Distribution Of Lactic Acid Bacteria Research Articles

English

In areas where conventional sewer systems are not possible, innovative and low-cost methods are needed to get rid of pathogens in human urine. Treatment through acidification is a reliable method. In this study, the effect of fresh cabbage waste, potato peel, and teff flour water as substrate for lactic acid treatment of source-separated urine was investigated. Laboratory scale batch experiments were conducted to compare the substrates for pH 4 and high distribution of lactic acid bacteria (LAB), important for urine hygienization and urea stabilization. It was found that with the addition of 10% molasses as a sugar supplement, fermentation of fresh cabbage waste could establish the desired effect for lactic acid treatment of source-separated urine. The final pH in the urine mixed with lactic acid in the ratio of 1:1 and 1:2 (lactic acid: urine) was 4.12 and 4.26, respectively. While the final pH in the 1:4 and control reactors was 8.3 and 9.2, respectively. Escherichia coli count was below the detection limit in both 1:1 and 1:2 reactors after 5 days, whereas the number of E. coli in the samples collected from 1:4 and control reactors showed only slight reduction until the final day of the treatment process. Urea decomposition improved in 1:1 and 1:2 reactors, while it kept increasing in 1:4 and control reactors. The results revealed that food waste produced lactic acid enhances pathogen inactivation, urea stabilization and reduce odors in human urine. Key words: Lactic acid, odor control, pathogen inactivation, urea stabilization

Distribution and antimicrobial activity of lactic acid bacteria from raw camel milk.

Consumer demand for natural pathogen-control agents for substitution of synthetic food preservatives and traditional antibiotics is increasing. This study aimed to reveal the distribution of lactic acid bacteria (LAB) in raw camel milk and to characterize their antimicrobial traits. The genetic identification by 16S rRNA sequencing of 58 LAB isolates showed the predominance of Enterococcus (24.2%), Lactococcus (22.4%) and Pediococcus (20.7%) genera in raw camel milk. These genera exhibited inhibitory activity against a broad spectrum of Gram-positive and Gram-negative bacteria including multidrug-resistant Salmonella. Among these LAB, two isolates—identified as Pediococcus pentosaceus CM16 and Lactobacillus brevis CM22—were selected for their strong bacteriocinogenic anti-listerial activity estimated at 1600 and 800 AU/mL, respectively. The bacteriocins produced were partially purified by ammonium sulphate precipitation and gel filtration and then biochemically characterized. The proteinaceous nature of bacteriocins was confirmed by the susceptibility to enzymes. These bacteriocins showed significant technological characteristics such as heat-resistance, and stability over a wide range of pH (2.0–10.0). In conclusion, these results indicated that Pediococcus pentosaceus CM16 and Lactobacillus brevis CM22 could be useful as potential probiotics. Moreover, their partially purified bacteriocins may play an important role as food preservatives and feed additives. To our knowledge, this is the first report describing the distribution of LAB population in raw camel milk and the characterization of their bacteriocins from the Arabian Peninsula of western Asia.

Use of γ-aminobutyric acid producing lactic acid bacteria as starters to reduce biogenic amines and cholesterol in Thai fermented pork sausage (Nham) and their distribution during fermentation

The objectives of this study were to reduce the amounts of biogenic amines (BAs) and cholesterol in Thai fermented pork sausage (Nham) using the γ-aminobutyric acid (GABA) producers, Pediococcus pentosaceus HN8 and Lactobacillus namurensis NH2, as a mixed starter (6 log CFU/g for each strain). The distribution of lactic acid bacteria (LAB) was also monitored to follow the prevalence of the mixed starter during fermentations. The starter cultures in the inoculated Nham sets (TSM, starter + 5 g/kg monosodium glutamate, MSG; and TSN, starter + no MSG) reduced the amounts of 7 BAs to meet the safety regulation requirements in the order of β-phenylethylamine > histamine > tyramine > putrescine > spermine > spermidine > cadaverine. In contrast, with the control fermentations (TNN, no starter + no MSG and TNM, no starter + MSG, 5 g/kg) only histamine was higher than the recommended level. Cholesterol content was also reduced by 35% in the GABA Nham set (TSM, GABA 3962 mg/kg) when compared with the TNN; and this was significantly lower than the popular commercial Nham brands (114–125 mg cholesterol/100 g). Determination of the LAB succession confirmed that the starter cultures played the biggest roles in reducing both the BAs and cholesterol levels.

