Predominant Lactic Acid Bacteria Research Articles

Evaluation of growth behavior of lactic acid bacteria isolated from kimchi via kinetic modeling

Lactic acid bacteria (LAB) are critical in kimchi fermentation. This study determined the effect of temperature on the growth of 11 predominant LAB (five psychrotrophic and six mesophilic strains) isolated from kimchi and analyzed their growth behavior using a kinetic model to understand changes in LAB communities during kimchi fermentation. The modified Gompertz model was more suitable for the growth of kimchi LAB rather than the logistic model in terms of RMSE, AICc, R2, adjusted R2, Af and Bf. Latilactobacillus sakei KCKM 0001 and Leuconostoc mesenteroides KCKM 0008 rapidly grew at all temperatures (5, 10, 15, 20, 25, 30, and 37 °C) among the strains analyzed for growth characteristics using the modified Gompertz model. Additionally, the growth of psychrotrophic strains was more active than that of the mesophilic strains, excluding L. sakei KCKM 0001 and Leu. mesenteroides KCKM 0008 at kimchi fermentation temperatures of 5–10 °C. The differences observed in the lag phase and maximum specific growth rate at each temperature showed a trend consistent with previously reported dominant LAB at kimchi fermentation temperatures. The predictive modeling results showed that the changes in LAB communities during kimchi fermentation could be explained by their growth behavior at different temperatures.

Controlled fermented sprouted mung bean containing ginger extract as a novel bakery bio-preservative for clean-label enriched wheat bread

Application of controlled fermented sprouted legumes is important in terms of improving quality and shelf-life of wheat bread. In the present study, after spontaneous fermentation of sprouted mung bean containing ginger extract (GE), the predominant lactic acid bacteria (LAB) isolates were screened based on their inhibitory activity against Aspergillus niger. Sequencing results of the PCR products led to the identification of Levilactobacillus brevis as the selected isolate with 73.12% antifungal effect. Then, the selected isolate was used as a protective starter culture in the controlled fermented sprouted mung bean (FSM). Production of wheat bread with FSM containing a protective starter culture and GE not only improved the textural features of the product, but also increased its mold-free shelf-life. Accordingly, wheat bread containing FSM and GE with crumb hardness of 9.52 N, specific volume of 3.53 cm3/g and weight loss of 15.95% had the most appropriate textural characteristics with the lowest fungal surface expansion (45.52% mold growth) after 7 days storage in a challenge test. Furthermore, there was no significant difference (P > 0.05) between this sample and control bread in terms of overall acceptability.

The predominant lactic acid bacteria and yeasts involved in the spontaneous fermentation of millet during the production of the traditional porridge Hausa koko in Ghana

Spontaneous fermentation of cereals like millet involves a diverse population of microbes from various sources, including raw materials, processing equipment, fermenting receptacles, and the environment. Here, we present data on the predominant microbial species and their succession at each stage of the Hausa koko production process from five regions of Ghana. The isolates were enumerated using selective media, purified, and phenotypically characterised. The LAB isolates were further characterised by 16S rRNA Sanger sequencing, typed using (GTG)5 repetitive-PCR, and whole genome sequencing, while 28S rRNA Sanger sequencing was performed for yeast identification. The pH of the millet grains ranged from mean values of 6.02—6.53 to 3.51—3.99 in the final product, depending on the processors. The mean LAB and yeast counts increased during fermentation then fell to final counts of log 2.77–3.95 CFU/g for LAB and log 2.10–2.98 CFU/g for yeast in Hausa koko samples. At the various processing stages, the counts of LAB and yeast revealed significant variations (p < 0.0001). The species of LAB identified in this study were Limosilactobacillus pontis, Pediococcus acidilactici, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Pediococcus pentosaceus, Lacticaseibacillus paracasei, Lactiplantibacillus plantarum, Schleiferilactobacillus harbinensis, and Weissella confusa. The yeasts were Saccharomyces cf. cerevisiae/paradoxus, Saccharomyces cerevisiae, Pichia kudriavzevii, Clavispora lusitaniae and Candida tropicalis. The identification and sequencing of these novel isolates and how they change during the fermentation process will pave the way for future controlled fermentation, safer starter cultures, and identifying optimal stages for starter culture addition or nutritional interventions. These LAB and yeast species are linked to many indigenous African fermented foods, potentially acting as probiotics in some cases. This result serves as the basis for further studies into the technological and probiotic potential of these Hausa koko microorganisms.

