scholarly journals Effectiveness of a Commercial Lactic Acid Bacteria Intervention Applied to Inhibit Shiga Toxin-Producing Escherichia coli on Refrigerated Vacuum-Aged Beef

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Katie R. Kirsch ◽  
Tamra N. Tolen ◽  
Jessica C. Hudson ◽  
Alejandro Castillo ◽  
Davey Griffin ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Shiga Toxin ◽  
Aging Process ◽  
Antagonistic Activity ◽  
E Coli ◽  
Application Method ◽  
Aging Period ◽  
Spoilage Bacteria ◽  
Intervention Efficacy

Because of their antagonistic activity towards pathogenic and spoilage bacteria, some members of the lactic acid bacteria (LAB) have been evaluated for use as food biopreservatives. The objectives of this study were to assess the antimicrobial utility of a commercial LAB intervention against O157 and non-O157 Shiga-toxigenic E. coli (STEC) on intact beef strip loins during refrigerated vacuum aging and determine intervention efficacy as a function of mode of intervention application. Prerigor strip loins were inoculated with a cocktail (8.9±0.1 log10 CFU/ml) of rifampicin-resistant (100.0 μg/ml; RifR) O157 and non-O157 STEC. Inoculated loins were chilled to ≤4°C and treated with 8.7±0.1 log10 CFU/ml LAB intervention using either a pressurized tank air sprayer (conventional application) or air-assisted electrostatic sprayer (ESS). Surviving STEC were enumerated on tryptic soy agar supplemented with 100.0 μg/ml rifampicin (TSAR) to determine STEC inhibition as a function of intervention application method (conventional, ESS) and refrigerated aging period (14, 28 days). Intervention application reduced STEC by 0.4 log10 CFU/cm2 (p<0.05), although application method did not impact STEC reductions (p>0.05). Data indicate that the LAB biopreservative may assist beef safety protection when utilized within a multi-intervention beef harvest, fabrication, and aging process.

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

2020 ◽  
Vol 10 (20) ◽  
pp. 7309
Author(s):  
Chrysa Voidarou ◽  
Athanasios Alexopoulos ◽  
Anastasios Tsinas ◽  
Georgios Rozos ◽  
Athina Tzora ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Fruits And Vegetables ◽  
Salmonella Spp ◽  
E Coli ◽  
Hazard Control ◽  
Spoilage Bacteria ◽  
Spoilage Microorganisms

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.

scholarly journals Autochthonous and Probiotic Lactic Acid Bacteria Employed for Production of “Advanced Traditional Cheeses”

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 412 ◽  
Author(s):  
Vincenzina Fusco ◽  
Grazia Quero ◽  
Palmiro Poltronieri ◽  
Maria Morea ◽  
Federico Baruzzi
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lactobacillus Rhamnosus ◽  
Probiotic Strain ◽  
Pilot Scale ◽  
Antagonistic Activity ◽  
Bacterial Strains ◽  
Traditional Cheeses ◽  
Spoilage Bacteria ◽  
Probiotic Lactic Acid Bacteria

Microbial characterization of two Italian traditional cheeses, Giuncata and Caciotta Leccese, was carried out, with the aim to isolate autochthonous bacterial strains to be used as starters to improve and standardize the quality of these cheeses. More than 400 bacterial isolates were found, using PCR-based identification, to belong to 12 species of the Streptococcus, Lactococcus, Lactobacillus, and Leuconostoc genera. The dominant strains were screened for antagonistic activity against pathogenic and spoilage bacteria and exopolysaccharide production, acidification, and proteolytic activity. Since Streptococcus macedonicus was found to be the most prevalent lactic acid bacteria species present in milk and in both types of cheese, the best performing strain of this species was successfully used, alone or in combination with a selected autochthonous Lactococcus lactis strain, in pilot-scale productions of Giuncata and Caciotta Leccese cheeses, respectively. The combined inoculums of selected autochthonous strains positively influenced the sensory characteristics of both Giuncata and Caciotta cheeses. Finally, the selected autochthonous cultures were enriched with a potentially probiotic Lactobacillus rhamnosus strain and successfully used in pilot-scale productions of these traditional cheeses. To the best of our knowledge, this is the first study reporting the use of an autochthonous S. macedonicus strain as a starter for the production of cheeses with added probiotics. In addition, the identification of the probiotic strain in the feces of healthy volunteers fed with the advanced traditional cheese proved its effectiveness as a carrier for the delivery of probiotics to the human body.

