The Use of Bacteriocin-Producing Pediococcus acidilactici to Control Postprocessing Listeria monocytogenes Contamination of Frankfurters1

1991 ◽  
Vol 54 (9) ◽  
pp. 681-686 ◽  
Author(s):  
ELAINE D. BERRY ◽  
ROBERT W. HUTKINS ◽  
ROGER W. MANDIGO
Keyword(s):  
Listeria Monocytogenes ◽  
No Reduction ◽  
Initial Level ◽  
Lag Time ◽  
Storage Conditions ◽  
Pediococcus Acidilactici ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Low Levels ◽  
Aerobic And Anaerobic

The ability of a bacteriocin-producing Pediococcus acidilactici to control postprocessing Listeria monocytogenes contamination of frankfurters was examined. Bacteriocin-producing P. acidilactici JD1–23 or its plasmid-cured derivative JD-M and a five-strain composite of L. monocytogenes were inoculated onto fully processed frankfurters. Under normal storage conditions at 4°C under vacuum, L. monocytogenes without added pediococci grew from an initial level of 104 CFU/g to a final level of 106 CFU/g over 60 d, with a lag time of 20–30 d. Under the same conditions, high levels (107 CFU/g) of either pediococcal strain inhibited growth of L. monocytogenes up to 60 d, although no reduction of cells occurred. With low levels of pediococci (103–104 CFU/g), Listeria grew, although the lag time was increased, and a bacteriocin effect was observed on frankfurters inoculated with JD1–23. In additional experiments done at 4°C and 15°C under aerobic and anaerobic conditions, levels of 107–108 CFU/g of either pediococci were observed to control Listeria growth on frankfurters at 15°C under anaerobic conditions for up to 15 d. At 4°C under aerobic conditions, L. monocytogenes grew on frankfurters inoculated with JD-M, while JD1–23 inhibited growth of the organism up to 30 d. At 15°C under aerobic conditions, L. monocytogenes grew in the presence of either pediococci, although a bacteriocin effect was indicated. Package atmosphere was observed to affect L. monocytogenes growth on this product.

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: VII. FERMENTATION OF WHEAT BY AEROBACILLUS POLYMYXA UNDER AEROBIC AND ANAEROBIC CONDITIONS

1946 ◽  
Vol 24f (1) ◽  
pp. 1-11 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Carbon Dioxide ◽  
Anaerobic Fermentation ◽  
Anaerobic Conditions ◽  
Mechanical Agitation ◽  
Fermentation Time ◽  
Aerobic Conditions ◽  
Ethanol Formation ◽  
Time Required ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Aeration by mechanical agitation of 15% wheat mash fermented by Aerobacillus polymyxa inhibited the formation of 2,3-butanediol and particularly of ethanol. Aeration of similar mashes by passage of finely dispersed air or oxygen at the rate of 333 ml. per minute per litre of mash increased the rate of formation and yield of 2,3-butanediol but inhibited ethanol formation. However, the over-all time required for the completion of fermentation was not shortened from the usual 72 to 96 hr. required for unaerated mashes. There was no evidence of a shift from fermentative to oxidative dissimilation. Under aerobic conditions, the final butanediol–ethanol ratio was approximately 3:1. Anaerobic conditions, as produced by the passage of nitrogen or hydrogen through the mash, increased the rate of formation of both butanediol and ethanol and shortened the fermentation time to about 48 hr. Under these conditions, the butanediol–ethanol ratio was reduced to about 1.3:1.0. Carbon dioxide gave a butanediol–ethanol ratio resembling that of anaerobic fermentation but did not reduce fermentation time.