Identification of bacteria associated with pap (Ogi/Akamu) stored at room and refrigerated temperatures

Stored pap (ogi/akamu) has been reported to harbor several microorganisms including bacteria. The study was focused on identification of bacteria associated with pap (ogi/akamu) stored at room and refrigerated temperatures. The assayed pap was produced by soaking yellow maize (500 g) in sterile water and allowed to ferment for 72h and then grinded using home blender, sieved with a muslin cloth to obtain the pap. The pap was divided into two equal parts. One part was stored at room temperature and the other stored in a refrigerator for 9days respectively. At every 24h, each of the samples was taken to the laboratory for examination. The serially diluted pap samples were inoculated into De man rogosa and sharpe agar, nutrient agar, mannitol salt agar, salmonella shigella agar and MacConkey agar respectively and were incubated at 37 ℃ for 24h. The numbers of microbial colonies on the nutrient agar plates were counted using a colony counter. The phenotypic characterizations were carried out on the isolates and molecular identification done on the predominant lactic acid bacteria. The phenotypic characterization revealed the isolated bacteria as Lactobacillus sp., Escherichia coli, Salmonella sp. and Staphylococcus aureus. The molecular characterization confirmed the predominant bacteria as Lactobacillus plantarum FPS. The total bacterial count was more at room temperature samples (±3.78CFU/ml) than refrigerated temperature (±0.41CFU/ml). There was significant difference between the recovered bacteria at room and refrigerated temperature (p&gt;0.05). The obtained result confirmed room temperature unsafe for storing pap and refrigerator temperature better option for storing them.

New generation of functional yogurts fermented with probiotic lactic acid bacteria isolated from human milk

Background: The cultures used in the production of "bio-yoghurts" typically consist of a blend of traditional yogurt starters, such as S. thermophilus and L. delbrueckii subsp. bulgaricus, along with probiotics like L. acidophilus, L. casei, L. reuteri, and Bifidobacterium spp. These probiotics, although beneficial, face challenges thriving in milk due to its short fermentation time (4–5 hours). The rapid acidification caused by the starter’s results in probiotic levels dropping below the "therapeutic minimum" during the intended refrigerated shelf life of the product. A potential solution to this issue lies in leveraging lactic acid bacteria isolated from the human milk which possess both robust probiotic characteristics and starter properties. Incorporating such strains in yogurt starter could address the acidity imbalance and contribute to maintaining optimal probiotic levels throughout the refrigerated shelf life of the product. Objective: This research aims to develop a new generation of sustainable functional yoghurts suitable for consumers of all ages using as starters predominant probiotic lactic acid bacteria isolated from the breast milk of healthy women. Results: This study marks the first implementation of the critical dilution culture method in sterile cow milk for the selection of predominant lactic acid bacteria (LABs) from women's breast milk. Remarkably, all samples yielded LAB capable of independently fermenting milk. Although breast milk is a good medium for the growth of residential lactic acid bacteria, it never coagulates due to low concentration of caseins. The isolated strains, identified as belonging to the species L. delbrueckii subsp. lactis, L. fermentum, L. casei subsp. sakei, Streptococcus thermophiles and Lactococcus lactis, exhibited probiotic and adaptive properties essential for gut colonization in humans. Utilizing symbiotic LAB starters were created functional yogurts with heightened technological, physicochemical, and sensory characteristics. Conclusions: Yogurts fermented using human milk LABs are safe and can be recommended as a functional dairy food, for pregnant women as well as for pre-term and full-term infants as a substitute/supplement for mother's milk. Moreover, these LABs can be included in infant formulas or used in pre-treatment of infant formula milk to improve its nutritional value and safety. Keywords: Breast milk, lactic acid bacteria, probiotic, milk fermentation, functional yogurt