Spoilage and Safety Characteristics of Ground Beef Treated with Lactic Acid Bacteria

2009 ◽  
Vol 72 (11) ◽  
pp. 2278-2283 ◽  
Author(s):  
A. R. HOYLE ◽  
J. C. BROOKS ◽  
L. D. THOMPSON ◽  
W. PALMORE ◽  
T. P. STEPHENS ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Modified Atmosphere Packaging ◽  
Ground Beef ◽  
Dose Titration ◽  
E Coli ◽  
Spoilage Bacteria ◽  
Brochothrix Thermosphacta ◽  
Plate Counts ◽  
Yeasts And Molds

Lactic acid bacteria (LAB) can decrease numbers of Escherichia coli O157:H7 and Salmonella in ground beef during storage. Two dose-titration studies were conducted in ground beef to determine dose levels of LAB needed to inhibit the pathogens. A second study evaluated whether LAB masked changes typically associated with the spoilage of ground beef displayed under refrigerated (0°C) or abusive (10°C) temperatures packaged in both traditional overwrap (TOP) and modified atmosphere packaging (MAP; 80% O2–20% CO2). Microbial analyses were conducted to determine spoilage endpoints and pathogen reduction. In the dose-titration study, Salmonella was reduced by 3 log cycles at all doses (106,107, and 108 LAB per g) after 3 days of storage and was eliminated after 5 days of storage. E. coli O157:H7 was reduced by 2 log cycles at all dosages after 3 days of storage and by 3 log cycles after 5 days of storage. In the spoilage studies, as expected, total aerobic plate counts and LAB populations in LAB-inoculated samples were higher than the controls initially, but the counts were similar near the end of the study. While total spoilage bacteria generally increased over time, very few differences existed between treatments stored at 0°C and 10°C in coliforms , Brochothrix thermosphacta, yeasts and molds, and Pseudomonas spp. counts for both the TOP and MAP samples. We conclude that LAB could potentially be added to ground beef in TOP and MAP as a processing intervention for E. coli O157:H7 and Salmonella without masking microbial spoilage characteristics.

scholarly journals INFLUENCE OF PREBIOTICS ON THE BIOLOGICAL ACTIVITY OF LACTIC ACID BACTERIA

2014 ◽  
Vol 20 ◽  
pp. 54-59
Author(s):  
N. O. Kravchenko ◽  
O. M. Dmytruk ◽  
L. V. Bozhok ◽  
V. O. Aheyev ◽  
O. V. Holovach
Keyword(s):  
Biological Activity ◽  
Lactic Acid ◽  
Gastrointestinal Tract ◽  
Lactic Acid Bacteria ◽  
Antagonistic Activity ◽  
Research Results ◽  
E Coli ◽  
Growth Activity ◽  
Different Origin

The paper presents the research results of prebiotics influence of different origin on the growth, enzymatic and antagonistic activity of representatives of normal cenosis of the cattle gastrointestinal tract. It was established that the lactulose prebiotic enhances growth activity of microorganisms from the gastrointestinal tract the most. Moreover, metabolites of aerobic bacilli had stimulated the most the antagonistic activity of lactic acid bacteria against S. typhimurium and E. coli.

Microbial Regulation of the Antagonistic Activity of Lactic Acid Bacteria Strains under the Influence of Transient Bacilli of the Bacillus Genus

2015 ◽  
Vol 2 (2) ◽  
pp. 45-49
Author(s):  
N. Kravchenko
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Stimulation Index ◽  
Intestinal Bacteria ◽  
Antagonistic Activity ◽  
Ultra Sound ◽  
E Coli ◽  
Pathogenic Escherichia Coli ◽  
Bacillus Genus ◽  
Inspection Service

Aim. To study the effect of metabolites and components of aerobic spore-forming bacilli cells (MCASB) of the Bacillus genus on the antagonistic activity of lactic acid bacteria. Methods. Lactic acid bacteria, sampled from rectal and oral swabs from calves, were used in the study. Strains of conditionally pathogenic Escherichia coli, 055k59 No. 3912, Staphylococcus aureus No. 906, Proteus mirabilis, No. 3177, obtained from the collection of the city sanitary-epidemiological inspection service, were used as test cultures. MCASB were prepared using autoclaved microbial mass of Bacillus subtilis production strain 44-p via treatment with lysozyme and ultra- sound. The antagonistic activity of lactic acid bacteria was determined by agar blocks method. Results. It was demonstrated that the addition of MCASB to the culture medium stimulates the antagonistic activity of lactic acid bacteria to pathogenic and conditionally pathogenic microorganisms of intestinal bacteria. The highest average stimulation index (2.56) of the antagonistic activity of lactic acid bacteria was found for E. coli 055k59 No. 3912. Conclusions. The results obtained may be used to improve the microbiological foundations of elaborating novel probiotic preparations.

scholarly journals Microbiological hazards at several stages of production and distribution of cooked sausages

2018 ◽  
Vol 53 (3) ◽  
pp. 201
Author(s):  
D. SERGELIDIS (Δ. ΣΕΡΓΚΕΛΙΔΗΣ) ◽  
A. ABRAHIM (Α. AMIN) ◽  
A. SARIMVEI (Α. ΣΑΡΗΜΒΕΗ) ◽  
C. GENIGEORGIS (Κ. ΓΕΝΗΠΩΡΓΗΣ)
Keyword(s):  
Lactic Acid ◽  
Thermal Treatment ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
Meat Products ◽  
Salmonella Spp ◽  
E Coli ◽  
Spoilage Bacteria ◽  
Cooked Meat ◽  
Cooked Meat Products

