Probiotic characteristics and safety evaluation of acid-tolerant lactic acid bacteria isolated from Suancai, a popular fermented vegetable in Northeast China.
This study aimed to isolate acid-tolerant lactic acid bacteria from Suancai, a traditional Chinese fermented vegetable, and evaluate their potential and safety as candidate probiotics. Fifteen dominant lactic acid bacteria strains were isolated from spontaneously fermented Suancai, and four isolates were selected based on their tolerance to acid and bile, as well as their autoaggregation, coaggregation, cell surface hydrophobicity, and adhesion capabilities. Based on 16S rRNA and pheS gene sequence analyses, the four strains were identified as Lactiplantibacillus plantarum (strain S5) and Levilactobacillus brevis (strains S1, H1, and H2). These strains were further evaluated for multiple in vitro probiotic properties. All four exhibited cholesterol removal capacity, DPPH and hydroxyl radical scavenging activity, gamma-aminobutyric acid production, and nitrite degradation ability. α-Glucosidase inhibitory activity was observed in three strains, with the exception of Levilactobacillus brevis S1. Additionally, all strains displayed antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Salmonella paratyphi B. Safety assessment revealed that the strains were sensitive to ampicillin, erythromycin, and penicillin, resistant to gentamycin, and negative for indole production and hemolytic activity. In conclusion, the four selected strains demonstrated favorable probiotic characteristics and safety profile, supporting their potential as candidate probiotics for functional food application.
- Research Article
22
- 10.1186/s12934-021-01658-4
- Sep 6, 2021
- Microbial Cell Factories
BackgroundOf the many neurotransmitters in humans, gamma-aminobutyric acid (GABA) shows potential for improving several mental health indications such as stress and anxiety. The microbiota-gut-brain axis is an important pathway for GABAergic effects, as microbially-secreted GABA within the gut can affect host mental health outcomes. Understanding the molecular characteristics of GABA production by microbes within the gut can offer insight to novel therapies for mental health.ResultsThree strains of Levilactobacillus brevis with syntenous glutamate decarboxylase (GAD) operons were evaluated for overall growth, glutamate utilization, and GABA production in typical synthetic growth media supplemented with monosodium glutamate (MSG). Levilactobacillus brevis Lbr-6108™ (Lbr-6108), formerly known as L. brevis DPC 6108, and Levilactobacillus brevis Lbr-35 ™ (Lbr-35) had similar growth profiles but differed significantly in GABA secretion and acid resistance. Lbr-6108 produced GABA early within the growth phase and produced significantly more GABA than Lbr-35 and the type strain Levilactobacillus brevis ATCC 14869 after the stationary phase. The global gene expression during GABA production at several timepoints was determined by RNA sequencing. The GAD operon, responsible for GABA production and secretion, activated in Lbr-6108 after only 6 h of fermentation and continued throughout the stationary phase. Furthermore, Lbr-6108 activated many different acid resistance mechanisms concurrently, which contribute to acid tolerance and energy production. In contrast, Lbr-35, which has a genetically similar GAD operon, including two copies of the GAD gene, showed no upregulation of the GAD operon, even when cultured with MSG.ConclusionsThis study is the first to evaluate whole transcriptome changes in Levilactobacillus brevis during GABA production in different growth phases. The concurrent expression of multiple acid-resistance mechanisms reveals niche-specific metabolic functionality between common human commensals and highlights the complex regulation of GABA metabolism in this important microbial species. Furthermore, the increased and rapid GABA production of Lbr-6108 highlights the strain’s potential as a therapeutic and the overall value of screening microbes for effector molecule output.
