scholarly journals Effects of Carbon Dioxide on Growth of Proteolytic Clostridium botulinum, Its Ability To Produce Neurotoxin, and Its Transcriptome

2009 ◽  
Vol 76 (4) ◽  
pp. 1168-1172 ◽  
Author(s):  
Ingrid Artin ◽  
David R. Mason ◽  
Carmen Pin ◽  
Jenny Schelin ◽  
Michael W. Peck ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Clostridium Botulinum ◽  
Stationary Phases ◽  
Expression Profiles ◽  
Modified Atmosphere Packaging ◽  
Growth Cycle ◽  
Enzyme Linked Immunosorbent Assay ◽  
Modified Atmosphere ◽  
Late Stationary Phase ◽  
Reverse Transcription Pcr

ABSTRACT The antimicrobial gas carbon dioxide is frequently used in modified atmosphere packaging. In the present study, the effects of CO2 (10 to 70%, vol/vol) on gene expression (measured using quantitative reverse transcription-PCR and a whole-genome DNA microarray) and neurotoxin formation (measured using an enzyme-linked immunosorbent assay [ELISA]) by proteolytic Clostridium botulinum type A1 strain ATCC 3502 were studied during the growth cycle. Interestingly, in marked contrast to the situation with nonproteolytic C. botulinum types B and E, CO2 had little effect on any of these parameters. At all CO2 concentrations, relative expression of neurotoxin cluster genes peaked in the transition between exponential and stationary phases, with evidence of a second rise in expression in late stationary phase. Microarray analysis enabled identification of coding sequences whose expression profiles matched those of the neurotoxin cluster. Further research is needed to determine whether these are connected to neurotoxin formation or are merely growth phase associated.

scholarly journals Effects of Carbon Dioxide on Neurotoxin Gene Expression in Nonproteolytic Clostridium botulinum Type E

2008 ◽  
Vol 74 (8) ◽  
pp. 2391-2397 ◽  
Author(s):  
Ingrid Artin ◽  
Andrew T. Carter ◽  
Elisabet Holst ◽  
Maria Lövenklev ◽  
David R. Mason ◽  
...  
Keyword(s):  
Gene Expression ◽  
Carbon Dioxide ◽  
Stationary Phase ◽  
Clostridium Botulinum ◽  
Modified Atmosphere Packaging ◽  
Carbon Dioxide Concentration ◽  
Maximum Growth ◽  
Exponential Phase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Modified Atmosphere

ABSTRACT Carbon dioxide is an antimicrobial gas commonly used in modified atmosphere packaging. In the present study, the effects of carbon dioxide on the growth of and neurotoxin production by nonproteolytic Clostridium botulinum type E were studied during the growth cycle. Quantitative reverse transcription-PCR and an enzyme-linked immunosorbent assay were used to quantify expression of the type E botulinum neurotoxin gene (cntE) and the formation of type E neurotoxin. The expression levels of cntE were similar in two strains, with relative expression peaking in the transition between exponential phase and stationary phase. In stationary phase, cntE mRNA expression declined rapidly. The cntE mRNA half-life was calculated to be approximately 9 minutes. Neurotoxin formation occurred in late exponential phase and stationary phase. High carbon dioxide concentrations delayed growth by increasing the lag time and decreasing the maximum growth rate. The effects of carbon dioxide concentration on relative neurotoxin gene expression and neurotoxin formation were significant. Expression of cntE mRNA and the formation of extracellular neurotoxin were twofold higher with a headspace carbon dioxide concentration of 70% (vol/vol) compared to 10% (vol/vol). This finding sheds a new, cautionary light on the potential risks of botulism associated with the use of modified atmosphere packaging.

