Indigenous Lactic Acid Bacteria Research Articles

ANTIFUNGAL AND ANTIBACTERIAL ACTIVITY OF SOME LACTOBACILLI ISOLATED FROM CAMEL’S MILK BIOTOPE IN THE SOUTH OF ALGERIA

Antifungal activity has been the subject of numerous recent works to fight the development of molds in food products and to reduce alteration. The objective of this study is the detection of new indigenous lactic acid bacteria (LAB) strains isolated from Algerian camel’s milk which have an antifungal activity. A number of 264 LAB were isolated from fermented camel’s milk where 80 rods isolates were identified by phenotypical, physiological and biochemical tests. All retained isolates belong to the genus Lactobacillus (Lb.). The antifungal activity was determined by using confrontation and overlay techniques. The screening of antifungal activity against Aspergillus niger, Aspergillus fumigatus and Penicillium sp. showed that 14 strains have an antifungal activity. These later isolates were identified as Lb. plantrarum, Lb. paracasei subsp. paracasei, Lb. brevis, Lb. rhamnosus and Lb. pentosus. These strains have shown an effect on mycelial growth and spore germination. Penicillium sp. is the most inhibited followed by Aspergillus ssp. No inhibitory activity could be detected against fungi with the supernatant. However, supernatant have an inhibitory activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Listeria ivanovii. P. aeruginosa is the only specie who has been affected by the neutralized supernatant. The redissolved dry supernatant of Lb. brevis revealed an inhibition of both fungal and bacterial indicator strains. Results suggest that camel’s milk LAB’s strains could be selected for application to control spoilage, fungal growth and pathogenic bacteria. The use of LAB producing antifungal metabolites represents a technological advantage for the food industry.

Microbial community dynamic in tomato fruit during spontaneous fermentation and biotechnological characterization of indigenous lactic acid bacteria

The present work aimed to study the microbial dynamics in tomato fruits under spontaneous fermentation process and the biotechnological properties of lactic acid bacteria (LAB) for future starter culture formulation. The isolation of native microbial species was performed using diverse specific media. Microbial identification was performed using the variability analysis and sequencing of ribosomal DNA-amplified fragments. Moreover, LAB (n = 85) were evaluated for several physiological and technological characteristics, including salinity and temperature tolerance, esculin and arginine hydrolysis, carbohydrate fermentation, exopolysaccharide production, and antagonistic activity. As well, lycopene, flavonoid, and antioxidant compounds were determined in fermented tomato samples. Bacterial isolates were assigned to ten bacterial genera, namely, Microbacterium, Bacillus, Staphylococcus, Pantoea, Flavobacterium, Enterobacter, and Citrobacter including three genera of LAB: Lactobacillus, Leuconostoc, and Enterococcus. Moreover, the amplification of ITS1-5.8S-ITS2 regions allowed the detection of Aspergillus fumigatus and three species of yeast: Candida carpophila, Meyerozyma caribbica, and Wickerhamomyces onychis. During the spontaneous fermentation, the majority of spoilage bacteria and fungi completely disappeared after the third week, whereas LAB and yeast remain until the end of fermentation. LAB exhibited important technological features and high antibacterial activity against human and food-borne pathogenic bacteria. Furthermore, LAB produced various antioxidants for fermented food products. Promising results of this study allowed the identification of the major encountered taxa during spontaneous fermentation of tomato and underline the importance of LAB as a starter culture to achieve microbiologically safe products providing prolonged stability and flavor of vegetable-derived foods.

Characterization of Diversity and Probiotic Efficiency of the Autochthonous Lactic Acid Bacteria in the Fermentation of Selected Raw Fruit and Vegetable Juices.

