细菌素的研究与应用进展

随着食品安全问题日益受到国际社会的重视,以食品腐败/致病菌为靶点的细菌素应用受到了广泛关注.细菌素作为安全的天然防腐剂,可通过成孔、抑制细胞壁/核酸/蛋白质合成等不同的作用方式有效地抵抗食源性病原体.然而,抗细菌素突变菌株的出现和传播正阻碍着食品安全,越来越多的人开始注意食源性病原体对细菌素的耐药性现象,这将有助于人们...     

细菌素的作用机制及在生产中的应用

细菌素是一类由微生物产生的具有抑菌活性的多肽或前体多肽类物质。本文主要介绍了细菌素的概念、分类、作用机制,细菌素与抗生素的区别及在生产中的应用。同时阐述了细菌素潜在应用价值。     

植物病原细菌的细菌素

植物病原细菌的细菌素吴健胜,王金生（江苏南京农业大学植保系,南京２１００９５）细菌素是一种细菌的某些菌系所产生的对该种细菌的另一些菌株或关系较近的细菌有杀伤作用,非复制性的含蛋白的抗菌物质［１］。继１９４６年Ｆｒｅｄｅｒｉｃｑ报道大肠杆菌产生的大肠杆...     

细菌粘附素的分子结构和装配机制

细菌感染的第一步是必须粘附于易感细胞,以获得立足点,在局部繁殖,释放毒素和酶类损坏组织,导致感染,细菌的粘附作用主要靠粘附素特异的识别结合到宿主细胞的受体,使细胞在局部定居,本文主要综述菌毛粘附素的分子结构及其因控制,菌毛粘附素如何通过四种典型途径装配,以及参与装配的蛋白质是如何协调功能的研究进展。     

乳酸菌细菌素的分子生物学研究进展

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…     

羊毛硫细菌素变体及其生物活性研究进展

羊毛硫细菌素是由细菌核糖体上合成并经翻译后加工修饰而成的一类抗菌肽。已经在多种G+细菌中发现有羊毛硫细菌素,大多对G+细菌有抑菌作用。羊毛硫细菌素的基因工程无法从单一的表达羊毛硫细菌素结构基因获得高活性的成熟羊毛硫细菌素。本研究综述了羊毛硫细菌素前体分子定向位点突变后,由修饰酶重新识别和修饰可产生结构变异的可分泌的变体分子和无法分泌的变体分子,对羊毛硫细菌素分子突变位点进行了分类和归纳,并总结了羊毛硫细菌素分子突变位点与其生物活性的关系。在现有羊毛硫细菌素应用成果有限的条件下,对于工程改造羊毛硫细菌素和增强其抑菌活性具有重要意义。     

益生菌产生的细菌素及其功能机制

细菌素是细菌核糖体合成的具有抑菌活性的小肽.细菌素的产生是益生菌重要的益生特性,它们天然无毒,不仅对食品腐败菌和人体致病菌有很好的抑菌活性,还具有有助益生菌定殖和调节肠道菌群等益生特性.本文综述了益生菌产生的细菌素的种类、条件性合成、益生功能及其作用机理等,以期为深入认识益生菌的益生功能及其作用方式,研究开发对人体有益...     

乳酸菌细菌素研究进展

乳酸菌是一类能从可发酵性碳水化合物产生大量乳酸的革兰氏阳性细菌的通称。它们在人、动物体内及人类环境中是一类重要的微生物。一些定居在嘴、鼻粘膜中;一些定居在消化道、肠道（双歧菌、肠球菌和一些乳杆菌）和阴道粘膜中（一些特殊的乳杆菌）。在这些生境小区里,它们中大多数不仅不致病,相反有益,可以抑制一些腐败菌和病原菌,从而维持体内这些小生境尤其是肠道内正常的微生态平衡［’］。同时,乳酸菌也是一类重要的工业微生物,广泛应用于轻工业、医药工业、食品工业、发酵工业和饲料工业上。通常在食品和发酵工业中应用的乳酸菌…     

细菌素的制备及其应用

近年来,具有抑菌活性的细菌素被发现在食品防腐保鲜、疾病治疗和其他许多相关方面有着广泛的应用价值,各种制备细菌素的方法也被广泛报道。本文概述了细菌素的制备方法以及其在诸多领域中的应用。     

Circular Bacteriocins: Biosynthesis and Mode of Action

Circular bacteriocins are a group of N-to-C-terminally linked antimicrobial peptides, produced by Gram-positive bacteria of the phylum Firmicutes. Circular bacteriocins generally exhibit broad-spectrum antimicrobial activity, including against common food-borne pathogens, such as Clostridium and Listeria spp. These peptides are further known for their high pH and thermal stability, as well as for resistance to many proteolytic enzymes, properties which make this group of bacteriocins highly promising for potential industrial applications and their biosynthesis of particular interest as a possible model system for the synthesis of highly stable bioactive peptides. In this review, we summarize the current knowledge on this group of bacteriocins, with emphasis on the recent progress in understanding circular bacteriocin genetics, biosynthesis, and mode of action; in addition, we highlight the current challenges and future perspectives for the application of these peptides.     

