Activity Of Lactic Acid Bacteria Research Articles

Exploration of ��-Glucuronidase Activity of Lactic Acid Bacteria Isolated from Kimchi

Exploration of ��-Glucuronidase Activity of Lactic Acid Bacteria Isolated from Kimchi

Bacteriocin Activity of Lactic Acid Bacteria Isolated from Rumen Fluid of Thin Tail Sheep

The objective of this study was to determine the activity and the stability of bacteriocin from lactic acid bacteria (BAL) isolated from rumen fluid of thin-tail sheep under the temperature (80, 100, and 121°C), pH (3, 7, and 10), and the length of storage (for 2 weeks under the temperature -8, 11, and 29°C). Lactic acid bacteria obtained by isolation, selection, and identification of thin-tailed sheep rumen fluid were used for bacteriocin production. The crude bacteriocin was partially purified using 70% ammonium sulfate, then was dialysis for 12 hours. The obtained bacteriocin then tested its inhibitory activity against E.coli (representing Gram-negative) and S. aureus (representing Gram-positive) under temperature (80, 100, and 121°C), pH (3, 7, and 10), and the length of storage (for 2 weeks under the temperature -8, 11, and 29°C). The data of bacteriocin activity based on pH, temperature, and the length of storage were analyzed with factorial, then when there was a significant difference of variable because treatment was continued with Duncan's Multiple Range Test (DMRT) test. The results showed that the bacteriocin activity of the three types of BAL against S.aureus is greater than E.coli. The highest activity was shown in pH 3, while the lowest activity was shown at pH 10 (P<0.01). The highest activity was shown at a heating temperature of 100°C, while the lowest activity was shown at a heating temperature of 80°C (P<0.01). The activity of bacteriocin produced by BAL 0 A, BAL 1 A, and BAL 4 C tended to be stable to the heating temperature of 80, 100, and 121°C but decreased with increasing pH value (pH 3, 7, and 10). The best of bacteriocin activity was found at pH 3 (acid), heating at 100°C, and stored at -8°C for 14 days.

A conserved motif liganding the [4Fe–4S] cluster in [4Fe–4S] fumarases prevents irreversible inactivation of the enzyme during hydrogen peroxide stress

Organisms have evolved two different classes of the ubiquitous enzyme fumarase: the [4Fe–4S] cluster-containing class I enzymes are oxidant-sensitive, whereas the class II enzymes are iron-free and therefore oxidant-resistant. When hydrogen peroxide (H2O2) attacks the most-studied [4Fe–4S] fumarases, only the cluster is damaged, and thus the cell can rapidly repair the enzyme. However, this study shows that when elevated levels of H2O2 oxidized the class I fumarase of the obligate anaerobe Bacteroides thetaiotaomicron (Bt-Fum), a hydroxyl-like radical species was produced that caused irreversible covalent damage to the polypeptide. Unlike the fumarase of oxygen-tolerant bacteria, Bt-Fum lacks a key cysteine residue in the typical “CXnCX2C″ motif that ligands [4Fe–4S] clusters. Consequently H2O2 can access and oxidize an iron atom other than the catalytic one in its cluster. Phylogenetic analysis showed that certain clades of bacteria may have evolved the full “CXnCX2C″ motif to shield the [4Fe–4S] cluster of fumarase. This effect was reproduced by the construction of a chimeric enzyme. These data demonstrate the irreversible oxidation of Fe–S cluster enzymes and may recapitulate evolutionary steps that occurred when microorganisms originally confronted oxidizing environments. It is also suggested that, if H2O2 is generated within the colon as a consequence of inflammation or the action of lactic acid bacteria, the inactivation of fumarase could potentially impair the central fermentation pathway of Bacteroides species and contribute to gut dysbiosis.

Effect of mixed species alcoholic fermentation on growth and malolactic activity of lactic acid bacteria.