The diversity of indigenous lactic acid bacteria (LAB) in fermented broccoli, cherry, ginger, white radish, and white-fleshed pitaya juices was analyzed using culture-independent and -dependent approaches. The major properties of selected probiotic strains, including dynamic variations in pH, viable cell counts, antibiotic resistance, bacterial adhesion to hydrophobic compounds, and survivability during simulated gastrointestinal transit, were investigated using broccoli as the fermentation substrate. In broccoli and ginger juices, the genus Lactobacillus occupied the dominant position (abundances of 79.0 and 30.3%, respectively); in cherry and radish juices, Weissella occupied the dominant position (abundances of 78.3 and 83.2%, respectively); and in pitaya juice, Streptococcus and Lactococcus occupied the dominant positions (52.2 and 37.0%, respectively). Leuconostoc mesenteroides, Weissella cibaria/soli/confusa, Enterococcus gallinarum/durans/hirae, Pediococcus pentosaceus, Bacillus coagulans, and Lactococcus garvieae/lactis subspecies were identified by partial 16S rRNA gene sequencing. In general, the selected autochthonous LAB isolates displayed no significant differences in comparison with commercial strains with regard to growth rates or acidification in fermented broccoli juice. Among all the isolates, L. mesenteroides B4-25 exhibited the highest antibiotic resistance profile (equal to that of L. plantarum CICC20265), and suitable adhesion properties (adhesion of 13.4 ± 5.2% ∼ 36.4 ± 3.2% and 21.6 ± 1.4% ∼ 69.6 ± 2.3% to ethyl acetate and xylene, respectively). Furthermore, P. pentosaceus Ca-4 and L. mesenteroides B-25 featured the highest survival rates (22.4 ± 2.6 and 21.2 ± 1.4%, respectively), after simulated gastrointestinal transit. These results indicated a high level of diversity among the autochthonous bacterial community in fermented fruit and vegetable juices, and demonstrated the potential of these candidate probiotics for applications in fermentation.

Fermented Dessert with Whey, Ingredients from the Peel of Jabuticaba (Myrciaria cauliflora) and an Indigenous Culture of Lactobacillus plantarum: Composition, Microbial Viability, Antioxidant Capacity and Sensory Features.

The use of agro-industrial wastes in combination with indigenous lactic acid bacteria is an interesting option to confer functional potential to food products. The microbial viability, chemical composition, antioxidant capacity, texture and sensory acceptability of a fermented dairy dessert containing the indigenous culture Lactobacillus plantarum CNPC003, whey and ingredients obtained from the jabuticaba (Myrciaria cauliflora) peel were compared with formulations without lactobacilli (control) or containing a commercial probiotic culture (Lactobacillus rhamnosus LR32). L. plantarum presented viability higher than 7 log CFU g−1 in the dessert, as did the commercial probiotic, for 21 days at 4 ± 1 °C. Total phenolic contents (45–60 mg gallic acid equivalents, GAE, 100 g−1) were comparable to those of other studies evaluating dairy products containing plant sources. The formulations were low in fat, presenting as acceptable for overall consumption, with attractive color and appreciable texture. Considering the total antioxidant capacity, 200–250 g of dessert would be necessary to capture 1 g of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The dessert with Lactobacillus plantarum CNPC003 is seen as a viable alternative for the use of whey and jabuticaba peel, as well as a potential functional food due to the concentration of lactobacilli reached, besides the presence of antioxidant phenolic compounds.

Characterization of indigenous Pediococcus pentosaceus, Leuconostoc kimchii, Weissella cibaria and Weissella confusa for faba bean bioprocessing