Autochthonous Fermentation as a Means to Improve the Bioaccessibility and Antioxidant Activity of Proteins and Phenolic Compounds of Yellow Pea Flour.

This study focused on evaluating the potential of the natural fermentation of pea flour to improve the release of antioxidant compounds. Preliminary fermentations of 36.4% w/w flour dispersions were performed in tubes under different conditions (24 and 48 h, 30 and 37 °C). Finally, fermented flours (FFs) were obtained in a bioreactor under two conditions: 1: 36.4% w/w, 24 h, 30 °C (FF1); 2: 14.3% w/w, 24 h, 37 °C (FF2). The pH values decreased to 4.4-4.7, with a predominance of lactic acid bacteria. As in the fermentations in tubes, an increment in the proteolysis degree (TNBS method) (greater for FF2), polypeptide aggregation and a decrease in their solubility, an increase in <2 kDa peptides, and an increase in the Oxygen Radical Absorption Capacity (ORAC) potency of PBS-soluble fractions after fermentation were demonstrated. Also, fermentation increased the proteolysis degree after simulated gastrointestinal digestion (SGID, COST-INFOGEST) with respect to the non-fermented flour digests, with some differences in the molecular composition of the different digests. ORAC and Hydroxyl Radical Averting Capacity (HORAC) potencies increased in all cases. The digest of FF2 (FF2D) presented the greater ORAC value, with higher activities for >4 kDa, as well as for some fractions in the ranges 2-0.3 kDa and <0.10 kDa. Fermentation also increased the 60%-ethanol-extracted phenolic compounds, mainly flavonoids, and the ORAC activity. After SGID, the flavan-3-ols disappeared, but some phenolic acids increased with respect to the flour. Fermentation in condition 2 was considered the most appropriate to obtain a functional antioxidant ingredient.

Exploring the influence of garlic on microbial diversity and metabolite dynamics during kimchi fermentation

Garlic (Allium sativum) is a key ingredient in Korean cuisine, particularly in the preparation of kimchi, contributing to its flavor and taste. Garlic has been a potential resource for lactic acid bacteria (LAB) in kimchi. However, the mechanism by which it influences microbial diversity and metabolite production is unclear. This study investigated the effect of garlic on the bacterial composition of and metabolite changes in kimchi. To achieve this, four separate batches of kimchi were prepared with varying garlic concentrations (w/w): 0 %, 1 %, 2 %, and 4 %, and the bacterial communities and metabolite production were monitored. In the early stages of fermentation, the count of LAB, operational taxonomic units (OTUs), and Shannon index increased linearly with the increase in garlic content. This indicated that garlic is a rich resource and contributes to the diversity of LAB during kimchi fermentation. Compared with the kimchi samples with a lower garlic content, those with a high garlic content (≥2 %) exhibited increased abundance of Lactobacillus and Leuconostoc as well as noticeable differences in functional diversity, including carbohydrate, amino acid, and energy metabolisms. Correlation analysis between sugars, organic acids, and predominant LAB in the garlic-containing kimchi samples suggested that in kimchi samples with high garlic content, LAB played a significant role in the fermentation process by metabolizing sugars and producing organic acids. Overall, this study demonstrated that the addition of garlic has a positive impact on the bacterial diversity and metabolite production during kimchi fermentation, potentially affecting the fermentation process and flavor profile of kimchi.

