In vitro evaluation of Pediococcus acidilactici NCDC 252 for its probiotic attributes

In vitro probiotic attributes of Pediococcus acidilactici, viz. tolerance to acidity and bile salt, phenol resistance, lactic acid production, antioxidant activity, cell surface hydrophobicity, lysozyme resistance and the presence of β‐galactosidase, proteolytic, lipase and peptidoglycan hydrolase activities, were studied. The strain was found to be rich in different proteolytic activities, β‐galactosidase and antioxidant activities, and produced lactic acid. The studies conducted support that P. acidilactici national collection of dairy cultures (NCDC) 252 is a potential probiotic for humans with all the essential basic probiotic properties. This testing is useful to gain insight into this strain and its mechanism of action. All these attributes add to its therapeutic importance and industrial significance.     

In vitro characterisation of probiotic properties of Enterococcus faecium and Enterococcus durans strains isolated from raw milk and traditional dairy products

In this study, some probiotic characteristics such as antimicrobial activity, vancomycin resistance, growth ability at pH, resistance to bile salts, bile salt deconjugation and hydrophobicity of 30 Enterococcus faecium and Enterococcus durans strains isolated and identified from raw milk and various dairy products were investigated. According to the study results, antimicrobial activity profiling, pH and bile salt resistance and bile salt deconjugation ability of Enterococcus strains varied depending on the species and strains and all the strains showed resistance to the tested bile salt concentrations. It was concluded that the E. faecium and E. durans strains tested showed probiotic characteristics and have the potential to be used in food production.     

Probiotic potential and biochemical and technological properties of Lactococcus lactis ssp. lactis strains isolated from raw milk and kefir grains

Lactococcus lactis ssp. lactis is one of the most important starter bacteria used in dairy technology and it is of great economic importance because of its use in the production of dairy products, including cheese, butter, cream, and fermented milks. Numerous studies have evaluated the biochemical and probiotic properties of lactococci; however, limited studies on the probiotic characteristics of lactococci were conducted using strains originating from raw milk and dairy products. Characterizing the probiotic properties of strains isolated from raw milk and fermented milk products is important in terms of selecting starter culture strains for the production of functional dairy products. In this study, biochemical properties (including antibiotic sensitivity, lipolytic activity, amino acid decarboxylation, antioxidant activity) and probiotic properties (including antimicrobial activity, growth in the presence of bile salts, bile salts deconjugation, and hydrophobicity) of 14 Lactococcus lactis strains isolated from raw milk and kefir grains were investigated. Strains originating from kefir grains had better characteristics in terms of antimicrobial activity and bile salt deconjugation, whereas strains from raw milk had better hydrophobicity and antioxidant activity characteristics. None of the strains were able to grow in the presence of bile salt and did not show amino acid decarboxylation or lipolytic activities. Biochemical and probiotic properties of L. lactis strains varied depending on the strain and some of these strains could be used as functional cultures depending on their properties. However, these strains did not possess all of the properties required to meet the definition of a probiotic.     

Lactic acid starter and probiotic bacteria: a comparative “in vitro” study of probiotic characteristics and biological barrier resistance

Probiotic characteristics (deconjugation of bile salts, hydrophobicity and β-galactosidase activity) and the resistance to biological barriers (gastric juice and bile salts) of 24 strains of lactic acid starter bacteria (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus and Lactococcus lactis) and 24 strains of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus rhamnosus and bifidobacteria) were compared. Among the probiotic bacteria tested, Lactobacillus acidophilus was the most interesting species since it showed high values of resistance to gastric juice and bile, hydrophobicity and β-galactosidase and bile salts deconjugation activities. Bifidobacterium bifidum strains showed the same behavior, although the values of the parameters investigated were slightly lower than those obtained for Lactobacillus acidophilus. On the other hand, it was demonstrated that Lactobacillus delbrueckii subsp. bulgaricus was the lactic acid starter species with the best probiotic characteristics among the starter species assessed. It was resistant to gastric juice and bile, and showed high values for β-galactosidase activity. On the other hand, lactic acid starter bacteria showed hydrophobicity values similar to or higher than those obtained for the strains of the Lactobacillus casei . According to the results found, the total probiotic value of a fermented dairy product should take into account not only the intestinal probiotic cultures used in the formulation but also the probiotic contribution of the lactic acid starter microflora.     

