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1.
摘要:【目的】分离纯化(Lactobacillus paracasei)HD1.7所产生的细菌素并分析其特性。【方法】细菌素Paracin 1.7的纯化采用色谱技术,其分子量检测采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE),利用琼脂扩散法测定细菌素活力。【结果】Paracin 1.7分离于我国传统发酵食品酸菜发酵液中,其产生菌为副干酪乳杆菌。 Paracin 1.7可以抑制其它微生物的生长,为细菌素。该菌在稳定期可产生大量Paracin 1.7。经过阳离子交换层析、凝胶过滤层析以及高效液相色谱(HPLC),对该细菌素进行了初步纯化,并经Tricine-SDS-PAGE检测其分子量大约为11 kDa。Paracin 1.7抑菌谱较广,其抑菌范围包括Proteus, Bacillus, Enterobacter, Staphylococcus, Escherichia, Lactobacillus, Microccus, Pseudomonas, Salmonella, Saccharomyces,其中有些为食品源致病菌。该细菌素在酸性及高温下稳定,对几种蛋白质酶敏感。该细菌素对敏感菌株的作用方式为抑菌。在4oC保存4个月后,Paracin 1.7的抑菌活性保持稳定。【结论】基于细菌素Paracin 1.7的性质,该细菌素可用作食品防腐剂。  相似文献   

2.
副干酪乳杆菌HD1.7群体感应行为   总被引:2,自引:1,他引:1  
【目的】Paracin1.7是从副干酪乳杆菌(Lactobacillus paracasei)HD1.7发酵液中提取的一种细菌素,本文主要研究菌株HD1.7在发酵过程中调控Paracin1.7代谢的群体感应机制。【方法】利用杯碟法检测不同生长条件下菌株HD1.7培养液的抑菌活性,通过调整培养基营养成分的多寡,控制培养液中细胞密度。【结果】菌株HD1.7的抑菌活性与其细胞密度密切相关,只有当细胞密度达到一定的阈值(OD600为0.8,菌体干重为0.331 1 g/L)时,菌株才能表现抑菌活性;以发酵上清液作为信号分子,当添加不同浓度信号分子至低于阈值浓度培养液后,菌株抑菌活性受到不同程度的影响,并且在去除信号分子后,菌株的抑菌活性明显降低。【结论】细菌素Paracin1.7是存在于HD1.7发酵液中的特殊的群体感应信号分子,可进行自我诱导。细菌素Paracin1.7的抑菌活性受到HD1.7群体感应系统的调控。  相似文献   

3.
一株短乳杆菌所产细菌素的部分特性   总被引:1,自引:0,他引:1  
为了研究分离自内蒙古传统发酵乳制品——"焦克"的短乳杆菌KLDS1.0373所产细菌素的部分生物学特性(抑菌谱,对酶、pH和温度的敏感性,作用方式)。短乳杆菌KLDS1.0373发酵液经硫酸铵沉淀和葡聚糖凝胶纯化后,测定其部分生物学特性,并采用Tricine-SDS-PAGE方法确定细菌素的分子量范围。结果表明:短乳杆菌KLDS1.0373所产细菌素的抑菌活性对热和pH不敏感,在100°C或121°C处理30 min后抑菌活力略有增强,可被多种蛋白酶失活,但对α-淀粉酶不敏感。该细菌素分子量约为3.8 kD,对多种革兰氏阳性和阴性菌有抑制作用,作用方式为杀菌。  相似文献   

4.
近年来,乳酸菌细菌素在食品防腐剂和医药领域有着广泛的应用前景,而细菌素的分离纯化是其分子结构及遗传学特性等相关研究的重要基础。离子交换色谱是细菌素分离纯化的主要手段之一。本文阐述了离子交换色谱原理,分析了影响离子交换色谱分离纯化细菌素的各种因素,探讨了细菌素分离纯化中离子交换色谱条件的选择。  相似文献   

5.
[目的]为明确根癌拮抗放线菌G-19的抑菌活性物质.[方法]采用SephadexLH-20柱层析、高效液相色谱及中压制备色谱等技术,对桃根癌拮抗放线菌G-19发酵液中的抑菌活性成分进行分离纯化,并通过LC-MS、NMR对其结构进行鉴定.[结果]分离得到化合物G-19-Ⅰ的结构为邻苯二甲酸二丁酯(DBP),化合物G-19-Ⅱ的结构为2-(4-羟基苯基)-3,4-二氢-2H-苯并吡喃-3,4,5,7-四醇,俗称无色天竺葵素.[结论]阐明了放线菌G-19抑菌活性成分的物质基础.  相似文献   

