microbial survivability. The wort and Vienna Lager beer can stimulate the baroprotective effect. The taxonomy of the novel strain was confirmed after whole genome sequencing (WGS) and comparative genomic analysis. More specifically, it contains a chromosome of 3.3 Mb with a GC content of 44.4%, indicative of the Lp. plantarum species. Accordingly, it possesses high genomic similarity (>98%) with other species members. Annotation algorithms revealed that the strain carries several genes involved in resistance to stress, including extreme temperature, hop bitters and high pressure, and adaptation to the brewing environment. Lastly, the strain does not code for toxins and virulence proteins and cannot produce biogenic amines.

Expanding the genetic programmability of Lactiplantibacillus plantarum.

Lactobacilli are ubiquitous in nature and symbiotically provide health benefits for countless organisms including humans, animals and plants. They are vital for the fermented food industry and are being extensively explored for healthcare applications. For all these reasons, there is considerable interest in enhancing and controlling their capabilities through the engineering of genetic modules and circuits. One of the most robust and reliable microbial chassis for these synthetic biology applications is the widely used Lactiplantibacillus plantarum species. However, the genetic toolkit needed to advance its applicability remains poorly equipped. This mini-review highlights the genetic parts that have been discovered to achieve food-grade recombinant protein production and speculates on lessons learned from these studies for L. plantarum engineering. Furthermore, strategies to identify, create and optimize genetic parts for real-time regulation of gene expression and enhancement of biosafety are also suggested.

Modeling the antimicrobial effects of olive mill waste extract, rich in hydroxytyrosol, on the growth of lactic acid bacteria using response surface methodology.

The objective of this study is to assess the inhibitory effects of an aqueous extract from olive oil mill waste (alperujo) on the growth of a lactic acid bacteria (LAB) cocktail consisting of various strains of Lactiplantibacillus pentosus and Lactiplantibacillus plantarum species. For this purpose, response surface methodology was employed using two independent variables (pH levels 3.5-5.55; hydroxytyrosol concentration ranging from 0.93-2990ppm). The response variable was the average inhibition per treatment on the LAB cocktail (expressed as a percentage). The developed model identified significant terms, including the linear effect of hydroxytyrosol and pH, their interaction, and the quadratic effect of pH. Maximum inhibition of the LAB cocktail was observed at progressively higher concentrations of hydroxytyrosol and lower pH values. Therefore, complete inhibition of LAB in the synthetic culture medium could only be achieved for concentrations of 2984ppm hydroxytyrosol at a pH of 3.95. These findings suggest that extracts derived from "alperujo" could be utilized as a natural preservative in acidified foods with a bitter flavor and antioxidant requirements.

Gut microbiome as therapeutic target for diabesity management: opportunity for nanonutraceuticals and associated challenges.

Diabesity is showing rising prevalence. Current treatment modalities include pharmacological and non-pharmacological approaches, yet associated with various drawbacks. Recently, gut microbial dysbiosis is documented as a crucial factor in the pathogenesis of diabesity. Targeting gut microbiome using modulators shows promising therapeutic strategy for diabesity management. In this line, nanonutraceuticals represent new class of gut microbial modulators. The present article explores the potential of nanonutraceuticals including nanoprobiotics, nanoprebiotics, and plant-derived nanovesicles that are fabricated on the ecofriendly food based scaffold with gut microbial modulatory potential for diabesity management. A number of compelling evidences from different studies support Bifidobacterium, Enterococcus, and Bacteroides genera and Lactobacillus plantarum and Akkermansia muciniphila species significant in diabesity management. The probable mechanisms reported for gut microbial dysbiosis-induced diabesity are mentioned. The review findings suggest gut microbiome as significant therapeutic target for diabesity management. Moreover, ecofriendly nanonutraceuticals developed using natural products including food-grade materials are efficient modulators of gut microbiome and indicate next-generation diabesity therapeutics. Clinical studies are imperative as further exploration may provide new dimensions to the future research.

NMR-Based Metabolomic Study on Phaseolus vulgaris Flour Fermented by Lactic Acid Bacteria and Yeasts.

In recent years, fermented foods have attracted increasing attention due to their important role in the human diet, since they supply beneficial health effects, providing important sources of nutrients. In this respect, a comprehensive characterization of the metabolite content in fermented foods is required to achieve a complete vision of physiological, microbiological, and functional traits. In the present preliminary study, the NMR-based metabolomic approach combined with chemometrics has been applied, for the first time, to investigate the metabolite content of Phaseolus vulgaris flour fermented by different lactic acid bacteria (LAB) and yeasts. A differentiation of microorganisms (LAB and yeasts), LAB metabolism (homo- and heterofermentative hexose fermentation), LAB genus (Lactobacillus, Leuconostoc, and Pediococcus), and novel genera (Lacticaseibacillus, Lactiplantibacillus, and Lentilactobacillus) was achieved. Moreover, our findings showed an increase of free amino acids and bioactive molecules, such as GABA, and a degradation of anti-nutritional compounds, such as raffinose and stachyose, confirming the beneficial effects of fermentation processes and the potential use of fermented flours in the production of healthy baking foods. Finally, among all microorganisms considered, the Lactiplantibacillus plantarum species was found to be the most effective in fermenting bean flour, as a larger amount of free amino acids were assessed in their analysis, denoting more intensive proteolytic activity.

