Bacteriocin-like Substance Research Articles

In vitro Characterization of Enterococcus faecium strain LCM08 as a probiotic

Background: Under the present situations, where health improvement has become the major concern, food supplements, augmenting health is a matter of interest. Presently, the concept of "functional foods" possessing medicinal attributes has been reborn as probiotics. Acid-tolerant and Gram-positive Lactic acid bacteria (LAB), being the major class of probiotics, possess health-promoting characteristics, provide better health with a robust immune system, and treat various digestive and neurological disorders. Hence, the aim of the present study was the isolation and identification of LAB.
 Methodology: The LAB were isolated from various sources, including food products and clinical samples. Enterococcus faecium LCM08 being the most potent isolate tested for probiotic traits, including viability under acidic conditions, biological concentrations of bile salts and enzymes.
 Results: A total of fifty-four strains were isolated, of which 7.2% showed broad-spectrum inhibition against the tested pathogens. Amongst them, Enterococcus faecium LCM08 owing to its broad-spectrum antagonism, when tested for its ability to withstand acidic conditions, displayed 63.58% viability and 72.19% survivability in the presence of bile salts. Moreover, strain sustained in the presence of digestive enzymes including protease (94.65%), trypsin (93.57%) and pancreatin (75.0%) as well as exhibited growth at temperatures ranging between 25˚C and 30˚C where the maximum viable counts recorded as 95% and 96.4%. The strain also produced antimicrobial metabolites at neutral pH. However, elevated temperatures (45˚C-50˚C) inhibited the production of bacteriocin-like inhibitory substances.
 Conclusion: The preliminary investigations revealed that Enterococcus faecium LCM08 possesses the key attributes pre-requisite for a probiotic candidate.

A New Approach to Harness Probiotics Against Common Bacterial Skin Pathogens: Towards Living Antimicrobials

In this study, the potential of certain lactic acid bacteria—classified as probiotics and known to be antimicrobially active against pathogens or food-poisoning microorganisms—was evaluated with respect to their activity against bacterial skin pathogens. The aim of the study was to develop a plaster/bandage for the application of inhibitory substances produced by these probiotics when applied to diseased skin. For this purpose, two Streptococcus salivarius strains and one Lactobacillus plantarum were tested for production of antimicrobials (bacteriocin-like substances) active against Gram-positive and Gram-negative pathogens using established methods. A newly designed membrane test ensured that the probiotics produce antimicrobials diffusible through membranes. Target organisms used were Cutibacterium acnes, Staphylococcus aureus, and Pseudomonas aeruginosa. Moreover, the L. plantarum 8P-A3 strain was tested against additional bacteria involved in skin disorders. The Lactobacillales used were active against all potential skin pathogens tested. These probiotics could be enclosed between polymer membranes—one tight, the other permeable for their products, preserved by vacuum drying, and reactivated after at least three months storage. Importantly, the reactivated pads containing the probiotics demonstrated antibacterial activity on agar plates against all pathogens tested. This suggests that the probiotic containing pads may be topically applied for the treatment of skin disorders without the need for a regular antibiotic treatment or as an adjunctive therapy.

Bacteriocin-Like Inhibitory Substances from Probiotics as Therapeutic Agents for Candida Vulvovaginitis.

Probiotics can potentially prevent and treat diseases. We examined the inhibitory activity of bacteriocin-like inhibitory substances (BLISs) from potentially probiotic lactobacilli and streptococci on Candida albicans and non-Candida albicans clinical isolates from women with vulvovaginitis. Using agar well diffusion assays, BLISs inhibited both Candida albicans and non-Candida albicans isolates. The BLIS from L. pentosus isolates had the highest anti-Candida activity (33/45; 73.3%), followed by BLISs from isolates of L. paracasei subsp. paracasei (31/45; 68.9%), L. rhamnosus I (30/45; 66.7%), L. delbrueckii subsp. lactis I (30/45; 66.7%), and S. uberis II (30/45; 66.7%). Upon characterization according to the retained activity under variable physical and chemical conditions, the BLISs showed stability against heat, pH, and surfactants, but were protease-sensitive, which suggests a proteinaceous nature of the active substances. Using crystal violet assays, the BLISs reduced the Candida biofilm biomass significantly as compared to a control group that lacked BLISs. In vivo testing of the antagonistic activity was performed using the Galleria mellonella (G. mellonella) larvae model. BLISs significantly improved survival in G. mellonella larvae treated with Candida isolates on the first, second, and seventh days, as compared to larvae inoculated with Candida only (p < 0.01). The results show that BLISs can be used as biotherapeutic agents in vulvovaginal candidiasis.