6.
血链球菌细菌素抑菌活性研究   总被引:2,自引:0,他引:2  
检测分离纯化的血链球菌细菌素对牙周可疑致病菌的抑制作用。通过羟基磷灰石(HA)柱层析、SephadexG-150凝胶柱层析、中空纤维柱超滤脱盐、浓缩纯化提取血链球菌细菌素,以具核梭杆菌为指示菌,洞平板法检测细菌素的抑菌活性。经HA柱层析得到4个相互分离的组分,经洞平板法检测,第Ⅱ峰的蛋白具有抑菌活性,冻干后得纯化后的细菌素,终产率为0.082%;1mg/mL的细菌素溶液可形成17mm的抑菌环,最小抑菌浓度为62.5μg/mL。血链球菌细菌素对牙周可疑致病菌具有较强的拮抗作用。  相似文献   

7.
[目的]应用数学统计法对副干酪乳杆菌HD1.7的固定细胞制备和发酵条件进行优化,以提高细菌素产量.[方法]用2(6-2)部分因子分析法筛选对细菌素产量影响显著的因子,发现海藻酸钠浓度、接种量和发酵时间对细菌素的产生影响显著.利用最陡爬坡法逼近最大响应区域.用Box-Behnken设计确定最佳海藻酸钠浓度、接种量和发酵时间,并进行分批重复发酵.[结果]固定化生产细菌素的最佳条件是海藻酸钠浓度2.8%、CaC2,浓度5%、固定化时间4 h、菌体包埋量1/20、发酵时间63 h和固定化细胞的接种量8.2%,在此基础上用固定化细胞进行分批重复发酵,每批细菌素的发酵周期为24 h.[结论]通过对固定化细胞制备和发酵条件的优化,固定化细胞在327 h的分批重复发酵中细菌素的总体产量比游离细胞提高了19%,发酵液中无明显细胞渗漏现象且实现了细胞的重复利用,为细菌素的进一步研究和最终提取奠定了基础.  相似文献   

8.
从分离自内蒙古传统乳制品的67株乳酸菌中筛选得到一株产生类细菌素的布氏乳杆菌KLDS1.0364, 对其所产类细菌素进行初步分离纯化, 同时研究其所产类细菌素的生物学特性。KLDS1.0364无细胞发酵上清液经阳离子交换树脂纯化后, 采用tricine-SDS-PAGE测定类细菌素分子量, 并测定了类细菌素的部分特性。KLDS1.0364产生的类细菌素分子量约为21.6kD, 对热和pH值稳定, 可被多种蛋白酶失活, 不能被过氧化氢酶和α-淀粉酶失活。KLDS1.0364产生的类细菌素的作用方式是杀菌, 且抑菌谱广, 可抑制多种革兰氏阳性菌、革兰氏阴性菌和真菌。  相似文献   

9.
一株布氏乳杆菌所产类细菌素的初步纯化与部分特性   总被引:7,自引:1,他引:6  
从分离自内蒙古传统乳制品的67株乳酸菌中筛选得到一株产生类细菌素的布氏乳杆菌KLDS1.0364,对其所产类细菌素进行初步分离纯化,同时研究其所产类细菌素的生物学特性.KLDS1.0364无细胞发酵上清液经阳离子交换树脂纯化后,采用tricine-SDS-PAGE测定类细菌素分子量,并测定了类细菌素的部分特性.KLDS1.0364产生的类细菌素分子量约为21.6kD,对热和pH值稳定,可被多种蛋白酶失活,不能被过氧化氢酶和α-淀粉酶失活.KLDS1.0364产生的类细菌素的作用方式是杀菌,且抑菌谱广,可抑制多种革兰氏阳性菌、革兰氏阴性菌和真菌.  相似文献   

10.
乳酸菌细菌素的分子生物学研究进展   总被引:11,自引:2,他引:9  
乳酸菌是一大类发酵糖产生大量乳酸的兼性厌氧菌 ,广泛应用于医药、食品、发酵等工业 ,主要包括乳杆菌( L actobacillus)、乳球菌 ( L actococcus)、明串珠菌( L euconostoc )、片球菌 ( Pediococcus )、链球菌( Streptococcus)、肠球菌 ( Enterococcus)、双歧杆菌( Bifidobacterium)和肉食杆菌 ( Carnobacterium)等属 [1 ]。许多乳酸菌除产生乳酸、乙酸和双乙酰外 ,还可产生一些具有抑菌或杀菌作用的细菌素 ( bacteriocin) ,在食品防腐保鲜中起重要作用 [2 ] 。细菌素的含义可以这样理解。细菌素是由某些细菌在代谢过程中通过核糖体合…  相似文献   