Microbial screening of animal skin bags used in traditional cheesemaking

Bouhezza is a traditional Algerian cheese produced and ripened in goatskin bags called Djeld. The aim of this study was to characterize the microbial ecosystem from Djeld (fresh and dried Djeld for making Bouhezza cheese) and the changes introduced by Lben microflora during its preparation and to identify its role in cheesemaking and its safety. Two replicates of fresh and dried skin bags (FS and DS) were sampled and analyzed before and after contact with Lben. The microbiological results showed no pathogens. Skins observed before the addition of Lben were less populated 2.86 and 3.20 log CFU cm−2 than skins examined after the addition of Lben (approximately 6.0 log CFU cm−2), suggesting a potential role of Lben in releasing some microorganisms into the skin during its time in the Djeld. However, an increase in mesophilic lactic acid bacteria and yeasts was observed in Lben after different periods of interaction with the skin. PCR-TTGE revealed the predominance of lactic acid bacteria (Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Staphylococcus equorum subsp. linens, Lactococcus cremoris, Streptococcus thermophilus) and a few high-GC-content bacteria (Lacticaseibacillus paracasei, Brevibacterium casei). Transfer of several microbial species was observed between the goatskin bag biofilm and Lben during the overnight interaction. Bands corresponding to Lacticaseibacillus paracasei, Brevibacterium casei, and Lactobacillus delbrueckii subsp. lactis were detected in the fresh skin profile and in Lben after contact with the fresh skin. Lacticaseibacillus paracasei was found in dried skin and Lben after contact with dry skin. Lactobacillus helveticus and Enterococcus faecalis appeared in the Lben profile and persisted in Lben and the biofilm-covered dry skin after interaction. These results demonstrate an exchange of specific microbial populations between goatskin bag biofilm and Lben during the traditional preparation method, suggesting that the diversity of goatskin biofilm contributes to the microbial diversity of Lben used in the production of Bouhezza cheese.

Profile of lactic acid bacteria (MALDI-TOF-MS) and physico-chemical and microbiological characteristics of the raw milk and fresh artisanal cheese from Serra Geral, Minas Gerais, Brazil

Artisanal cheese from Serra Geral, Minas Gerais, Brazil, stands out for its cultural asset and socio-economic relevance. However, standards of identity and quality and the peculiar terroir associated with the edaphoclimatic conditions have not been established. Therefore, the production flow diagram and the physico-chemical and microbiological quality of the raw milk, pingo (natural starter culture), production benches, water and fresh cheese were investigated for the first time. In addition, lactic acid bacteria (LAB) from cheese and its production environment were identified by MALDI-TOF. For that, 12 cheese making facilities were selected. The raw milk and pingo showed adequate physico-chemical characteristics for cheesemaking; however, high microbial counts were found. In the water, total and thermotolerant coliforms were also identified. The fresh cheeses were classified as ‘high moisture and fat’ and ‘soft mass’. Most physico-chemical parameters were satisfactory; however, there were high counts of total coliforms, Staphylococcus spp. and coagulase-positive staphylococci. There were high counts of LAB in the raw milk, pingo, bench surface and fresh cheese. A total of 84 microbial biotypes from MRS agar were isolated. Lactococcus lactis was the predominant LAB, followed by Lactococcus garvieae. Leuconostoc mesenteroides (benches), Leuconostoc pseudomesenteroides (fresh cheese), and Enterococcus faecium (pingo) were identified sporadically. These results indicate the risks to public health associated with the consumption of the fresh cheese, and measures to improve its safety are needed.

Effect of Three Different Preservatives on the Microbiota of Shalgam, a Traditional Lactic Acid Fermented Beverage.

