Detection and preliminary characterization of a bacteriocin (plantaricin 35d) produced by a Lactobacillus plantarum strain

Lactic acid bacteria (134) from Italian sausages were tested for the production of antimicrobial substances (bacteriocins). Six percent of these showed antibacterial activity against one or several closely related microorganisms used as indicators. Lactobacillus plantarum 35d in particular produced a bacteriocin of high activity (320 AU ml(-1)) and a wide range of antimicrobial activity including S. aureus, L. monocytogenes, and A. hydrophila. The bacteriocin withstood heating at 80 degrees C for 120 min and storage at 4 degrees C for 6 months. The mode of action was identified as bactericidal. The apparent molecular weight of the bacteriocin extracted with n-butanol was estimated to be 4.5 kDa.     

The locus responsible for production of plantaricin S,a class IIb bacteriocin produced by Lactobacillus plantarum LPCO10, is widely distributed among wild-type Lact. plantarum strains isolated from olive fermentations

The genes plsA and plsB encoding for production of plantaricin S (Pls), a two-peptide bacteriocin produced by Lactobacillus plantarum LPCO10, are commonly distributed among wild-type Lact. plantarum strains isolated from olive fermentations. Among 68 independent isolates from different olive processing plants in South Spain, 15 of them were shown to produce bacteriocins that were active against other lactic acid bacteria, as well as spoilage and pathogenic bacteria. On the basis of PCR amplification and hybridization with specific probes, the Pls operon was detected in all the bacteriocin producer strains but not in the non-producer ones. Purification and subsequent amino acid sequencing of the bacteriocin produced by some of the 15 isolates yielded both the alpha and beta peptides from Pls. These results suggest that bacteriocin production contributes an ecological advantage for the wild-type Lact. plantanum strains in the colonization of the spontaneous, traditional olive fermentation process.     

植物乳杆菌(Lactobacillus plantarum)CW5的筛选及细菌素抑菌活性的研究

为了提高抑菌活性,对植物乳杆菌(Lactobacillus plantarum)CW5产细菌素的发酵条件进行了优化,分别研究了培养时间、温度、接种量、培养基起始pH、培养基碳源、氮源等因素对细菌素产生的影响,通过单因素水平实验和正交实验,确定产细菌素的最佳培养基组合和最佳发酵条件为:葡萄糖3%,胰蛋白胨1.5%,蛋白胨1.5%,酵母膏1%,硫酸镁0.058%,吐温80 0.2%,30℃培养24 h,培养基起始pH为6.5,接种量2%。CW5在优化前效价为367.82 IU/mL,优化后效价为1619.85 IU/mL,提高了340.39%。     

Mode of action, purification and amino acid sequence of plantaricin C19, an anti-Listeria bacteriocin produced by Lactobacillus plantarum C19.

Plantaricin C19, an anti-Listeria bacteriocin, was successfully purified by adsorption to and release from producing cells at low pH combined with reverse phase high-performance liquid chromatography (HPLC). The purification resulted in a 900-fold increase in specific activity with a yield of 15% of the original activity. Mass spectrometry analysis gave a molecular weight of 3845.3. Protein microsequencing identified 36 amino acids. Plantaricin C19 is rich in both hydrophobic and basic amino acids in good accordance with its basic and hydrophobic character. Comparison of the amino acid sequence of plantaricin C19, with the sequence of some other anti-Listeria bacteriocins produced with lactic acid bacteria, revealed that plantaricin C19 has in its N-terminal region the consensus sequence--YYGNGL--(uniquely with Valine instead of Leucine as found in all other bacteriocins), identifying plantaricin C19 as a pediocin-like bacteriocin. Plantaricin C19 exerted a bacteriostatic action on sensitive cells of Listeria grayi IP 6818 in BHI broth. No loss of intracellular K+, Mg2+ or UV-absorbing materials was observed. Adsorption of plantaricin C19 on L. grayi CIP 6818 decreased in the presence of salts.     

