Leuconostoc mesenteroides subsp. mesenteroides LB7 isolated from apple surface inhibits P. expansum in vitro and reduces patulin in fruit juices.

This research aimed to isolate lactic acid bacteria (LAB) from apple surface and to reveal their potential to inhibit the growth of Penicillium expansum. Besides, their ability to detoxify fruit juices contaminated with mycotoxin patulin, produced by this fungi, was also studied. The isolation was performed on a typical MRS medium under ambient conditions. The molecular identification of the strains was done by sequencing the 16S rRNA genes. Antifungal activities of the isolated strains have been evaluated using dual agar plate assay protocol. A total of 11 LAB isolates was obtained from apples. These isolates showed phenotypic traits consistent with the genera of LAB. They have been identified as Leuconostoc mesenteroides subsp. mesenteroides and Weissella paramesenteroides. Among them, the strain LB7 showed exciting inhibitory activities in vitro against P. expansum. LB7 also successfully detoxified homemade and commercial fruit juices contaminated with patulin. Further research will bring the application prospects of these LABs in food biocontrol and biopreservation strategies.

Effect of Seafood (Gizzard Shad) Supplementation on the Chemical Composition and Microbial Dynamics of Radish Kimchi during Fermentation.

This study investigated the impact of supplementing radish kimchi with slices of gizzard shad, Konosirus punctatus (boneless - BLGS, or whole - WGS) on the kimchi's chemical and microbial composition for different fermentation durations. Higher levels of amino nitrogen (N), calcium (Ca) and phosphorus (P) were observed in the supplemented kimchi groups compared to those in the control and further, Ca and P levels were highest in the WGS kimchi group. Microbial composition analysis revealed noticeable differences between the three groups at different fermentation durations. The predominant species changed from Leuconostoc rapi to Lactobacillus sakei at the optimal- and over-ripening stages in the control kimchi group. The predominant species in the BLGS kimchi group was L. rapi at all stages of fermentation, whereas the predominant species in the WGS kimchi group was L. rapi at the optimal-ripening stage, and both L. sakei and L. rapi at the over-ripening stage. Significant correlations were observed by analysis of the Spearman's rank between and within the chemical and microbial composition over fermentation durations. Altogether, gizzard shad supplementation may be used to optimize the desired microbial population to obtain the preferable fresh kimchi flavour by the release of certain inorganic elements and amino N.

Lactobacillus delbrueckii subsp. bulgaricus F17 and Leuconostoc lactis H52 supernatants delay the decay of strawberry fruits: a microbiome perspective.

Strawberries are vulnerable to physical injuries and microbial invasion. To explore if beneficial lactic acid bacteria can improve the shelf life and edible quality of postharvest strawberry fruits, the effects of Lactobacillus delbrueckii subsp. bulgaricus (ital.) F17 (F17) and Leuconostoc lactis (ital.) H52 (H52) inoculation on the strawberry microbial community structure and saleable characteristics were examined by bacterial 16S rRNA and fungal ITS sequencing techniques. Lactobacillus (ital.) F17 and Leuconostoc lactis (ital.) H52 isolated from the traditional fermented yak milk in the Qinghai-Tibetan Plateau were used as the potential probiotic inocula. Samples from treated strawberries stored at 25 °C for 0, 12, 24, 48, and 72 hours were analyzed for their pH, weight loss percentage, decay percentage, total soluble solid content (SSC) and microbial counts, and for microbiome community diversity and canonical correspondence analysis. The results showed that F17 and H52 did not only significantly reduce the weight loss and decay percentage of strawberry fruits, but also delayed the decrease of the total SSC and pH (P < 0.05). In addition, F17 and H52 significantly inhibited the growth and colonization of aerobic mesophilic bacteria, yeast, mold and coliform bacteria. In particular, by comparing the microbiota composition of the samples, F17 significantly inhibited Pantoea, Mycospherella, unclassified_Pleosporales, Aureobasidium and Phoma at the genus level, whereas H52 inhibited Bacillus, Streptophyta, Mycospherella, Aureobasidium and Phoma. Moreover, analysis of alpha and beta diversity revealed that F17 and H52 had a significantly greater inhibitory effect on bacterial species compared to fungi. The results of canonical correspondence analysis revealed that the total SSC and pH were positively correlated with bacteria, whereas the decay percentage, weight loss percentage and total SSC were positively associated with fungi. Additionally, Podosphaera, Hanseniaspora, Botrytis and unclassified_Pleosporales were positively correlated with strawberry fruit decay and weight loss percentage. As a general result, Lactobacillus F17 and Leuconostoc lactis H52 have the potential to promote biological preservation, which is economically important to reduce the loss due to strawberry spoilage.

