Characterization and Identification of Pediococcus Species Isolated from Forage Crops and Their Application for Silage Preparation

Pediococcus species isolated from forage crops were characterized, and their application to silage preparation was studied. Most isolates were distributed on forage crops at low frequency. These isolates could be divided into three (A, B, and C) groups by their sugar fermentation patterns. Strains LA 3, LA 35, and LS 5 are representative isolates from groups A, B, and C, respectively. Strains LA 3 and LA 35 had intragroup DNA homology values above 93.6%, showing that they belong to the species Pediococcus acidilactici. Strain LS 5 belonged to Pediococcus pentosaceus on the basis of DNA-DNA relatedness. All three of these strains and strain SL 1 (Lactobacillus casei, isolated from a commercial inoculant) were used as additives to alfalfa and Italian ryegrass silage preparation at two temperatures (25 and 48°C). When stored at 25°C, all of the inoculated silages were well preserved and exhibited significantly (P < 0.05) reduced fermentation losses compared to that of their control in alfalfa and Italian ryegrass silages. When stored at 48°C, silages inoculated with strains LA 3 and LA 35 were also well preserved, with a significantly (P < 0.05) lower pH, butyric acid and ammonia-nitrogen content, gas production, and dry matter loss and significantly (P < 0.05) higher lactate content than the control, but silages inoculated with LS 5 and SL 1 were of poor quality. P. acidilactici LA 3 and LA 35 are considered suitable as potential silage inoculants.     

饲料乳酸菌的分离鉴定及优良菌株筛选

对从饲料玉米、高粱、麦秆及棉花中筛选出的乳酸菌进行分类鉴定和综合性分析。用MRS+CaCO3固体培养基从棉花中分离出乳酸菌18株、高粱中30株、饲料玉米中18株、麦秆中18株。经形态学、生理生化试验进行初步鉴定并按产酸试验,耐盐及耐酸试验挑选出32株产酸率强的乳酸菌对其进行16S rDNA分子鉴定。结果显示,32株菌都具有良好的耐盐、耐酸能力;经生理生化和16S rDNA基因序列鉴定可知32株乳酸菌分属于两个属,即乳杆菌属、肠球菌属,4个种,即干酪乳杆菌(Lactobacilluscasei)、肠道球菌(Entercoccus faecium)、植物乳杆菌(Lactobacillus plantarum)、海氏肠球菌(Entercoccus hirae)。4种饲料原料中肠道球菌普遍存在。除了这种乳酸菌以外,棉花有干酪乳杆菌、植物乳杆菌、海氏肠球菌,玉米和麦秆内有植物乳杆菌。从饲料中筛选出4株具有较强产酸能力的乳酸菌,可进一步研发成青贮饲料添加剂。     

Characterization and Antibacterial Activity Against Helicobacter pylori of Lactic Acid Bacteria Isolated from Thai Fermented Rice Noodle

Probiotics and Antimicrobial Proteins - A total of 32 lactic acid bacteria (LAB) were isolated from Khanom-jeen, a Thai traditional fermented rice noodle. They belonged to the genus Leuconostoc...     

广西传统发酵米粉中乳酸菌的分离鉴定

对广西传统米粉发酵液中的乳酸菌进行分离筛选,获得6株纯培养优势菌株。通过形态学鉴定及16S rDNA序列分析,结果表明其中4株乳酸菌属于戊糖片球菌(Pediococcus pentosaceus),另外2株鉴定为植物乳杆菌(Lactobacillus plantarum)。这2种乳酸菌均为对人类及动物安全的益生菌,该结果将为传统发酵米粉中有益微生物资源的挖掘和利用奠定基础。     