Bacteriocins from lactic acid bacteria and their potential in the preservation of fruit products

Bacteriocins produced by lactic acid bacteria (LAB) are well-recognized for their potential as natural food preservatives. These antimicrobial peptides usually do not change the sensorial properties of food products and can be used in combination with traditional preservation methods to ensure microbial stability. In recent years, fruit products are increasingly being associated with food-borne pathogens and spoilage microorganisms, and bacteriocins are important candidates to preserve these products. Bacteriocins have been extensively studied to preserve foods of animal origin. However, little information is available for their use in vegetable products, especially in minimally processed ready-to-eat fruits. Although, many bacteriocins possess useful characteristics that can be used to preserve fruit products, to date, only nisin, enterocin AS-48, bovicin HC5, enterocin 416K1, pediocin and bificin C6165 have been tested for their activity against spoilage and pathogenic microorganisms in these products. Among these, only nisin and pediocin are approved to be commercially used as food additives, and their use in fruit products is still limited to certain countries. Considering the increasing demand for fresh-tasting fruit products and concern for public safety, the study of other bacteriocins with biochemical characteristics that make them candidates for the preservation of these products are of great interest. Efforts for their approval as food additives are also important. In this review, we discuss why the study of bacteriocins as an alternative method to preserve fruit products is important; we detail the biotechnological approaches for the use of bacteriocins in fruit products; and describe some bacteriocins that have been tested and have potential to be tested for the preservation of fruit products.     

60种食药两用中药抗菌防腐作用研究

本实验利用无菌24-孔板采用连续稀释法对60味食药两用中药进行了抗19种常见食品腐败菌的快速筛选,得到有明显抗菌作用的中药5种:丁香、花椒、高良姜、甘草、乌梅。其中:丁香、花椒、高良姜为香料,有较强的抗真菌作用;乌梅对所测细菌有较强抑制作用,将丁香、花椒、高良姜等等量组成复方进行抗菌实验,得出该复方的醇提物抗菌作用强于水提物,在浓度为1/80时对所有被测菌均有抑制作用。     

Phenotypic and Genotypic Characterization of Bacteriocins in Enterococcal Isolates of Different Sources

A collection of 57 enterococcal isolates from different origin (including river, treatment plant, spring and garbage water, soil, animal, and vegetables from Aydın) was screened for the production of bacteriocins. Enterococci were identified at species levels as Enterococcus faecium (34), E. hirae (6), E. casseliflavus (4), E. durans (4), E. faecalis (4), E. mundtii (3) and E. avium (2). Of the 57 isolates 40 of them inhibited the growth of at least one indicator bacterium. Based on our PCR results 54 strains possesed enterocin genes. The genes of entA and entB were the most frequently detected structural genes among the PCR positive strains (54 and 53 strains, respectively) and the entB gene was always associated with entA gene. The highest combination of enterocin genes (24 of 54 strains) detected was entA, entB, entP and entL50A/B. The enterocins AS-48 and CylL_LS genes were not found. Three enterococcal isolates, 2 E. faecium and 1 E. hirae were not harbour any of tested enterocin genes. No correlation between the presence of enterocin structural genes and the origin of the strain was detected, also no relationship seemed to exist between the tested enterocin genes and the activity spectra of isolates. Genes encoding bacteriocins are widely disseminated among enterocci from different origin and more studies should be done for evaluate industrial potential of bacteriocins.     

海洋无脊椎动物抗菌肽研究进展及其在食品保鲜中的应用

海洋无脊椎动物抗菌肽抑菌广谱,稳定性高,且对生物体本身无害,其应用日益引起大量研究者的关注。综述了抗菌肽的几种类型、抑菌机理,介绍了海洋无脊椎动物抗菌肽研究进展、存在的问题并分析其在食品保鲜中的应用前景。     

Recent trends and technological development in plasma as an emerging and promising technology for food biosystems

The rising need for wholesome, fresh, safe and “minimally-processed” foods has led to pioneering research activities in the emerging non-thermal technology of food processing. Cold plasma is such an innovative and promising technology that offers several potential applications in the food industry. It uses the highly reactive, energetic and charged gas molecules and species to decontaminate the food and package surfaces and preserve the foods without causing thermal damage to the nutritional and quality attributes of food. Cold plasma technology showed promising results about the inactivation of pathogens in the food industry without affecting the food quality. It is highly effective for surface decontamination of fruits and vegetables, but extensive research is required before its commercial utilization. Recent patents are focused on the applications of cold plasma in food processing and preservation. However, further studies are strongly needed to scale up this technology for future commercialization and understand plasma physics for getting better results and expand the applications and benefits. This review summarizes the emerging trends of cold plasma along with its recent applications in the food industry to extend shelf life and improve the quality of food. It also gives an overview of plasma generation and principles including mechanism of action. Further, the patents based on cold plasma technology have also been highlighted comprehensively for the first time.     