The interest towards legumes in food applications has risen over the past decades. However, the presence of antinutritional factors (ANF) and the poor technological performances still restricts their application in food fortification. In this study, four lactic acid bacteria (LAB) isolated from faba bean were applied as starter cultures for faba bean bioprocessing. None of the strains employed produced exopolysaccharides from raffinose, on the contrary, they did with sucrose as substrate. The fermented doughs were characterized and the strains were compared for their adaptation capacity and metabolic performance including the formation of dextrans, the degradation of ANF and the ability to improve antioxidant activity and in vitro protein digestibility (IVPD). A contribution to the proteolysis was given by the presence of endogenous enzymes, responsible for the increase of peptides and amino acids in dough from irradiated flour. However, the LAB strains further enhanced proteolysis. Weissella cibaria VTT E-153485 led to the highest peptide release and consequentially to the highest IVPD. In doughs fermented with Pediococcus pentosaceus VTT E-153483 and Leuconostoc kimchi VTT E-153484, phytic acid was reduced to more than half the initial concentration. Inoculated doughs had significantly lower content of oligosaccharides after 24 h of incubation compared to the controls. The most efficient raffinose consumption was found for Leuc. kimchi and W. cibaria. Doughs inoculated with weissellas contained >1% of dextrans. Weissella confusa VTT E-143403 induced a significant increment in viscosity (ca. 7 times higher than the controls). This study revealed that well-characterized, indigenous LAB provided beneficial biotechnological features in faba bean dough processing and contributed to its implementation in the food production.

Sensory Evaluation of Yogurt-like Set and Yogurt-like Drink Produced by Indigenous Probiotic Strains for Market Test

Lactic acid bacteria have been isolated from several Indonesian indigenous fermented foods and screened for the potential strains as probiotic candidates. The aim of this study was to evaluate sensory properties and respondents’ preference of yogurt-like set and yogurt-like drink with various Indonesian indigenous probiotic strains produced by dairy industry. Indigenous probiotics of Lactobacillus plantarum MUT-7 and Lactobacillus plantarum DAD-13 were used to produce yogurt-like set and yogurt-like drink. Family perception toward yogurt-like drink was performed in Yogyakarta involving 100 family members. The yogurt-like products were also compared to yogurt containing commercial Lactobacilus bulgaricus and Streptococus thermophilus or commercial yogurt produced by dairy company. Several sensory evaluation toward sensory properties and panelist’s preference were performed in different cities. The result showed that the indigenous probiotic L. plantarum DAD-13 and L. plantarum MUT-7 were potential to be used as a starter culture for the production of yogurt-like set and yogurt-like drink. The combination of indigenous probiotics and indigenous lactic acid bacteria S. thermophilus DAD-11 resulted in better sensory properties of yogurt set compared to combination of L. bulgaricus and S. thermophilus.

Susceptibility of gut indigenous lactic acid bacteria in BALB/c mice to oral administered Lactobacillus plantarum

Cells of Lactobacillus plantarum strains AN1 and Tennozu-SU2 exert anti-inflammatory responses in ICR mouse models of inflammatory bowel disease and protective effects against S. Typhimurium infection in BALB/c mice, respectively. To clarify the existence of L. plantarum-susceptible gut indigenous bacteria, AN1 and Tennozu-SU2 cells were administered to BALB/c mice via drinking water. Gene amplicon sequencing of 16S rRNA of caecal content revealed that the AN1 and Tennozu-SU2 cells affected the abundance of caecal indigenous lactobacilli, but the effect on the dominant Clostridiales and Bacteroidales was not clear. With Blood and Liver (BL) agar containing 5% v/v horse blood, six typical colonies from faecal samples were detected as the principal lactobacilli. Among them, two typical colonies were isolated and identified to be AN1 and Tennozu-SU2. Two and one typical colonies detected in all mice were identified to be L. reuteri and L. murinus, respectively. The other one was identified and estimated to be indigenous L. plantarum detected in the Tennozu-SU2 group.

Phenotypic identification of indigenous fungi and lactic acid bacteria isolated from ’gatot’ an Indonesian fermented food