11.
对从乳酸菌酸菜发酵液中分离到的能产生抑菌物质的菌株进行了鉴定,并对该菌的发酵产物进行了提取和性质研究。经形态学、生理生化与16SrDNA序列分析鉴定该菌株为副干酪乳杆菌(Lactobacillus paracasei)。抑菌谱试验表明:除酵母菌外,该抑菌物质对革兰氏阳性、阴性菌和多种致病菌均有较强的抑制作用。经有机溶剂萃取法获得了抑菌物质的粗提物,胰蛋白酶水解证明抑菌物质具有蛋白质性质,尿素-SDS-PAGE不连续凝胶电泳法测得抑菌物质的分子量为14000左右。  相似文献   

12.
Aims:  Characterization and purification of a new bacteriocin produced by Lactobacillus plantarum LP 31 strain, isolated from Argentinian dry-fermented sausage.
Methods and Results:  Lactobacillus plantarum LP 31 strain produces an antimicrobial compound that inhibits the growth of food-borne pathogenic bacteria. It was inactivated by proteolytic enzymes, was stable to heat and catalase and exhibited maximum activity in the pH range from 5·0 to 6·0. Consequently, it was characterized as a bacteriocin. It was purified by RP (reverse-phase) solid-phase extraction, gel filtration chromatography and RP-HPLC. Plantaricin produced by Lact. plantarum LP 31 is a peptide with a molecular weight of 1558·85 Da as determined by Maldi-Tof mass spectrometry and contains 14 amino acid residues. It was shown to have a bactericidal effect against Pseudomonas sp., Staphylococcus aureus , Bacillus cereus and Listeria monocytogenes.
Conclusions:  The bacteriocin produced by Lact. plantarum LP 31 may be considered as a new plantaricin according to its low molecular weight and particular amino acid composition.
Significance and Impact of the Study:  In view of the interesting inhibitory spectrum of this bacteriocin and because of its good technological properties (resistance to heat and activity at acidic pH), this bacteriocin has potential applications as a biopreservative to prevent the growth of food-borne pathogens and food spoilage bacteria in certain food products.  相似文献   

13.
AIMS: The aim of this work was to purify and characterize antibacterial compounds produced by Lactobacillus murinus strain L1. METHODS AND RESULTS: Antagonistic activity was observed in a deferred agar-spot assay against spoilage and pathogenic bacteria, but not against lactobacilli. The inhibitory activity occurred between pH 3.0 and 5.0, and was heat stable. The active compounds were purified by gel filtration chromatography and two peaks of antibacterial activity were observed using Bacillus cereus ATCC 11778 and Shigella sonnei ATCC 11060 as indicator strains. Two active low molecular weight compounds were responsible for this phenomenon and UV spectroscopy, gas chromatography and mass spectrometry were used to characterize them. One of them is lactic acid, while the other is a mono-substituted aromatic ring apparently constituted by group residues of m/z 192 linked in tandem to phenylalanine. CONCLUSIONS: Lactobacillus murinus produces at least two low molecular weight compounds active against B. cereus and Sh. sonnei. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first purification of a new broad-spectrum antibacterial compound from Lact. murinus which inhibits various pathogenic and food spoilage bacteria without acting on other lactobacilli. Using it as a biotechnological control agent of bacterial spoilage may be a promising possibility for the food industry.  相似文献   