Metabolite Profiles of Lactic Acid Bacteria in Grass Silage

The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydroxybenzoic acid, (trans, trans)-3,4-dihydroxycyclohexane-1-carboxylic acid, p-hydrocoumaric acid, vanillic acid, azelaic acid, hydroferulic acid, p-coumaric acid, hydrocaffeic acid, ferulic acid, and caffeic acid. Among these metabolites, the antifungal compounds 3-phenyllactic acid and 3-hydroxydecanoic acid were previously isolated in our laboratory from liquid cultures of the same LAB strains by bioassay-guided fractionation. It was concluded that other metabolites, e.g., p-hydrocoumaric acid, hydroferulic acid, and p-coumaric acid, were released from the grass by the added LAB strains. The antifungal activities of the identified metabolites in 100 mM lactic acid were investigated. The MICs against Pichia anomala, Penicillium roqueforti, and Aspergillus fumigatus were determined, and 3-hydroxydecanoic acid showed the lowest MIC (0.1 mg ml⁻¹ for two of the three test organisms).     

Probiotic Properties of Lactic Acid Bacteria Isolated from Water-Buffalo Mozzarella Cheese

This study evaluated the probiotic properties (stability at different pH values and bile salt concentration, auto-aggregation and co-aggregation, survival in the presence of antibiotics and commercial drugs, study of β-galactosidase production, evaluation of the presence of genes encoding MapA and Mub adhesion proteins and EF-Tu elongation factor, and the presence of genes encoding virulence factor) of four LAB strains (Lactobacillus casei SJRP35, Leuconostoc citreum SJRP44, Lactobacillus delbrueckii subsp. bulgaricus SJRP57 and Leuconostoc mesenteroides subsp. mesenteroides SJRP58) which produced antimicrobial substances (antimicrobial peptides). The strains survived the simulated GIT modeled in MRS broth, whole and skim milk. In addition, auto-aggregation and the cell surface hydrophobicity of all strains were high, and various degrees of co-aggregation were observed with indicator strains. All strains presented low resistance to several antibiotics and survived in the presence of commercial drugs. Only the strain SJRP44 did not produce the β-galactosidase enzyme. Moreover, the strain SJRP57 did not show the presence of any genes encoding virulence factors; however, the strain SJRP35 presented vancomycin resistance and adhesion of collagen genes, the strain SJRP44 harbored the ornithine decarboxylase gene and the strain SJRP58 generated positive results for aggregation substance and histidine decarboxylase genes. In conclusion, the strain SJRP57 was considered the best candidate as probiotic cultures for further in vivo studies and functional food products development.     

Behavior of Psychrotrophic Lactic Acid Bacteria Isolated from Spoiling Cooked Meat Products

Three kinds of lactic acid bacteria were isolated from spoiling cooked meat products stored below 10°C. They were identified as Leuconostoc mesenteroides subsp. mesenteroides, Lactococcus lactis subsp. lactis, and Leuconostoc citreum. All three strains grew well in MRS broth at 10°C. In particular, L. mesenteroides subsp. mesenteroides and L. citreum grew even at 4°C, and their doubling times were 23.6 and 51.5 h, respectively. On the other hand, although the bacteria were initially below the detection limit (<10 CFU/g) in model cooked meat products, the bacterial counts increased to 10⁸ CFU/g at 10°C after 7 to 12 days.     

Cholesterol Assimilation by Lactic Acid Bacteria and Bifidobacteria Isolated from the Human Gut

The objective of this study was to evaluate the effect of human gut-derived lactic acid bacteria and bifidobacteria on cholesterol levels in vitro. Continuous cultures inoculated with fecal material from healthy human volunteers with media supplemented with cholesterol and bile acids were used to enrich for potential cholesterol assimilators among the indigenous bacterial populations. Seven potential probiotics were found: Lactobacillus fermentum strains F53 and KC5b, Bifidobacterium infantis ATCC 15697, Streptococcus bovis ATCC 43143, Enterococcus durans DSM 20633, Enterococcus gallinarum, and Enterococcus faecalis. A comparative evaluation regarding the in vitro cholesterol reduction abilities of these strains along with commercial probiotics was undertaken. The degree of acid and bile tolerance of strains was also evaluated. The human isolate L. fermentum KC5b was able to maintain viability for 2 h at pH 2 and to grow in a medium with 4,000 mg of bile acids per liter. This strain was also able to remove a maximum of 14.8 mg of cholesterol per g (dry weight) of cells from the culture medium and therefore was regarded as a candidate probiotic.     