Consumption of a Leuconostoc holzapfelii-enriched synbiotic beverage alters the composition of the microbiota and microbial extracellular vesicles.

Synbiotics, the combination of probiotics and prebiotics, are known to confer health benefits via intestinal microbiota modulation. However, significant intestinal microbiota alterations can be difficult to determine in intervention studies based on solely bacterial stool metagenomic analysis. Intestinal microbiota constituents secrete 20-200-nm-sized extracellular vesicles (EVs) containing microbial DNA, proteins, and lipids that are distributed throughout the body, providing an alternative target for microbiota metagenomic analysis. Here, we determined the impact of a synbiotic beverage enriched with the kimchi-derived bacterium Leuconostoc holzapfelii (L. holzapfelii) on the intestinal microbiota and local and circulatory microbiota-derived EV composition of healthy Korean adults. We isolated microbial DNA from stool bacteria, stool EVs, and urinary EVs and conducted next-generation sequencing of the 16S rDNA V3-V4 regions before and after synbiotic consumption. The species diversity of circulating urinary EVs was significantly increased after synbiotic consumption, while stool bacterial and EV diversity remained unchanged. Furthermore, we found that while a single genus was decreased among the stool bacteria constituents, stool EVs and urinary EVs showed significant alterations in four and eight genera, respectively. Blood chemistry assays revealed that synbiotic consumption significantly lowered aspartate aminotransferase (AST) serum levels, particularly in subjects with starting levels above the normal range (>40 UI/L). In conclusion, the L. holzapfelii-enriched synbiotic beverage greatly altered serum AST levels and microbial EV composition in urine and stool, while only minor changes were observed in the gut microbiota composition. Based on these findings, we suggest the potential use of microbiota-derived EVs as surrogate markers in future predictive diagnosis studies.

Pseudofructophilic Leuconostoc citreum Strain F192-5, Isolated from Satsuma Mandarin Peel.

Fructophilic lactic acid bacteria (FLAB), composed of Fructobacillus spp., Lactobacillus kunkeei, and Lactobacillus apinorum, are unique in that they prefer d-fructose over d-glucose as a carbon source. Strain F192-5, isolated from the peel of a satsuma mandarin and identified as Leuconostoc citreum, grows well on d-fructose but poorly on d-glucose and produces mainly lactate and acetate, with trace amounts of ethanol, from the metabolism of d-glucose. These characteristics are identical to those of obligate FLAB. However, strain F192-5 ferments a greater variety of carbohydrates than known FLAB. Comparative analyses of the genomes of strain F192-5 and reference strains of L. citreum revealed no signs of specific gene reductions, especially genes involved in carbohydrate transport and metabolism, in the genome of F192-5. The bifunctional alcohol/acetaldehyde dehydrogenase gene (adhE) is conserved in strain F192-5 but is not transcribed. This is most likely due to a deletion in the promoter region upstream of the adhE gene. Strain F192-5 did, however, ferment d-glucose when transformed with a plasmid containing the allochthonous adhE gene. L. citreum F192-5 is an example of a pseudo-FLAB strain with a deficiency in d-glucose metabolism. This unique phenotypic characteristic appears to be strain specific within the species L. citreum This might be one of the strategies lactic acid bacteria use to adapt to diverse environmental conditions.IMPORTANCE Obligate fructophilic lactic acid bacteria (FLAB) lack the metabolic pathways used in the metabolism of most carbohydrates and differ from other lactic acid bacteria in that they prefer to ferment d-fructose instead of d-glucose. These characteristics are well conserved at the genus or species level. Leuconostoc citreum F192-5 shows similar growth characteristics. However, the strain is metabolically and genomically different from obligate FLAB. This is an example of a strain that evolved a pseudo-FLAB phenotype to adapt to a fructose-rich environment.

A therapeutic benefit of daptomycin against glycopeptide-resistant gram-positive cocci bloodstream infections under neutropenia.