Isolation of lactic acid bacteria from sweet potato <i>shochu</i> mash and their influence on <i>shochu</i> quality

In this study, the distribution of lactic acid bacteria (LAB) in typical sweet potato shochu mash was investigated. The number of bacterial cells peaked on the second day of the second-stage fermentation and gradually decreased as the fermentation process progressed. Sequences of 16S rRNA genes in isolated LAB revealed that the majority of LAB strains in the sweet potato shochu mash belonged to Lactobacillus plantarum, L. fermentum, and L. casei groups. Investigation of physiological characteristics showed that the L. casei group had high ability to assimilate citric acid; in fact, resulting increases in lactic acid, formic acid, and acetic acid were confirmed. The laboratory scale fermentation test using the characteristic LAB revealed changes in organic acid compositions in the second stage fermented mash, and in flavor components in shochu, increases in the levels of diacetyl and diethyl succinate-- both of which were derived from LAB-- were particularly prominent. Furthermore, sensory testing confirmed the influence of LAB. Taken together, the results indicate that certain LAB in sweet potato shochu mash influence the quality of the final shochu product.

Glucose metabolic flux distribution of Lactobacillus amylophilus during lactic acid production using kitchen waste saccharified solution

The 13C isotope tracer method was used to investigate the glucose metabolic flux distribution and regulation in Lactobacillus amylophilus to improve lactic acid production using kitchen waste saccharified solution (KWSS). The results demonstrate that L. amylophilus is a homofermentative bacterium. In synthetic medium, 60.6% of the glucose entered the Embden–Meyerhof–Parnas (EMP) to produce lactic acid, whereas 36.4% of the glucose entered the pentose phosphate metabolic pathway (HMP). After solid–liquid separation of the KWSS, the addition of Fe3+ during fermentation enhanced the NADPH production efficiency and increased the NADH content. The flux to the EMP was also effectively increased. Compared with the control (60.6% flux to EMP without Fe3+ addition), the flux to the EMP with the addition of Fe3+ (74.3%) increased by 23.8%. In the subsequent pyruvate metabolism, Fe3+ also increased lactate dehydrogenase activity, and inhibited alcohol dehydrogenase, pyruvate dehydrogenase and pyruvate carboxylase, thereby increasing the lactic acid production to 9.03 g l−1, an increase of 8% compared with the control. All other organic acid by-products were lower than in the control. However, the addition of Zn2+ showed an opposite effect, decreasing the lactic acid production. In conclusion it is feasible and effective means using GC-MS, isotope experiment and MATLAB software to integrate research the metabolic flux distribution of lactic acid bacteria, and the results provide the theoretical foundation for similar metabolic flux distribution.

Distribution of lactic acid bacteria in fermented mare's milk in Mongolian region

Distribution of lactic acid bacteria in fermented mare's milk in Mongolian region

Evaluation of Pediococcus pentosaceus strains isolated from Idly batter for probiotic properties in vitro

Idly batter is a traditional fermented food in South India and distribution of lactic acid bacteria (LAB) varies with season. Six bacteriocinogenic Pediococcus pentosaceus strains isolated from Idly batter were evaluated for probiotic properties in vitro. These isolates exhibited effective inhibition against various intestinal Gram positive and negative pathogens like Escherichia coli. These isolates especially, VJ13, VJ31 and VJ49 could tolerate 0.3% bile salt, gastric and intestinal conditions. All isolates exhibited strong auto-aggregation and co-aggregation (against Listeria monocytogenes and E. coli) with higher hydrophobicity and thus they could eliminate pathogen and prevent its adhesion to intestinal cells. All isolates except VJ41 assimilate cholesterol effectively, suggesting that they can lower the cholesterol, and because they produce β-galactosidase they can be used for lactose intolerance. Heat-killed P. pentosaceus VJ13 also assimilated cholesterol (19%) but not as effectively as live strains (73%). Among these isolates, VJ13 and VJ49, which exhibited efficient probiotic property, were evaluated for in vitro adhesion with Caco-2 cells. These isolates adhere more effectively with Caco-2 cells than the intestinal pathogen L. monocytogenes and prevent the pathogen adhesion to intestinal cells. Among these isolates, VJ13 has beneficial probiotic properties which can be exploited for formulation of functional foods.