Shalgam is a traditional Turkish beverage derived from the natural fermentation of purple carrots (Daucus carota) that boasts valuable antioxidant and prebiotic properties. These features of shalgam increase efforts to enhance its shelf life and ensure safe consumption. In this study, the effects of three different preservatives (sodium benzoate, potassium sorbate, or natamycin) on the physicochemical and microbiological properties of shalgam produced at laboratory scale and stored at room temperature for six months were investigated. Each preservative was used in four different concentrations (25, 100, 400, and 800 mg/L) to assess their impacts on the population of lactic acid bacteria (LAB) and yeast. After determining the total acidity and pH of the samples, colorimetric measurements were performed. The isolated LAB were defined using the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/TOF MS) method. The addition of preservatives did not significantly affect the pH of the shalgam samples (3.44-3.52) compared to the control sample (3.43). However, a slight increase was observed in the total acidity of preservative-treated samples, with the highest level (5.61 g/L lactic acid) recorded in samples containing 100 mg/L sodium benzoate. Lacticaseibacillus paracasei subsp. paracasei, which has the potential to impart probiotic properties to shalgam, was the predominant LAB species in both non-treated and preservative-treated samples. The use of preservatives significantly reduced the total number of yeasts, which may cause spoilage in shalgam. The results indicate that using sodium benzoate at a concentration of 100 mg/L is the optimum method for shalgam production, resulting in the highest total acidity value obtained. Overall, the findings provide a significant contribution to prolonging the shelf life of shalgam, a beverage with immense production and consumption potential worldwide.

Bacteriocin-like inhibitory substances as green bio-preservatives; nanoliposomal encapsulation and evaluation of their in vitro/in situ anti-Listerial activity

In this study, predominant lactic acid bacteria (LAB) isolated from a traditional pickle (Persian pickled Litteh) were screened based on their ability to produce bacteriocin-like inhibitory substances (BLIS) with inhibitory effects on foodborne bacteria tested. The isolated BLIS was also characterized using liquid chromatography-mass spectrometry (LC-MS), and loaded into nanoliposomes; then, it's in vitro and in situ inhibitory effects were evaluated. Sequencing results of the PCR products led to the identification of Lactococcus lactis LI04 as the selected BLIS-producing LAB. The highest inhibitory activity of the BLIS was observed against Listeria monocytogenes PTCC 1298, which was significantly (P < 0.05) higher than the other foodborne bacteria studied. According to LC-MS analysis, presence of two peptides with retention times of 1.45 and 1.76 min corresponding to mass to charge ratio of 456.45 and 194.79 was approved in the BLIS. Produced empty and BLIS-loaded nanoliposomes had diameters of 92.99 and 139.10 nm, respectively. Results of Fourier transform infrared analysis showed that BLIS loading induced high degree of hydration in nanoliposomes. The increased Tm of loaded nanoliposomes (verified by differential scanning calorimetry) implied that the rigidity of liposomal membrane was enhanced. The loaded nanoliposomes were also able to maintain their inhibitory activity after treatment in simulated gastrointestinal conditions and commercial sterilization; whereas, the free (non-encapsulated) BLIS lost its effect. Furthermore, anti-Listerial activity of nanoliposomal BLIS after pasteurization was higher than the free BLIS. The highest release of the BLIS from nanoliposomes at 4 °C was observed after 16 days' storage. After this period, anti-Listerial activity of nanoliposomal BLIS was significantly higher than the free BLIS in the produced homemade beef steak.

Alcoholic fermentation drives the selection of Oenococcus oeni strains in wine but not in cider

Oenococcus oeni is the predominant lactic acid bacteria species in wine and cider, where it performs the malolactic fermentation (MLF). The O. oeni strains analyzed to date form four major genetic lineages named phylogroups A, B, C and D. Most of the strains isolated from wine, cider, or kombucha belong to phylogroups A, B + C, and D, respectively, although B and C strains were also detected in wine. This study was performed to better understand the distribution of the phylogroups in wine and cider. Their population dynamics were determined by qPCR all through wine and cider productions, and the behavior of the strains was analyzed in synthetic wines and ciders. Phylogroups A, B and C were all represented in grape must and throughout the alcoholic fermentation, but on the transition to MLF, only phylogroup A remained at high levels in all wine productions. In the case of cider, phylogroups A, B and C were detected in stable levels during the process. When they were tested in synthetic wine and cider, all phylogroups performed MLF, but with different survival rates depending on the ethanol content. In this sense, ethanol and fermentation kinetics are the main agent that drives the selection of phylogroup A strains in wine, while B and C strains dominates in cider containing less ethanol.