Astriani A, Diniyah N, Jayus J, Nurhayati N. 2018. Phenotypic identification of indigenous fungi and lactic acid bacteria isolated from ’gatot’ an Indonesian fermented food. Biodiversitas 19: 947-954. As a traditional Indonesian food made from cassava, ‘gatot' has special attracted characters of black appearance and chewy texture, mainly as a result of certain fungi and lactic acid bacteria (LAB) during the spontaneous fermentation. However, many producers were failed to gain these typical properties since much unwanted microbial strain often appears during the spontaneous fermentation. Therefore, this study was conducted to isolate and identify the indigenous fungi and LAB which predominantly contributed in fermentation of cassava during ‘gatot’ production. Fungi and LAB were isolated from conventionally made of the ‘gatot’ followed by the phenotypic identification of the isolates based on the morphological and physiological properties. The fungi isolates were morphologically distinguished by the type of mycelia, the shape, and color of the sporangium, while the LAB strains were identified by the type of cell and colony form. In addition, the physiological behavior of the LAB isolates was characterized by their typical growth temperature, its catalase activity and its fermentation profile using BBL crystal kit test. The predominant fungi isolates were identified as Botryodiplodia theobromae, Rhizopus oligosporus, Trichoderma sp. and Aspergillus niger. B. theobromae had greyish white to black color of mycelia when it mature. R. oligosporus had globose sporangium and blackish grey color of the mature mycelia. Trichoderma sp. had green color of the mature sporangium and mycelia. A. niger had yellow color of the mycelia and black color of sporangium. Meanwhile, the indigenous LAB was majority identified as Lactobacillus manihotivorans, Bacillus licheniformis, Brevibacillus brevis and Lactobacillus fermentum. Those bacteria were gram-positive, rods shape, catalase-negative and grew optimally at 37oC. The LAB also arise frequently in many spontaneously fermented food. B. theobromae, R. oligosporus, L. manihotivorans, and L. fermentum were potential and non-pathogenic microbial, which can be used as a starter culture to produce ‘gatot’ under controlled fermentation process.

Improving quality of common reed (Phragmites communis Trin.) silage with additives.

ObjectiveCommon reed (Phragmites communis Trin.) could potentially provide an alternative resource for silage; however, its silage quality is poor. The aim of this study was to investigate the factors in reed that contribute to poor quality and determine how the use of additives at ensiling could improve fermentation quality.MethodsIn Experiment 1, we determined the chemical composition and the presence of indigenous lactic acid bacteria (LAB) in reed. We further examined fermentation quality of reed silage under conditions without additives (NA) and treated glucose (G), lactic acid bacteria (L), and their combination (G+L). In Experiment 2, silage of NA, and with an addition of cellulase and lactic acid bacteria (CL) were prepared from harvested reed. The harvested reeds were fertilized at nitrogen concentrations of 0, 4, 8, and 12 g N/m2 and were harvested thrice within one year.ResultsThe indigenous LAB and fermentable carbohydrates are at extremely low concentrations in reed. Reed silage, to which we added G+L, provided the highest quality silage among treatments in Experiment 1. In Experiment 2, N fertilization had no negative effect on silage quality of reed. The harvest times decreased fermentable carbohydrate content in reed. The CL treatment provided a higher lactic acid content compared to the NA treatment. However, the quality of CL treated silage at the second and third harvests was significantly lower than at the first harvest, due to a reduction in carbohydrates caused by frequent harvesting.ConclusionThe causes of poor quality in reed silage are its lack of indigenous LAB and fermentable carbohydrates and its high moisture content. In addition, reed managed by frequent harvesting reduces carbohydrate content. Although the silage quality could be improved by adding CL, higher-quality silage could be prepared by adding fermentable carbohydrates, such as glucose (rather than adding cellulases).

Selection of indigenous lactic acid bacteria presenting anti-listerial activity, and their role in reducing the maturation period and assuring the safety of traditional Brazilian cheeses