Evaluation of the Estimation Capability of Response Surface Methodology and Artificial Neural Network for the Optimization of Bacteriocin-Like Inhibitory Substances Production by Lactococcus lactis Gh1.

Bacteriocin-like inhibitory substances (BLIS) produced by Lactococcus lactis Gh1 had shown antimicrobial activity against Listeria monocytogenes ATCC 15313. Brain Heart Infusion (BHI) broth is used for the cultivation and enumeration of lactic acid bacteria, but there is a need to improve the current medium composition for enhancement of BLIS production, and one of the approaches is to model the optimization process and identify the most appropriate medium formulation. Response surface methodology (RSM) and artificial neural network (ANN) models were employed in this study. In medium optimization, ANN (R2 = 0.98) methodology provided better estimation point and data fitting as compared to RSM (R2 = 0.79). In ANN, the optimal medium consisted of 35.38 g/L soytone, 16 g/L fructose, 3.25 g/L sodium chloride (NaCl) and 5.40 g/L disodium phosphate (Na2HPO4). BLIS production in optimal medium (717.13 ± 0.76 AU/mL) was about 1.40-fold higher than that obtained in nonoptimised (520.56 ± 3.37 AU/mL) medium. BLIS production was further improved by about 1.18 times higher in 2 L stirred tank bioreactor (787.40 ± 1.30 AU/mL) as compared to that obtained in 250 mL shake flask (665.28 ± 14.22 AU/mL) using the optimised medium.

Purification and characterization of bacteriocins-like inhibitory substances from food isolated Enterococcus faecalis OS13 with activity against nosocomial enterococci

Nosocomial infections caused by enterococci are an ongoing global threat. Thus, finding therapeutic agents for the treatment of such infections are crucial. Some Enterococcus faecalis strains are able to produce antimicrobial peptides called bacteriocins. We analyzed 65 E. faecalis isolates from 43 food samples and 22 clinical samples in Egypt for 17 common bacteriocin-encoding genes of Enterococcus spp. These genes were absent in 11 isolates that showed antimicrobial activity putatively due to bacteriocins (three from food, including isolate OS13, and eight from clinical isolates). The food-isolated E. faecalis OS13 produced bacteriocin-like inhibitory substances (BLIS) named enterocin OS13, which comprised two peptides (enterocin OS13α OS13β) that inhibited the growth of antibiotic-resistant nosocomial E. faecalis and E. faecium isolates. The molecular weights of enterocin OS13α and OS13β were determined as 8079 Da and 7859 Da, respectively, and both were heat-labile. Enterocin OS13α was sensitive to proteinase K, while enterocin OS13β was resistant. Characterization of E. faecalis OS13 isolate revealed that it belonged to sequence type 116. It was non-hemolytic, bile salt hydrolase-negative, gelatinase-positive, and sensitive to ampicillin, penicillin, vancomycin, erythromycin, kanamycin, and gentamicin. In conclusion, BLIS as enterocin OS13α and OS13β represent antimicrobial agents with activities against antibiotic-resistant enterococcal isolates.

Characterization of Enterococcus faecium EO1 isolated from mutton and activity of bacteriocin-like substances in the control of Listeria monocytogenes in fresh mutton sausage

The aim of this study was to isolate and characterize bacteriocinogenic lactic acid bacteria (LAB) from mutton carcasses after slaughter. The study also evaluated the activity of bacteriocin-like substances (BLS) for control of Listeria monocytogenes in fresh mutton sausage. The cell-free supernatant (CFS) was obtained and its antimicrobial activity was quantified. The presence of genes encoding enterocin was evaluated by molecular techniques. Another aspect assessed was the action in situ of BLS produced by these isolates for control of Listeria monocytogenes in fresh mutton sausage, experimentally contaminated. Six isolates presented phenotypic and genotypic characteristics of safety. Also, the antibacterial peptides present in the CFS showed stability at different temperatures, pH, NaCl and cure salt concentrations, as well as potential against L. monocytogenes Scott A. The isolate identified as Enterococcus faecium EO1 showed gene coding for the production of enterocin A and produced bacteriocin after 6 h of growth (400 AU. mL−1). Based on this, the CFS of EO1 (5 and 10%) was applied in fresh mutton sausage, being significantly effective for control of L. monocytogenes during 21 days of refrigerated storage (4.07 log CFU. g−1). Therefore, the potential for preservation of food has been demonstrated through the use of CFS containing bacteriocin-like substances from E. faecium EO1 in fresh mutton sausage.