Growth and Sporulation Potential of Clostridium perfringens in Aerobic and Vacuum-Packaged Cooked Beef

1994 ◽  
Vol 57 (5) ◽  
pp. 393-398 ◽  
Author(s):  
V. K. JUNEJA ◽  
B. S. MARMER ◽  
A. J. MILLER
Keyword(s):  
Clostridium Perfringens ◽  
Food Poisoning ◽  
Ground Beef ◽  
Viable Count ◽  
Anaerobic Conditions ◽  
Vegetative Cells ◽  
Aerobic Conditions ◽  
C Storage ◽  
Meat Samples ◽  
Aerobic And Anaerobic

Growth of Clostridium perfringens in aerobic-and anaerobic-(vacuum) packaged cooked ground beef was investigated. Autoclaved ground beef was inoculated with ~3.0-log10 CFU/g of C. perfringens, packaged and stored at various temperatures. Vegetative cells and heat-resistant spores were enumerated by plating unheated and heated (75°C for 20 min) meat samples on tryptose-sulfite-cycloserine agar. Clostridium perfringens grew to >7 logs within 12 h at 28, 37 and 42°C under anaerobic atmosphere and at 37 and 42°C under aerobic conditions. At 28°C under aerobic conditions, growth was relatively slow and total viable count increased to >6 logs within 36 h. Similarly, growth at 15°C in air was both slower and less than under vacuum. Regardless of packaging, the organism either declined or did not grow at 4, 8 and 12°C. Spores were not found at <12°C. Spores were detected as early as 8 h at 42°C under anaerobic conditions, but in general, the type of atmosphere had little influence on sporulation at ≥28°C. Temperature abuse (28°C storage) of refrigerated products for 6 h will not permit C. perfringens growth. However, cyclic and static temperature abuse of such products for relatively long periods may lead to high and dangerous numbers of organisms. Reheating such products to an internal temperature of 65°C before consumption would prevent food poisoning since the vegetative cells were killed.

scholarly journals Comparison of three neutralizing broths for environmental sampling of low levels of Listeria monocytogenes desiccated on stainless steel surfaces and exposed to quaternary ammonium compounds

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Fengmin Li ◽  
Zhihan Xian ◽  
Hee Jin Kwon ◽  
Jiyoon Yoo ◽  
Laurel Burall ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Storage Conditions ◽  
Ammonium Compound ◽  
Environmental Sampling ◽  
High Concentration ◽  
Environmental Test ◽  
Steel Surfaces ◽  
Low Levels

Abstract Background An effective environmental sampling method involves the use of a transport/neutralizing broth with the ability to neutralize sanitizer residues that are collected during sampling and to maintain viability of stressed Listeria monocytogenes (Lm) cells. Results We applied Lm onto stainless steel surfaces and then subjected Lm to desiccation stress for 16–18 h at room temperature (RT, 21–24 °C). This was followed by the subsequent application of Whisper™ V, a quaternary ammonium compound (QAC)-based sanitizer, diluted to 400 ppm and 8000 ppm of active quat, for 6 h. We then sampled Lm with sponges pre-moistened in three transport broths, Dey/Engley (D/E) broth, Letheen broth and HiCap™ broth, to generate environmental samples that contained sanitizer residues and low levels of stressed Lm, which were subsequently analyzed by an enrichment-based method. This scheme conformed with validation guidelines of AOAC International by using 20 environmental test portions per broth that contained low levels of Lm such that not all test portions were positive (i.e., fractional positive). We showed that D/E broth, Letheen broth and HiCap™ broth performed similarly when no quat or 400 ppm of quat was applied to the Lm contaminating stainless steel surfaces. However, when 8000 ppm of quat was applied, Letheen broth did not effectively neutralize the QAC in the samples. These comparisons were performed on samples stored under three conditions after collection to replicate scenarios of sample transport, RT for 2 h, 4 °C for 24 h and 4 °C for 72 h. Comparisons under the three different scenarios generally reached the same conclusions. In addition, we further demonstrated that storing Letheen and HiCap™ broths at RT for two months before sampling did not reduce their capacity to neutralize sanitizers. Conclusions We developed a scheme to evaluate the ability of transport broths to neutralize QAC sanitizers. The three transport broths performed similarly with a commonly used concentration of quat, but Letheen broth could not effectively neutralize a very high concentration of QAC. The performance of transport broths was not significantly affected under the assessed pre-sampling and post-sampling storage conditions.

scholarly journals In vivo cycling of the Escherichia coli transcription factor FNR between active and inactive states