Composition and changes of microflora in the manufacturing process of traditional hurood

Hurood is a kind of cheese product by a unique Mongolian dairy artisanal production method. Because the microbes directly contribute to the quality and physicochemical properties of hurood, it is essential to understand the microbial structure and properties of hurood. In this study, we separated and detected 319 species of lactic acid bacteria (LAB) from four different fermentation stages of hurood. The predominant LAB isolates were Lactococcus lactis, which represented 52.4% of all isolates. The metagenomic sequencing technology results revealed that the microbial diversity decreased gradually during the hurood manufacturing process, and some non-LAB from the environment were detected. A correlation analysis showed that L. lactis could inhibit the growth and reproduction of non-LAB (P < 0.05). A metabolic pathway difference analysis showed that the biosynthesis pathways of B vitamins and unsaturated fatty acids and the carbohydrate degradation pathway were significantly enriched in hurood (P < 0.05), which might affect its texture and flavor development. In conclusion, this study provides a better understanding of the dynamic changes in the microbial community and dominant microbes at each fermentation stage in hurood, which provides theoretical support for optimizing the microbial structure of the hurood fermentation stages and improving product quality.

Functional food obtained from fermentation of broccoli by-products (stalk): Metagenomics profile and glucosinolate and phenolic compounds characterization by LC-ESI-QqQ-MS/MS

This research revalues broccoli stalk by-product as a novel fermented health food, using its autochthonous microbiota. Broccoli stalk slices were packed into glass jars, brine was added (6% w/v), and two dressings were studied: garlic, and mustard seeds. No dressing was used as control. Natural fermentation was carried out at 25 °C for 6 days followed by a further 6 days storage at 4 °C. The identification of individual glucosinolates and phenolic compounds was performed by LC-ESI-QqQ-MS/MS. At day 3, the highest content in functional compounds such as glucoerucin and indolic glucosinolates as glucobrassicin, 4-methoxy-glucobrassicin and 4-hidroxy-glucobrassicin, and phenolic acids and flavonoids as sinapic acid, 4-O-feruloyl quinic acid and quercetin-3-O-diglucoside was found. At day 6, the broccoli stalks reached the maximum counts in lactic acid bacteria (>8 log cfu g−1), remaining stable until day 12 at 4 °C, including as the main genera Lactobacillus and Leuconostoc. Metagenomic analysis identified 1009 bacteria genera; Latilactobacillus sakei was the most predominant lactic acid bacteria species, followed by Lactobacillus curvatus, Leuconostoc kimchi and Leuconostoc carnosum. This is an example of a vegan and functional food product, based on a circular economy model, using broccoli by-products.

Bacterial Diversity and Dynamics during Spontaneous Cheese Whey Fermentation at Different Temperatures