Optimization of Cultivation Conditions for the Lactobacillus reuteri LR1 Strain to Improve the Biosynthesis of Bacteriocin-Like Substances

The article presents the results of optimization of the culturing conditions to increase the production of bacteriocin-like compounds (presumably including reuterin) by the Lactobacillus reuteri strain LR1. The strain Escherichia coli ATCC 25922, an opportunistic microorganism, the content of which is standardized in foods by the Food Safety Legislation, was selected as an indicator strain of antimicrobial activity. The nutrient medium for L. reuteri LR1 cultivation was optimized to increase the production of bacteriocin-like compounds, and the parameters of two-stage growth of the producer were established: (1) cultivation on the initial medium for biomass accumulation and (2) growth on a water–glycerol medium to convert glycerol to antimicrobial compounds, presumably reuterin. The first stage was carried out as follows: the L. reuteri LR1 culture (5%) was inoculated into a medium with the following composition: hydrolyzed milk—250 mL/L; yeast extract—10 g/L; peptone—5 g/L; glucose—20 g/L; sodium acetate—5.0 g/L; monosubstituted potassium phosphate—2.0 g/L; magnesium sulfate—0.2 g/L, and manganese sulfate—0.5 g/L, pH 6.4–6.6. The cultivation was carried out for 18 h at (37 ± 1)°С. The second stage included the incubation of the obtained biomass in 200 mM of glycerol-containing aqueous solution, pH 6.6, for 2 h at 37°С. The zone of E. coli inhibition caused by the produced bacteriocin-like compounds was 25 mm.

A newly-isolated Bacillus subtilis BSC35 produces bacteriocin-like inhibitory substance with high potential to control Clostridium perfringens in food

Previous studies on Bacillus subtilis-producing bacteriocins (or bacteriocin-like inhibitory substance, BLIS) against Clostridium perfringens provided with limited information to show their potentials. In this study, B. subtilis BSC35 was newly-isolated and its BLIS-containing cell-free supernatant exhibited a strong antimicrobial activity (maximum 24 mm of lysis zone in standard well diffusion assay) against all the tested C. perfringens strains (22 farm isolates and 2 references). The culture condition was optimized (30 °C, 240 rpm, TSB at pH 7.5) to maximize BLIS BSC35 production and stability of BLIS BSC35 was tested. After zymogram study following partial purification, BLIS BSC35 was measured approximately 4 kDa in size. Finally, when cell-free-supernatant or B. subtilis BSC35 culture was used to control C. perfringens in liquid medium and a food model (Cheonggukjang), as low as 0.1% and 104 CFU/g addition, respectively, was enough to strongly inhibit the growth of C. perfringens with a rapid bactericidal mode of action, implying high anti-C. perfringens potentials and wide range of applicabilities.

Recovery of a Bacteriocin-Like Inhibitory Substance from Lactobacillus bulgaricus FTDC 1211 Using Polyethylene-Glycol Impregnated Amberlite XAD-4 Resins System.

Lactobacillus bulgaricus is a LAB strain which is capable of producing bacteriocin substances to inhibit Staphylococcus aureus. The aim of this study was to purify a bacteriocin-like inhibitory substance (BLIS) produced by L. bulgaricus FTDC 1211 using an aqueous impregnated resins system consisting of polyethylene-glycol (PEG) impregnated on Amberlite XAD4. Important parameters influencing on purification of BLIS, such as the molecular weight and concentration of PEG, the concentration and pH of sodium citrate and the concentration of sodium chloride, were optimized using a response surface methodology. Under optimum conditions of 11% (w/w) of PEG 4000 impregnated Amberlite XAD4 resins and 2% (w/w) of sodium citrate at pH 6, the maximum purification factor (3.26) and recovery yield (82.69% ± 0.06) were obtained. These results demonstrate that AIRS could be used as an alternate purification system in the primary recovery step.