Identification of Lactic Acid Bacteria from Chili Bo, a Malaysian Food Ingredient

Ninety-two strains of lactic acid bacteria (LAB) were isolated from a Malaysian food ingredient, chili bo, stored for up to 25 days at 28°C with no benzoic acid (product A) or with 7,000 mg of benzoic acid kg⁻¹ (product B). The strains were divided into eight groups by traditional phenotypic tests. A total of 43 strains were selected for comparison of their sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) whole-cell protein patterns with a SDS-PAGE database of LAB. Isolates from product A were identified as Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus farciminis, Pediococcus acidilactici, Enterococcus faecalis, and Weissella confusa. Five strains belonging to clusters which could not be allocated to existing species by SDS-PAGE were further identified by 16S rRNA sequence comparison. One strain was distantly related to the Lactobacillus casei/Pediococcus group. Two strains were related to Weissella at the genus or species level. Two other strains did not belong to any previously described 16S rRNA group of LAB and occupied an intermediate position between the L. casei/Pediococcus group and the Weissella group and species of Carnobacterium. The latter two strains belong to the cluster of LAB that predominated in product B. The incidence of new species and subspecies of LAB in chili bo indicate the high probability of isolation of new LAB from certain Southeast Asian foods. None of the isolates exhibited bacteriocin activity against L. plantarum ATCC 14917 and LMG 17682.     

EZAL-MY96乳酸菌种菌株分离鉴定

目的：对引进法国罗地亚EZAL-MY96直投式酸奶发酵剂(DVS)进行菌株分离鉴定。方法：利用半选择性培养基进行发酵剂菌株分离,并采用糖发酵实验和RAPD指纹图谱进行鉴定。结果：EZAL-MY96中球菌的平板菌落与光镜显微观察、糖发酵实验和RAPD指纹图谱均只有1种情况,而杆菌均有2种情况。结论：从EZAL-MY96菌种中共分离到3株菌,其中1株鉴定为嗜热链球菌,1株为德氏乳杆菌保加利亚亚种,另1株为未知的乳杆菌。     

Identification and characterization of Lactic Acid Bacteria isolated from Tibetan Qula cheese

Fourteen strains of Lactic Acid Bacteria (LAB) isolated from Qula, a Tibetan traditional yak cheese, were divided into four groups (A-D) according to morphological and biochemical characteristics. On the basis of the 16S rRNA gene sequence analysis, group A and group B strains were placed in the cluster making up the genus Leuconostoc, which together with Leuconostoc mesenteroides and Leuconostoc pseudomesenteroides, formed a distinct cluster. The group C strain was clearly identified as Enterococcus faecium by forming a very well defined cluster with this species. The group D strains were placed in the lactobacilli cluster with Lactobacillus plantarum and Lactobacillus pentosus being the closely related species. On the basis of DNA-DNA hybridization, strains in the groups A, B, C and D were identified as Leuconostoc mesenteroides subsp. dextranicum, Leuconostoc pseudomesenteroides, Enterococcus faecium and Lactobacillus plantarum, respectively. Leuconostoc mesenteroides subsp. dextranicum was the dominate member of the population.     