In recent years, there is an increasing interest from the winemaking industry for the use of mixed fermentations with Starmerella bacillaris (synonym Candida zemplinina) and Saccharomyces cerevisiae, due to their ability to modulate metabolites of oenological interest. The current study was carried out to elucidate the effect of this fermentation protocol on the growth and malolactic activity of lactic acid bacteria (LAB) used for malolactic fermentation (MLF) and on the chemical and volatile profile of Nebbiolo wines and their chromatic characteristics. To this end, two LAB species, namely Lactobacillus plantarum and Oenococcus oeni, were inoculated at the beginning and at the end of the alcoholic fermentation (AF) performed by pure and mixed yeast using the abovementioned yeasts. The different yeast inoculation protocols and the combination of species tested influenced greatly the interactions and behavior of the inoculated yeasts and LAB during AF and MLF. For both LAB species, inoculation timing was critical to how rapidly MLF started and finished. Fermentation inoculated with L. plantarum, at the beginning of the AF, completed MLF faster than those inoculated with O. oeni. The presence of Starm. bacillaris in mixed fermentation promoted LAB growth and activity, in particular, O. oeni. Furthermore, LAB species choice had a greater impact on the volatile and chromatic profile of the wines than inoculation time. These findings reveal new knowledge about the importance of LAB species choice and inoculation time to ensure fast MLF completion and to improve wine characteristics in mixed fermentation with Starm. bacillaris and S. cerevisiae.

Isolation, Screening, and Identification of Proteolytic Lactic Acid Bacteria from Indigenous Chao Product

ABSTRACTThe aim of the study was to isolate, select, and identify proteolytic lactic acid bacteria (LAB) from chao, a traditional fermented fish from Pangkajene and Kepulauan Regency, South Sulawesi, Indonesia. LAB was isolated by poured plate method. Proteolytic LAB were selected using agar skim milk media. Protease activity of LAB was determined based on the amount of tyrosine released in unit/mL. Proteolytic LAB were identified using API 50 CHL kit and 16S rRNA gene sequence analysis. The result showed that a total of 60 isolates were obtained from chao, and 57% of them were cocci-shape. Fifteen isolates were halotolerant proteolytic LAB. Their R values and protease activity were 2.11–3.39 and 0.267–0.304 U/mL, respectively. Identification by API 50 CHL kit showed that four rod-shape isolates were Lactobacillus plantarum, and two others were Lactobacillus curvatus. Cocci-shape isolates could not be identified as cocci bacterium. Rep-PCR results showed that there were two kinds of bands, namely thick and thin. Two isolates were selected from two types of bands that had the highest R for the analysis of 16S rRNA gene sequences, namely Ags1-3 and Ags7-3. The results showed that Ags1-3 isolate was identified as Lactobacillus plantarum and Ags7-3 as Pediococcus acidilactici.

An electricalchemical method to detect the branch-chain aminotransferases activity in lactic acid bacteria

In this study, an electrochemical system was established to detect the branched-chain amino acid aminotransferase (BCAT) activity in lactic acid bacteria (LAB). A nanocomposite of chitosan (CS) with multi-walled carbon nanotubes (MWCNTs) was synthesized, and the composite solution were uniformly spread over the glassy carbon electrode (GCE) surface by drop-casting to fabricate an electrochemical biosensor. The composite was characterized by scanning electron microscopy (SEM) and cyclic voltammetry (TEM). Results indicated that the MWCNTs–CS/GCE electrode exhibited higher stability and sensitivity, compared with the GCE electrode. The linear response for nicotinamide adenine dinucleotide (NADH) was 1.0–9.0 μM and the response limit was 0.12 µM. The system effectively and sensitively detected the BCAT activity by NADH concentration in the LAB culture, comparing with the optical method. The culture condition of LAB was optimized by using this system, evidencing that established method was available to detect the BCAT activity of LAB.

Establishment Limitation Constrains the Abundance of Lactic Acid Bacteria in the Napa Cabbage Phyllosphere.