14.
产碱性磷酸酶乳杆菌的筛选鉴定、酶的纯化及特性   总被引:1,自引:1,他引:0       下载免费PDF全文
【背景】碱性磷酸酶(alkaline phosphatase,ALP)是生物体内参与磷酸代谢的调控酶,不同物种的ALP性质与其生理功能有关,提纯后的ALP常用作工具酶,广泛应用于基因工程中,但目前关于乳酸菌中ALP的相关研究甚少。【目的】筛选出一株产ALP且具有潜在益生作用的乳杆菌,对该酶进行分离纯化,并对其性质进行探究,为今后益生菌的开发利用和ALP的工业化生产提供新的微生物资源。【方法】采集蒙古国4个地区的酸马奶样品,通过显色反应初筛和酶活检测复筛对产酶菌株进行筛选,经形态学观察、生理生化鉴定及16S rRNA基因序列同源性比较分析进行菌种鉴定。采用超声破碎法提取ALP,经硫酸铵沉淀、DEAE-52离子交换层析、Sephadex G-200凝胶过滤层析纯化该酶,SDS-PAGE电泳法检测其纯度。【结果】从78株乳酸菌中分离筛选出一株产ALP酶活性最高的乳杆菌(编号为Z23),16S rRNA基因序列长度为1 473 bp,鉴定结果表明为鼠李糖乳杆菌。纯化后的酶比活力为180.27 U/mg,纯化倍数为48.37,酶活回收率为17.05%,该酶亚基相对分子质量为46.7 kD。菌株所产ALP的最适温度为37℃,4℃时酶活最为稳定;最适pH为9.5,在pH 9.0-10.0之间,酶活稳定性可达90%以上;Mg2+和K+对ALP有明显激活作用,Ba2+和Cu2+在低浓度时对ALP有激活作用,高浓度时有抑制作用,Ca~(2+)、Zn~(2+)和EDTA对ALP有强烈的抑制作用。以不同浓度的p-NPP为底物,测得酶的Km值为3.42 mmol/L,Vmax值为1.24 mmol/(L·min)。【结论】本研究对蒙古国地区酸马奶中的益生菌资源有了更为明确的认知,为今后碱性磷酸酶产生菌的筛选和酶的应用开辟了新途径。  相似文献   

15.
【目的】以新疆古尔班通古特沙漠的生物结皮为样品,通过培养、筛选、分离得到一株高产胞外多糖(EPS)的菌株XJ-27,对XJ-27菌株所产的胞外多糖进行分离纯化,并对其絮凝性进行研究。【方法】利用DEAE sepharose CL-6B阴离子层析和Sephadex G100凝胶层析的方法对胞外多糖进行纯化,通过紫外分析方法和高效凝胶渗透色谱进行纯度的测定,利用高效凝胶渗透色谱法(HP-GPC)测定其分子量,以高岭土为体系对其絮凝性进行研究。【结果】利用层析分离的方法共得到2个胞外多糖的组分,对其中一个组分进一步纯化,得到组分EPS-I。结果表明,EPS-I纯度较高,分子量为575 kD。同时对胞外多糖的絮凝性进行了研究,结果表明该胞外多糖对高岭土为体系的絮凝率为80.4%。【结论】菌株XJ-27产胞外多糖,其胞外多糖具有絮凝性,对该胞外多糖进行分离纯化后,得到分子量为575 kD的多糖组分EPS-I。  相似文献   

16.
A low molecular weight active fragment of potato proteinase inhibitor IIPB was obtained by incubating the inhibitor with an equimolar amount of trypsin [EC 3.4.21.4] at pH 8 and 30 degrees for 16 hr, followed by gel filtration through Sephadex G-50, treatment with trichloroacetic acid, and CM-cellulose chromatography. The purified active fragment consisted of a single peptide chain with a molecular weight of 4,300, comprising 39 amino acid residues. It retained very strong inhibitory activity against chymotrypsin [EC 3.4.21.1] and subtilisin [EC 3.4.21.14]. However, the yield of this active fragment was rather low and was variable. On further incubation with trypsin, it was converted into smaller inactive peptides.  相似文献   

17.
18.
A plasma inhibitor of tonin activity in the rat, was purified by ammonium sulfate precipitation, ion-exchange of chromatography, and gel filtration. Its purity was investigated by analytical electrophoresis on polyacrylamide gel and by ultracentrifugation sedimentation velocity. The molecular weight (360 000) of the purified inhibitor was determined by sodium dodecyl sulfate electrophoresis and its isoelectric point (4.5) by gel isoelectrofocusing. The Stokes radius (640 nm) was evaluated by gel filtration studies and a frictional ratio (f/fo) of 1.95 was calculated from the molecular weight and Stokes radius. Kinetic studies using angiotensin I as substrate showed that the inhibition of tonin by the purified inhibitor was noncompetitive and does not exceed 70%. Electrophoresis showed the same mobility for [125I]tonin bound to plasma proteins and for [125I]tonin bound to the purified inhibitor. The inhibitor may be a protein resembling half of the dimeric protease inhibitor rat alpha 1-macroglobulin or human alpha 2-macroglobulin.  相似文献   

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