Antibiotic-resistant infections remain to be a major issue for all over the world. Although appropriate diagnosis and rapid treatment initiation are crucially important particularly in immunocompromised patients, selection of antibiotics without identification of causative bacteria is often challenging. A 44-year-old woman with acute myeloid leukemia (AML) under myelosuppression suffered from teicoplanin-resistant gram-positive cocci bacteremia. Taking severe neutropenia due to chemotherapy and glycopeptide-resistance into account, teicoplanin was empirically substituted with daptomycin, which led to prompt defervescence. This microorganism later turned out to be Leuconostoc lactis (L. Lactis), and daptmycin was continued to use based on antimicrobial susceptibility tests. As a result, empiric use of daptomycin successfully controlled glycopeptide-resistant gram-positive cocci bacteremia under neutropenia. This is the first report of daptomycin treatment for L. lactis bacteremia in a patient with AML under neutropenia. Our findings suggest that daptomycin would be a suitable treatment option for glycopeptide-resistant gram-positive cocci bloodstream infections, especially in myelosuppressive patients.

Leuconostoc strains isolated from dairy products: Response against food stress conditions.

A systematic study about the intrinsic resistance of 29 strains (26 autochthonous and 3 commercial ones), belonging to Leuconostoc genus, against diverse stress factors (thermal, acidic, alkaline, osmotic and oxidative) commonly present at industrial or conservation processes were evaluated. Exhaustive result processing was made by applying one-way ANOVA, Student's test (t), multivariate analysis by Principal Component Analysis (PCA) and Matrix Hierarchical Cluster Analysis. In addition, heat adaptation on 4 strains carefully selected based on previous data analysis was assayed. The strains revealed wide diversity of resistance to stress factors and, in general, a clear relationship between resistance and Leuconostoc species was established. In this sense, the highest resistance was shown by Leuconostoc lactis followed by Leuconostoc mesenteroides strains, while Leuconostoc pseudomesenteroides and Leuconostoc citreum strains revealed the lowest resistance to the stress factors applied. Heat adaptation improved thermal cell survival and resulted in a cross-resistance against the acidic factor. However, all adapted cells showed diminished their oxidative resistance. According to our knowledge, this is the first study regarding response of Leuconostoc strains against technological stress factors and could establish the basis for the selection of "more robust" strains and propose the possibility of improving their performance during industrial processes.

Lactic acid bacteria of the Leuconostoc genus with high innate immunity-stimulating activity.

We screened lactic acid bacteria that exhibited high innate immunity-stimulating activity by monitoring muscle contraction activity in silkworms. Heat-treated fractions of lactic acid bacteria, Leuconostoc carnosum #7-2, Leuconostoc gelidum #4-2, and Leuconostoc mesenteroides 8/11-3, had high (250-460 units/mg) innate immunity-stimulating activity. These lactic acid bacteria proliferated in milk to concentrations of 1 × 106 colony forming unit/mL. The present findings suggest that the silkworm muscle contraction assay is useful for screening lactic acid bacteria with high innate immunity-stimulating activity, and that the assay can be used for the production of fermented foods made from milk.

Decreased sugar concentration in vegetable and fruit juices by growth of functional lactic acid bacteria.

Leuconostoc carnosum #7-2, L. gelidum #4-2, and L. mesenteroides 8/11-3, which were isolated from fermented plant foods, are lactic acid bacteria. We previously reported that these bacteria are functional lactic acid bacteria whose innate immunity-stimulating activities are high based on a silkworm muscle contraction assay. The concentrations of these three lactic acid bacteria increased to more than 1 × 106 colony forming units (cfu)/mL in various vegetable and fruit juices when the pH values were appropriately adjusted. As the bacteria grew in the vegetable and fruit juices, the pH decreased and the concentrations of total sugars and glucose also decreased. These findings suggest that these functional lactic acid bacteria can be used to produce vegetable and fruit juices with reduced sugar levels, which is expected to be beneficial for human health.

Reassessment of the succession of lactic acid bacteria in commercial cucumber fermentations and physiological and genomic features associated with their dominance.