Patterns of phyllosphere diversity have become increasingly clear with high-throughput sequencing surveys, but the processes that control phyllosphere diversity are still emerging. Through a combination of lab and field experiments using Napa cabbage and lactic acid bacteria (LAB), we examined how dispersal and establishment processes shape the ecological distributions of phyllosphere bacteria. We first determined the abundance and diversity of LAB on Napa cabbage grown at three sites using both culture-based approaches and 16S rRNA gene amplicon sequencing. Across all sites, LAB made up less than 0.9% of the total bacterial community abundance. To assess whether LAB were low in abundance in the Napa cabbage phyllosphere due to a limited abundance in local species pools (source limitation), we quantified LAB in leaf and soil samples across 51 vegetable farms and gardens throughout the northeastern United States. Across all sites, LAB comprised less than 3.2% of the soil bacterial communities and less than 1.6% of phyllosphere bacterial communities. To assess whether LAB are unable to grow in the phyllosphere even if they dispersed at high rates (establishment limitation), we used a gnotobiotic Napa cabbage system in the lab with experimental communities mimicking various dispersal rates of LAB. Even at high dispersal rates, LAB became rare or completely undetectable in experimental communities, suggesting that they are also establishment limited. Collectively, our data demonstrate that the low abundance of LAB in phyllosphere communities may be explained by establishment limitation.IMPORTANCE The quality and safety of vegetable fermentations are dependent on the activities of LAB naturally present in the phyllosphere. Despite their critical role in determining the success of fermentation, the processes that determine the abundance and diversity of LAB in vegetables used for fermentation are poorly characterized. Our work demonstrates that the limited ability of LAB to grow in the cabbage phyllosphere environment may constrain their abundance on cabbage leaves. These results suggest that commercial fermentation of Napa cabbage proceeds despite low and variable abundances of LAB across different growing regions. Propagule limitation may also explain ecological distributions of other rare members of phyllosphere microbes.

AKTIVITAS ANTIMIKROBA BAKTERI ASAM LAKTAT YANG DIISOLASI DARI MAKANAN TRADISIONAL FERMENTASI KHAS BATAK “NANIURA”

Lactic acid bacteria (LAB) could be isolated from various fermented food products. One potential source of LAB is traditional fermented food. The aim of the study was to isolate and investigate antimicrobial activity of LAB isolated from traditional Batak food, “naniura”. The LAB isolates were characterized by Gram staining, fermentation type and catalase test. The investigation of antimicrobial activity of LAB against pathogenic bacteria were conducted using disc diffusion method. The results showed that 6 isolates of BAL were successfully isolated namely BN1, BN2, BN3, BN4, BN5 and BN6 had characteristics of Gram positive, rod shaped and catalase negative. All selected isolate have heterofermentation type. Four isolates (BN1, BN2, BN5 and BN6) were able to inhibit S. aureus, E. coli and S. typhi with inhibition zone diameters ranging from 6,9 to 12,3 cm. Based on the result, it was concluded that LAB isolated from naniura has potential as a source of probiotics.

Inhibition of Nitric Oxide Production, Oxidative Stress Prevention, and Probiotic Activity of Lactic Acid Bacteria Isolated from the Human Vagina and Fermented Food.

In this study, lactic acid bacteria (LAB) with antioxidative and probiotic activities were isolated from the vaginas of Korean women and from fermented food. Among 34 isolated LAB strains, four strains (MG4221, MG4231, MG4261, and MG4270) exhibited inhibitory activity against nitric oxide production. The MG4221 and MG4270 strains were identified as Lactobacillus plantarum, and MG4231 and MG4261 were identified as Lactobacillus fermentum. These strains were able to tolerate pepsin and pancreatin, which is required for probiotic potential. The antioxidant effects of culture filtrates obtained from selected strains included 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging capacity. Most of the culture filtrates had effective DPPH scavenging activity.In conclusion, the selected strains have significant activities and are potentially applicable to the development of functional foods. These strains might also contribute to the prevention and control of several diseases associated with oxidative stress, when used as functional probiotics.