Tyrosinase Inhibitory and Anti-oxidative Effects of Lactic Acid Bacteria Isolated from Dairy Cow Feces

Overproduction and accumulation of melanin cause a number of skin diseases. The inhibitors of tyrosinase are important for the treatment of skin diseases associated with hyper-pigmentation after UV exposure and application in cosmetics for whitening and depigmentation. Reactive oxygen species (ROS) including hydrogen peroxide are generated by chemical substances and metabolic intermediates and cause various diseases including cancer and heart diseases. We have isolated four different lactic acid bacteria (LAB) strains from dairy cow feces and investigated the tyrosinase inhibition and anti-oxidative effects of culture filtrates prepared from the isolated bacteria, which are designated as EA3, EB2, PC2, and PD3. To investigate optimal culture conditions isolated LAB strains, the measurements of tyrosinase inhibitory and anti-oxidative activities were performed. The results of tyrosinase inhibitory activities revealed that Enterococcus sp. EA3 showed about 65% at culture conditions (14 h, 30 °C, pH 8, and 0% NaCl), Enterococcus sp. EB2 about 65% at culture conditions (12 h, 30 °C, pH 9, and 0% NaCl), Pediococcus sp. PC2 about 80% at culture conditions (20 h, 30 °C, pH 6, and 0% NaCl), and Pediococcus sp. PD3 about 80% at culture conditions (20 h, 30 °C, pH 8, and 0% NaCl), respectively. In addition, anti-oxidative activities against four different LAB strains showed approximately more than 30% at optimal conditions for the measurements of tyrosinase inhibitory activities. From the results, we have suggested that the isolated four LAB strains could be useful for a potential agent for developing anti-oxidants and tyrosinase inhibitors.     

In Vitro Characterization of Lactic Acid Bacteria Isolated from Bovine Milk as Potential Probiotic Strains to Prevent Bovine Mastitis

Probiotics and Antimicrobial Proteins - Bovine mastitis causes economic losses on dairy farms worldwide. Lactic acid bacteria (LAB) in animal health are an alternative tool to avoid antibiotic...     

Diversity and Probiotic Potential of Lactic Acid Bacteria Isolated from Horreh,a Traditional Iranian Fermented Food

The aim of this study was to evaluate the probiotic potential of lactic acid bacteria (LAB) strains isolated from Horreh. Some probiotic properties, e.g., resistance to acid, bile tolerance, antibacterial activity, and antibiotic susceptibility, were investigated. A total of 140 Gram-positive and catalase-negative isolates from Horreh were subjected to identification and grouping by cultural methods and the 16S rRNA sequencing. The new isolates were identified to be Lactobacillus (fermentum, plantarum, and brevis) Weissella cibaria, Enterococcus (faecium and faecalis), Leuconostoc (citreum and mesenteroides subsp. mesenteroides) and Pediococcus pentosaceus. Probiotic potential study of LAB isolates showed that Lb. plantarum and Leu. mesenteroides subsp. mesenteroides isolates were able to grow at pH 2.5 and 3.5. Lactobacillus plantarum (isolate A44) showed the highest cell hydrophobicity (84.5%). According to antibacterial activity tests, Listeria innocua and Staphylococcus aureus were the most sensitive indicators against the selected LAB strains, while Escherichia coli and Bacillus cereus were the most resistant. In addition, all the isolated LAB species were resistant to vancomycin. The results of the present study suggested that the Lactobacillus fermentum and plantarum isolated from Horreh, characterized in this study, have potential use for industrial purposes as probiotics.     

Evaluation of Probiotic Potential of Bacteriocinogenic Lactic Acid Bacteria Strains Isolated from Meat Products