蜂粮中Lactobacillus kunkeei的益生特性研究

蜂粮是植物花粉、蜂蜜和蜜蜂唾液的发酵混合物,是营养丰富的天然食材。作者从蜂粮中分离到61株乳酸杆菌,经16S rRNA基因测序,鉴定为Lactobacillus kunkeei。首先,用邻苯二甲醛法对61株L.kunkeei进行胆固醇去除能力检测,其中5株菌胆固醇去除能力均大于15%,菌株B35对胆固醇的去除率达到(29.07±1.30)%。随后,对这5株L.kunkeei进行酸耐受性、胆盐耐受性、抗生素耐药性及抑菌等益生特性进行研究。耐酸实验和耐胆盐实验结果表明,5株L.kunkeei均具有良好的耐酸性和胆盐耐受性。药敏试验结果表明,5株L.kunkeei对4种临床常用抗生素(红霉素、克林霉素、庆大霉素、万古霉素)均敏感。通过琼脂扩散法抑菌实验,发现5株L.kunkeei对大肠埃希氏菌、金黄色葡萄球菌均有一定的抑菌作用。B35菌株的细胞黏附性能良好,对Caco-2细胞的黏附率达到3.32%。从蜂粮中分离到5株具有良好益生特性的菌株,其中菌株B35的益生特性最佳,为益生菌的开发与利用提供了新的菌种资源。     

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

The 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.     

Evaluation of probiotic potential and anti-hyperglycemic properties of a novel <Emphasis Type="Italic">Lactobacillus</Emphasis> strain isolated from water kefir grains

A total of eight strains of lactic acid bacteria were isolated from water kefir grains and assessed for their in vitro α-glucosidase inhibitory activity. Lactobacillus mali K8 demonstrated significantly higher inhibition as compared to the other strains, thus was selected for in vitro probiotic potential characterization, antibiotic resistance, hemolytic activity and adaptation to pumpkin fruit puree. L. mali K8 demonstrated tolerance to pH 2.5 and resisted the damaging effects of bile salts, pepsin and pancreatin, comparable to that of Lactobacillus rhamnosus GG ATCC 53103 (reference strain). Lack of hemolytic activity and susceptibility to the five standard antibiotics indicated the safety of the K8 strain. This strain showed singular properties to be used as starters in the pumpkin fruit puree fermentation. These preliminary in vitro tests indicated the safety and functionality of the K8 strain and its potential as a probiotic candidate.     

罗非鱼源肠道益生菌的分离鉴定及其体外益生特性分析

为了筛选出优良的鱼源益生菌,作者以吉富罗非鱼(Oreochromis niloticus)为实验材料,进行肠道芽孢杆菌和乳酸菌的分离、鉴定,并对分离得到的菌株进行抑菌活性、耐酸性、耐胆盐、人工胃肠液耐受、溶血活性和抗生素敏感性等体外益生特性分析。结果表明,从罗非鱼肠道中共分离得到109株菌,其中包括79株乳酸菌和30株芽孢杆菌,经过一系列的实验最终筛选出3株乳酸乳球菌（Lactococcus lactis）。生物学特性研究表明,3株菌均无溶血活性,对抗生素具有一定的敏感性,对强酸、胆盐和人工胃肠液具有一定的耐受性,对水产病原菌具有不同的抑菌活性。筛选得到的3株菌丰富了鱼源益生菌资源,它们均可作为优良的鱼源益生菌候选菌株。其中,菌株R1对强酸和人工胃肠液耐受性最强,菌株R29耐胆盐能力最强,可进行进一步的益生特性研究,挖掘其作为食品源益生菌的益生效果。     

In vitro probiotic evaluation of potential antioxidant lactic acid bacteria isolated from idli batter fermented with Piper betle leaves