Toxin Production by Clostridium botulinum Type E in Packaged Channel Catfish

1997 ◽  
Vol 60 (11) ◽  
pp. 1358-1363 ◽  
Author(s):  
PING CAI ◽  
MARK A. HARRISON ◽  
YAO-WEN HUANG ◽  
JUAN L. SILVA
Keyword(s):  
Channel Catfish ◽  
Clostridium Botulinum ◽  
Modified Atmosphere Packaging ◽  
Toxin Production ◽  
Storage Conditions ◽  
Mouse Bioassay ◽  
Modified Atmosphere ◽  
Oxygen Barrier ◽  
Botulinum Type ◽  
Clostridium Botulinum Type E

Channel catfish were inoculated with 3 to 4 log spores/g of a mixed pool of four strains of C. botulinum type E (Beluga, Minnesota, G21-5, and 070) and were packaged with an oxygen-permeable overwrap, in an oxygen-barrier bag with a modified atmosphere of CO2-N2 (80:20) or in a master bag with the same modified atmosphere. Packaged fish were stored at either 4°C and sampled at intervals over 30 days or at 10°C and sampled at intervals over 12 days. An additional master bag treatment in which overwrap-packaged catfish was stored first at 4°C, then removed from the master bags and stored at 10°C, was sampled at intervals over 18 days. Toxin production was evaluated using the mouse bioassay. Aerobic psychrotrophic and anaerobic populations were enumerated, and product spoilage characteristics were noted. Under abusive storage conditions of 10°C, there was no difference among the potential for toxin production in the packaged fish, with botulinum toxin detected on fish from each package type by day 6. At 4°C, toxin production was detected on day 9 in the overwrapped packages, while it was on day 18 in the modified atmosphere packaging. No toxin was found in the master bags held continually at 4°C. Toxin was detected on day 18 from samples initially held at 4°C in the master bag and subsequently held at 10°C. Spoilage preceded toxin production for samples stored at 4°C for each type of packaging. At 10°C, spoilage and toxin detection times coincided.

scholarly journals Total quality index of commercial oyster mushroom Pleurotus sapidus in modified atmosphere packaging

2019 ◽  
Vol 121 (8) ◽  
pp. 1871-1883 ◽  
Author(s):  
Wan Abd Al Qadr Imad Wan-Mohtar ◽  
Anita Klaus ◽  
Acga Cheng ◽  
Shardana Aiga Salis ◽  
Sarina Abdul Halim-Lim
Keyword(s):  
Carbon Dioxide ◽  
Quality Index ◽  
Modified Atmosphere Packaging ◽  
Oyster Mushroom ◽  
Total Phenolic ◽  
Modified Atmosphere ◽  
Total Quality ◽  
Content Type ◽  
Pleurotus Sapidus ◽  
Control Feedback

Purpose The purpose of this paper is to identify the strain of oyster mushroom (OM) Pleurotus sapidus cultivated in a local (commercial) farm, and to generate a total quality index (TQI) on the strain using different modified atmosphere packaging (MAP) gas mixtures. Design/methodology/approach A phylogenetic tree was constructed using the MEGA software to identify the specific strain of P. sapidus grown in a local farm. The effects of MAP on fresh fruiting bodies of the identified strain were determined under three conditions: high carbon dioxide packaging (HCP: 20 per cent CO2, 15 per cent O2), low carbon dioxide packaging (LCP: 2 per cent CO2, 30 per cent O2) and high nitrogen packaging (HNP: 85 per cent N2, 15 per cent O2). All samples were stored at 4 oC for up to ten days, and subjected to total phenolic content (TPC), colour retention (CR) and sensory analysis. Quality parameters such as chewiness and odour were used to obtain the TQI. Findings From the phylogenetic analysis, a new strain (P. sapidus strain QDR) with 99 per cent similarity to P. sapidus was identified. Among the three MAP treatments, HCP recorded the highest TPC (2.85 mg GAE/g) and CR (60.36) after ten days, although only its CR was significantly different (p<0.05) from the control. Feedback from 30 sensory panellists indicated that both HCP and LCP were generally more effective in retaining the colour–odour of OM. The optimum TQI for HCP was obtained based on the observed parameters, which is useful for the large-scale packaging of OM. Originality/value Scientific evidence has revealed that packaging trend for commercially grown OM affects consumer’s acceptance.