Microbiological analysis of wine produced in the laboratory using pineapple and watermelon fruits fermented by Kloeckera apiculata

This research focuses on the microbiological analysis of wine produced in a laboratory using pineapple and watermelon fruits fermented by Kloeckera apiculata. The study aimed at evaluating the microbial composition, including yeast, bacteria, and mold, and the physicochemical properties of the wine during the fermentation process. The experiment was conducted using two batches of fruit, pineapple, and watermelon, separately fermented using Kloeckera apiculata. Samples were collected at different stages of fermentation and analyzed for microbial composition, pH, alcohol content, and total acidity. The yeasts, mold, and bacteria present were enumerated and isolated by spread plate techniques and incubated at room temperatures for 24h. Resultant colonies were enumerated and identified by a standard protocol. The results showed that Kloeckera apiculata dominated the microbial population during the fermentation process. No mold was isolated due to the low level of oxygen present in the fermentor. Three bacteria species were identified and confirmed during the fermentation to be Lactobacillus plantarum, Lactobacillus brevis, and Pediococcus species which are non-pathogenic bacteria and did not constitute any threat to health rather added a sour taste to the wine and also decreased the pH of the wine. The wine produced from pineapple had a higher alcohol content and lower acidity than the wine produced from watermelon. These findings demonstrate the potential of Kloeckera apiculata for the production of wine using tropical fruits and highlight the importance of microbiological analysis in the quality control of wine production.

Selection of mixed starters for the preparation of traditional Moroccan bread

The main objective of this work was the selection of mixed starters with a combination of Lactic Acid Bacteria (LAB) and yeast strains for traditional bread production in Morocco. For this, a total of 21 LAB strains and 36 yeast strains were isolated from different traditional sourdough. Dough fermentation were assessed by monitoring physicochemical parameters including, titratable acidity, decrease of pH and lactic acid, ethanol and CO2 production. A total of six yeasts and four LAB were selected for their technological performances. Morphological, physiological and biochemical identification performed using API identification kits confirmed that these strains belonged to Saccharomyes cerevisiae, Candida humilis and Saccharomyces exiguus species, and Lactobacillus plantarum and Lactobacillus casei species for yeasts and LAB respectively. The yeast S3-L2 and the LAB ODBL5 strains exhibited the best performances among the selected ones; S3-L2 yeast strain were able to produce ΔV=23mL of CO2 and showed the highest values of ethanol and biomass production (2.87 g/L and 1.25 10^9 UFC/mL, respectively). Whereas OD-BL5 LAB strains produced 13.9 g/L of lactate in dough. These findings lead to consider these two strains very good candidates for the formulation of an effective mixed starter for bread preparation. Subsequently, sensorial analysis results showed that bread prepared using mixed starter No. 24 composed of the two selected species exhibited better exterior appearance, golden and crispy crust, large volume and honeycomb crumb, compared to the control.

The Use of Multiplex PCR Reactions to Identification of Lactic Acid Bacteria of Dangke

Abstract: Lactic acid bacteria can be isolated from various types of milk including dairy products. Dangke is an Indonesian traditional cheese made by Enrekang community, South Sulawesi. This study aims to identify the lactic acid bacteria by multiplex PCR method which are isolated from dangke obtained from Enrekang Regency. This type of research used descriptive research with laboratory observation methods was performed on 30 cups of dangke are obtained from the markets in 5 sub-districts producing dangke in Enrekang Regency: they are the sub-districts of Cendana, Enrekang, Anggeraja, Alla, and Baraka. The results showed that Lactobacillus acidophilus was the most identified (33.33%) compared to Lactobacillus plantarum (16.67%). Based on the results of the research that has been carried out, it can be concluded that the lactic acid bacteria have been identified in dangke samples obtained from several sub-districts producing dangke in Enrekang Regency are Lactobacillus acidophilus and Lactobacillus plantarum species. Thus, we suggest that this laboratory technique is used to confirm the various species of lactic acid bacteria so it can prove more rapid and exactly that dangke is the rich content of lactic acid bacteria as probiotic candidate.

Vaginal Lactobacillus Impair Candida Dimorphic Switching and Biofilm Formation.

Lactobacillus spp. generally dominate the vaginal microbiota and prevent pathogen adhesion and overgrowth, including Candida spp., by various mechanisms. Although Candida spp. can be commensal, in certain conditions they can become pathogenic, causing vulvovaginal candidiasis. The insurgence of candidiasis is related to the expression of Candida virulence factors, including morphologic switching and biofilm formation. Germ tubes, pseudohyphae, and hyphae promote Candida tissue invasion, biofilms increase persistence and are often resistant to antifungals and host immune response. Here, we explored the inhibitory activity of vaginal Lactobacillus strains belonging to Lactobacillus crispatus, Lactobacillus gasseri, Limosilactobacillus vaginalis, and Lactiplantibacillus plantarum species towards Candida virulence factors. With the aim to investigate the interrelation between mode of growth and functionality, supernatants were collected from lactobacilli planktonic cultures and, for the first time, from adherent ones, and were evaluated towards Candida dimorphic switching and biofilm. Candida biofilms were analyzed by multiple methodologies, i.e., crystal violet staining, MTT assay, and confocal microscopy. Lactobacillus supernatants reduce Candida switching and biofilm formation. Importantly, L. crispatus supernatants showed the best profile of virulence suppression, especially when grown in adherence. These results highlight the role of such species as a hallmark of vaginal eubiosis and prompt its employment in new probiotics for women’s health.