Characterization of Lactobacillus isolates from fermented olives and their bacteriocin gene profiles (original) (raw)
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Applied and Environmental Microbiology, 1994
Bacteriocin-producing Lactobacillus plantarum LPCO10 and its non-bacteriocin-producing, bacteriocinimmune derivative, L. plantarum 55-1, were evaluated separately for growth and persistence in natural Spanish-style green olive fermentations. Both strains were genetically marked and selectively enumerated using antibiotic-containing media. Plasmid profile and bacteriocin production (bac + ) were used as additional markers. When olive brines were inoculated at 10 5 CFU/ml, the parent strain, LPCO10, proliferated to dominate the epiphytic microflora, sharing high population levels with other spontaneously occurring lactobacilli and persisting throughout the fermentation (12 weeks). In contrast, the derivative strain could not be isolated after 7 weeks. Stability of both plasmid profile and bac + (LPCO10 strain) or bac - (55-1 strain) phenotype was shown by L. plantarum LPCO10 and L. plantarum 55-1 isolated throughout the fermentation. Bacteriocin activity could be found in the L. plant...
Lactic acid bacteria from fermented table olives
Food Microbiology, 2012
Table olives are one of the main fermented vegetables in the world. Olives can be processed as treated or natural. Both have to be fermented but treated green olives have to undergo an alkaline treatment before they are placed in brine to start their fermentation. It has been generally established that lactic acid bacteria (LAB) are responsible for the fermentation of treated olives. However, LAB and yeasts compete for the fermentation of natural olives. Yeasts play a minor role in some cases, contributing to the flavour and aroma of table olives and in LAB development. The main microbial genus isolated in table olives is Lactobacillus. Other genera of LAB have also been isolated but to a lesser extent. Lactobacillus plantarum and Lactobacillus pentosus are the predominant species in most fermentations. Factors influencing the correct development of fermentation and LAB, such as pH, temperature, the amount of NaCl, the polyphenol content or the availability of nutrients are also reviewed. Finally, current research topics on LAB from table olives are reviewed, such as using starters, methods of detection and identification of LAB, their production of bacteriocins, and the possibility of using table olives as probiotics.
Lactobacillus pentosus dominates spontaneous fermentation of Italian table olives
LWT - Food Science and Technology, 2014
Culture-dependent and -independent approaches were applied to identify the bacterial species involved in Italian table olive fermentation. Bacterial identification showed that Lactobacillus pentosus was the dominant species although the presence of Lactobacillus plantarum, Lactobacillus casei, Enterococcus durans, Lactobacillus fermentum and Lactobacillus helveticus was observed. Rep-PCR allowed to obtain strain-specific profiles and to establish a correlation with table olive environment. PCR-DGGE (Denaturing Gradient Gel Electrophoresis) confirmed the heterogeneity of bacterial community structure in fermented table olives as well as the prevalence of L. pentosus. The strains were characterized on the basis of technological properties (NaCl tolerance, b-glucosidase activity and the ability to grow in synthetic brine and in presence of 1 g/100 mL oleuropein). L. pentosus showed a high capacity of adaptation to the different conditions characterizing the olive ecosystem. This species showed the highest percentage of strains able to grow in presence of 10 g/100 mL NaCl, oleuropein and in the synthetic brine.
Lactobacillus casei, dominant species in naturally fermented Sicilian green olives
International Journal of Food Microbiology, 2004
This study investigated the phenotypic and genotypic characteristics of lactic acid bacteria in naturally fermented green olives, collected from different areas of Sicily. Both classical biochemical tests and PCR/Restriction Fragments Length Polymorphism (RFLP) of 16S rDNA were used to characterize the isolates. The identity of the isolates was obtained by the partial sequencing analysis of the 16S rDNA. The BioMerieux software assigned the 13 heterofermentative strains to the Lactobacillus brevis species; 24 homofermentative strains were classified as Lactobacillus casei and the remaining 11 homofermentative lactobacilli were identified as Lactobacillus plantarum. The rapid ID 32 STREP test identified coccal-shaped strains as Enterococcus faecium species. The PCR/RFLP analysis showed a remarkable bacterial heterogeneity within the isolates. The 16S rDNA partial sequencing did not confirm biochemical identification, revealing a strong dominance of isolates belonging to the L. casei species. It is noteworthy that this species has never been reported as dominant species in fermented vegetables. A combination of molecular and biochemical analysis allowed the identification of species involved in natural food fermentations.