Evaluation of the Botulism Hazard from Vegetables in Modified Atmosphere Packaging

1997 ◽  
Vol 60 (10) ◽  
pp. 1208-1214 ◽  
Author(s):  
ANN E. LARSON ◽  
ERIC A. JOHNSON ◽  
CHARLES R. BARMORE ◽  
MYRA D. HUGHES
Keyword(s):  
Clostridium Botulinum ◽  
Modified Atmosphere Packaging ◽  
Gas Production ◽  
Modified Atmosphere ◽  
Green Beans ◽  
Transmission Rates ◽  
Number Of Microorganisms ◽  
Uninoculated Control ◽  
Co2 Level ◽  
Control Samples

The ability of Clostridium botulinum types A, B, and E spores to grow and produce botulinal toxin was investigated in five vegetables (lettuce, cabbage, broccoli, carrots, and green beans) packaged under vacuum or in air. The vegetables were packaged in two types of polyethylene-based bags differing in oxygen and carbon dioxide transmission rates. Vegetables were inoculated with a heat-shocked spore mixture of seven proteolytic and three nonproteolytic strains of C. botulinum types A, B, and E, Inoculated samples and uninoculated controls were incubated at 4, 12, or 21°C. Vegetables were tested for botulinal toxin prior to spoilage, at the onset of spoilage, and after gross spoilage had occurred as evaluated by odor, sliminess and loss of turgidity, gas production, and liquid accumulation in the packages. In nearly all vegetables during incubation the pH decreased, the number of microorganisms increased, the O2 level decreased, and the CO2 level increased. Botulinal toxin was detected in all grossly spoiled broccoli samples incubated at 21°C, in half of the inoculated grossly spoiled broccoli samples incubated at 12°C, and in one-third of the inoculated grossly spoiled lettuce samples incubated at 21°C. The pH of the toxic samples of lettuce and broccoli were 4.48 to 4.88 and 5.72 to 6.62, respectively, and the percent O2 ranged from nondetectable in lettuce to 0.40 to 1.76% in broccoli. The toxic vegetables were considered inedible. No botulinal toxin was detected in any cabbage, carrot, or green bean samples, or in any uninoculated control samples. The data suggest that the probability of botulinal toxin being produced prior to spoilage is less than 1 in 105 in the foods examined.

Prolonged Shelf Life and Reduced Drip Loss of Chicken Filets by the Use of Carbon Dioxide Emitters and Modified Atmosphere Packaging

2014 ◽  
Vol 77 (7) ◽  
pp. 1133-1141 ◽  
Author(s):  
ASKILD L. HOLCK ◽  
MARIT K. PETTERSEN ◽  
MARIE H. MOEN ◽  
ODDVIN SØRHEIM
Keyword(s):  
Carbon Dioxide ◽  
Shelf Life ◽  
Production Efficiency ◽  
Modified Atmosphere Packaging ◽  
Storage Period ◽  
Co2 Concentration ◽  
Life Extension ◽  
Modified Atmosphere ◽  
Drip Loss ◽  
C Storage

Modified atmosphere packaging containing CO2 is widely used for extending the shelf life of chicken meat. Active packaging by adding CO2 emitter sachets to packages of meat is an alternative to traditional modified atmosphere packaging. The purpose of the study was to investigate the shelf life of chicken filets under different CO2 concentrations at 4°C storage. The inhibition of microbial growth was proportional to the CO2 concentration. Storage in 100% CO2 both with and without a CO2 emitter sachet gave a microbiological shelf-life extension of 7 days compared with 60% CO2. Carnobacterium divergens, Carnobacterium sp., and Lactococcus sp. were the dominating species at the end of the storage period. During storage in pure CO2, the carbon dioxide dissolved in the meat and caused the collapse of the packages. The resulting squeeze of the meat lead to a severe increase in drip loss. The drip loss was reduced profoundly by using the CO2 emitting sachet in the packages. The addition of CO2 emitters can easily be implemented at industrial packaging lines without reduction in production efficiency.

scholarly journals MODIFIED ATMOSPHERE PACKAGING OF GRAPES

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 677b-677
Author(s):  
Elhadi M. Yahia
Keyword(s):  
Carbon Dioxide ◽  
Modified Atmosphere Packaging ◽  
Modified Atmosphere ◽  
Low Density ◽  
Atmospheric Conditions ◽  
Atmospheric Gases ◽  
Thompson Seedless ◽  
Carbon Dioxide Gas ◽  
Polyethylene Bags ◽  
Very High