Microbiology ◽  
2005 ◽  
Vol 151 (12) ◽  
pp. 4063-4070 ◽  
Author(s):  
David P. Dibden ◽  
Jeffrey Green
Keyword(s):  
Escherichia Coli ◽  
De Novo ◽  
Oxygen Availability ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Fnr Protein ◽  
Transcription Regulators ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

FNR proteins are transcription regulators that sense changes in oxygen availability via assembly–disassembly of [4Fe–4S] clusters. The Escherichia coli FNR protein is present in bacteria grown under aerobic and anaerobic conditions. Under aerobic conditions, FNR is isolated as an inactive monomeric apoprotein, whereas under anaerobic conditions, FNR is present as an active dimeric holoprotein containing one [4Fe–4S] cluster per subunit. It has been suggested that the active and inactive forms of FNR are interconverted in vivo, or that iron–sulphur clusters are mostly incorporated into newly synthesized FNR. Here, experiments using a thermo-inducible fnr expression plasmid showed that a model FNR-dependent promoter is activated under anaerobic conditions by FNR that was synthesized under aerobic conditions. Immunoblots suggested that FNR was more prone to degradation under aerobic compared with anaerobic conditions, and that the ClpXP protease contributes to this degradation. Nevertheless, FNR was sufficiently long lived (half-life under aerobic conditions, ∼45 min) to allow cycling between active and inactive forms. Measuring the abundance of the FNR-activated dms transcript when chloramphenicol-treated cultures were switched between aerobic and anaerobic conditions showed that it increased when cultures were switched to anaerobic conditions, and decreased when aerobic conditions were restored. In contrast, measurement of the abundance of the FNR-repressed ndh transcript under the same conditions showed that it decreased upon switching to anaerobic conditions, and then increased when aerobic conditions were restored. The abundance of the FNR- and oxygen-independent tatE transcript was unaffected by changes in oxygen availability. Thus, the simplest explanation for the observations reported here is that the FNR protein can be switched between inactive and active forms in vivo in the absence of de novo protein synthesis.

scholarly journals Transcriptomic Analysis of Listeria monocytogenes in Response to Bile Under Aerobic and Anaerobic Conditions

2021 ◽  
Vol 12 ◽  
Author(s):  
Damayanti Chakravarty ◽  
Gyan Sahukhal ◽  
Mark Arick ◽  
Morgan L. Davis ◽  
Janet R. Donaldson
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Responses ◽  
Listeriolysin O ◽  
Gi Tract ◽  
Anaerobic Conditions ◽  
Transcript Levels ◽  
Comprehensive Information ◽  
Associated Proteins ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Listeria monocytogenes is a gram-positive facultative anaerobic bacterium that causes the foodborne illness listeriosis. The pathogenesis of this bacterium depends on its survival in anaerobic, acidic, and bile conditions encountered throughout the gastrointestinal (GI) tract. This transcriptomics study was conducted to analyze the differences in transcript levels produced under conditions mimicking the GI tract. Changes in transcript levels were analyzed using RNA isolated from L. monocytogenes strain F2365 at both aerobic and anaerobic conditions, upon exposure to 0 and 1% bile at acidic and neutral pH. Transcripts corresponding to genes responsible for pathogenesis, cell wall associated proteins, DNA repair, transcription factors, and stress responses had variations in levels under the conditions tested. Upon exposure to anaerobiosis in acidic conditions, there were variations in the transcript levels for the virulence factors internalins, listeriolysin O, etc., as well as many histidine sensory kinases. These data indicate that the response to anaerobiosis differentially influences the transcription of several genes related to the survival of L. monocytogenes under acidic and bile conditions. Though further research is needed to decipher the role of oxygen in pathogenesis of L. monocytogenes, these data provide comprehensive information on how this pathogen responds to the GI tract.