高产细菌素菌株WJ K84-1的诱变筛选及其对植物病原菌抑菌机理的研究

以发根土壤杆菌K84为供试菌株,对其进行紫外诱变,采用定向竞争选择技术,筛选出高产细菌素的目的菌株WJK84-1,并对根癌农杆菌的抑菌作用及其抑菌机理进行了研究。通过琼脂扩散法和液体培养法测试表明,WJK84-1菌株和其产生的P-2001细菌素均对C58病原菌有明显的抑制作用。蛋白电泳谱带分析示出,细菌素对C58病原菌的作用是抑制蛋白合成,使其蛋白总量表达水平呈下降趋势,尤其是大分子量蛋白含量下降显著,有的蛋白谱带(R1、R4)缺失,且随细菌素浓度的增加,抑制作用更加强烈。扫描电镜观察,细菌素作用后的菌体不同部位出现缢痕,直至缢缩成颗粒状残体而死亡。透射电镜观察进一步证明,C58菌细胞膜被裂解,细胞结构被破坏而致死。樱桃接瘤实验表明,WJK84-1菌株和其产生细菌素均可抑制根瘤发生,抑瘤率达到83．4％左右。     

Purification and characterization of an antimicrobial peptide produced by <Emphasis Type="Italic">Pseudomonas</Emphasis> sp. strain 4B

An antimicrobial peptide produced by a bacterium isolated from the effluent pond of a bovine abattoir was purified and characterized. The strain was characterized by biochemical profiling and 16S rDNA sequencing as Pseudomonas sp. The antimicrobial peptide was purified by ammonium sulfate precipitation, gel filtration, and ion exchange chromatography. Direct activity on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was observed. A major band on SDS-PAGE suggested that the antimicrobial peptide has a molecular mass of about 30 kDa. The substance was inhibitory to a broad range of indicator strains, including pathogenic and food spoilage bacteria such as Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, among other. The partially purified antimicrobial substance remained active over a wide temperature range and was resistant to all proteases tested. This substance showed different properties than other antimicrobials from Pseudomonas species, suggesting a novel antimicrobial peptide was characterized.     

Fluorescence anisotropy analysis of the mechanism of action of mesenterocin 52A: speculations on antimicrobial mechanism

Mesenterocin 52A (Mes 52A) is a class IIa bacteriocin produced by Leuconostoc mesenteroides subsp. mesenteroides FR52, active against Listeria sp. The interaction of Mes 52A with bacterial membranes of two sensitive Listeria strains has been investigated. The Microbial Adhesion to Solvents test used to study the physico-chemical properties of the surface of the two strains indicated that both surfaces were rather hydrophilic and bipolar. The degree of insertion of Mes 52A in phospholipid bilayer was studied by fluorescence anisotropy measurements using two probes, 1-(4-trimethylammonium)-6-phenyl-1,3,5-hexatriene (TMA-DPH) and DPH, located at different positions in the membrane. TMA-DPH reflects the fluidity at the membrane surface and DPH of the heart. With Listeria ivanovii CIP 12510, Mes 52A induced an increase only in the TMA-DPH fluorescence anisotropy, indicating that this bacteriocin affects the membrane surface without penetration into the hydrophobic core of the membrane. No significant K⁺ efflux was measured, whereas the ΔΨ component of the membrane potential was greatly affected. With Listeria innocua CIP 12511, Mes 52A caused an increase in the fluorescence of TMA-DPH and DPH, indicating that this peptide inserts deeply in the cytoplasmic membrane of this sensitive strain. This insertion led to K⁺ efflux, without perturbation of ΔpH and a weak modification of ΔΨ, and is consistent with pore formation. These data indicate that Mes 52A interacts at different positions of the membrane, with or without pore formation, suggesting two different mechanisms of action for Mes 52A depending on the target strain.     

Chlamydomonas reinhardtii-expressed multimer of Bacteriocin LS2 potently inhibits the growth of bacteria

Bacteriocin LS2 was isolated from the Lactobacillus salivarius BGHO1 strain in 2012. Since then, its antibacterial activity has not been examined. Here, Chlamydomonas reinhardtii was used to express a C-terminal hemagglutinin (HA) and 6×His double tagged three repeats of Bacteriocin LS2 (3×Bacteriocin LS2). 3×Bacteriocin LS2 expression was stable following passaging in C. reinhardtii cells for six months and its yield accounted for 0.28% of total soluble proteins of the host cells. C. reinhardtii-derived 3×Bacteriocin LS2 inhibited the growth of four tested bacteria of both gram-positive and gram-negative with minimum inhibitory concentration (MIC) values between 75 and 90 μg/mL, indicating that this peptide is more potent than other bacteriocins like nesin and bacteriocin MA047A which have a MIC beyond 165 μg/mL in general. The recombinant 3×Bacteriocin LS2 maintained high stability over a wide range of temperature and pHs, showed tolerance to proteases, exhibited low hemolytic activity against rabbit erythrocytes and low cytotoxicity to human embryonic kidney 293 T (HEK 293 T) cells. In addition, C. reinhardtii-derived 3×Bacteriocin LS2 penetrated cell membranes and destroyed the morphology of targeted bacterial cells to different extents. In summary, our study shows that C. reinhardtii can be used as a platform for the production of active Bacteriocin LS2.