Grapes (Vitis vinifera L. cv. Thompson Seedless) were packed in low density (LDPE) and high density (HDPE) polyethylene bags (Bag size: 25×25 cm containing 300 g of fruit). LDPE and HDPE films had a thickness of 38.7 and 28.2 μm, water permeability of 960 and 720 g/m2.hr.atm., and O2 permeability of 7030 and 3700 cc/m2.day.atm., respectively. Carbon dioxide gas (400 cc) was introduced to the bag immediately after sealing, after 2 weeks. and/or after 4 weeks. Fruits were evaluated after 3 months at 0°C. CO2 was about 30% immediately after introducing the gas but its concentration was reduced to less than 1% within 3 to 4 days. O2 was maintained very high (higher than 10%) in all packages. Water loss and shriveling were very low. However, decay incidence was high in all packages. In-package atmospheric conditions were not appropriate in all treatments to suppress decay activities. Further studies will be carried out with films less permeable to atmospheric gases, and fruits will be evaluated after shorter storage periods.

scholarly journals MODIFIED ATMOSPHERE PACKAGING: TEMPERATURE DEPENDENCE OF THE RQ “BREAKPOINT”

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1139c-1139
Author(s):  
Randolph Beaudry ◽  
Arthur Cameron
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Temperature Dependence ◽  
Oxygen Concentration ◽  
Modified Atmosphere Packaging ◽  
Oxygen Demand ◽  
Carbon Dioxide Production ◽  
Modified Atmosphere ◽  
Lower Oxygen ◽  
The Difference

The steady-state oxygen concentration at which blueberry fruit began to exhibit anaerobic carbon dioxide production. (i.e., the RQ breakpoint) was determined for fruit held at 0, 5, 10, 15, 20 and 25 C using a modified atmosphere packaging (MAP) system. As fruit temperature decreased, the RQ breakpoint occurred at lower oxygen concentrations. The decrease in the RQ breakpoint oxygen is thought to be due to a decreasing oxygen demand of the cooler fruit.The decrease in oxygen demand and concomitant decrease in oxygen flux would have resulted in a decrease in the difference in the oxygen concentrate on between the inside and outside of the fruit and thus decreased the minimum amount of oxygen tolerated. The implications on MAP strategies will be discussed.

scholarly journals Decreased mRNA and Protein Expression of BDNF, NGF, and their Receptors in the Hippocampus from Suicide: An Analysis in Human Postmortem Brain

2013 ◽  
Vol 6 ◽  
pp. CPath.S12530 ◽  
Author(s):  
Ritabrata Banerjee ◽  
Anup K. Ghosh ◽  
Balaram Ghosh ◽  
Somnath Bhattacharyya ◽  
Amal C. Mondal
Keyword(s):  
Nerve Growth Factor ◽  
Expression Profiles ◽  
Postmortem Brain ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Human Postmortem Brain ◽  
Reverse Transcription Pcr ◽  
Treatment Of Depression ◽  
Mrna And Protein Expression ◽  
Postmortem Brains

Despite the devastating effect of suicide on numerous lives, there is still a lack of knowledge concerning its neurochemical aspects. There is increasing evidence that brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are involved in the pathophysiology and treatment of depression through binding and activating their cognate receptors TrkB and TrkA respectively. The present study was performed to examine whether the expression profiles of BDNF and/or TrkB as well as NGF and/or TrkA were altered in the hippocampus of postmortem brain of the participants, who had committed suicide and whether these alterations were associated with specific psychopathologic conditions. These studies were performed on the hippocampus of 21 suicide victims and 19 non-psychiatric control individuals. The protein and mRNA levels of BDNF, TrkB, NGF, and TrkA were determined by sandwich enzyme-linked immunosorbent assay, Western blot and reverse transcription-PCR. Given the importance of BDNF and NGF and their cognate receptors in mediating physiological functions, including cell survival and synaptic plasticity, our findings of reduced expression of BDNF, TrkB, NGF, and TrkA on both the protein and mRNA levels of postmortem brains of suicide victims suggest that these molecules may play an important role in the pathophysiological aspects of suicidal behavior.

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