Fifty one (51) samples of several types of cooked sausage paste, prepared by two meat factories in N. Greece were examined. TPC of these samples ranged between 5,3-6,3 Log10CFU/g. Coliforms were regularly present reaching populations of 93->2.400 MPN/g and lactic acid bacteria ranged between 5-6,3 Log10CFU/g. L. monocytogenes was detected in 56 and 38,4% of the samples collected in each factory. E. coli was detected in 20 and 16,6%, and Salmonella spp in 12 and 16,6% respectively. Neither pathogens nor coliforms were detected in 51 samples of cooked sausages originated from the same pastes examined before. No recovery of any injured cells of the pathogenic bacteria and coliforms was observed after their storage at 4°C for 20 days. TPC of the cooked sausage samples, after thermal treatment, ranged between 3-4,7 Log10CFU/g and consisted mainly of lactic acid bacteria (range <2-4,5 Log10CFU/g) and sporeformers (range 3-4,5 Log10CFU/g). After 20 days storage at 4°C the TPC and lactid acid bacteria counts of the cooked sausages, increased by <1 Log. We also examined 16 surface and center samples of cooked sausages and meat products without casings, consisting of big meat pieces (bacon, smoked ham,etc). Surface TPC ranged between 5-5,3 Log10CFU/g and from the center of the meats they ranged between 2-3,5 Log1 0CFU/g. Coliforms, E. coli, L. monocytogenes and Salmonella spp were not detected. Lactic acid bacteria were the main flora. Furthermore we examined surface samples of cooked meat products, without casings, during several stages following thermal treatment and up to storage for 24 h at 4° C, without any protective package. TPC immediately after thermal treatment were <2 Log^CFU/g, after cooling with water increased they increased at 3 Log10CFU/g and remained the same during the following 24 h storage at 4°C. Coliforms were detected in the stored products. Their populations exceeded 2.400 MPN/g on the surface of the samples after storage for a few days at 4°C. It is assumed that the flora on the surface of these products originated from the environment and the cooling water. Finally we examined 69 samples from surfaces of the slicing and packaging equipment of cooked meat products in 3 meat factories and 28 samples from 12 super markets. L. monocytogenes was detected in 6 and 14,2% of the samples that originated from the slicing blades in the factories and super markets respectively. The results of this study underline the importance of GMP for the prevention of contamination of cooked sausages with pathogens and the control of the growth of the spoilage bacteria population which minimize the self life of these products. This is especially true after thermal treatment during peeling and slicing.

DEVELOPMENT OF A MULTIWELL ANTAGONISTIC ACTIVITY ASSAY FOR THE DETECTION OF BACTERIOCIN PRODUCTION BY LACTIC ACID BACTERIA

2009 ◽  
Vol 17 (1) ◽  
pp. 32-45 ◽  
Author(s):  
KAOUTAR YAAKOUBI ◽  
NOREDDINE BENKERROUM ◽  
FLORENT WIOROWSKI ◽  
FRANÇOISE SANSON ◽  
JULIEN HAYDERSAH ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Antagonistic Activity ◽  
Bacteriocin Production ◽  
Activity Assay

Spray-Drying of Bacteriocin-Producing Lactic Acid Bacteria

1999 ◽  
Vol 62 (7) ◽  
pp. 773-777 ◽  
Author(s):  
GIANLUIGI MAURIELLO ◽  
MARIA APONTE ◽  
ROSAMARIA ANDOLFI ◽  
GIANCARLO MOSCHETTI ◽  
FRANCESCO VILLANI
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Cell Survival ◽  
Spray Drying ◽  
Antagonistic Activity ◽  
Cellular Damage ◽  
Bacteriocin Activity ◽  
Lactobacillus Curvatus ◽  
Significant Difference ◽  
Inhibitory Spectrum

Cell survival, cellular damage, and antagonistic activity were investigated after spray-drying of four bacteriocin-producing strains of lactic acid bacteria: Lactococcus lactis subsp. lactis 140, isolated from natural whey culture and producing a narrow-inhibitory spectrum bacteriocin); L. lactis subsp. lactis G35, isolated from pizza dough and producing nisin; Lactobacillus curvatus 32Y and Lactobacillus sp. 8Z, isolated from dry sausages. Trials were performed with bacteria suspended in skimmed milk or directly grown in whey. Three air temperatures at the inlet of the drier (160, 180, and 200°C) and three flow rates (10, 13, and 17 ml/min) were assayed. Cell viability and bacteriocin activity of the dried materials were determined immediately after the process and after 5, 15, 30, and 60 days of storage at 4°C. There was no significant difference between the two feeding suspensions in cell survival, always decreasing with the increase of inlet-air temperature. No loss of bacteriocin activity was detected in reconstituted powders, nor was any loss of ability to produce bacteriocin found after drying. Investigations of sensitivity to NaCl revealed only temporary damage to dried bacteria. During storage for 2 months at 4°C, all samples, but mainly the lactococcal strains, displayed a gradual decrease in cell survival. Bacteriocin activity remained at the same level, allowing powders to be considered as effective biopreservatives.

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