- Research Article
7
- 10.1007/s10142-023-01085-1
- May 12, 2023
- Functional & Integrative Genomics
Gamma-aminobutyric acid (GABA) is a crucial inhibitory neurotransmitter in the sympathetic nervous system that exerts regulatory effects on the blood, immune, and nervous systems. GABA production in som-fak, a traditional fermented fish of Thailand, has been attributed to the activity of lactic acid bacteria (LAB). The present study aims to characterize the LAB isolates and compare the genomes and GABA synthesis genes of selected isolates capable of GABA production. Thirteen isolates demonstrating GABA synthesis capability were identified based on their phenotypic and genotypic characteristics. Seven isolates (group I: LSF3-3, LSF8-3, LSF9-1, LSF9-3, LSF9-6, LSF9-7, and LSF10-14) were identified as Levilactobacillus brevis with 99.78-100% similarity. LSF2-1, LSF3-2, LSF5-4, and LSF6-5 (group II) were identified as Lactiplantibacillus pentosus with 99.86-100% similarity. Strain LSF1-1 (group III) was identified as Pediococcus acidilactici (99.47%), and LSF10-4 (group IV) was identified as Pediococcus pentosaceus with 99.93% similarity. The GABA production of isolates ranged from 0.087 to 16.935g/L. The maximum production of 16.935g/L from 3% monosodium glutamate was obtained from strain LSF9-1. Gene and genome analysis revealed that L. brevis LSF9-1 has multiple gad genes in the genome, such as gadB1, gadB2, gadC1, and gadC2, making it the potential strain for GABA production. Additionally, the genome analysis of P. acidilactici LSF1-1 consists of gadA, gadB, and gadC, which respond to controlling GABA production and export. Furthermore, strain LSF1-1 was considered safe, containing no virulence factors. Thus, Levilactobacillus brevis LSF9-1 and Pediococcus acidilactici LSF1-1 have the potential for GABA production and probiotic use in future studies.
- Research Article
1
- 10.3390/ijms252413696
- Dec 21, 2024
- International journal of molecular sciences
Gamma-aminobutyric acid (GABA) has been attributed to health-promoting properties and has received attention from the food industry as an attractive bioactive compound for the development of functional foods. Some lactic acid bacteria (LAB) produce GABA through a glutamate decarboxylase encoded by gadB and a glutamate/GABA antiporter encoded by gadC. In this study, we develop a molecular screening method based on a polymerase chain reaction able to detect those genes in different LAB species through the use of novel multispecies primers. PCR was performed in 92 LAB strains of six different species. The primer pair designed for gadB allowed its identification in Lactiplantibacillus plantarum, Lactococcus cremoris, Lactococcus lactis, Levilactobacillus brevis, Limosilactobacillus fermentum, and Limosilactobacillus reuteri strains. For gadC, two different primer pairs were designed for its detection in different species. Glutamate decarboxylase activity (GAD assay) and GABase enzymatic quantification were also assessed. Among those strains showing glutamate decarboxylase activity, 93.2% harbored the gadB gene, and those showing GABA production had the gadB gene and exhibited glutamate decarboxylase activity. PCR detection of gadB correlates strongly with GABA production and constitutes a good strategy for the selection of LAB with high yields (>18 mM) that could be used for the development of GABA-enriched functional foods.
- Research Article
24
- 10.1016/j.fbio.2023.103450
- Dec 11, 2023
- Food Bioscience
Evaluation of new candidate probiotic lactobacillus strains isolated from a traditional fermented food- multigrain-millet dosa batter
- Research Article
1
- 10.1128/spectrum.03194-24
- Mar 17, 2025
- Microbiology spectrum
Native grasses possess rich diversity and contribute to enhancing the nutritional value of silage, promoting digestion and absorption, thus improving the health of livestock such as cattle and sheep. However, in northern China, the silage fermentation process occurs at relatively low temperatures, necessitating the use of cold-tolerant lactic acid bacteria (LAB). This study examined the effect of Pediococcus acidilactici (L10), a strain selected for its low-temperature tolerance, added to native grass silage at 5°C (LT), 15°C (MT), and room temperature 25°C (CK) for 60 days. The organization of the microbial community and the metabolomic profiles were examined. The results showed that temperature significantly (P < 0.05) influenced the pH, lactic acid (LA) concentration, and LAB populations of the silage after 60 days. The water-soluble carbohydrates (WSC) and crude protein (CP) contents in the LT treatment were significantly higher than those in the CK treatment, and the pH in the LT treatment was significantly lower than in the CK treatment. In terms of the dynamic alterations within the microbial community, Pediococcus acidilactici prevailed in the LT treatment, whereas Lactobacillus plantarum was the major genus in the MT treatment, and the CK treatment was characterized by the dominance of Lactobacillus plantarum and Levilactobacillus brevis. The study also revealed that bacterial behavior and metabolism were influenced by two-component systems and quorum sensing. At 5°C the upregulation of citric acid, salicylic acid, and