Behavior of Lactobacillus plantarum and Saccharomyces cerevisiae in fresh and thermally processed orange juice

Lactobacillus plantarum and Saccharomyces cerevisiae are acid-tolerant microorganisms that are able to spoil citrus juices before and after pasteurization. The growth of these microorganisms in orange juice with and without pasteurization was investigated. Two samples of orange juice were inoculated with ca. 10(5) CFU/ml of each microorganism. Others were inoculated with ca. 10(7) CFU/ml of each microorganism and then thermally treated. L. plantarum populations were reduced by 2.5 and <1 log10 CFU/ml at 60 degrees C for 40 s and at 55 degrees C for 40 s, respectively. For the same treatments, S. cerevisiae populations were reduced by >6 and 2 log10 CFU/ml, respectively. Samples of heated and nonheated juice were incubated at 15 degrees C for 20 days. Injured populations of L. plantarum decreased by ca. 2 log10 CFU/ml during the first 70 h of storage, but those of S. cerevisiae did not decrease. The length of the lag phase after pasteurization increased 6.2-fold for L. plantarum and 1.9-fold for S. cerevisiae, and generation times increased by 41 and 86%, respectively. The results of this study demonstrate the differences in the capabilities of intact and injured cells of spoilage microorganisms to spoil citrus juice and the different thermal resistance levels of cells. While L. plantarum was more resistant to heat treatment than S. cerevisiae was, growth recovery after pasteurization was faster for the latter microorganism.     

植物乳杆菌JLA-9产细菌素的分离纯化

将来源于东北传统发酵酸菜中的植物乳杆菌JLA-9产的细菌素进行分离纯化,首先利用饱和度为80%的硫酸铵溶液对发酵上清液进行沉淀粗分离。复溶后利用Sephadex LH-20进行凝胶层析纯化,之后采用Hitrap QFF进一步进行离子交换层析纯化,利用反相高效液相色谱(Reversed-Phase High Performance Liquid Chromatography,RP-HPLC)C_(18)柱进行最终纯化,得到单一活性抑菌组分,说明细菌素得到基本纯化,经基质辅助激光解吸电离飞行时间质谱(Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry,MALDI-TOF/MS)确定该细菌素的分子质量约为0.9 kDa左右。采用琼脂扩散法测定了细菌素对常见的食源性致病菌和腐败菌的抑菌效果,结果显示该细菌素具有较好的抑制作用。     

Inactivation of Saccharomyces cerevisiae and Lactobacillus plantarum in orange juice using ultra high-pressure homogenisation

Yeasts and lactic acid bacteria are the usual contaminants in orange juice and responsible for decreasing the shelf life of the product. Ultra high-pressure homogenisation has been shown to be an alternative to the traditional thermal pasteurisation of pumpable foods. The product was pumped through a homogeniser valve at 100 MPa, 150 MPa, 200 MPa, 250 MPa and 300 MPa using two synchronized overlapped intensifiers at a flow rate of approximately 270 mL/min. The inlet temperature was kept at 10 °C, pH at 4.1 and soluble solids at 10.0 °Bx. After processing, the product was immediately cooled to 4 °C and the microbiological count was determined. The study showed that Lactobacillus plantarum and Saccharomyces cerevisiae are sensible to ultra high-pressure homogenisation treatment. The results indicated that pressures higher than 250 MPa were able to completely destroy initial loads of 1.2 × 107 UFC/mL of L. plantarum and 2.9 × 105 UFC/mL of S. cerevisiae in orange juice, making this technology a promising way to nonthermally process orange juices.Industrial relevanceThis paper deals with inactivation of microorganism contaminants of orange juice using dynamic ultra high process technology. It is of industrial interest and relevance to evaluate the use of this non-thermal emerging technology to process fluid foods that may result into better taste, optimum product functionality, safety and quality characteristics.     

Characterization of bacteriocin ST8KF produced by a kefir isolate Lactobacillus plantarum ST8KF

Lactobacillus plantarum ST8KF, isolated from kefir, produced a 3.5 kDa bacteriocin (bacST8KF) active against Lb. casei, Lb. salivarius, Lb. curvatus and Listeria innocua. BacST8KF was sensitive to proteolytic enzymes, but stable between pH 2.0 and 10.0, and heat resistant (20 min at 121 °C). BacST8KF did not adsorb to the surface of the producer cell. Maximum activity (25,600 AU mL⁻¹) was recorded in MRS broth with glucose, in MRS broth with glucose replaced by sucrose, and in MRS broth with glucose, supplemented with KH₂PO₄ after 24 h at 30 °C. Tri-ammonium citrate and glycerol in excess of 5.0 g L⁻¹ repressed bacST8KF production. Production of bacST8KF increased from 800 AU mL⁻¹ after 3 h of fermentation in MRS broth at 30 °C to 12,800 AU mL⁻¹ after 9 h and to 51,200 AU mL⁻¹ after 27 h. These results suggest that bacST8KF may be a secondary metabolite and shows that its mode of activity is bacteriostatic.     