Fermentation
Table olives are an important fermented product of the Mediterranean area consumed all over the world. In our era, the food industry requires a safe and stable final product with desirable characteristics for the consumer. In the present study, two different experimental fermentations (L, with Lactiplantibacillus plantarum strains, and LY, with L. plantarum strains and Wickerhamomyces anomalus strain) were conducted and monitored up to 180 days and compared with a spontaneous fermentation, used as control (C). The safety and stability of table olives were determined by applying a plate count and quantitative real-time PCR (qPCR) approach. Compared with the control sample (C), experimental fermentations showed a faster acidification and a good inhibition rate of spoilage bacteria, indicating the safety of the process. Quantitative PCR data confirmed the abundance of the Lactobacillus group in both experimental table olives, confirming the importance of the starter cultures for the st...
Isolation of Lactic Acid Bacteria from Naturally Fermented Algerian Olives
Journal of King Saud …, 2005
Twenty-two isolates of lactic acid bacteria isolated from the spontaneous fermentation of olives were identified on the basis of the phenotypic criteria. Eleven of them were identified as Lactobacillus plantarum which was followed by 4 Lactococcus lactis ssp. lactis and 7 Enterococcus spp. Cell free supernatant of Lactobacillus plantarum OL9 was active against Lactobacillus, Enterococcus, Propionibacterium and Erwinia (of spoilage significance). The antibacterial activity was attributed to bacteriocin like substances.
A Review on Adventitious Lactic Acid Bacteria from Table Olives
Foods, 2020
Spontaneous fermentation constitutes the basis of the chief natural method of processing of table olives, where autochthonous strains of lactic acid bacteria (LAB) play a dominant role. A thorough literature search has unfolded 197 reports worldwide, published in the last two decades, that indicate an increasing interest in table olive-borne LAB, especially in Mediterranean countries. This review attempted to extract extra information from such a large body of work, namely, in terms of correlations between LAB strains isolated, manufacture processes, olive types, and geographical regions. Spain produces mostly green olives by Spanish-style treatment, whereas Italy and Greece produce mainly green and black olives, respectively, by both natural and Spanish-style. More than 40 species belonging to nine genera of LAB have been described; the genus most often cited is Lactobacillus, with L. plantarum and L. pentosus as most frequent species—irrespective of country, processing method, or ...
Selection of Lactiplantibacillus Strains for the Production of Fermented Table Olives
Microorganisms, 2022
Lactiplantibacillus strains (n. 77) were screened for technological properties (e.g., xylose fermentation, EPS production, antimicrobial activity, tolerance to NaCl and phenolic compounds, oleuropein degradation and hydroxytyrosol formation) relevant for the production of fermented table olives. Survival to olive mill wastewater (OMW) and to simulated gastro-intestinal tract (GIT), the capability to grow at different combinations of NaCl and pH values, radical scavenging activities and biofilm formation were further investigated in 15 selected strains. The screening step revealed high diversity among Lactiplantibacillus strains. Most of the strains were able to ferment xylose, while only a few strains produced EPS and had inhibitory activity against Y. lipolytica. Resistance to phenolic compounds (gallic, protocatechuic, hydroxybenzoic and syringic acids), as well as the ability to release hydroxytyrosol from oleuropein, was strain-specific. OMWs impaired the survival of selected st...