L-proline was ascribed to the modification of glycolysis and the tricarboxylic acid cycle. Salicylic acid was significantly (P < 0.05) positively correlated with Lactiplantibacillus plantarum, while L-proline had significantly (P < 0.05) positive correlations with Pediococcus acidilactici, Lactococcus lactis, and Weissella confusa. These findings suggest that the addition of isolated Pediococcus acidilactici can enhance the quality of low-temperature native grass silage by regulating microbial metabolic pathways and community composition.IMPORTANCEThis study aimed to screen and identify low-temperature-resistant lactic acid bacteria (LAB) strains from native fermented silage of grassland pastures, evaluating their impact on silage quality in cold conditions. Under natural conditions, LAB on forage grasses are present in low numbers and exhibit insufficient activity, which is further hindered by low temperatures during ensiling, leading to slow fermentation. The findings highlighted the effects of low temperatures on the microbial community, fermentation characteristics, and metabolomic profiles of silage. After anaerobic fermentation, the main LAB strains at different temperatures were Levilactobacillus brevis, Lactiplantibacillus plantarum, and Pediococcus acidilactici, with Pediococcus acidilactici being dominant at 5°C. Temperature significantly affected the pH, lactic acid content, and water-soluble carbohydrates of silage, indicating an interaction between LAB strains and fermentation temperature. The study suggests that adding Pediococcus acidilactici can enhance silage quality by regulating microbial metabolic pathways and composition under low-temperature conditions.
- Research Article
11
- 10.4014/jmb.1409.09081
- Apr 28, 2015
- Journal of Microbiology and Biotechnology
The production of gamma-aminobutyric acid (GABA) using GABA-producing lactic acid bacteria (LAB) has been considered to be an attractive strategy. However, some LAB may produce biogenic amines (BA), which may be of concern from the safety viewpoint. The aim of the present study was to characterize the production of GABA and BA in the soybean pastes fermented by Aspergillus oryzae (A. oryzae) FMB S46471 and GABA-producing Lactobacillus brevis (L. brevis) GABA 100. After a ripening period of 90 days, the levels of BA (putrescine, cadaverine, histamine, and tyramine) and GABA in the fermented soybean were assessed by highperformance liquid chromatography. The soybean pastes fermented by A. oryzae and L. brevis showed a range of 7,130-11,592 mg/kg for GABA, 178-305 mg/kg for tyramine, 139-163 mg/kg for putrescine, 7.4-10.8 mg/kg for histamine, and 7.1-7.9 mg/kg for cadaverine, whereas the soybean pastes fermented by A. oryzae only showed a range of 30-1,671 mg/kg for GABA, 0.8-189 mg/kg for tyramine, 1.3-85 mg/kg for putrescine, up to 3.6 mg/kg for histamine, and 0.2-2.4 mg/kg for cadaverine. The results showed that the production of GABA was accompanied by the increase in the production of BA, even though the production levels of histamine and cadaverine were very low. This is the first study to simultaneously characterize the production of BA and GABA in GABA-enriched fermented soybean pastes, and warrants further study to minimize the production of BA while optimizing the production of GABA.
- Research Article
1
- 10.54987/jobimb.v12i1.935
- Jul 31, 2024
- Journal of Biochemistry, Microbiology and Biotechnology
Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the mammalian brain, and it possesses several physiological properties, such as depression reduction and anxiety release. GABA production by microbial synthesis is favoured over other methods like enzymatic and chemical synthesis due to the ease of operation and less formation of harmful pollutants. Lactic acid bacteria are widely applied for GABA production because of high GABA yield and their Generally Recognized as Safe (GRAS) status , which is critical in food and ingredient safety. In this study, various fermentation conditions, including incubation time, pH, temperature, monosodium glutamate (MSG) concentration, pyridoxal-5’-phosphate (PLP) concentration and glucose concentration were screened by one-factor-at-a-time strategy to achieve the optimal GABA production by a potential probiotic strain, Lactiplantibacillus plantarum B13. The result revealed the strain exhibited the optimal GABA production of 19.073 ± 0.5214 g/L with the highest GABA productivity of 0.424 g/L/h under fixed conditions: incubation time of 66 hours, pH 5.5, temperature of 35°C, MSG concentration of 5% (w/v), PLP concentration of 0.7 mM PLP and glucose concentration of 60 g/L. The findings of this study show that fermentation parameters are dependent on species and strains due to the different properties of glutamic acid decarboxylase enzymes and optimization of single parameters is important as a preliminary step to identify the range of fermentation factors that affect GABA yield prior further research endeavours. This study also has great implications for GABA production by L. plantarum B13 and provides a prerequisite for developing new healthy products enriched with GABA as daily supplements to support relaxation and regulate mood, reduce stress and promote better sleep.