Distribution of lactic acid bacteria in garlic (Allium sativum) and green onion (Allium fistulosum) using SDS-PAGE whole cell protein pattern comparison and 16S rRNA gene sequence analysis

Distributions of lactic acid bacteria (LAB) in garlic and green onion samples as kimchi sub-ingredients were analyzed by comparing the SDS-PAGE whole cell protein patterns and 16S rRNA gene sequence analysis. In total, 245 LAB were isolated from 10 garlic samples and differentiated into 7 groups by comparing SDS-PAGE whole cell protein patterns. The groups were identified as Leuconostoc, Weissella, and Lactobacillus through the 16S rRNA gene sequence analysis. A total of 115 LAB were isolated from 7 green onion samples, differentiated into 6 groups, and identified as Weissella, Leuconostoc, and Lactococcus. Leuconostoc was the most dominated LAB in garlic and Weissella was the most dominated LAB in green onion. The LAB identified in this study was found as dominant microorganisms in kimchi. This result suggests the possible contribution of LAB in garlic and green onion to the bacterial microflora of kimchi, especially during early stage of fermentation.

Pomegranate Borne Fungicidal Lactic Acid Bacteria and their Biodiversity

The present work was aimed at the determination of distribution of lactic acid bacteria on aerial surfaces of pomegranate, and evaluation of the antifungal potential for their possible use as biocontrol agent. Maximum population of lactic acid bacteria was detected on flowers of Bhagwa and Ganesh variety, although the count was higher in Bhagwa (P < 0.05). The population of lactic acid bacteria on different sample types was significant (P < 0.05) during April and October season, and the count was always higher in October season. Potent antifungal isolates were identified by phenotypic characters (Gram positive card kit) and partial 16S rDNA sequencing as Lactobacillus brevis, Enterococcus faecium, Lactococcus lactis ssp. cremoris and Lactococcus lactis ssp. lactis. Of the 200 lactic acid bacteria isolates, 124 were antagonistic towards Fusarium graminearum as determined by agar overlay technique. Out of these, 26 were able to retain the antifungal activity after long term storage of 12 months at 4 °C. Thus, pomegranate plant is an excellent source for diverse antifungal lactic acid bacteria.

Elaboration of Tempranillo wines at two different pHs. Influence on biogenic amine contents

The aim of this work was to study the effect of pH on biogenic amine formation during the elaboration and conservation (7 months) of Tempranillo wines. Grapes at two pHs (3.4 and 3.7) were vinified to achieve this purpose. After alcoholic fermentation the wines were either inoculated with a commercial malolactic starter or not inoculated. Identification and clonal distribution of lactic acid bacteria and amino acid concentration were determined in an attempt to explain the biogenic amine generation. The results showed that the pH of the must influenced the clonal distribution of the Oenococcus oeni strains which conducted the malolactic fermentation and also the concentration of amino acids in the wines after alcoholic fermentation. These aspects could account for the higher biogenic amine formation in wines with the lowest pH during malolactic fermentation. In these wines, inoculation with a malolactic starter was favourable since it produced a lower biogenic amine concentration after malolactic fermentation. Furthermore, the pH also influenced the concentration of amino acids after malolactic fermentation and the lactic acid bacteria distribution during the conservation of the wines. These aspects allow explaining the greater formation of histamine, tyramine and putrescine in the wines with the lowest pH vinified via lactic acid bacteria inoculation after seven months of conservation.