Lactic acid bacteria isolated from food sources can be introduced as probiotics because of their health‐promoting and nonpathogenic characteristics. Eight lactic acid bacteria from idli batter fermented with Piper betle leaves were selected to screen the antioxidant potential and biofilm‐forming ability. Five isolates exhibited good antioxidant potential and biofilm formation and showed antagonistic activity against the pathogenic biofilm‐forming Staphylococcus aureus. Further, in vitro probiotic properties of five isolates exhibited excellent acid tolerance, bile tolerance, simulated gastrointestinal juice tolerance, auto‐aggregation and co‐aggregation and hydrophobicity and showed resistance to antibiotics such as ciprofloxacin, nalidixic acid, norfloxacin and colistin. Isolates also showed positive bile salt hydrolase activity, cholesterol assimilation, β‐galactosidase production and mucin binding ability. The isolate KJBB10 exhibited good adhesion and pathogen exclusion percentage with human colon cancer cells (HCT‐15 and HT‐29). Hence, the isolates KJBB10, KJBB56 and KJBC06 can be used as beneficial probiotic starter cultures for the formulation of functional foods.     

Molecular cloning,expression and characterization of bile salt hydrolase from Lactobacillus rhamnosus E9 strain

Bile salt hydrolase (BSH) enzyme, commonly found in probiotic bacteria of gut origin, catalyzes the hydrolysis of glycine and/or taurine-conjugated bile salts allowing for colonization of the bacteria in the gut and contributing to a decrease in levels of cholesterol. However an excessive deconjugation of tauro-conjugated bile salts and production of secondary bile acid can have harmful side-effects. The aim of this study was to characterize the activity of BSH enzymes from Lactobacillus rhamnosus E9, a popular probiotic strain. The bsh gene was cloned, expressed, purified and characterized in Escherichia coli BLR(DE3) strain. The hydrolysis activities and substrate specificities of the recombinant BSH (rBSH) enzyme were examined using six different bile acids. Nucleotide sequence analysis results indicated that the bsh of E9 contained an open reading frame (ORF) of 1014 and nucleotides encoding a 338-amino acid protein with a molecular weight of 37 kDa. Five catalytically important amino acids and the amino acid motifs located around the active site were highly conserved. The rBSH showed a slight preference towards glycine-conjugated to tauro-conjugated bile salts. This confirms that it is a safe strain for probiotics and its preference for glycine-conjugated bile salts should be further investigated.     

Potentially probiotic acetic acid bacteria isolation and identification from traditional dairies microbiota

Among probiotics, acetic acid bacteria (AAB) can be used as preservative agents because of their high fermentation and acidification activities. This study aimed to isolate, identify and biologically characterise Acetobacter strains from traditional Iranian dairy products. Acetobacter strains were identified by catalase assay, Gram staining, and combined repetitive sequence‐based PCR [(GTG)₅‐PCR fingerprints] and 16S rDNA gene sequencing. We identified eight strains belonging to four species, including Acetobacter aceti, Acetobacter indonesiensis, Acetobacter cibinongensis and Acetobacter syzygii. The molecular techniques could be used as an effective and rapid alternative tool to identify and characterise dairy‐associated AAB. Primary probiotic assessments, including low pH and high bile salt tolerance tests, antagonistic activity test against pathogens, and antibiotic susceptibility confirmed the probiotic properties of these AAB, particularly A. cibinongensis 34L strain, which was isolated from curd. Therefore, this strain can be introduced as novel candidate probiotics that could be used in the food industry.     

The application of flow cytometry to the characterisation of a probiotic strain Lactobacillus reuteri DPC16 and the evaluation of sugar preservatives for its lyophilization

In this study, we applied flow cytometric (FCM) analyses to characterize the resistance of a probiotic strain Lactobacillus reuteri DPC16 (DPC16) against diverse stresses. Two fluorescent probes, propidium iodide (PI) and carboxylfluorescein diacetate (cFDA), were combined to the FCM method to reveal multiple cellular statuses of DPC16. The FCM results confirmed that the DPC16 strain had probiotic potential in respect of acid tolerance and bile acid resistance, whereby more than 60% of DPC16 bacteria remained intact after 1 h exposure to pH 2.0, and over half of DPC16 bacteria were unaffected by the presence of bile salts at a concentration of 0.2 g/100 mL for 1 h even without nutrient supply. In addition, the comparison among a number of lyo-preservatives for the DPC16 strain confirmed that lactose was able to maintain over 60% viable DPC16 bacteria after the lyophilization and subsequent storage period, outperforming all the other selected sugars. To conclude, the superior stress resistance of the novel DPC16 strain was confirmed by the FCM analyses in this study. The FCM technique also proved to be readily incorporated into probiotics research, and capable of providing insightful information.     