Screening of Lactic Acid Bacteria Isolated From Philippine Traditional Fermented Products: Potential Probiotic Bacteria with Antimicrobial and Cytotoxic Activities

Thirty (30) isolates of lactic acid bacteria (LAB) from Philippine traditionally‐prepared fermented products, namely: fermented soy‐bean paste, fermented mustard and fermented rice‐fish mixture were studied for their in vitro antimicrobial and cytotoxic activities. Seventeen (17) isolates were identified as Lactobacillus plantarum, while 13 isolates were identified as Enterococcus spp. using 16S rDNA sequences. The phylogenetic tree revealed that there were three clusters of LAB with 100% similarity level. Disc diffusion method was used to determine the antibacterial activity of LAB against Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922, while the modified agar overlay method was used to determine the antifungal activity of LAB isolates on the yeast Candida albicans, and the dermatophytes Microsporum gypseum, Trichophyton rubrum and Epidermophyton floccosum. The filter‐sterilized LAB culture supernatants were evaluated for their cytotoxicity to mammalian colon cancer cell lines HT‐29 and HCT116, and normal human dermal fibrolasts HDFn using resazurin assay (PrestoBlue™). Colchicine was the positive control. No antimicrobial activity was observed against the bacterial test organisms and the yeast Candida albicans. On the other hand, all of the tested LAB strains were fungicidal for all the test dermatophytes. Cytotoxicity index profiles of all the LAB supernatants tested showed that these were cytotoxic to HT‐ 29 and HCT116 colon cancer cell lines, but were not cytotoxic for the normal HDFn cells. Results provide strong support for the role of the lactic acid bacteria studied for antifungal treatment and anticancer therapy.Support or Funding Information1. DOST‐SEI, Accelerated Science Technology Human Resource Development Program2. Center for Environmental and Natural Science Research, De La Salle University, Taft Avenue, Manila3. De La Salle University, College of Science, Biology DepartmentThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Characterization and antioxidant ability of potential probiotic lactic acid bacteria in ogi liquor and lemon juice-ogi liquor

Ogi is an indigenous edible fermented cereal slurry but the steep liquor is usually wasted or administered as therapeutic to suppress certain illnesses. The combination of lemon juice and ogi steep liquor (OSL) is known to possess bioactive metabolites. This study evaluated potential probiotic lactic acid bacteria (LAB) in different OSL (Zea mays, Sorghum bicolor, and Pennisetum glaucum L.) and lemon juice-ogi steep liquor (LJOSL) based on low pH, bile and lysozyme tolerances, hydrophobicity and auto-aggregation, antibiotic, cholesterol removal, exopolysaccharide production, β-galactosidase, and antimicrobial and hemolytic activities using standard methods. Presumptive LAB were sequenced and assayed for radical scavenging using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and lipid peroxidation inhibitory (LPI) tests. Presumptive LAB counts were higher in maize OSL (0 h:5.09 log CFU/ml) and combined cereal OSL (24–48 h:7.65 and 7.72 log CFU/ml) but decreased in all steep liquors at 72 h, except in millet OSL (7.72 log CFU/ml). A total of 120 LAB isolates were randomly selected. Based on pH and bile tolerances, 14 isolates were comparable to reference strains. All these isolates demonstrated probiotics properties except for three that did not show γ-hemolysis. Sequenced LAB isolates were identified as Lactobacillus plantarum, Lactobacillus fermentum, Pediococcus pentosaceus, and Weissella cibara. DPPH activities of LAB gradually increased during fermentation with the highest activity of DPPH (58.77%) and LPI (57.94%) activity in L. plantarum. Strong correlations were found between DPPH and LPI in all the selected isolates. The antioxidant property of probiotic LAB in OSL and LJOSL could contribute to its therapeutic nature.