Artisanal raw milk cheeses are highly appreciated dairy products in Brazil and ensuring their microbiological safety has been a great need. This study reports the isolation and characterization of lactic acid bacteria (LAB) strains with anti-listerial activity, and their effects on Listeria monocytogenes during refrigerated shelf-life of soft Minas cheese and ripening of semi-hard Minas cheese. LAB strains (n = 891) isolated from Minas artisanal cheeses (n = 244) were assessed for anti-listerial activity by deferred antagonism assay at 37 °C and 7 °C. The treatments comprised the production of soft or semi-hard Minas cheeses using raw or pasteurized milk, and including the addition of selected LAB only [Lactobacillus brevis 2-392, Lactobacillus plantarum 1-399 and 4 Enterococcus faecalis (1-37, 2-49, 2-388 and 1-400)], L. monocytogenes only, selected LAB co-inoculated with L. monocytogenes, or without any added cultures. At 37 °C, 48.1% of LAB isolates showed anti-listerial capacity and 77.5% maintained activity at 7 °C. Selected LAB strains presented a bacteriostatic effect on L. monocytogenes in soft cheese. L. monocytogenes was inactivated during the ripening of semi-hard cheeses by the mix of LAB added. Times to attain a 4 log-reduction of L. monocytogenes were 15 and 21 days for semi-hard cheeses produced with raw and pasteurized milk, respectively. LAB with anti-listerial activity isolated from artisanal Minas cheeses can comprise an additional barrier to L. monocytogenes growth during the refrigerated storage of soft cheese and help shorten the ripening period of semi-hard cheeses aged at ambient temperature.

Ensilage of oats and wheatgrass under natural alpine climatic conditions by indigenous lactic acid bacteria species isolated from high-cold areas.

Five different species of selected broad-spectrum antibiotic lactic acid bacteria isolated from extremely high–cold areas were used as starters to ferment indigenous forage oats and wheatgrass under rigid alpine climatic conditions. The five isolates were Lactobacillus plantarum QZ227, Enterococcus mundtii QZ251, Pediococcus cellicola QZ311, Leuconostoc mesenteroides QZ1137 and Lactococcus lactis QZ613, and commercial Lactobacillus plantarum FG1 was used as the positive control and sterile water as the negative control. The minimum and maximum temperatures were −22°C and 23°C during the fermentation process, respectively. The pH of wheatgrass silage fermented by the QZ227 and FG1 inocula reached the expected values (≤4.15) although the pathogens detected in the silage should be further investigated. All of the inocula additives used in this study were effective in improving the fermentation quality of oat silage as indicated by the higher content of lactic acid, lower pH values (≤4.17) and significant inhibition of pathogens. QZ227 exhibited a fermentation ability that was comparable with the commercial inoculum FG1 for the whole process, and the deterioration rate was significantly lower than for FG1 after storage for 7 months. The pathogens Escherichia coli, mold and yeast were counted and isolated from the deteriorated silage. E. coli were the main NH3-N producer while F. fungi and yeast produced very little.

Lactobacillus plantarum AN1 cells increase caecal L. reuteri in an ICR mouse model of dextran sodium sulphate-induced inflammatory bowel disease

To clarify the different effects of live and heat-killed probiotics on inflammatory bowel disease (IBD), the anti-inflammatory and protective effects of Lactobacillus plantarum AN1 cells isolated from the fermented fish aji-narezushi on murine macrophage RAW264.7 cells and in ICR mice with dextran sodium sulphate (DSS)-induced IBD were determined. L. plantarum AN1 cells showed anti-inflammatory activities in vitro, indicated by secretion of nitric oxide (NO) from RAW264.7 cells in the presence and absence of Escherichia coli 0111 lipopolysaccharide (LPS). L. plantarum AN1 cells also protected RAW264.7 cells against hydrogen peroxide toxicity. There was no difference between these effects in heat-killed and ultraviolet irradiation-killed cells. In the murine IBD model, both live and heat-killed L. plantarum AN1 cells via drinking water tended to ameliorate atrophy of colon length, mucosal tissue damage, and spleen enlargement. Amplicon sequencing of 16S rDNA (V4) revealed that both live and heat-killed AN1 cells increased abundance of indigenous lactic acid bacteria, particularly Lactobacillus reuteri. The results suggest that increased indigenous lactic acid bacterial abundance and feeding with L. plantarum AN1 cells synergistically improve effects against IBD.