泡菜中乳酸菌的分离鉴定及抗性筛选

该研究从泡菜中分离乳酸菌,通过形态观察及分子生物学技术对其进行鉴定,并对其进行人工胃液和胆盐耐受性试验,以期筛选性能优良乳酸菌。结果表明,从泡菜中共分离出71株乳酸菌,经鉴定分别为消化乳杆菌（Lactobacillus alimentarius）32株、植物乳杆菌（Lactobacillus plantarum）27株、发酵乳杆菌（Lactobacillus fermentium）1株、棒状乳杆菌（Lactobacillus coryniformis）2株、有害片球菌（Pediococcus damnosus）9株。其中,植物乳杆菌和发酵乳杆菌可用于食品,且植物乳杆菌S74和S78具有较高的抗人工胃液能力,存活率分别为（94.73±4.56）%、（108.73±7.16）%;菌株S74在0.3%的胆盐中的生长效率[（7.41±3.28）%]低于菌株S78[（10.04±4.90）%]。说明植物乳杆菌S78在pH 3.0的人工胃液和0.3%的胆盐环境均具有良好的耐受能力,在功能性泡菜及益生菌产品方面具有一定的开发潜力。     

Acid, bile, and heat tolerance of free and microencapsulated probiotic bacteria

ABSTRACT:  Eight strains of probiotic bacteria, including Lactobacillus rhamnosus , Bifidobacterium longum, L. salivarius, L. plantarum , L. acidophilus , L. paracasei , B. lactis type Bl-O4, and B. lactis type Bi-07, were studied for their acid, bile, and heat tolerance. Microencapsulation in alginate matrix was used to enhance survival of the bacteria in acid and bile as well as a brief exposure to heat. Free probiotic organisms were used as a control. The acid tolerance of probiotic organisms was tested using HCl in MRS broth over a 2-h incubation period. Bile tolerance was tested using 2 types of bile salts, oxgall and taurocholic acid, over an 8-h incubation period. Heat tolerance was tested by exposing the probiotic organisms to 65 °C for up to 1 h. Results indicated microencapsulated probiotic bacteria survived better ( P < 0.05) than free probiotic bacteria in MRS containing HCl. When free probiotic bacteria were exposed to oxgall, viability was reduced by 6.51-log CFU/mL, whereas only 3.36-log CFU/mL was lost in microencapsulated strains. At 30 min of heat treatment, microencapsulated probiotic bacteria survived with an average loss of only 4.17-log CFU/mL, compared to 6.74-log CFU/mL loss with free probiotic bacteria. However, after 1 h of heating both free and microencapsulated probiotic strains showed similar losses in viability. Overall microencapsulation improved the survival of probiotic bacteria when exposed to acidic conditions, bile salts, and mild heat treatment.     

Bile salt deconjugation activity of Propionibacterium strains and their cholesterol co‐precipitation abilities

The present study investigated the deconjugation of bile salts and co‐precipitation of cholesterol with deconjugated bile salts by seven Propionibacterium spp. strains in vitro. Propionibacterium spp. could deconjugate sodium glycocholate (1.53–5.31 mM) and sodium taurocholate (0.08–0.25 mM) bile salts. The highest cholesterol precipitation (47.8 µg/mL) was determined with Propionibacterium freudenreichii subsp. freudenreichii SP3 strain in a 0.15% oxgall‐containing medium. Significant (P < 0.05) correlations were observed between cholesterol co‐precipitation and deconjugation of sodium glycocholate among the strains. In vitro bile salt deconjugation activity studies of P. freudenreichii subsp. freudenreichii SP3 strain revealed that this strain may have potential as a probiotic strain for deconjugation of bile salts in vivo studies.     