Lactic Acid Bacterial Vaginosis among Outpatients in Addis Ababa

Background: Bacterial vaginosis (BV) is a polymicrobial syndrome in which a decrease in vaginal acidity and concentration of lactobacilli is accompanied by an increase of other pathogenic micro-organisms. The distribution of lactic acid bacteria in vaginal environment of Ethiopian women has not been documented.Objective:To assess the frequency of bacterial vaginosis in women visiting a gynecological clinic in Addis Ababa and to characterize the most common lactic acid bacteria isolated from vaginal fluid.Methods: Vaginal samples from a total of 100 women aged between 18 and 60 years and visiting a gynecological clinic in Addis Ababa were collected between January and June, 2008 and analyzed for their microbial flora. Their Nugent score was determined microscopically and Lactic acid bacteria were isolated, characterized and their drug resistance determined.Results: BV frequency among these study women was 32%. Only 15% were symptomatic as detected by the presence of malodor or abnormal discharge. The majority (44%) was in the age group of 18-30 years and less than a quarter of them had BV. It was also detected in about a third of women belonging to the two major religious denominations hadBV. The frequency of BV among pregnant women was low. The frequency of BV in women with prior abortion was slightly higher than 1/3. A total of 350 lactic acid bacterial isolates were obtained and 40% of them belonged toLactococcus species. Lactobacillus, Leuconostoc, and Pediococcus were encountered at different frequencies. Resistance was seen against all drugs at various frequencies among the LAB (Lactic Acid Bacteria) isolates.Resistance of LAB to all antibiotics tested ranged between 20% and 42%, and the least resistance was noted against vancomycin. All women who had been positive for bacterial vaginosis were accordingly treated.Conclusion: Bacterial vaginosis may contribute to adverse reproductive outcomes. Prevalence of bacterial vaginosis in this study compares well with other African studies. The species richness and relative abundance of vaginal lactic acid bacteria in this study may be considered to design better probiotic products as bacterial replacement therapy.

Biological and Genetic Classification of Canine Intestinal Lactic Acid Bacteria and Bifidobacteria

To investigate the distribution of lactic acid bacteria (LAB) inhabiting canine intestines, a total of 374 gram-positive LAB and bifidobacteria (BF) isolated from large intestinal contents in 36 dogs were classified and identified by phenotypic and genetic analyses. Based on cell morphological sizes, these isolates were divided into seven biotypes containing the genera Lactobacillus, Bifidobacterium, Enterococcus, and Streptococcus. The LAB and BF isolates were classified into 38 chemotypes based on SDS-PAGE protein profile analysis of whole cells. Furthermore, partial 16S rDNA sequencing analysis demonstrated the presence of 24 bacterial species in the 38 chemotypes from 36 dogs. The identified species consisted of ten species belonging to the genus Lactobacillus (78.8%), seven species to the genus Bifidobacterium (6.8%), five species to the genus Enterococcus (11.6%), one species of Streptococcus bovis (2.0%), and one species of Pediococcus acidilactici (0.8%). In particular, the most predominant species in canine intestines were L. reuteri, L. animalis, and L. johnsonii and were found in the high frequency of occurrence of 77.8, 80.6, and 86.1%, respectively. Besides these, Enterococcus faecalis, Bifidobacterium animalis subsp. lactis, Pediococcus acidilactici, and Streptococcus bovis were also isolated in the present study. The sequences of the isolates also showed high levels of similarity to those of the reference strains registered previously in the DDBJ and the similarity was above 97.2%. Their partial 16S rRNA genes were registered in the DDBJ.

Isolation and identification of lactic acid bacteria from soil using an enrichment procedure

To survey, and identify and classify the ecological distribution of lactic acid bacteria from soil in Japan and Taiwan. Acid-producing bacteria were isolated from 68 soil samples, collected from Japan and Taiwan, in the rhizospheres of fruit trees, from the floor of a henhouse and around a horse farm. All isolates were identified by physiological and genetic tests. Thirty-two of the 54 isolates were identified as lactic acid bacteria (LAB), 16 as spore-forming lactic acid bacteria, five as Clostridium and one as Bacillus. These lactic acid bacteria represent five genera: Lactobacillus, Lactococcus, Enterococcus, Leuconostoc and Weissella. A high rate of isolating lactic acid bacteria was obtained from soil. This study suggests that soil may be a common source for the isolation of lactic acid bacteria.