Comparative studies of versatile extracellular proteolytic activities of lactic acid bacteria and their potential for extracellular amino acid productions as feed supplements

BackgroundIncreasing understanding on the functions of amino acids (AA) has led to new commercial applications and expansion of the worldwide markets. However, the current technologies rely heavily on non-food grade microorganism and chemical synthesis for the production of AA. Several studies reported that lactic acid bacteria (LAB) have the capability of producing AA owing to their well-established proteolytic system and amino acid biosynthesis genes. Hence, the objectives of this study were to explore the extracellular proteolytic activity of LAB isolated from various Malaysian fermented foods and their potential to produce AA extracellularly as feed supplements.ResultsAll the studied LAB isolates were versatile extracellular protease producers, whereby extracellular protease activities were detected from acidic to alkaline pH (pH 5, pH 6.5, pH 8) using qualitative and quantitative proteolytic assays. The highest proteolytic activity at pH 5 (15.76 U/mg) and pH 8 (19.42 U/mg) was achieved by Lactobacillus plantarum RG14, while Lactobacillus plantarum RS5 exhibited the highest proteolytic activity of 17.22 U/mg at pH 6.5. As for the results of AA production conducted in de Man, Rogosa and Sharpe medium and analysed by high pressure liquid chromatography system, all LAB isolates were capable of producing an array of AA. Generally, Pediococcus sp. showed greater ability for AA production as compared to Lactobacillus sp. Moreover, the studied LAB were able to produce a few major feed supplement AA such as methionine, lysine, threonine and tryptophan. P. pentosaceus TL-3 recorded the highest methionine and threonine productivity of 3.72 mg/L/h and 5.58 mg/L/h respectively. However, L. plantarum I-UL4 demonstrated a lysine productivity of 1.24 mg/L/h, while P. acidilactici TP-6 achieved up to 1.73 mg/L/h of tryptophan productivity.ConclusionAll the 17 studied LAB isolates possessed versatile extracellular proteolytic system and have vast capability of producing various amino acids including a few major feed supplement AA such as methionine, lysine, threonine and tryptophan. Despite AA production was strain dependent, the studied LAB isolates possessed vast potential and can be exploited further as a bio-agent or an alternative amino acids and bioactive peptide producers.

ЩОДО ПИТАННЯ ПРО УТВОРЕННЯ БІОГЕННИХ АМІНІВ У ХАРЧОВИХ ПРОДУКТАХ

У статті показано, що особливої популярності останнім часом набувають фермен-товані продукти. Однак у процесі виробництва зрілих вин, сирів, ковбас і багатьох рибних продуктів утворюються біогенні аміни в результаті декарбоксилювання вільних амінокислот під дією ферментних систем мікробного походження при порушенні умов зберігання. Біогенні аміни - це група азотовмісних органічних сполук з аліфатичною (путресцин, кадаверин, спермін, спермидин), ароматичною (тирамін, фенілетиламін) або гетероциклічною (гістамін, триптаміну) структурою. Деякі з них мають велику біологічну активність (гістамін, серотонін, дофамін, тирамін), інші (путресцин і кадаверин) підсилюють токсичну дію гістаміну на організм людини. В окремих випадках, коли вміст гістаміну в десятки разів перевищує гранично допустимий рівень, риба може набувати гострого смаку. Отруєння гістаміном можуть мати летальний результат. Аналіз літературних даних показав, що до причин утворення біогенних амінів відносять: мікробіологічну якість вихідної сировини, умови і терміни зберігання сировини і готової продукції, наявність декарбоксілазно позитивних мікроорганізмів.

Antibacterial Activity of Lactic Acid Bacteria to Improve Shelf Life of Raw Meat.

Lactic Acid Bacteria （LAB） are generally recognized as safe. It has been used to increase the shelf-life of fermented products, and its antimicrobial action is based on the metabolites secretions, such as lactic acid, hydrogen peroxide, reuterin, bacteriocins and the like-bacteriocins substances. It has been proven that LAB are able to inhibit deteriorating bacteria of raw meat, but improper handling of live cultures could lead to spoilage. So, the use of their bacteriocins, small antimicrobial peptides, could be an alternative. Besides reducing the number of spoilage bacteria, it seeks to inhibit pathogenic bacteria such as Salmonella, enterohemorrhagic Escherichia coli and Listeria. The food industry uses few bacteriocins and now bacterial resistance has been reported. For that reason, the search of novel bacteriocins produced by LAB is a priority. Moreover, the natural microbiota of meat could be a reservoir of LAB.