- Research Article
14
- 10.3390/app12020660
- Jan 10, 2022
- Applied Sciences
Lactic acid bacteria (LAB) play an important role as natural food preservatives. However, the characterization of the variety of their metabolites is limited. The objective of this study was to determine the production of specific metabolites of Lacticaseibacillus rhamnosus, Levilactobacillus brevis and Lactiplantibacillus plantarum by an optimized liquid chromatography with an ultraviolet/diode detection (HPLC-UV/DAD) method and to investigate their potential antimicrobial activity against specific food pathogens. Based on the results of this study, the main metabolites detected in Levilactobacillus brevis were 103.4 μg mL−1 DL-p-Hydroxyphenyllactic acid (OH-PLA) and 2.59 μg mL−1 vanillic acid, while 216.2 μg mL−1 OH-PLA, 19.0 μg mL−1 salicylic acid, 3.7 μg mL−1 vanillic acid, 6.9 μg mL−1 ferulic acid, 4.2 μg mL−1 benzoic acid and 1.4 μg mL−1 4-Hydrocinnamic acid were identified in the Lactiplantibacillus plantarum strain and 147.6 μg mL−1 OH-PLA and 4.9 μg mL−1 ferulic acid were identified in Lacticaseibacillus rhamnosus. This study provides alternative approaches for the molecules involved in the antimicrobial activity of food microorganism fermentation. These molecules may be used as antimicrobial ingredients in the food industry instead of conventional chemical preservatives.
- Research Article
- 10.31083/j.fbe1601007
- Mar 11, 2024
- Frontiers in Bioscience-Elite
Traditional Bulgarian fermented foods are prominent for their uniqueness of local ingredients, production methods, and endemic microbial species. The present research investigated the diversity and beneficial biological potential of lactic acid bacteria (LAB) isolated from various types of unique Bulgarian fermented foods. Species identification was performed via 16S rDNA sequencing. Biological activity was evaluated by determining antibacterial activity (via agar well diffusion assay), H2O2 production, spectrophotometrically determined auto- and co-aggregation, microbial adhesion to hydrocarbon, and biofilm formation. The biosafety of the isolated lactic acid bacteria was established based on hemolytic activity and phenotypic and genotypic antibiotic susceptibility. Forty-five strains were isolated from fermented foods (sauerkraut, fermented green tomatoes, fermented cucumbers, kefir, white cheese, and Izvara (curdled milk)). Five species were detected: Lactiplantibacillus plantarum, Levilactobacillus koreensis, Levilactobacillus brevis, Lactobacillus helveticus, and Levilactobacillus yonginensis. The most prominent species was L. plantarum, at 47%. For the first time, L. koreensis and L. yonginensis, isolated from unique Bulgarian fermented foods, are reported in this study. The antibacterial effect of the cell-free supernatants was evaluated. An antagonistic effect was observed against Escherichia coli (57%) and Salmonella enterica subsp. enterica serotype Enteritidis (19%) for several L. plantarum strains. Only one L. brevis (Sauerkraut, S15) strain showed activity against E. coli. The best autoaggregation ability at hour 4 was observed for L. koreensis (fermented cucumbers, FC4) (48%) and L. brevis S2 (44%). The highest percentage of co-aggregation with Candida albicans, at hou 4 in the experiments, was observed for strains L. koreensis (fermented green tomato, FGT1) (70%), L. plantarum strains S2 (54%), S13 (51%), and S6 (50%), while at hour 24 for strains L. koreensis FGT1 (95%), L. brevis (Kefir, K7) (89%), L. plantarum S2 (72%), and L. koreensis FC2 (70%). Seven of the isolated LAB strains showed hydrophobicity above 40%. Our results showed that the ability of biofilm formation is strain-dependent. No hemolytic activity was detected. The antibiotic resistance to 10 antibiotics from different groups was tested phenotypically and genotypically. No amplification products were observed in any strains, confirming that the isolates did not carry antibiotic-resistance genes. Traditional fermented Bulgarian foods can be considered functional foods and beneficial LAB sources.