Functional Properties of Pediococcus Species Isolated from Traditional Fermented Cereal Gruel and Milk in Nigeria

Pediococcus species were isolated from ogi, fermented cow and sheep milk. Functional properties such as hydrogen peroxide production, tolerance to simulated gastric transit with pepsin and bile salts, bile salt hydrolytic (BSH) activity, in vitro adherence assay and antimicrobial characteristics were carried out. The strains tolerated bile salts and BSH activity was positive. Pediococcus acidilactici OB4 survived gastric transit after 180min comparable to a probiotic strain, L. acidophilus CNRZ1923. The strains exhibited good adhesion to the three extracellular matrices. Two isolates (P. acidilactici OB4 and P. pentosaceus SM3) produced bacteriocin. Bacteriocins were stable at pH 4-9 and on treatment with lipase, catalase, α-amylase and lysozyme, while their activity was lost on treatment with proteinase K, pronase E, pepsin and trypsin. The bacteriocins produced by P. pentosaceus SM3 was heat stable at 100°C for 10 min while P. acidilactici OB4 was stable at 100°C for 30 min. The bacteriocin produced by P. acidilactici OB4 was identified as PedA while P. pentosaceus SM3 was PedB. The bacteriocins had relative heat stability, high anti-listerial activity and a good spectrum of activity against some pathogenic microorganisms. The results demonstrated possible inclusion in a starter culture fermentation process of food and dairy products and safety characteristics.     

Molecular characterization of antimicrobial Lactobacillus isolates and evaluation of their probiotic characteristics in vitro for use in poultry

A total of 113 lactic acid bacteria (LAB) were isolated from crop, gizzard, intestine and ceca regions of broiler chicken. Thirteen Lactobacillus isolates were selected based on their ability to grow on acidic pH and inhibition of enteric bacterial pathogens. They were identified using 16S rRNA and recA gene sequencing and evaluated for probiotic properties in vitro. These isolates showed effective inhibition against enteric bacterial pathogens like Escherichia coli and fungal pathogens, such as Aspergillus niger, A. flavus, Penicillium expansum, P. roqueforti, Candida albicans and Eurotium species. Analysis of 16S rRNA and recA gene sequences revealed that isolates belonged to Lactobacillus plantarum. They exhibited tolerance to bile salts (0.4%), gastric and intestinal conditions with bile salt hydrolase activity, suggesting their ability to survive during gastrointestinal transit and exert their probiotic action on host organism. They showed cell surface hydrophobicity (39–58%), auto-aggregation (60–80%) and co-aggregation with enteric pathogens like E. coli (49–62%) and Listeria monocytogenes (26–38%). Thus, they could potentially be bactericidal to pathogens and prevent their colonization on intestinal epithelium. They are non-pathogenic (γ-hemolytic) and negative for mucin degradation. Among these isolates, L. plantarum VJI21 and VJC1 showed more adherence to HT-29 cells than the enteric pathogen E. coli and prevented pathogen adherence to intestinal cells. L. plantarum VJI21 and VJC1, having potent probiotic properties, are considered good candidates for further studies in vivo towards the development of probiotic feed supplement in the poultry industry.     

An Improved Method of Microencapsulation of Probiotic Bacteria for Their Stability in Acidic and Bile Conditions during Storage