Lactobacillus paracasei CD4 as potential indigenous lactic cultures with antioxidative and ACE inhibitory activity in soymilk hydrolysate

The present study evaluates indigenous Lactic acid bacteria (LAB) isolated from different fermented foods for their fermentation efficiency in soymilk generating anti-oxidative and anti-angiotensin-converting enzyme (ACE) activity in soymilk hydrolysate. The efficiency of lactic cultures to ferment soymilk was evaluated by fermenting 100 mL of soymilk with 1% of lactic cultures, incubated for 24 h at 37 °C. The efficiency of fermentation was determined in terms of degree of hydrolysis of soymilk which ranged from 7.17 to 11.09% for different cultures. Further, the fermented hydrolysate fraction was evaluated for its free radical scavenging activity and ACE inhibitory activity. The fermented soymilk hydrolysate from Lactobacillus rhamnosus GG, Brevibacilllus aydinogluensis, Brevibacillus thermoruber resulted in higher free radical scavenging activity ranging from 62 to 67% as compared to unfermented control (18.4%). However, ACE inhibitory activity was observed only in the hydrolysate from the strains of Lactobacillus paracasei CD4 and B. thermoruber HM34. The principal component analysis of the antioxidative properties of different cultures indicated that the release of total phenolic content and increase in free radical scavenging activity is strain specific.

Identification and Characterization Indigenous of Lactobacillus spfrom Bovine Rumen Fluidof Slaughterhouse

The discovery and characterisation of indigenous lactic acid bacteria (LAB) are important for diversity microbes as candidate probiotic. This research was aimed to identify lactic acid bacteria isolate from isolation process of local bovine rumen fluid from slaughterhouse in Surabaya Indonesia. Genotypic testing was conducted by analyzing 16S rDNA and biochemical identification. DNA of sample isolate was isolated and then amplified in vitro through the PCR method. Determination of nucleotide sequence of 16S rDNA was performed with sequencing method. The result of nucleotide sequence was than compared with GenBank database. The BLAST was then applied to identify the phylogenetic tree. Based on the biochemical characterization and nucleotide sequences, that isolate was identified as Lactobacillus rhamnosus subsp TG15. The result of this research showed that L.rhamnosus subsp TG15 showed viability bacteria in MRSA as control as much as 1.1 x 108 CFU/ml, mean while in MRSA pH 2, L.rhamnosus subsp TG15 showed its viability as much as 9.3 x 106 CFU/ml. Viability of isolate on bile tolerance 0.3% was 2.4 x 107 CFU/ml). Index antagonist bacteria test on S.aureus showed inhibition diameter as much as 2.0 mm and in antagonist test on E.coli as much as 2.5 mm. Based on the result, it could be concluded that this research found a new strain of lactic acid bacteria, L.rhamnosus subsp TG15 and that isolate has ability as the probiotic candidate. Keywords: L.rhamnosus subsp TG15; survival on acidity; bile salts; S.aureus and E.coli

Selection and use of indigenous mixed starter cultures for mustard leaves fermentation and the improvement of cuocai characteristics

To improve the characteristics and safety of traditional cuocai, the selection and use of mixed starter cultures is important. This study aimed to isolate the main indigenous lactic acid bacteria (LABs) and yeast species from spontaneous fermented mustard leaves, and they were used as starter cultures to ferment mustard leaves. Five predominant LABs, namely Q-1 (Enterococcus faecalis), G-1 (Lactobacillus plantarum), G-3 (Lactobacillus pentosus), and G-2 and G-4 (Lactobacillus buchneri) strains, and the two yeast strains J-1 (Issatchenkia orientalis) and J-2 (Issatchenkia occidentalis) were isolated from cuocai. From the results, Lb. plantarum and I. orientalis strains exhibited strong growth ability, fast acidification, and potent low-pH tolerance. Therefore, they were chosen as the mixed starter cultures to ferment mustard leaves. During the process of culture-dependent fermented mustard leaves, the changes of acidity, total crude protein, and total sugar were similar to those of culture-independent fermented mustard leaves, while the nitrite content of culture-dependent fermented mustard leaves was significantly lower than that of culture-independent fermented cuocai. According to gas chromatography-mass spectrometry analysis, the main volatile flavor compounds of fermented mustard leaves were alcohols, aldehydes, esters, and sulfides. There was no significant difference of volatile flavor compounds between the processes of culture-dependent and culture-independent fermentations. Therefore, it was suggested that Lb. plantarum and I. orientalis strains could be used to ferment cuocai instead of the traditional ferment method to control the quality and shelf safety of cuocai. © 2017 Society of Chemical Industry.