Effectiveness of Bacteriocin-Producing Lactic Acid Bacteria and Bifidobacterium Isolated from Honeycombs against Spoilage Microorganisms and Pathogens Isolated from Fruits and Vegetables

Screening natural products for bacteriocin-producing bacteria may be the equilibrium point between the consumer demand for mild processing and the industry’s need for hazard control. Raw unprocessed honeycombs filled with oregano honey from the alpine mountainous territory of Epirus, Greece were screened for bacteriocinogenic lactic acid bacteria and Bifidobacterium spp., with inhibitory action towards some pathogens and spoilage microorganisms isolated from fresh fruits and vegetables (number and type of strains: three E. coli, two L. monocytogenes, two Salmonella spp., two B.cereus, two Erwinia spp., one Xanthomonas spp., L. innocua (ATCC 33090TM) and E. coli 0157:H7 (ATCC 69373)). Among the 101 collected isolates (73 Lactobacillus, 8 Lactococcus, 8 Leuconostoc and 12 Bifidobacterium species) from the oregano honeycombs (an original finding since there are no other reports on the microbial biodiversity of the flora of the oregano honey), 49 strains of lactic acid bacteria (LAB) and Bifidobacterium spp. were selected and tested for their bacteriocin-producing capacity (34 Lactobacillus, 6 Lactococcus, 5 Leuconostoc and 4 Bifidobacterium). The antibacterial activity exerted by the tested LAB and Bifidobacterium strains was not of the same potency. Our results suggest that the main molecules involved in the antimicrobial activity are probably bacteriocin-like substances (a conclusion based on reduced antibacterial activity after the proteolytic treatment of the cell-free supernatant of the cultures) and this antimicrobial activity is specific for the producing strains as well as for the target strains. The spoilage bacteria as well as the reference microorganisms showed increased resistance to the bacteriocin-like substances in comparison to the wild-type pathogens.

Influence of Culture Conditions and Medium Compositions on the Production of Bacteriocin-Like Inhibitory Substances by Lactococcus lactis Gh1.

Antibacterial peptides or bacteriocins produced by many strains of lactic acid bacteria have been used as food preservatives for many years without any known adverse effects. Bacteriocin titres can be modified by altering the physiological and nutritional factors of the producing bacterium to improve the production in terms of yield and productivity. The effects of culture conditions (initial pH, inoculum age and inoculum size) and medium compositions (organic and inorganic nitrogen sources; carbon sources) were assessed for the production of bacteriocin-like inhibitory substances (BLIS) by Lactococcus lactis Gh1 in shake flask cultures. An inoculum of the mid-exponential phase culture at 1% (v/v) was the optimal age and size, while initial pH of culture media at alkaline and acidic state did not show a significant impact on BLIS secretion. Organic nitrogen sources were more favourable for BLIS production compared to inorganic sources. Production of BLIS by L. lactis Gh1 in soytone was 1.28-times higher as compared to that of organic nitrogen sources ((NH4)2SO4). The highest cell concentration (XmX = 0.69 ± 0.026 g·L−1) and specific growth rate (μmax = 0.14 h−1) were also observed in cultivation using soytone. By replacing carbon sources with fructose, BLIS production was increased up to 34.94% compared to BHI medium, which gave the biomass cell concentration and specific growth rate of 0.66 ± 0.002 g·L−1 and 0.11 h−1, respectively. It can be concluded that the fermentation factors have pronounced influences on the growth of L. lactis Gh1 and BLIS production. Results from this study could be used for subsequent application in process design and optimisation for improving BLIS production by L. lactis Gh1 at larger scale.

Screening and identification of bacteriocin-like inhibitory substances producing lactic acid bacteria from fermented products

Abstract A total of 544 isolates of lactic acid bacteria isolated from fermented products: 451 isolates from fermented products from Thailand and 93 isolated from French fermented products were screened for bacteriocin production. 10 isolates showed antimicrobial activities. Identification of the selected strains by random amplification of polymorphic DNA-polymerase change reaction using the primers E1, E2 and M13 showed three different RAPD patterns. One of the isolates from each product was chosen and good antimicrobial activity were displayed by 3 strains including MP6/2, PKS2-1 and OV1-1 producing in MRS broth bacteriocin-like substance (BLIS) inhibiting Candida albicans ATCC 90028, Carnobacterium maltraromaticum NCDO 2760, Lactobacillus sakei subsp. sakei JCM 1157, Listeria innocula CIP 80.11, Listeria ivanovii SLCC 2379, Pseudomonasc aeruginosa ATCC 27853, Staphylococcus aureus CIP 76.25 and Streptococcus mutans used as indicator strains. However, inhibitory activities of MP6/2 and PKS2-1 were related to the production of either organic acid, while OV2-1 was not affected by heating. The inhibitory activities of these three isolates were sensitive to proteolytic enzymes. 16S rDNA gene sequencing allowed to identify the MP6/2 as Pediococcus pentosaceus while PKS2-1 and OV1-1 were identified as Enterococcus faecium. It was concluded that the obtained isolates may be used as bio-preservative cultures to produce fermented foods.