In this study, the probiotic potential of five bacteriocin-producing lactic acid bacteria (LAB) strains, isolated from meat products, was investigated. They were presumptively identified as Lactococcus lactis subsp. cremoris CTC 204 and CTC 483, L. lactis subsp. hordinae CTC 484, and Lactobacillus plantarum CTC 368 and CTC 469 according to morphological, biochemical, and physiological characteristics. Analysis of genetic variability (random amplified polymorphic (RAPD)-PCR) and whole-cell proteins (SDS-PAGE) revealed similarity between Lactobacillus strains and variability among Lactococcus strains. The evaluation of the probiotic potential showed that the five LAB strains were tolerant to pH 2.0, and only strain CTC 469 was tolerant to the lowest concentration of the bile salts evaluated (0.1%). All strains showed survival or growth ability at 4, 25, and 37 °C, and tolerance at ??20 °C. Although strain CTC 204 in TSB Broth supplemented with MgSO₄ showed the highest intensity of biofilm production, this compound was produced by all of them. The safety assessment showed that no thermonuclease, hemolytic, or gelatinase activities were detected. All strains were resistant to erythromycin and sensitive to amoxicillin and phenoxymethylpenicillin; furthermore, CTC 204 was resistant to chloramphenicol, CTC 368 and CTC 469 to chloramphenicol and vancomycin, CTC 483 to tetracycline and vancomycin, and CTC 484 to clindamycin and chloramphenicol. The evaluated strains showed biogenic amine production; the lowest levels were produced by CTC 204 and CTC 368 strains. It was concluded that CTC 204 and CTC 368 strains have the greatest potential for becoming probiotics.     

一组鸡源乳酸菌产乳酸及其耐受特性研究*

研究了12株（K9、D17、C1、C12、D11、D14、C2、D9、K6、C21、D1和D7）分离自肉鸡肠道的乳酸菌的产乳酸能力及其中3株产酸能力强的菌株的耐受特性。12株乳酸菌产乳酸结果表明：12h内,K6产乳酸速度最快,其次为K9和C1,24h时,D17乳酸浓度最高,48h时C1终乳酸浓度最高。K9、D17和C1的耐受试验结果表明：C1菌株耐酸能力最强,pH2时,C1菌株培养3h后还能检测到活菌,D17和K9菌株培养1h后就已经检测不到活菌。在胆盐浓度0．08％-0．40％范围内,C1、D17和K9均有一定的耐受能力,随着胆盐浓度的升高,C1、D17和K9的存活数呈现缓慢的下降趋势。3株菌中D17耐热能力最强,经80％处理后仍有10^4.9／mL存活数,而K9和C1已检测不到活菌;C1对热最敏感,65℃处理后存活数由10^8／mL降为10^3／mL。     

几株乳酸菌的分离鉴定

通过厌氧分离技术,从鸡肠道和西红柿花面分离得到五株产乳酸细菌,根据《伯杰细菌鉴定手册》（第八版）［１］鉴定ＳＢ１、ＳＢ２４５１、ＳＢ３１５１均为干酪乳杆菌（Ｌ．ｃａｓｅｉ）,Ａ、ＳＡ则可能是乳酸菌的一个新种。五株菌均为同型发酵,乳酸产量均达到９６％以上．对抗生素等药物及低ｐＨ有一定耐受性,是益生素饲料添加剂的优良菌种［２］。     

Identification of some Bacteria from Paddy Antagonistic to Several Rice Fungal Pathogens

The effect of 23 bacterial strains from ricefields in the tropics on rice seed germination and on radicle and hypocotyl development of four rice cultivars was determined. There was a varietal difference in response to seed bacterization with the different bacterial strains. Germination of cv. IR58 increased from 78 to 93 %, that of cv. IR64, from 89 to 97 %. Less effects on germination of cvs IR42 and IR36 were observed. All strains inhibited the mycelial growth of Rhizoctonia solani in vitro. The three strains, identified as Bacillus subtilis, inhibited the mycelial growth of eight fungal pathogens whereas the other strains were pathogen-specific. Seed bacterization with these bacterial strains provided a sheath blight protection of 4. 5 to 73 % in the glasshouse trial. These 23 bacterial strains were identified by phenotypic tests using the API systems, morphological and biochemical features, and by comparison of electrophoretic patterns after sodium dodecyl sulphate polyacrylamide gel electrophoresis. Bacterial strains were identified (number of strains in brackets) as: Bacillus subtilis (3), Bacillus laterosporus (1), Bacillus pumilus (1), Pseudomonas aeruginosa (7), Pseudomonas belonging to section 1 (5), Erwina herbicola-like (1), and Serratia marcescens (1). The features of the other four strains were similar to Serratia except for the DNAase and lipase activities.