Assessment of probiotic characteristics of lactic acid bacteria isolated from fermented yak milk products of Sikkim, India: Chhurpi, Shyow, and Khachu

ABSTRACTThe present study documents the probiotic attributes of indigenous lactic acid bacteria (LAB) isolated from local fermented Yak milk products namely Chhurpi, Shyow and Khachu prepared in the northern and eastern region of Sikkim in the Himalayas. Samples were collected aseptically and a total of 170 LAB was isolated and screened for putative probiotic properties like hypocholesteromic effect, acid tolerance, bile tolerance, bile salt hydrolase (BSH) activity and cell surface hydrophobicity. It was observed that 70 LAB isolates showed cholesterol lowering activity, out of which 35 isolates were selected that showed 50% and less cholesterol reducing effect in vitro. Acid tolerance test revealed good tolerance of 12 isolates at pH 2.5 and pH 2.0 for up to 2 hours. The tolerance to 0.5% and 1% of three bile salts acid revealed more growth in MRS broth containing taurocholic acid with the isolates revealing good BSH activity leading to bile acid deconjugation. The cell surface hydrophobicity ranged from 20–95%. Furthermore, 16S rRNA gene sequencing revealed Lactobacillus plantarum YD5S and YD9S, L. pentosus YD8S, L. paraplantarum YD11S, Enterococcus lactis YHC20 and E. faecium YY1 as the best isolates with technological properties. The isolates may serve as potential probiotic candidates with potential for hypocholesteromic benefits in the future.

Indigenous Probiotic Lactobacillus Isolates Presenting Antibiotic like Activity against Human Pathogenic Bacteria.

Background: Indigenous lactic acid bacteria are well known probiotics having antibacterial activity against potentially pathogenic bacteria. This study aims to characterize the curd lactobacilli for their probiotic potentiality and antagonistic activity against clinical bacteria. Methods: Four curd samples were processed microbiologically for the isolation of lactic acid bacteria (LAB). The LAB strains obtained were identified by conventional methods: cultural aspect, gram-staining, biochemical and sugar fermentation tests. The probiotic properties were justified with tolerance to low-pH, bile salt and sodium chloride, and the antagonistic activity of the lactobacilli against human pathogenic bacteria (Escherichia coli, Proteus vulgaris, Acinetobacter baumannii and Salmonella enterica serovar Typhi) was assessed. Hemolytic activity and antibiotic susceptibility were determined for the lactobacilli isolates, and the cumulative probiotic potential (CPP) values were recorded. Result: Four lactobacilli isolates, L. animalis LMEM6, L. plantarum LMEM7, L. acidophilus LMEM8 and L. rhamnosus LMEM9, procured from the curd samples, survived in low-pH and high bile salt conditions, and showed growth inhibitory activity against the indicator bacteria by agar-well (zone diameter of inhibition; ZDIs: 13.67 ± 0.58–29.50 ± 2.10 mm) and agar overlay (ZDIs: 11.33 ± 0.58–35.67 ± 2.52 mm) methods; the average growth inhibitory activity of lactobacilli ranged 233.34 ± 45.54–280.56 ± 83.67 AU/mL, against the test bacterial pathogens. All the lactobacilli were non-hemolytic and sensitive to most of the test antibiotics. The CPP values of the isolated LAB were recorded as 80–100%. Conclusion: The curd lactobacilli procured might be used as the valid candidates of probiotics, and bio-therapeutics against bacterial infection to humans.