In Vitro Evaluation of Potential Probiotic Strain Lactococcus lactis Gh1 and Its Bacteriocin-Like Inhibitory Substances for Potential Use in the Food Industry.

Determination of a microbial strain for the joining into sustenance items requires both in vitro and in vivo assessment. A newly isolated bacteriocin-like inhibitory substance (BLIS) producing lactic acid bacterium, Lactococcus lactis Gh1, was isolated from a traditional flavour enhancer and evaluated in vitro for its potential applications in the food industry. Results from this study showed that L. lactis was tolerant to NaCl (≤ 4.0%, w/v), phenol (≤0.4%, w/v), 0.3% (w/v) bile salt, and pH 3. BLIS from L. lactis showed antimicrobial activity against Listeria monocytogenes ATCC 15313 and was susceptible to 10 types of antibiotics. The absence of haemolytic activity and the presence of acid phosphatase and naphthol-AS-BI-phosphohydrolase were observed in L. lactis. L. lactis could coagulate milk and showed a negative response to amylolytic and proteolytic activities and did not secrete β-galactosidase. The antimicrobial activity of BLIS was completely abolished at 121°C. The BLIS was conserved at 4°C in BHI and MRS medium up to 6-4months, respectively. BLIS activity was more stable in BHI as compared to MRS after four freeze-thaw cycles and was not affected by a wide range of pH (pH 4-8). BLIS was sensitive to proteinase k and resistant to catalase and trypsin. The antimicrobial activity was slightly reduced by acetone, ethanol, methanol, and acetonitrile at 10% (v/v) and also towards Tween-80, urea, and NaCl 1% (v/v). Results from this study have demonstrated that L. lactis has a vast potential to be applied in the food industry, such as for the preparation of starter culture, functional foods, and probiotic products.

Antibacterial and antifungal activity of crude and freeze-dried bacteriocin-like inhibitory substance produced by Pediococcus pentosaceus

Pediococcus pentosaceus LBM 18 has shown potential as producer of an antibacterial and antifungal bacteriocin-like inhibitory substance (BLIS). BLIS inhibited the growth of spoilage bacteria belonging to Lactobacillus, Enterococcus and Listeria genera with higher activity than Nisaplin used as control. It gave rise to inhibition halos with diameters from 9.70 to 20.00 mm, with Lactobacillus sakei being the most sensitive strain (13.50–20.00 mm). It also effectively suppressed the growth of fungi isolated from corn grain silage for up to 25 days and impaired morphology of colonies by likely affecting fungal membranes. These results point out that P. pentosaceus BLIS may be used as a new promising alternative to conventional antibacterial and antifungal substances, with potential applications in agriculture and food industry as a natural bio-controlling agent. Moreover, cytotoxicity and cell death induction tests demonstrated cytotoxicity and toxicity of BLIS to human colon adenocarcinoma Caco-2cells but not to peripheral blood mononuclear cells, with suggests possible applications of BLIS also in medical-pharmaceutical applications.

Increase of bacteriocin-like activity of &lt;i&gt;Bacillus thuringiensis&lt;/i&gt; strain by improving nutriculture medium composition