Influence of consortia of lactic acid microorganisms on the dynamics of active and titratable acidity at the main stage of fermentation of white cabbage

Fermented cabbage is traditionally produced naturally, where under the action of lactic acid bacteria contained in raw materials, carbohydrates are converted into lactic acid. However, the direct fermentation process does not always lead to an optimal quality product. That is why the use of lactic acid microorganisms is a good alternative to the direct fermentation of cabbage, as with the help of starter cultures the process can be controlled. In this connection, the use of strains of lactic acid microorganisms allows to achieve rapid production of lactic and acetic acids and leads to a rapid decrease in pH, which in turn leads to the suppression of pathogenic microflora, and therefore to the creation of favorable conditions for the fermentation process. The aim of this study was to study the effect of consortia of lactic acid microorganisms on the dynamics of active and titratable acidity in the main stage of fermentation of white cabbage of the variety "Parus". For the study, the prepared modified model medium (MMC) from cabbage was used. In this work, we used lactic acid bacteria Leuconostoc mesenteroides and its consortia: L. mesenteroides + L. casei, L. mesenteroides + L. plantarum, L. mesenteroides + L. brevis, L. mesenteroides + L. casei + L. plantarum, L. mesenteroides + L. plantarum + L. brevis, L. mesenteroides + L. brevis + L. casei. Mathematical processing was carried out according to the obtained experimental data. Analysis of experimental data showed that at the main stage of fermentation the relationship of lactic acid microorganisms in the studied consortia was expressed by synergistic and antagonistic properties. In this case, the best results on the dynamics of growth of active and titratable acidity were obtained in consortiums L. mesenteroides + L. plantarum, L. mesenteroides + L. casei + L. plantarum, L. mesenteroides + L. plantarum + L. brevis.

Bile salt hydrolase activity is present in nonintestinal lactic acid bacteria at an intermediate level.

It is generally considered that bile salt hydrolase (BSH) activity is hardly detected in nonintestinal lactic acid bacteria (LAB). The aim of this study was to investigate the distribution and intensity of BSH activity in LAB isolated from naturally fermented vegetables and milk. A total of 624 lactic acid bacterial strains classified into 6 genera and 50 species were isolated from 144 naturally fermented vegetable samples and 103 naturally fermented milk samples, and their BSH activity was screened by gas chromatography with electron capture detection. The BSH-positive strains were further analyzed quantitatively for their deconjugation ability against six human-conjugated bile salts by HPLC based on the disappearance of the conjugated bile salts from the reaction mixture. The results showed that 39% of the strains possessed BSH activity distributed in 24 lactic acid bacterial species. The strains of the fermented vegetable origin showed a 0.5-fold higher incidence of BSH-positive strains than those of the fermented milk origin, and the lactic acid bacilli exhibited 2.5-fold higher incidence of BSH-positive strains than the lactic acid cocci in general. The strains of the fermented vegetable origin generally had greater bile salt deconjugation ability than those of the fermented milk origin. More than 97% and 93% of the BSH-positive strains exhibited a greater substrate preference for glycoconjugated bile salts than tauroconjugated bile salts and for dihydroxy bile salts than trihydroxy bile salts, respectively. This study demonstrated that BSH activity was also present in nonintestinal LAB.

Antifungal Activity of Lactic Acid Bacteria Isolated from Peanuts, Gari, and Orange Fruit Juice against Food Aflatoxigenic Molds

ABSTRACTThis study aims to evaluate the antifungal activity of lactic acid bacteria (LAB) from some Cameroonian food commodities against mycotoxigenic and spoilage molds. Following LAB isolation, the antifungal activity of the isolates was assessed. The organic acids were quantified using high-performance liquid chromatography and the ability of the LAB to reduce mold biomass and aflatoxin production was evaluated. The LAB were identified and the biopreservative potential of strain LO3 was evaluated on tomato paste. Nine percent of the strains isolated showed broad antifungal activity. The activity was due to the effect of organic acids comprising lactic, acetic, 4-hydroxy-3-phenyllactic and 3-phenyllactic acids. Lactobacillus plantarum LO3 exhibiting the highest and broadest antifungal activity was selected and showed the capacity to inhibit fungal growth and aflatoxin production in vitro. Moreover, this strain and its cell-free supernatant showed the ability to prevent aflatoxigenic mold growth in tomato paste without altering its physico-chemical and organoleptic properties.