A compositional re-assessment of the microbiota present in commercial cucumber fermentation using culture independent and dependent methods was conducted, with emphasis on lactic acid bacteria (LAB). Two commercial cucumber fermentation tanks were monitored by measuring pH, dissolved oxygen and temperature, and used as sources of samples for microbial plating, genomic DNA extraction and measurement of organic acids and carbohydrates by HPLC. Six additional commercial tanks were included to identify the dominant microorganisms using molecular methods. A comparative analysis of the publically available genome sequences corresponding to the LAB found in cucumber fermentations was completed to gain an understanding of genomic features possibly enabling dominance. Analyses of the microbiota suggest Lactobacillales prevail in cucumber fermentations, including in order of prevalence Lactobacillus pentosus, Lb. plantarum, Lb. brevis, Weissella spp., Pediococcus ethanolidurans, Leuconostoc spp. and Lactococcus spp. It was observed that Lb. pentosus and Lb. plantarum have comparatively larger genomes, higher gene counts, uniquely distribute the ribosomal clusters across the genome as opposed to close to the origin of replication, and possess more predicted amino acids prototrophies and selected biosynthesis related genes. It is theorized that Lb. pentosus and Lb. plantarum dominance in cucumber fermentations is the result of their genetic make-up.

Community dynamics and metabolite target analysis of spontaneous, backslopped barley sourdough fermentations under laboratory and bakery conditions.

Barley flour is not commonly used for baking because of its negative effects on bread dough rheology and loaf volume. However, barley sourdoughs are promising ingredients to produce improved barley-based breads. Spontaneous barley sourdough fermentations were performed through backslopping (every 24h, 10days) under laboratory (fermentors, controlled temperature of 30°C, high dough yield of 400) and bakery conditions (open vessels, ambient temperature of 17-22°C, low dough yield of 200), making use of the same batch of flour. They differed in pH evolution, microbial community dynamics, and lactic acid bacteria (LAB) species composition. After ten backsloppings, the barley sourdoughs were characterized by the presence of the LAB species Lactobacillus fermentum, Lactobacillus plantarum, and Lactobacillus brevis in the case of the laboratory productions (fast pH decrease, pH<4.0 after two backslopping steps), and of Leuconostoc citreum, Leuconostoc mesenteroides, Weissella confusa and Weissella cibaria in the case of the bakery productions (slow pH decrease, pH4.0 after eight backslopping steps). In both sourdough productions, Saccharomyces cerevisiae was the sole yeast species. Breads made with wheat flour supplemented with 20% (on flour basis) barley sourdough displayed a firmer texture, a smaller volume, and an acceptable flavour compared with all wheat-based reference breads. Hence, representative strains of the LAB species mentioned above, adapted to the environmental conditions they will be confronted with, may be selected as starter cultures for the production of stable barley sourdoughs and flavourful breads.

Isolation and characterization of dextran produced by Leuconostoc citreum NM105 from manchurian sauerkraut.

A water-soluble exopolysaccharide (EPS) was produced by Leuconostoc ctireum NM105 from homemade manchurian sauerkraut. After culturing the strain in Man-Rogosa-Sharpe medium containing 5% sucrose at 25°C for 48h, the EPS was purified and a yield of 23.5g/L was achieved. The EPS consisted exclusively of glucose and the weight-average molecular weight was 1.01×10(8)Da. The structural characterization of the purified EPS determined by FT-IR, (1)H, (13)C and two-dimensional NMR spectroscopy demonstrated that the glucan contained α-(1→6)-linked d-glucopyranose units, 2,6-linked d-glucopyranose units and terminal α-d-glucopyranose units at a ratio of 1:1:1. The microstructure of the dried dextran appeared a sheet-like smooth glittering and highly branched surface. The NM105 dextran showed high water solubility and excellent water retention. All the results suggested that the highly α-(1→2) branched dextran might have the potential to serve as valuable polymers applied in foods, cosmetics and other fields.

Isolation of Lactic Acid Bacteria Showing Antioxidative and Probiotic Activities from Kimchi and Infant Feces.

The purpose of this study was to investigate lactic acid bacteria with antioxidative and probiotic activities isolated from Korean healthy infant feces and kimchi. Isolates A1, A2, S1, S2, and S3 were assigned to Lactobacillus sp. and isolates A3, A4, E1, E2, E3, and E4 were assigned to Leuconostoc sp. on the basis of their physiological properties and 16S ribosomal DNA sequence analysis. Most strains were confirmed as safe bioresources through nonhemolytic activities and non-production of harmful enzymes such as ß-glucosidase, ß- glucuronidase and tryptophanase. The 11 isolates showed different resistance to acid and bile acids. In addition, they exhibited antibacterial activity against foodborne bacteria, especially Bacillus cereus, Listeria monocytogenes, and Escherichia coli. Furthermore, all strains showed significantly high levels of hydrophobicity. The antioxidant effects of culture filtrates of the 11 strains included 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging capacity, 2.2'- azino-bis (2-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity, and superoxide dismutase activity. The results revealed that most of the culture filtrates have effective scavenging activity for DPPH and ABTS radicals. All strains appeared to have effective superoxide dismutase activity. In conclusion, the isolated strains A1, A3, S1, and S3 have significant probiotic activities applicable to the development of functional foods and health-related products. These strains might also contribute to preventing and controlling several diseases associated with oxidative stress, when used as probiotics.