The effect of temperature (32–50 °C) on bacterial dynamics and taxonomic structure was evaluated during spontaneous whey fermentation for lactic acid production. Bacterial plate count in fresh whey (5 log CFU/mL) increased in two orders of magnitude after 60 h of fermentation (7 log CFU/mL), followed by one log reduction after 120 h (6 log CFU/mL) at 37 and 42 °C. Streptococcus and Lactobacillus counts ranged between 5–9 and 5–8 log CFU/mL, respectively. High-throughput sequencing of the 16S rRNA gene (V3-V4 region) used as a taxonomic marker revealed thirteen different bacterial phyla. Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were detected in all fermentation treatments (32–50 °C, 0–120 h), where Firmicutes was the predominant phylum. Bacterial diversity included more than 150 bacterial genera with predominant lactic acid bacteria (belonging to Firmicutes) such as Lactobacillus, Lactococcus, Streptococcus, and Tetragenococcus. At the species level, fresh whey presented 61 predominant species (relative abundance &gt; 0.05%); however, only 57.4% of these resisted the fermentation conditions (most of them belonging to lactic acid bacteria genera). Tetragenococcus halophilus, Lactococcus lactis, and Enterococcus casseliflavus were the predominant bacteria found in all treatments. Temperatures between 37–42 °C were more favorable for lactic acid production and could be considered appropriate conditions for fermented whey production and for the standardization of some artisanal cheese-making processes requiring acid whey addition for milk coagulation. The diversity of native beneficial bacteria found in fresh whey offers attractive technological characteristics, and their fermentative capacity would represent a biotechnological option to add value to cheese whey.

Nutritional profile and antioxidant capacities of fermented millet and sorghum gruels using lactic acid bacteria and yeasts

ABSTRACT Predominant lactic acid bacteria and yeasts isolated during the spontaneous fermentation of millet and sorghum were investigated for technological characteristics and food safety. Nutritional profile and antioxidant capacities were monitored. The pH reduced in both malted millet and sorghum slurries to 3.31 and 3.45 respectively. Lactobacillus fermentum KL4, Lb. plantarum MOBL1, Candida tropicalis OBY6 and C. tropicalis MKY6 were selected for high production of lactic acid, diacetyl, and hydrogen peroxide. These strains were safe for use as starter cultures. Starter culture fermented malted millet and sorghum slurries possessed significantly (p < .05) higher niacin and riboflavin content, total phenolics and flavonoid contents. Fermented malted millet slurry (MKC) demonstrated the highest magnesium and potassium contents of 114.2 and 212.13 mg/100 g while spontaneously fermented unmalted sorghum slurry (OBS) the least of 40.2 and 82.3 mg/100 g respectively. Fermented malted millet slurry (MKC) possessed the highest DPPH scavenging activity of 98.2%, while the unmalted spontaneous sorghum slurry (OBS) the least of 60.3%. For ferric reducing antioxidant power, the malted starter culture fermented sorghum slurry (MOBC) displayed the highest value of 998.3 mg/g AAE while unmalted spontaneous millet slurry (KS) the least of 260.2 mg/g AAE after 72 h fermentation time, respectively. Unmalted starter-produced Ogi-baba (OBC) exhibited the significantly highest overall sensory acceptability of 7.50 while the least was the spontaneous fermented malted Ogi-baba (MOBS) with a value of 5.10 (p < .05). The results indicated that Koko and Ogi-baba from whole grains are important sources of nutraceuticals and promising fermented cereal gruels.

저장기간에 따른 다양한 식품 내 유산균의 동정 및 유산균 수 변화

According to the National Health and Nutrition Examination Survey (KNHANES), the eating habit patterns and perspectives of consumers change according to dietary life changes. Consumers are becoming increasingly interested in healthy and functional foods. The lactic acid bacteria (LAB) and probiotics have health-promoting functions and can facilitate the growth of useful bacteria, inhibit harmful bacteria, and promote smooth bowel movements. This study compared the contents of LAB in various foods, including biscuit, sand, and chocolate, according to the storage period of LAB-containing products and analyzed the predominant LAB at the end of storage. Upon examining the changes in the viability of lactic acid bacteria over a storage period of 7 months, we found that cell viability was maintained at 5.20—9.04 Log CFU/g on MRS agar and 5.60—9.18 Log CFU/g on BCP agar. The results of cross-testing by a certified food safety agency by the MFDS, demonstrated that cell viability was maintained at 5.65—8.34 Log CFU/g; additionally, cross-validation comparison results showed a similarity of 76.0%—100%. This indicated high accuracy of results and maintenance of the constant viability of lactic acid bacteria. The detected lactic acid bacteria in various foods were identified as Lactiplantibacillus (96—100%), Weissella confusa (99%), and Streptococcus thermophiles (99%). The expressed content of LAB on the outer packaging paper of the products was suitable for determining LAB content.