酿酒酵母与植物乳杆菌复合发酵对面条储藏特性的影响

为探究酿酒酵母与植物乳杆菌复合发酵对面条储藏特性的影响.采用质构仪(TA)、低场脉冲核磁共振仪(LF-NMR)、X-射线衍射仪(XRD)对面条在4℃储藏期间的品质变化进行分析.结果表明,与空白组相比,发酵面条的断条率低,吸水率无显著性差异(P>0.0.5),pH下降,可滴定酸(TTA)值上升;在相同储藏时间内发酵面条的...     

Characterization of a highly thermostable extracellular lipase from Lactobacillus plantarum

After screening for the presence of lipase activity in lactobacilli isolated from "chouri?o", a traditional Portuguese dry fermented sausage, a strain of Lactobacillus plantarum (DSMZ 12028) was chosen for extracellular lipase characterisation and purification. Proteinase K did not significantly affect lipolytic activity, as opposed to trypsin, which completely eliminated this activity. Among NaCl, Ca2+, EDTA, BSA, glycerol, Mn2+ and Mg2+, only Mn2+ and Mg2+ stimulated the lipase. Purification by gel filtration chromatography and gel electrophoresis revealed four bands, between 98 and 45 kDa, all with lipolytic activity against olive oil.     

植物乳杆菌和酿酒酵母发酵菠萝汁的性能比较及产物分析

采用植物乳杆菌（Lactobacillus plantarum）和酿酒酵母（Saccharomyces cerevisiae）分别进行单菌与混菌发酵菠萝汁,并比较分析不同接菌方式下菠萝汁的发酵性能及发酵体系中的产物。结果表明,相同接种量发酵72 h后,植物乳杆菌单独发酵活菌数可达108 CFU/mL,分别约为酿酒酵母单独发酵和二者混合发酵活菌数的3倍和10倍;植物乳杆菌的接入使发酵液pH降至3.21,而酿酒酵母的接入使菠萝汁中氨基酸态氮降至3.15×10-4 mg/L,糖类物质几乎被消耗殆尽。发酵产物分析结果发现,植物乳杆菌单独发酵产生大量乳酸（每升增加12.02 g/L）和少量乙酸（每升增加0.40 g/L）,影响了口感,而酿酒酵母单独发酵则使菠萝汁中原有的香气物质损失较多（4种）。综合分析,采用二者混合发酵,既可保有菠萝本身的营养物质和特有香气,又可赋予其一定的发酵风味,获得口感良好的菠萝发酵饮品。     

Coculture-inducible bacteriocin activity of Lactobacillus plantarum strain J23 isolated from grape must

Detection and characterization of bacteriocin production by Lactobacillus plantarum strain J23, recovered from a grape must sample in Spain, have been carried out. Bacteriocin activity was degraded by proteolytic enzymes (trypsin, alfa-chymotrypsin, papaine, protease, proteinase K and acid proteases), and it was stable at high temperatures (121 degrees C, 20min), in a wide range of pH (1-12), and after treatment with organic solvents. L. plantarum J23 showed antimicrobial activity against Oenococcus oeni, and a range of Lactobacillus and Pediococcus species. Bacteriocin production was detected in liquid media only when J23 was cocultivated with some inducing bacteria, and induction took place when intact cells or 55 degrees C heated cells of the inducer were cocultivated with J23, but not with their autoclaved cells. Bacteriocin activity of J23 was not induced by high initial J23 inocula, and it was detected in cocultures during the exponential phase. The presence of ethanol or acidic pH in the media reduced bacteriocin production in the cocultures of J23 with the inducing bacteria. The presence of plantaricin-related plnEF and plnJ genes was detected by PCR and sequencing. Nevertheless, negative results were obtained for plnA, plnK, plNC8, plS and plW genes.     