Probiotic potential of selected lactic acid bacteria strains isolated from Brazilian kefir grains.

A total of 34 lactic acid bacteria isolates from 4 different Brazilian kefir grains were identified and characterized among a group of 150 isolates, using the ability to tolerate acidic pH and resistance to bile salts as restrictive criteria for probiotic potential. All isolates were identified by amplified ribosomal DNA restriction analysis and 16S rDNA sequencing of representative amplicons. Eighteen isolates belonged to the species Leuconostoc mesenteroides, 11 to Lactococcus lactis (of which 8 belonged to subspecies cremoris and 3 to subspecies lactis), and 5 to Lactobacillus paracasei. To exclude replicates, a molecular typing analysis was performed by combining repetitive extragenic palindromic-PCR and random amplification of polymorphic DNA techniques. Considering a threshold of 90% similarity, 32 different strains were considered. All strains showed some antagonistic activity against 4 model food pathogens. In addition, 3 Lc. lactis strains and 1 Lb. paracasei produced bacteriocin-like inhibitory substances against at least 2 indicator organisms. Moreover, 1 Lc. lactis and 2 Lb. paracasei presented good total antioxidative activity. None of these strains showed undesirable enzymatic or hemolytic activities, while proving susceptible or intrinsically resistant to a series of clinically relevant antibiotics. The Lb. paracasei strain MRS59 showed a level of adhesion to human Caco-2 epithelial cells comparable with that observed for Lactobacillus rhamnosus GG. Taken together, these properties allow the MRS59 strain to be considered a promising probiotic candidate.

Probiotic Properties of Leuconostoc mesenteroides Isolated from Aguamiel of Agave salmiana.

Four lactic acid bacteria, Leuconostoc mesenteroides subsp. mesenteroides, were isolated from aguamiel the sap obtained from Agave salmiana from México and identified by 16S rRNA gene sequence analysis. The probiotic potential of these strains was evaluated and compared with a commercial probiotic (Lactobacillus plantarum 299v) from human origin. All the strains survived the in vitro gastrointestinal simulation conditions: the stomach simulation (3 h, pH 2, 37 °C) and the intestinal simulation (4 h, bile salts 0.5%, 37 °C). All the strains showed a strong hydrophilic character with n-hexadecane and chloroform assays, and all the strains showed a mucin adhesion rate similar to that of L. plantarum 299v. The strains of L. mesenteroides subsp. mesenteroides exhibited similar antimicrobial activity against some pathogens in comparison with L. plantarum 299v. Some antibiotics inhibited the growth of the strains. L. mesenteroides subsp. mesenteroides exhibited in vitro probiotic potential, and it could be better characterized through future in vivo tests.

Exploring the strain-specific attachment of Leuconostoc gelidum subsp. gasicomitatum on food contact surfaces.

The psychrotrophic lactic acid bacterium (LAB) Leuconostoc gelidum subsp. gasicomitatum has emerged as one of the most prevalent specific spoilage organisms (SSOs) of packaged, cold-stored food products in Northern Europe. The whole genome sequencing of the type strain L. gelidum subsp. gasicomitatum LMG 18811(T) revealed genes encoding for proteins related to adhesion. In the present study the attachment of six food and environmental isolates was monitored on stainless steel (SS) and glass surfaces incubated (7 °C for 5-9 days) in two food simulating substrates (i.e. sweet bell pepper juice and boiled eggs in brine). The selection encompassed unique genotypes, isolated from different food products or sampling sites as well as slime-forming biotypes. The evaluation of the attached cells was performed with the bead vortexing method and a viability staining assay coupled with epifluorescence microscopy. On SS surfaces the slime-formers showed the lowest attachment (3.3-4.5 logCFU/cm(2)), while strain L. gelidum subsp. gasicomitatum ab2, which was isolated from an acetic acid bath in a vegetable salad company, reached significantly higher populations of attached cells exceeding 7 logCFU/cm(2). Strain ab2 formed dense cell aggregations on SS after 9 days of incubation in sweet bell pepper juice. The attachment ability of L. gelidum subsp. gasicomitatum on surfaces documented in the present study extends our knowledge and understanding of the spoilage potential and intra-subspecies diversity of this microbe.