Variability of the microbiota in traditional Caciocavallo, Scamorza and Caciotta cheeses manufactured with raw milk and natural cultures

Numerical and taxonomical variability of dominant microbial groups was investigated for 52 lots of traditional raw milk cheeses Caciocavallo, Scamorza and Caciotta from two dairy manufacturers. Microorganisms were characterised by 16S rRNA gene sequencing and detection of specific genes. Different lactic acid bacteria (LAB) growth dynamics between dairies, switches in the predominant LAB species and lot‐specific presence of certain bacterial groups were observed. The presence of virulence genes in enterococcal isolates, the presence of a tyrosine decarboxylase (tdcA) gene in a Lacticaseibacillus paracasei isolate and water activity (aw) and pH permissive for pathogen growth indicated the need for interventions that stabilise the microbiota.

Isolation and Characterization of Potential Starter Cultures from the Nigerian Fermented Milk Product nono.

Nono, an important traditional fermented dairy food produced from cow’s milk in Nigeria, was studied for microbial diversity and for starter culture development for industrial production. On the basis of a polyphasic approach, including phenotypic and genotypic methods such as 16S rRNA gene sequencing, repetitive element PCR (rep-PCR) fingerprinting metagenomics, and whole genome sequencing, we identified Lactobacillus (Lb.) helveticus, Limosilactobacillus (L.) fermentum, Lb. delbrueckii, and Streptococcus (S.) thermophilus as predominant bacterial species involved with milk fermentation during traditional nono production in Nigeria, while the predominant yeast species in nono was identified as Saccharomyces cerevisiae. Using metagenomics, Shigella and potential pathogens such as enterobacteria were detected at low levels of abundance. Strains of the predominant lactic acid bacteria (LAB) were selected for starter cultures combination on the basis of their capacities for rapid growth in milk and reduction of pH below 4.5 and their gelling characteristic, which was demonstrated noticeably only by the S. thermophilus strains. Whole genome sequence analysis of selected bacterial strains showed the largest assembled genome size to be 2,169,635 bp in Lb. helveticus 314, while the smallest genome size was 1,785,639 bp in Lb. delbrueckii 328M. Genes encoding bacteriocins were not detected in all the strains, but all the LAB possessed genes potentially involved in diacetyl production and citrate metabolism. These bacteria isolated from nono can thus be used to improve the microbial safety quality of nono in Nigeria, in addition to improving technological parameters such as gelling viscosity, palatability, and product consistency.

Microbiological quality and safety of Brazilian artisanal cheeses.

The establishment of norms that regulates the production and trade of Brazilian Artisanal Cheeses (BAC) has been stimulating many small farmers for this activity. The predominance of lactic acid bacteria (LAB) is a typical characteristic of BAC, which confers desirable attributes to artisanal cheeses. However, these products can be contaminated by other microbial groups, including those that indicate hygienic failures during production and may cause spoilage, or even microorganisms that pose risks to consumers' health. A systematic review of the literature published from January 1996 to November 2020 was carried out to identify scientific data about production characteristics and microbiological aspects of BAC, with a major focus on quality and safety status of these traditional products. Studies that fulfilled the inclusion criteria indicated that artisanal chesses produced in Brazil still do not satisfactorily meet the microbiological criteria established by the national laws, mainly due to the high counts of coagulase-positive Staphylococcus and coliforms. Despite low prevalence, pathogens such as Salmonella and Listeria monocytogenes were isolated in some BAC. This review contributed to better understanding microbiological aspects of BAC, the data compiled by the authors highlight the need to improve hygiene practices along the production chain of these traditional cheeses.