- Research Article
16
- 10.3390/foods12030599
- Feb 1, 2023
- Foods
Lactic acid bacteria (LAB) are valuable for the production of fermented dairy products. We investigated the functional traits of LAB isolated from artisanal cheeses and raw sheep milk, assessed their safety status, and explored the genetic processes underlying the fermentation of carbohydrates. Lactiplantibacillus plantarum had the largest and more functional genome compared to all other LAB, while most of its protein-encoding genes had unknown functions. A key finding of our analysis was the overall absence of acquired resistance genes (RGs), virulence genes (VGs), and prophages, denoting that all LAB isolates fulfill safety criteria and can be used as starter or adjunct cultures. In this regard, the identified mobile genetic elements found in LAB, rather than enabling the integration of RGs or VGs, they likely facilitate the uptake of genes involved in beneficial functions and in the adaptation of LAB in dairy matrices. Another important finding of our study was that bacteriocins and CAZymes were abundant in LAB though each species was associated with specific genes, which in turn had different activity spectrums and identified applications. Additionally, all isolates were able to metabolize glucose, lactose, maltose, and sucrose, but Lactiplantibacillus plantarum was strongly associated with the fermentation of rhamnose, mannose, cellobiose, and trehalose whereas Levilactobacillus brevis with the utilization of arabinose and xylose. Altogether these results suggest that to fully exploit the beneficial properties of LAB, a combination of strains as food additives may be necessary. Interestingly, biological processes involved in the metabolism of carbohydrates that are not of direct interest for the dairy industry may yield valuable metabolites or activate pathways associated with beneficial health effects. Our results provide useful information for the development of new probiotic artisanal cheeses and probiotic starter cultures.
- Research Article
- 10.3389/fmicb.2025.1579393
- Jul 23, 2025
- Frontiers in Microbiology
In this study, lactic acid bacteria were isolated from traditional fermented foods in Guizhou. The fermentation supernatant and cell disruption extract were used to screen lactic acid bacteria with α-glucosidase inhibitory activity, and the active lactic acid bacteria strains with potential hypoglycemic effect were screened. The results showed that 10 strains were screened from 27 strains of lactic acid bacteria with α-glucosidase inhibitory activity, of which 5 strains had good acid and bile salt tolerance. The best acid resistance was XG01, and the survival rate was as high as 98.5%. ST01 had the strongest tolerance to bile salt, up to 77.3%. The lactic acid bacteria cell extracts of HLG01, YR01, ST01 and XG01 could better inhibit the activity of α-glucosidase, and the inhibition rates were 39.27, 38.6, 38.53, and 34.4%, respectively. The fermentation supernatant of JR01 could better inhibit the activity of α-glucosidase, and the inhibition rate reached 33.8%. Through molecular biological identification, HLG01, YR01, and ST01 were were Lactiplantibacillus plantarum, XG01 was Pediococcus pentosaceus, and JR01 was Weissella cibaria. Weissella cibaria JR01 is the first reported lactic acid bacterium with α-glucosidase inhibitory activity. Five strains of lactic acid bacteria with good tolerance were screened out, which provided a strain basis for the subsequent study of the hypoglycemic effect of lactic acid bacteria and the development of various functional foods.
- Research Article
6
- 10.1080/08905436.2023.2267121
- Oct 2, 2023
- Food Biotechnology
This study aimed to evaluate and characterize lactic acid bacteria for their probiotic attributes from traditional fermented food, Finger millet batter, and to explore the ability of probiotic lactic acid bacteria to inhibit food borne pathogens. Among all 40 isolates, five bioactive isolates Lactiplantibacillus plantarum MYSRD57, Lacticaseibacillus paracasei MYSRD68, Lactiplantibacillus plantarum MYSDS3, Lactiplantibacillus plantarum MYSDS4 and Lactiplantibacillus plantarum MYSDVN3 with best probiotic attributes were selected and presented in this study. The antimicrobial efficacy of Lactobacillus and their cell free supernatant were effective in controlling pathogens all the foodborne pathogens in vitro. Furthermore, these strains exhibited important probiotic characteristics, such as antibiotics susceptibility, anti-hemolytic activity, tolerance to acidic pH, phenol, sodium chloride, 0.3% bile and survival ability at different temperatures. All the strains were also exhibited high auto-aggregation and cell surface hydrophobicity. Therefore, our findings demonstrated important probiotic features of lactic acid bacteria , while inhibiting multiple pathogens, suggesting possible applications of these potential probiotics strains.