Screening of lactic acid bacteria that can form mixed-species biofilm with Saccharomyces cerevisiae.

The abilities of lactic acid bacteria (LAB) to form mixed-species biofilm with Saccharomyces cerevisiae in a static co-culture were investigated out of 168 LAB stock cultures, and two Lactobacillus plantarum strains (D71 and E31) and one Leuconostoc mesenteroides strain K01 were found to form mixed-species biofilm with S. cerevisiae BY4741. SEM observation showed that there was no significant difference in morphological properties among these three mixed-species biofilms and they resembled that formed by S. cerevisiae with L. plantarum ML11-11 previously isolated from a brewing sample of Fukuyama pot vinegar. The co-aggregation assays showed that L. plantarum D71 and L. plantarum E31 could co-aggregate with S. cerevisiae similarly to L. plantarum ML11-11, while L. mesenteroides K01 had no ability to co-aggregate with yeast. The above results indicate that aggregation followed by direct cell-to-cell contact is required for mixed-species biofilm formation between these L. plantarum strains and S. cerevisiae, though some different mechanism may be involved in biofilm formation between L. mesenteroides strain and S. cerevisiae.

Lactic acid bacterial population dynamics during fermentation and storage of Thai fermented sausage according to restriction fragment length polymorphism analysis.

This study applied restriction fragment length polymorphism (RFLP) analysis to identify the lactic acid bacteria (LAB) isolated from "mum" Thai fermented sausages during fermentation and storage. A total of 630 lactic acid bacteria were isolated from the sausages prepared using 2 methods. In Method 1, after stuffing, the sausages were stored at 30 °C for 14 days. In Method 2, after stuffing and storage at 30 °C for 3 days, the sausages were vacuum-packed and stored at 4 °C until Day 28. The sausages were sampled on Days 0, 3, 14, and 28 for analyses. The 16S rDNA was amplified and digested using restriction enzymes. Of the restriction enzymes evaluated, Dde I displayed the highest discrimination capacity. The LAB were classified and 7 species were identified For Methods 1 and 2, during fermentation, the Lactobacillus sakei and Lactobacillus plantarum species were dominant. For Method 2, the proportion of Leuconostoc mesenteroides markedly increased during storage, until L. sakei and Ln. mesenteroides represented the dominant species. The identification of LAB in the sausage samples could facilitate the selection of appropriate microorganisms for candidate starter cultures for future controlled mum production.

Spoilage potential of psychrotrophic lactic acid bacteria (LAB) species: Leuconostoc gelidum subsp. gasicomitatum and Lactococcus piscium, on sweet bell pepper (SBP) simulation medium under different gas compositions.

Sweet bell peppers are a significant constituent of retail, chilled-stored and packaged food products like fresh salads, marinades and ready-to-eat (RTE) meals. Previously, through general screening of the Belgian market and by means of source tracking analysis in a plant manufacturing minimally processed, vegetable salads the susceptibility of fresh-cut sweet bell peppers to lactic acid bacterium (LAB) contamination was substantiated. The determination of the metabolic profiles of Leuconostoc gelidum subsp. gasicomitatum and Lactococcus piscium, two major psychrotrophic, spoilage-related LAB species, on sweet bell pepper (SBP) simulation medium under different packaging conditions - 1.) vacuum: 100% N2, 2.) air: 21% O2, 79% N2, 3.) MAP1: 30% CO2, 70% N2 and 4.) MAP2: 50% O2, 50% CO2 - facilitated a better understanding of the spoilage potential of these microbes as well as the presumptive contribution of O2 in the spectrum of produced volatile organic compounds (VOCs) associated with poor organoleptic properties of food products. Generally, none of the applied gas compositions inhibited the growth of the 4 L. gelidum subsp. gasicomitatum isolates, however the presence of O2 resulted in buttery off-odors by inducing primarily the accumulation of diacetyl and pungent "vinegar" smell due to acetic acid. The 3 tested isolates of L. piscium varied greatly among their growth dynamics and inhibition at MAP2. They exhibited either weak spoilage profile or very offensive metabolism confirming significant intraspecies diversity.