ISOLASI DAN AKTIVITAS ANTI MIKROBA BAKTERI ASAM LAKTAT DARI FERMENTASI NIRA KELAPA SAWIT

The aim of the study was to isolate lactic acid bacteria (LAB) from palm oil sap and to investigate the anti microbial activity of LAB against pathogen bacteria, Staphylococcus aureus and Escherichia coli using disc diffusion method. Palm oil sap were enriched using spesific medium MRS (Man Rogosa Sharpe) broth overnight, serial dilution were conducted and the culture were spread on the surface of MRS agar and then incubated for 48 hours. The result showed the total colonies of LAB were 1,4 x 107 CFU/mL. 6 colonies were randomly selected namely EHN1, EHN2, EHN3, EHN4, EHN5 and EHN6. The selected colonies are classified as Gram positive and bacilli in morphology. Antimicrobial activity against pathogenic bacteria was investigated using disc diffusion method. Antimicrobial activity of isolates against E.coli and S.aureus were 12,2 mm; 9mm; 11mm; 11mm; 10,5mm; 12 mm dan 13,5mm; 11mm; 12mm; 11,5mm; 12mm; 12,5mm respectively. from these result it can be concluded that LAB isolated from oil palm sap has potential as probiotic.

Antioxidative and Probiotic Activities of Lactic Acid Bacteria Isolated from Traditional Artisanal Milk Cheese from Northeast China

The antioxidant activities and probiotic properties of lactic acid bacteria (LAB) selected from traditional artisanal milk cheese from Northeast China were investigated in this study. Among the 322 isolates, 175 LAB were identified through probiotic characterizations. Twenty-three out of the 175 strains exhibited antibacterial activity against more than four enteropathogenic bacteria. The antioxidant action of 23 LAB was evaluated by different methods, including scavenging of hydroxide radicals, DPPH radicals, superoxide anions, and ABTS+ radical cation. The ability to resist hydrogen peroxide and superoxide dismutase activity was also studied. These strains significantly showed antioxidative capacity compared with a non-antioxidative strain, closely followed by the standard probiotic strain Lactobacillus rhamnosus GG or even better. Based on 16S ribosomal RNA-sequence analysis, the 23 isolates belonged to the species Lactobacillus plantarum (16), Lactobacillus paracasei (2), Enterococcus faecium (2), Lactobacillus helveticus (1), Weissella paramesenteroides (1), and Pediococcus pentosaceus (1). In addition, five out of the 23 strains were susceptible to most of the tested antibiotics, showed extremely high levels of hydrophobicity similar to or better than the reference strain L. rhamnosus GG, and did not exhibit any hemolytic activity. These five strains were also confirmed safe through bacterial translocation. Results suggest that at least five probiotic candidates can be explored as prospective antioxidants and used as a potential antioxidant strain to be utilized in the development of functional foods and new starter cultures.

Lactic acid bacteria isolated from Brazilian Minas artisanal cheeses and their in vitro antagonisms against Mycobacterium bovis BCG

The consumption of raw milk and its products is a risk factor associated with zoonotic tuberculosis. Lactic acid bacteria (LAB) show inhibitory activity against Mycobacterium bovis, the causative agent of tuberculosis. The aim of this study was to assess the in vitro antagonistic activity of LAB from Brazilian Minas artisanal cheese against M. bovis bacillus Calmette‐Guérin (BCG). Nine LAB were tested against M. bovis BCG in five in vitro antagonistic assays. Four lactobacilli gave the best results in all the experiments. This could be due to their growth rate, acid and bacteriocin production. In conclusion, LAB are capable of inhibiting M. bovis BCG viability.