The development of the nutriculture medium composition and the optimal concentrations of its constituent components to increase the bacteriocin-like activity of the strain Bacillus thuringiensis ssp. Dakota are presented. The study was carried out using a multifactor experiment with further processing of statistical data in order to optimize the basic nutriculture medium and maximize the activity of the target product. Sources of nitrogen (peptone and yeast extract) and carbon (glycerin and glucose) were used as optimization factors. The control growth medium was medium "A", traditionally used for the cultivation of bacteria of the genus Bacillus. The degree of impact of the studied factors on the effective feature was determined using the model of multiple linear regression of the first order, whereby the optimal ratio of the components was calculated on the basis of the quadratic model. The ability of the Bacillus thuringiensis ssp. dakota strain to produce a bacteriocin-like substance (BLIS) was revealed. The dependence of BLIS synthesis on the cultivation medium was established: on the carbohydrate-free medium, the antimicrobial activity of BLIS was 1.5 times lower than that on the medium containing glucose and glycerin. To obtain maximum BLIS activity, the carbohydrate medium was optimized using a multifactor experiment performed by the method of orthogonal Latin rectangles. Mathematical models of linear regression of the first and second order were constructed depending on the concentration of nutrient medium components. The optimal concentration of the components was determined on the basis of a second-order regression model that takes into account the effects of the interaction of factors and the nonlinearity of the process. As a result of optimization of the nutrient medium, the quantitative composition of the components of the culture medium was determined: peptone – 9 g/l; yeast extract – 2.6; glycerol – 5.6 g/l, on which the antimicrobial activity of BLIS increased by 60% compared with the activity on the initial medium. It was shown that the synthesis of BLIS, unlike the synthesis of delta-endotoxin, is not regulated by catabolite repression of carbon.

Development and viability of probiotic orange juice supplemented by Pediococcus acidilactici CE51

Several studies demonstrate that dairy products are the main foodstuffs that employ probiotic bacteria in their composition. The main objective of this study was to characterize the CE51 isolate as a potential probiotic strain and also develop and evaluate the viability of probiotic orange juice drink. In total, 152 lactic acid bacteria were isolated from food samples. The bacteriocin-like substance producing isolate was sequenced by 16S rDNA. Probiotic potential was evaluated by survival in de Man Rogosa Sharpe broth in pH 2.0, 2.5, and 3.5 and in the presence of bile salts (0.3, 0.6, and 0.9%) for up to 180 min. Probiotic orange juice was developed at pH4.5 and pH6.5 with an initial inoculum of 106 CFU/ml. The juices were stored at 4 °C and 30 °C for up to 35 days. Only one isolate presented antimicrobial activity against Listeria monocytogenes which was genetically identified as Pediococcus acidilactici CE51. The probiotic potential was confirmed by its resistance to acid pH and bile salts presence. The two probiotic juice formulations presented counts between 7.2 and 8.5 log CFU/ml after 35 days at 4 °C and 30 °C. Therefore, orange juice could act as an ideal food matrix for probiotic beverage of Pediococcus acidilactici CE51.

Bioprospecting of probiotics with antimicrobial activities against Salmonella Heidelberg and that produce B-complex vitamins as potential supplements in poultry nutrition

The demand for animal protein for human consumption has been risen exponentially. Modern animal production practices are associated with the regular use of antibiotics, potentially increasing the emerging multi-resistant bacteria, which may have a negative impact on public health. In poultry production, substances capable of maximizing the animals’ performance and displaying an antimicrobial activity against pathogens are very well desirable features. Probiotic can be an efficient solution for such a task. In the present work, lactic acid bacteria (LAB) were isolated from chicken cecum and screened for their antagonistic effect towards many pathogens. Their capacity of producing the B-complex vitamins folate and riboflavin were also evaluated. From 314 isolates, three (C43, C175 and C195) produced Bacteriocin-Like Inhibitory Substances (BLIS) against Staphylococcus aureus (inhibition zones of 18.9, 21.5, 19.5 mm, respectively) and also inhibited the growth of Salmonella Heidelberg. The isolate C43 was identified as Enterococcus faecium, while C173 and C195 were both identified as Lactococcus lactis subsp. lactis. Moreover, the isolates L. lactis subsp. lactis strains C173 and C195 demonstrated high potential to be used as probiotic in poultry feed, in addition to their advantage of producing folate (58.0 and 595.5 ng/mL, respectively) and riboflavin (223.3 and 175.0 ng/mL, respectively).

The potential of probiotics for treating acne vulgaris: A review of literature on acne and microbiota.