ABSTRACT: The purpose of this study was to develop a method for applying an extra coating of palm oil and poly‐L‐lysine (POPL) to alginate (ALG) microcapsules to enhance the survival of probiotic bacteria. Eight strains of probiotic bacteria including Lactobacillus rhamnosus, Bifidobacterium longum, L. salivarius, L. plantarum, L. acidophilus, L. paracasei, B. lactis type Bl‐O4, and B. lactis type Bi‐07 were encapsulated using alginate alone or alginate with POPL. Electron microscopy was used to measure the size of the microcapsules and to determine their surface texture. To assess if the addition of POPL improved the viability of probiotic bacteria in acidic conditions, both ALG and POPL microcapsules were inoculated into pH 2.0 MRS broths and their viability was assessed over a 2‐h incubation period. Two bile salts including oxgall bile salt and taurocholic acid were used to test the bile tolerance of probiotic bacteria entrapped in ALG and POPL microcapsules. To assess the porosity and the ability of the microcapsule to hold small molecules in an aqueous environment a water‐soluble fluorescent dye, 6‐carboxyflourescin (6 FAM), was encapsulated and its release was monitored using a UV spectrophotometer. The results indicated that coating the microcapsules with POPL increased the overall size of the capsules by an average of 3 μm ± 0.67. However, microcapsules with added POPL had a much smoother surface texture when examined under an electron microscope. The results also indicated that the addition of POPL to microcapsules improved the average viability of probiotic bacteria by > 1 log CFU/mL when compared to ALG microcapsules at 2 h of exposure to acidic conditions. However, similar plate counts were observed between ALG and POPL microcapsules when exposed to bile salts. This suggests that an extra coating of POPL could be readily broken down by bile salts that are commonly found in the lower gastrointestinal tract (GIT). Upon testing the porosity of the microcapsules, findings suggest that POPL microcapsules were less porous and hold 52.2% more fluorescent dye over a 6‐wk storage period.     

Relationship between gastrointestinal tolerance and exopolysaccharide production of propionibacteria strains under different pH and bile conditions

In this study, we report the effects of exposure to simulated gastric and intestinal juices on the survival of six strains of dairy propionibacteria. Gastrointestinal tolerance of propionibacteria strains was highly variable, depending on the strain and pH (P < 0.05). Exopolysaccharides (EPS) production of six propionibacteria strains under different pH conditions and bile concentrations was also studied. A positive correlation was obtained between the EPS production quantity of the strains and tolerance to simulated gastric juices at pH 2.0, 3.0 (P < 0.05). This investigation showed that high EPS production may be important in the selection of probiotic strains for resistance to upper gastrointestinal system conditions.     

驼乳制品中抑制α-淀粉酶和α-葡萄糖苷酶活性乳酸菌的筛选及益生特性研究

目的:本研究以新疆阿勒泰地区的驼乳制品为研究对象,筛选对α-淀粉酶和α-葡萄糖苷酶有抑制活性的优良乳酸菌。方法:采用稀释涂布法分离纯化菌株,DNS和pNPG法筛选对α-淀粉酶和α-葡萄糖苷酶有抑制活性的菌株,通过耐酸性、耐胆盐、模拟胃肠道环境耐受性、抑菌性、抗氧化活性实验评价菌株的益生特性。结果:从驼乳制品中共计获得34株菌株,其中6株对α-淀粉酶和α-葡萄糖苷酶有抑制活性,经过形态学和16S rRNA分子鉴定,确定有4株为植物乳杆菌Lactiplantibacillus plantarum,2株为副干酪乳杆菌Lactiplantibacillus paracasei。6株乳酸菌对α-淀粉酶的抑制活性都达到50%以上,其中X34对α-淀粉酶的抑制率最高达到88.59%。本实验中筛选的乳酸菌对α-葡萄糖苷酶的抑制率在11%~16%之间,X31抑制率最高为15.43%。6株乳酸菌在不同pH（1.0、2.0、3.0）和不同浓度胆盐（1、2、3 g/L）的培养基中均可存活。6株乳酸菌在模拟胃液和肠液中的存活率分别达到83%和90%以上。对羟自由基和超氧阴离子自由基的清除率超过90%以上,其中X29对羟自由基的清除率最高为92.43%,对超氧阴离子自由基清除率最强的是X33清除率达到94.04%。6株乳酸菌对大肠杆菌、沙门氏菌和金黄色葡萄球菌有一定的抑制作用,其中X31对大肠杆菌的最大抑菌圈直径为19.63 mm,X23对沙门氏菌抑菌圈最大达到19.85 mm,菌株X33对金黄色葡萄球菌的抑菌圈直径最大为19.17 mm。结论:从驼乳制品中筛选到6株具有潜在降糖活性的乳酸菌,对强酸、胆盐和胃肠液有一定的耐受性,抗氧化能力较强,具有抑制致病菌的效果,为后期研发功能性降糖饮品提供益生菌株。