Lactic acid bacteria isolated from soy sauce mash in Thailand.

Fourteen sphere-shaped and 30 rod-shaped lactic acid bacteria were isolated from soy sauce mash of two factories in Thailand. These strains were separated into two groups, Group A and Group B, by cell shape and DNA-DNA similarity. Group A contained 14 tetrad-forming strains, and these strains were identified as Tetragenococcus halophilus by DNA similarity. Group B contained 30 rod-shaped bacteria, and they were further divided into four Subgroups, B1, B2, B3, and B4, and three ungrouped strains by phenotypic characteristics and DNA similarity. Subgroup B1 contained 16 strains, and these strains were identified as Lactobacillus acidipiscis by DNA similarity. Subgroup B2 included two strains, and the strains were identified as Lactobacillus farciminis by DNA similarity. Subgroup B3 contained five strains. The strains had meso-diaminopimelic acid in the cell wall, and were identified as Lactobacillus pentosus by DNA similarity. The strains tested produced DL-lactic acid from D-glucose. Subgroup B4 contained four strains. The strains had meso-diaminopimelic acid in the cell wall, and they were identified as Lactobacillus plantarum by DNA similarity. Two ungrouped strains were homofermentative, and one was heterofermentative. They showed a low degree of DNA similarity with the type strains tested, and were left unnamed. The distribution of lactic acid bacteria in soy sauce mash in Thailand is discussed.

Characterization and distribution of lactic acid bacteria in cassava fermentation during fufu production

One hundred and thirty four lactic acid bacterial strains isolated during the 96‐h period of cassava fermentation for fufu production were identified. The spectrum and proportion of the strains include Lactobacillus plantarum, 81%; Leuconostoc mesenteroides, 16%; Lact. cellobiosus, 15%; Lact. brevis, 9%; Lact, coprophilus, 5%; Lact. lactis, 4%; Leuc. lactis, 3% and Lact. bulgaricus, 1%. The isolates were characterized into strains. The succession among the lactic isolates was established. Lactobacillus plantarum was identified as the most dominant lactic acid bacterial strain involved in the fermentation.

DNA‐DNA homology, physiological characteristics and distribution of lactic acid bacteria isolated from maize silage

Lactic acid bacteria represent a dynamic bacterial group in maize silages. their establishment, variations and characterization have been studied by investigating 22 samples taken at different times during the ensilage process. After a preliminary screening based on physiological characteristics, 100 of 229 strains isolated were chosen for further taxonomic investigation. Twenty‐nine strains of homo‐fermentative lactobacilli were identified as Lactobacillus plantarum, L. casei and L. coryniformis subsp. coryniformis; 24 heterofermentative strains were allotted to the species L. buchneri, L. brevis, L. fermentum and Leuconostoc paramesenteroides; 22 coccal strains were assigned to Pediococcus pentosaceus and P. acidilactici and 25 coccal strains were identified as Enterococcus faecium, Streptococcus lactis and Strep. bovis. A few strains remained unidentified.

Characterization and Distribution of Lactic Acid Bacteria from Traditional Cocoa Bean Fermentations in Bahia

Bacteria of the families Lactobacilaceae and Streptococcaceae were isolated from cocoa beans fermented by the traditional method used in the State of Bahia (Brazil). During the first 48 hr of the process these bacteria were better established than the yeasts. This observation differs from those reported by other researchers working in other countries. Identification studies showed eight homolactic species: Lactobacillus plantarum, Lactobacillus casei, Lactobacillus delbrueckii, Lactobacillus acidophilus, Lactobacillus lactis, Pediococcus cerevisiae, Pediococcus acidilactici, Streptococcus lactis and two heterolactic species: Leuconostoc mesenteroides and Lactobacillus brevis. L. plantarum was found better distributed and the thermophile L. delbrueckii was found to constitute 26% of the population at 16 hr.