Acne is known as a chronic inflammatory skin disease with sever adverse effects on quality of life in the patients. The increasing resistance to antibiotics has decreased their effectiveness in treating acne. As viable microbial dietary supplements, probiotics provide health benefits through fighting pathogens and maintaining the homeostasis of the gut and skin microbiome. The present article reviewed the potential of probiotics as beneficial microorganisms for treating acne vulgaris. This review of literature was conducted through a bibliographic search of popular databases, including Science Direct, PubMed, Scielo and Medline, using keywords such as probiotics, prebiotics, synbiotics, microbiome, and acne vulgaris to determine potential applications of these beneficial microbiomes in treating acne vulgaris. Acne lesions are associated with increases in proportion of Propionibacterium acnes as a skin commensal bacterium. The environmental studies showed inhibitory effects of probiotics on P. acnes, mediating by antibacterial proteins and bacteriocin-like inhibitory substances, and their immunomodulatory effects onkeratinocytes and epithelial cells. Probiotics were also found to inhibit cytokine IL-8 in epithelial cells and keratinocytes, suggesting immunomodulatory activities. Moreover, glycerol fermentation by Staphylococcus epidermidis was found to be a natural skin defense against acne and an overgrowth inhibitor of P. acnes. As an antimicrobial agent in lotions and cosmetic formulations, Lactococcus sp. can decrease the inflammatory mediators that are produced by P. acnes and cause vasodilation, edema, mast cell degranulation and TNF-alpha release. Oral administration of probiotics was found to constitute an adjuvant therapy to conventional modalities for treating mild-to-moderate acne vulgaris.

Bacteriocin-like inhibitory substance of Pediococcus pentosaceus as a biopreservative for Listeria sp. control in ready-to-eat pork ham.

The growing demand of consumers for synthetic chemical-free foods has increased the search for natural preservatives such as bacteriocins and bacteriocin-like inhibitory substances (BLIS) to give them adequate microbiological safety, sensory characteristics, and shelf life. In this study, the antimicrobial activity of BLIS produced by Pediococcus pentosaceus ATCC 43200 was compared with that of nisin. Lactobacillus sakei ATCC 15521, Listeria seeligeri NCTC 11289, Enterococcus En2052 and En2865, and Listeria monocytogenes CECT 934 and NADC 2045 exhibited larger inhibition halos in BLIS-treated than in Nisaplin-treated samples, unlike Listeria innocua NCTC 11288. In artificially contaminated ready-to-eat pork ham, BLIS was effective in inhibiting the growth of L. seeligeri NCTC 11289 for 6days (counts from 1.74 to 0.00 log CFU/g) and ensured lower weight loss (2.7%) and lipid peroxidation (0.63mg MDA/kg) of samples compared with the control (3.0%; 1.25mg MDA/kg). At the same time, coloration of ham samples in terms of luminosity, redness, and yellowness as well as discoloration throughout cold storage was not influenced by BLIS or Nisaplin taken as a control. These results suggest the potential use of P. pentosaceus BLIS as a biopreservative in meat and other food processing industries.

Genome and metabolites analysis reveal insights into control of foodborne pathogens in fresh-cut fruits by Lactobacillus pentosus MS031 isolated from Chinese Sichuan Paocai

Abstract The presence of pathogens in fresh-cut fruits represents a risk for the public health since these products generally do not receive any further treatment before consumption. In this study, a Lactobacillus pentosus MS031 was isolated from Sichuan Paocai with broad antibacterial activity against foodborne pathogens. Antimicrobial peptides produced by the L. pentosus MS031 had broad activity and resistance to heat, but they were sensitive to proteinases and their activity vanished under alkaline condition. Bacteriocin-like substance obtained by pH-absorption related methods showed activity only against Staphylococcus aureus. However, cell-absorbed substance and cell-secreted into culture substance had activity against both S. aureus and Escherichia coli. Foodborne pathogens in fresh-cut fruit mixture were controlled by the metabolites of the L. pentosus MS031 that Listeria monocytogenes was reduced by 96.3 %, Salmonella typhi and E. coli were decreased to an undetectable level. The complete genome of the L. pentosus MS031 was sequenced using Illumina and MinION nanopore platform with a size of 3,805,216 bp, consisting of one chromosome and eight plasmids. After mining using BAGEL4, two novel bacteriocins, pentocin MS1 and pentocin MS2, were identified. Furthermore, fragments of 5 antimicrobial peptides were identified by LC–MS/MS in the fermentation supernatant. In addition, antimicrobial cyclic dipeptides and small compounds were identified in the antimicrobial metabolites. The results indicate antimicrobial metabolites of the L. pentosus MS031 can control foodborne pathogens in fresh-cut product during subsequent cold storage, which is significant for food industry.