Characterization of a Bacteriocin from Lactobacillus plantarum Strain LR/14

A rhizospheric isolate of a lactic acid bacterium, identified as Lactobacillus plantarum strain LR/14, was characterized to produce a bacteriocin. A supernatant from 20h culture growth was used as the source of bacteriocin. The antimicrobial compound showed remarkable stability at high temperatures (100°C for 30 min and 121°C for 15 min under 15 psi pressure) and to the presence of organic solvents, detergents and surfactants. It was also active in the pH regime of pH 2.0–6.0. Moreover, the compound was stable under different storage temperatures as tested up to 24 months. While antimicrobial function was not lost by catalase or β-glycerophosphate treatment, the same was sensitive to a number of proteolytic enzymes. The crude preparation inhibited not only related strains but also other gram-positive and gram-negative bacteria, such as Staphylococcus aureus, Listeria monocytogenes and urogenic E. coli. Bacteriocinogenic activity co-migrated as a single protein band on tricine-SDS-PAGE with molecular mass of ～3.6 kDa.     

植物乳杆菌亚油酸异构酶的分离纯化及其性质研究

经硫酸铵分级沉淀、阴离子交换层析和凝胶过滤,由植物乳杆菌(LactobacillusplantarumL 2 9)分离纯化得到亚油酸异构酶,分子量为4 3ku。对其酶学性质进行研究,结果表明,温度37℃、pH 6 0时酶活性较高;Co2 + 、Fe2 + 可提高酶的活性,Cu2 + 、Zn2 + 则对酶活力有抑制作用;该酶作用于亚油酸的Km=2 5 3×10 -5mol/L ,Vmax=2 5 7×10 -8mol/ (min·mg)。     

植物乳杆菌对高产酯酿酒酵母酒精发酵及酯醇代谢的影响

在高粱汁培养基内同时接种植物乳杆菌（Lactobacillus plantarum）和高产酯酿酒酵母（Saccharomyces cerevisiae）,探究植物乳杆菌及其代谢产物对高产酯酿酒酵母酒精发酵及酯醇代谢的影响。结果表明：植物乳杆菌对高产酯酿酒酵母生长及酒精发酵的影响不大,发酵结束后残糖量均＜5 g/L,乙醇含量为74～78 g/L;植物乳杆菌使高产酯酿酒酵母乙酸乙酯和高级醇产量下降,分别最多下降了15.31%、36.14%;培养基内不同乳酸质量浓度使酿酒酵母乙酸乙酯产量提高,乳酸质量浓度为7.1 g/L时,乙酸乙酯最多提高了39.84%;培养基内乳酸质量浓度在1.8～7.1 g/L时,高产酯酿酒酵母高级醇的产量明显降低,特别是苯乙醇的产量显著下降,下降了25.05%～75.64%。     

Characterization and adsorption of a Lactobacillus plantarum virulent phage

Bacteriophage infection of lactic acid bacteria is considered one of the biggest worldwide problems in the food industry. Bacteriophages may cause negative effects on the fermentation of various dairy-based products. A virulent bacteriophage was isolated from an abnormal fermentation liquid of Lactobacillus plantarum IMAU10120. The characterization and influence of temperature, pH, divalent cations, and chloramphenicol on the adsorption ability of this phage were evaluated. The results showed that this phage belonged to the Siphoviridae family. It exhibited a burst time of 135 min and a burst size of approximately 215 counts expressed per milliliter per infective center. No significant effect was shown to influence its viability and adsorption at 10 to 37°C. More than 90% of phages exhibited infectivity from pH 5 to 9. Divalent ions and chloramphenicol did not have a significant influence on the adsorption of this phage. The information obtained in this study will enrich the database of lactobacilli virulent phages and provide a basis of information for the control of phages in the food fermentation industry.     

Overview of Lactobacillus plantarum as a promising bacteriocin producer among lactic acid bacteria

Chemical preservatives have been traditionally used during the manufacturing of processed products. However, the continuous growing interest of consumers for fresh and natural products makes it necessary to search for alternative compounds. In this context, food industries have been widely using lactic acid bacteria (LAB) as natural preservatives, due to their ability to produce antibacterial compounds such as bacteriocins. Similarly, pharmaceutical industries have improved the use of these bacterial peptides, with antibacterial activity, trying to reduce the indiscriminate use of antibiotics in food products for human and animal consumption. Among LAB, Lactobacillus plantarum can be adapted to various niches thanks to its ability to ferment a wide range of carbohydrates. Additionally, it can be used as starter culture in food fermentations and as an ingredient for probiotic foods, contributing to the organoleptic characteristics of foods at the same time prolonging the shelf-life and safety of these products. The amount of valuable substances obtained from L. plantarum species isolated from different ecological niches is also worth noting, thus proving it to be one of the most important and versatile species among LAB.