AEROBIC AND ANAEROBIC P32LABELLING OF PHOSPHOLIPIDS AND ADENOSINE PHOSPHATES IN HYPOTONIC HOMOGENATES OF RAT BRAIN

1957 ◽  
Vol 35 (10) ◽  
pp. 799-809 ◽  
Author(s):  
J. F. Berry ◽  
W. C. McMurray
Keyword(s):  
Steady State ◽  
Rat Brain ◽  
Specific Activity ◽  
Steady State Concentration ◽  
Anaerobic Conditions ◽  
Inorganic P ◽  
Aerobic Conditions ◽  
Adenosine Phosphates ◽  
State Concentration ◽  
Aerobic And Anaerobic

Under aerobic conditions, a suitably 'reinforced' homogenate of rat brain prepared in distilled water was capable of labelling lipid P, ATP, ADP, and AMP from inorganic P32. The labelling was 'uncoupled' by the addition of DNP. The DNP decreased the specific activity of each of the above compounds and decreased the steady-state concentrations of ATP, with an increase in the concentrations of inorganic P, ADP, and AMP. Fluoride increased the specific activity of the lipid P and the steady-state concentration of ATP. Cyanide decreased the specific activity of lipid P and both the specific activity and the steady-state concentration of ATP.Under anaerobic conditions, the labelling of the lipid P and the adenosine phosphates was as good as that observed in the presence of oxygen. The anaerobic labelling of both lipid P and the adenosine phosphates was less sensitive to DNP or cyanide and more sensitive to iodoacetate than the aerobic labelling. In contrast to the aerobic labelling, the anaerobic labelling was inhibited by fluoride.In most instances, changes in the labelling of lipid P corresponded to those observed for the labelling of ATP. An exception was the labelling of lipid P that occurred under aerobic conditions in the presence of fluoride. Here the specific activity of the lipid P was related to the concentration rather than to the specific activity of ATP.

The energy metabolism of adult Haemonchus contortus, in vitro

Parasitology ◽  
1978 ◽  
Vol 77 (3) ◽  
pp. 255-271 ◽  
Author(s):  
P. F. V. Ward ◽  
N. S. Huskisson
Keyword(s):  
Energy Metabolism ◽  
Haemonchus Contortus ◽  
Aerobic Incubation ◽  
Anaerobic Conditions ◽  
Physically Active ◽  
Aerobic Conditions ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

SummaryA comparison was made of the major excretory products when adult Haemonchus contortus worms were incubated with D-[U-14C]glucose under aerobic and anaerobic conditions. Catabolites measured were propan-1-ol, acetate, n-propionate and CO2 and the only major difference was that nearly twice as much CO2 both in terms of quantity and radioactivity was excreted under aerobic than anaerobic conditions. The worms were also much more physically active under aerobic conditions. When worms were incubated under aerobic conditions with increasing amounts of fluoroacetate their CO2 production was progressively reduced to the anaerobic level. Their movement and their ability to clump together was also progressively reduced. After aerobic incubation with fluoroacetate and D-[U-14C]g1ucose the quantity and radioactivity of citrate within worms increased greatly. When worms were similarly incubated anaerobically no increase in citrate occurred, no radioactivity was associated with the citrate and the worms appeared physically unaffected. When worms were incubated aerobically with fluoro[1-14C]acetate they produced radioactive fluorocitrate.

scholarly journals Diverse effects of nitric oxide reductase NorV on Aeromonas hydrophila virulence-associated traits under aerobic and anaerobic conditions

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Jin Liu ◽  
Yuhao Dong ◽  
Nannan Wang ◽  
Shuiyan Ma ◽  
Chengping Lu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Aeromonas Hydrophila ◽  
Dependent Manner ◽  
Nitric Oxide Reductase ◽  
Wild Type ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Significant Difference ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Abstract NorV has been known to be an anaerobic nitric oxide reductase associated with nitric oxide (NO) detoxification. Recently, we showed that the norV gene of Aeromonas hydrophila was highly upregulated after co-culturing with Tetrahymena thermophila. Here, we demonstrated that the transcription and expression levels of norV were upregulated in a dose-dependent manner after exposure to NO under aerobic and anaerobic conditions. To investigate the roles of norV in resisting predatory protists and virulence of A. hydrophila, we constructed the norV gene-deletion mutant (ΔnorV). Compared to the wild type, the ΔnorV mutant showed no significant difference in growth at various NO concentrations under aerobic conditions but significantly stronger NO-mediated growth inhibition under anaerobic conditions. The deletion of norV exhibited markedly decreased cytotoxicity, hemolytic and protease activities under aerobic and anaerobic conditions. Also, the hemolysin co-regulated protein (Hcp) in the ΔnorV mutant showed increased secretion under aerobic conditions but decreased secretion under anaerobic conditions as compared to the wild-type. Moreover, the inactivation of norV led to reduced resistance to predation by T. thermophila, decreased survival within macrophages and highly attenuated virulence in zebrafish. Our data indicate a diverse role for norV in the expression of A. hydrophila virulence-associated traits that is not completely dependent on its function as a nitric oxide reductase. This study provides insights into an unexplored area of NorV, which will contribute to our understanding of bacterial pathogenesis and the development of new control strategies for A. hydrophila infection.