Assorted Lactic Acid Bacteria with Yeasts in Alcohol Submerged Fermentation Step of Vinegar Production

In the spontaneous vinegar fermentation process, diverse microorganisms considered as crucial microorganisms to succession of the vinegar fermentation control most pathogenic microorganisms. The predominant communities in fermented vinegar are acetic acid bacteria (AAB) functioning at the last step of acetic acid formation. However, lactic acid bacteria (LAB) also present in the vinegar, help produce high, quality vinegar and involve in the initial phase of starch degradation and alcohol production. In this study, the research was performed to understand the effects of LAB together with yeasts, Saccharomyces cerevisiae on on alcoholic and acetification production. In the experiment, mixtures of isolated LAB from fermented banana vinegar were tested for their functions together with yeasts in the alcoholic fermentation step. The results showed that indigenous LAB had more predominant effective species helping the induction of sugar but reduction in pH. This observation thus indicated the importance of inoculated LAB isolates in vinegar fermentation process as enhancer of the quality in vinegar fermentation.

Isolation of Lactic Acid Bacteria with Cholesterol-Lowering Activity from Digestive Tracts of Indonesian Native Chickens

The aim of the study was to identify the cholesterol-lowering activity of indigenous lactic acid bacteria isolated from the small intestine, cecum, and colon of Indonesian native chickens and evaluated for bile salt hydrolase (BSH) activity in vitro by using MRS media added taurodeoxycholic acid (TDCA) and CaCl2. The quantitative measurement of cholesterol-lowering activity of LAB was investigated by using soluble cholesterol containing MRS broth (100 µg/mL of cholesterin) and incubated at 37 °C for 48 h. Cholesterol content in supernatant was analyzed using microplate reader. The highest percentage of cholesterol reduction found in isolates from colon of native chicken with the value of 17.43% and identified as Lactobacillus plantarum. Based on phylogenetic tree analysis, this isolate was closely related to L. plantarum strain LGFCP4 (accession number KM199683.1) isolated from GIT of Guinea fowl from India. It could be concluded that L. plantarum AKK-30 had cholesterol-lowering activity.

Molecular Identification of Indigenous Lactic Acid Bacteria, Partial Purification and Characterization of β-Galactosidase Produced

<p>β-Galactosidase is enzyme which hydrolyze lactose to glucose and galactose, as lactose hydrolyzer. To know indigenous lactic acid bacteria (LAB) characteristics, indigenous LAB identification, partial purification and characterization of β-galactosidase produced was researched. LAB was molecularly identified, β-galactosidase partial purification was conducted by precipitation followed dialysis. β-Galactosidase characterization was based on optimum activities of pH and temperature. The results show that LAB was identified as <em>Lactobacillus plantarum</em> B123. Optimum activity of precipited β-galactosidase was reached at 50 % ammonium sulphate. Activity and specific activity of 50 % precipited β-galactosidase were 95.675 U · mg<sup>–1</sup> and 32.268 U · mg<sup>–1</sup>, respectively. Precipited β-galactosidase resulted a purification level of 3.99 fold, a yield of 38.73 %, and a specific activity of 32.27 U · mg<sup>–1</sup> protein, while dialyzed β-galactosidase resulted 7.61 fold, 10.67 %, and 61.53 U· mg<sup>–1</sup> protein. Optimum temperature and pH for crude β-galactosidase were found at 55 °C and 7.0, respectively, while that dialyzed β-galactosidase were optimized at 50 °C and 7.0. Based on partial purification and characterization, <em>Lactobacillus plantarum</em> B123 is indigenous LAB which good for production of β-galactosidase.</p><div><p class="Els-keywords"><em> </em></p><p class="Els-keywords"><strong>Keywords:</strong> characterization; dialysis; lactic acid bacteria; <em>Lactobacillus plantarum</em> B 123; β-galactosidase.</p></div>