- Research Article
19
- 10.3390/biology11101523
- Oct 18, 2022
- Biology
Simple SummaryPotential probiotic bacteria for aquacultured species should be naturally occurring and non-pathogenic in the native habitat of the host, easy to culture, and able to grow in the intestine of the host. Se nanoparticles (Se0Nps) can be effectively used as a growth promoter, antioxidant, and immunostimulant agent in aquacultured species. Dietary supplementation with probiotics and Se0Nps contributes to the balance of the intestinal microbiota and probiotics have been proposed as an alternative to chemotherapeutants and antibiotics to prevent disease outbreaks, to mitigate the negative effects of stress and to strengthen the antioxidant capacity and the immune system of fish. Our results reported the isolation of a probiotic strain obtained from healthy rainbow trout. The strain was identified as Lactiplantibacillus plantarum species. This strain showed characteristics typically present in probiotics and, concurrently, the capacity to biosynthesize Se0Nps. The supplementation of the rainbow trout fish diet with LABS14-Se0Nps showed a positive effect on innate immune response parameters, oxidative status, well-being, and a better growth performance than the supplementation of the diet with the bacterium LABS14 alone. Therefore, we propose LABS14-Se0Nps as a promising alternative for the nutritional supplementation for rainbow trout or even other salmonids.Lactic acid bacteria (LAB), obtained from rainbow trout (Oncorhynchus mykiss) intestine, were cultured in MRS medium and probiotic candidates. Concurrently, producers of elemental selenium nanoparticles (Se0Nps) were selected. Probiotic candidates were subjected to morphological characterization and the following tests: antibacterial activity, antibiotic susceptibility, hemolytic activity, catalase, hydrophobicity, viability at low pH, and tolerance to bile salts. Two LAB strains (S4 and S14) satisfied the characteristics of potential probiotics, but only strain S14 reduced selenite to biosynthesize Se0Nps. S14 strain was identified, by 16S rDNA analysis, as Lactiplantibacillus plantarum. Electron microscopy showed Se0Nps on the surface of S14 cells. Rainbow trout diet was supplemented (108 CFU g−1 feed) with Se0Nps-enriched L. plantarum S14 (LABS14-Se0Nps) or L. plantarum S14 alone (LABS14) for 30 days. At days 0, 15, and 30, samples (blood, liver, and dorsal muscle) were obtained from both groups, plus controls lacking diet supplementation. Fish receiving LABS14-Se0Nps for 30 days improved respiratory burst and plasmatic lysozyme, (innate immune response) and glutathione peroxidase (GPX) (oxidative status) activities and productive parameters when compared to controls. The same parameters also improved when compared to fish receiving LABS14, but significant only for plasmatic and muscle GPX. Therefore, Se0Nps-enriched L. plantarum S14 may be a promising alternative for rainbow trout nutritional supplementation.