Performance of Response Surface and Davey Model for Prediction of Staphylococcus aureus Growth Parameters under Different Experimental Conditions

2004 ◽  
Vol 67 (6) ◽  
pp. 1138-1145 ◽  
Author(s):  
G. ZURERA-COSANO ◽  
A. M. CASTILLEJO-RODRÍGUEZ ◽  
R. M. GARCÍA-GIMENO ◽  
F. RINCÓN-LEÓN
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Rate ◽  
Response Surface ◽  
Growth Parameters ◽  
Growth Models ◽  
Lag Time ◽  
Anaerobic Conditions ◽  
Experimental Conditions ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

The combined effect of different temperatures (7 to 19°C), pH levels (4.5 to 8.5), sodium chloride levels (0 to 8%), and sodium nitrite levels (0 to 200 ppm) on the predicted growth rate and lag time of Staphylococcus aureus under aerobic and anaerobic conditions was studied. The two predictive models developed, response surface (RS) and the Davey model, provided reliable estimates of the two kinetic parameters studied. The RS provided better predictions of maximum specific growth rate, with bias factors of 1.06 and 1.31 and accuracy factors of 1.17 and 1.37, respectively, in aerobic and anaerobic conditions. The Davey model performed more accurately for lag time, with a bias factor of 1.12 and an accuracy factor of 1.49, for both aerobic and anaerobic conditions. Predictive growth models are a valuable tool, enabling swift determination of Staphylococcus aureus growth rate and lag time. These data are essential for ensuring staphylococcus-relatedquality and safety of food products.

scholarly journals Effect of Addition of Tryptophan on Aggregation of Apo-α-Lactalbumin Induced by UV-Light

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1577
Author(s):  
Zichen Zhao ◽  
Renjie Li ◽  
Mahesha M. Poojary ◽  
Søren B. Nielsen ◽  
Marianne N. Lund
Keyword(s):  
Uv Light ◽  
Bond Cleavage ◽  
Aerobic Condition ◽  
Amino Acid Residues ◽  
Exchange Reactions ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Induced Aggregation ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

UV-B illumination facilitates aggregation of alpha-lactalbumin (α-LA) by intramolecular disulfide bond cleavage followed by intermolecular thiol-disulfide exchange reactions. However, long term exposure to UV-B illumination may induce undesired oxidative modifications of amino acid residues in the protein. The purpose of this study was to examine the effect of UV-induced aggregation of apo-α-LA (a calcium-depleted form of α-LA) under aerobic and anaerobic conditions and by addition of tryptophan (Trp) as a photosensitizer. The addition of Trp to apo-α-LA illuminated under anaerobic conditions facilitated the highest level of free thiol release and disulfide-mediated aggregation as compared to without addition of Trp under both anaerobic and aerobic conditions. Addition of Trp under aerobic condition resulted in the lowest level of free thiols and disulfide-mediated aggregation and the aerobic conditions caused oxidation of the free Trp with formation of kynurenine and 5-hydroxy-Trp. Minor levels of the Trp oxidation product, 3-hydroxy-kynurenine (2% converted from Trp), was formed in apo-α-LA with added Trp under both aerobic and anaerobic conditions after UV-B treatment.

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