- Research Article
- 10.11134/btp.3s.2024.126
- Sep 12, 2024
- Eurasian Journal of Applied Biotechnology
Lactic acid bacteria are widely used to produce diverse type of fermented products. One of conventional applications for lactic acid bacteria is inclusion into sourdough for bread baking. These microorganisms play a key role in dough fermentation of rye flour or wheat and rye mixture since the yield of stable and well-leavened rye dough is possible only in acidic environment. Lately, despite the development of accelerated baking technologies and technological improvements, which in some cases eliminate the need for sourdough, interest in the tradition of making bread using sourdough as a source of flavoring, nutrient and health-enhancing compounds is constantly growing across the globe. It is natural therefore that focus of the researchers is centered on seeking new strains of lactic acid bacteria attractive as potential constituents of rye bread sourdough. Screening of strains-candidates to be included in the consortia for rye flour fermentation was conducted among collection cultures (23 strains), isolates from rye flour samples (154 strains) and among craft rye dough cultures for spontaneous fermentation kindly provided by private households of Minsk, Turov, Zhitkovichi (21 strains). Identification of lactic acid bacteria following examination of morphological, cultural, physiological and biochemical characteristics of the cultures and guided by the data of MALDI TOF mass spectrometry indicated that the compared microorganisms represented genera Lactiplantibacillus, Limosilactobacillus, Pediococcus, Weissella, Lactococcus. The majority of lactic acid bacteria isolated from rye flour samples belonged to genera Lactiplantibacillus and Pediococcus. Representatives of genera Lactiplantibacillus and Levilactobacillus prevailed among domestic variants of rye bread sourdoughs. Evaluation of acidogenic capacity of analyzed cultures upon 16 h fermentation in water-flour suspension by Neumann technique and organoleptic assessment of the obtained solutions sorted out for further studies 10 strains of lactic acid bacteria referred to species Levilactobacillus brevis (4 strains) Lactiplantibacillus plantarum (3 strains) and singular strains of species Lactiplantibacillus paraplantarum, Limosilactobacillus fermentum, Weissella cibaria. Glycosyl-hydrolases produced by lactic acid bacteria constituting starter cultures largely determine biochemical processes during fermentation of flour mixtures. Chromogenic substrates o-nitrophenyl-β-D-galactopyranoside, o-nitrophenyl-α-D-galactopyranoside, 4-nitrophenyl-β-D-glucopyranoside were used in 1 mmol concentration to assay activities of β-galactosidase, α-galactosidase, β-glucosidase, respectively. It was found that all tested bacteria of species Levilactobacillus brevis and Limosilactobacillus fermentum were characterized by synthesis of proteins with α-galactosidase and β-galactosidase activities in the course of growth on media with glucose and maltose. β-glucosidase activity was revealed in all representatives of species Lactiplantibacillus plantarum, Levilactobacillus brevis and Lactiplantibacillus paraplantarum. Amylolytic activity was detected in two Lactiplantibacillus plantarum strains, whereas bacteria of species Weissella cibaria displayed a weak β-glucosidase activity. An important criterion to select microbial constituents for dough fermentation is antagonistic activity toward contaminating microbiota. Antagonistic response of lactic acid bacterial cultures to causal agents of bread spoilage was demonstrated, including epidemiologically significant fungi of genera Fusarium, Aspergillus, Penicillium, etc. Analysis of obtained data has enabled to compose microbial consortia promising for further elaboration of technologies for producing active bread-making starter formulas with upgraded biotechnological properties and enhanced alimentary, nutritional and biological value.
- Research Article
- 10.52973/rcfcv-e35579
- Mar 23, 2025
- Revista Científica de la Facultad de Ciencias Veterinarias
The aim of this study was to isolate and to identify lactic acid bacteria from traditional cheeses of the Black See Region. Artvin Şor, Giresun Tecen, Kargı Tulum, Ordu Kesik and Trabzon Telli cheese were used as cheese samples of the Black Sea Region. The number of lactic acid bacteria in traditional cheese of the Black Sea Region were ranged from 4.62 ± 0.76 and to 7.87 ± 0.64 log cfu·g-1. Gram–positive and catalase–negative colonies were evaluated as lactic acid bacteria based on the morphological and biochemical properties. According to biochemical analysis results, 39 lactic acid bacteria strains were identified by 16S rDNA isolated from cheese samples. Based on the sequence analysis, the indigenous lactic acid bacteria population was identified as Enterococcus faecium (35.9%), as Levilactobacillus brevis (12.8%), as Lactiplantibacillus plantarum (15.3%), as Pediococcus acidilactici (7.6%), as Enterococcus durans (7.6%), as Lacticaseibacillus paracasei (5.1%), as Lacticaseibacillus casei (7.6%), as Leuconostoc mesenteroides (2.5%), as Leuconostoc lactis (2.5%) and as Weissella cibaria (2.5%). Enterococcus spp. was the dominant lactic acid bacteria in cheese sample. The present findings revealed that lactic acid bacteria populations varied depending on cheese types in terms of cell counts and diversity.
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