Attenuation of Microbial Growth on Modified Atmosphere-Packaged Fish

1983 ◽  
Vol 46 (7) ◽  
pp. 610-613 ◽  
Author(s):  
R. J. H. GRAY ◽  
D. G. HOOVER ◽  
A. M. MUIR
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Clostridium Botulinum ◽  
Microbial Growth ◽  
Lag Phase ◽  
Logarithmic Phase ◽  
Modified Atmosphere ◽  
Pomatomus Saltatrix ◽  
Salmonella Spp ◽  
Cynoscion Regalis ◽  
Positive Evidence

Four species of fish from Atlantic waters, Meronia americanus (perch), Cynoscion regalis (seatrout), Micropogon undulatis (croaker) and Pomatomus saltatrix (bluefish), were processed (gutted or filleted), packaged under carbon dioxide and refrigerated. Stability of the fish under the modified atmosphere preservation (MAP) system was compared to that of fish stored conventionally. Use of the MAP system resulted in a 45 to 55% increase in stability, primarily due to an extension in the lag phase of psychrotrophic organisms and to their reduced growth rate in the logarithmic phase. By the 10th day of storage, the conventionally packed fish always exhibited a 100-fold higher psychrotroph count than the CO2-packed fish. Levels of Vibrio parahaemolyticus were negligible in this MAP system and no Salmonella spp. or Staphylococcus aureus was detected, even at an abuse temperature (10°C) of storage. Positive evidence for preformed Clostridium botulinum toxin was lacking.

scholarly journals Modeling the Effect of Active Modified Atmosphere Packaging on the Microbial Stability and Shelf Life of Gutted Sea Bass

2019 ◽  
Vol 9 (23) ◽  
pp. 5019 ◽  
Author(s):  
Theofania Tsironi ◽  
Athina Ntzimani ◽  
Eleni Gogou ◽  
Maria Tsevdou ◽  
Ioanna Semenoglou ◽  
...  
Keyword(s):  
Growth Rate ◽  
Shelf Life ◽  
Microbial Growth ◽  
Modified Atmosphere Packaging ◽  
Sea Bass ◽  
Viable Count ◽  
Lag Phase ◽  
Modified Atmosphere ◽  
Total Viable Count ◽  
Microbial Stability

The aim of the study was the evaluation and mathematical modeling of the effect of active modified atmosphere packaging (MAP), by the incorporation of CO2 emitters in the package, on the microbial stability and shelf life of gutted sea bass during refrigerated storage. Gutted sea bass samples were packaged in modified atmosphere (50% CO2–40% N2–10% O2) with and without CO2 emitters (ACT-MAP, MAP) (gas/product volume ratio 3:1) and stored at isothermal conditions: 0 °C, 5 °C, and 10 °C. The gas concentration in the package headspace (%CO2, %O2) and microbial growth (total viable count, TVC, Pseudomonas spp., Enterobacteriaceae spp., lactic acid bacteria) were monitored during storage. The microbial growth was modeled using the Baranyi growth model, and the kinetic parameters (microbial growth rate, lag phase) were estimated at the tested temperature and packaging conditions. The results showed that the ACT-MAP samples presented significantly lower microbial growth compared to the MAP samples. The growth rate of the total viable count at 0 °C was 0.175 and 0.138 d−1 for the MAP and ACT-MAP sea bass, respectively (p < 0.05). The shelf life of the MAP sea bass at 0–10 °C (based on a final TVC value: 7 log CFU g−1) was extended 4–7 days with the addition of a CO2 emitter in the package. The CO2 concentration in the ACT-MAP samples was stabilized at approximately 60%, while the CO2 in the MAP samples was approximately 40% at the end of the shelf life.

scholarly journals Hoàn thiện quy trình phát hiện đồng thời 14 vi khuẩn gây bệnh đường ruột bằng kĩ thuật PCR-Reverse Dot Blot (PCR-RDB)

2020 ◽  
Vol 13 (1) ◽  
pp. 66-80
Author(s):  
Hồ Thị Thanh Thủy ◽  
Nguyễn Văn Trường ◽  
Nguyễn Bảo Toàn ◽  
Lao Đức Thuận ◽  
Trương Kim Phượng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Campylobacter Jejuni ◽  
Yersinia Enterocolitica ◽  
Vibrio Parahaemolyticus ◽  
Clostridium Botulinum ◽  
Escherichia Coli O157 ◽  
Dot Blot ◽  
Salmonella Spp ◽  
Shigella Spp ◽  
Reverse Dot Blot

Ngộ độc thực phẩm, với một trong những nguyên nhân chính do nhiễm khuẩn vẫn luôn là mối lo ngại, mang tính toàn cầu, được Tổ chức Sức khỏe Thế giới rất quan tâm. Việc xác định chính xác đối tượng vi khuẩn nhiễm vẫn luôn là một nhu cầu cấp thiết của các labo lâm sàng. Nghiên cứu trước đây của chúng tôi đã được công bố với việc thành công bước đầu trong việc xây dựng một quy trình dựa trên kĩ thuật PCR-Reverse Dot Blot (PCR-RDB) nhằm xác định đồng thời 12 vi khuẩn gây bệnh đường ruột ch yếu, bao gồm Bacillus cereus, Clostridium botulinum, Clostridium perfringen, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli O157:H7, Salmonella spp., Shigella spp.., Vibrio cholerae, Vibrio parahaemolyticus, Yersinia enterocolitica và Brucella spp. Chúng tôi tiếp tục phát triển nghiên cứu này nhằm hoàn thiện quy trình PCR-RDB bằng việc thiết kế bổ sung trên màng các loại mẫu dò nhằm làm chứng dương, chứng âm, chứng màu và chứng kiểm tra tín hiệu nền. Bên cạnh đó, xét nhu cầu lâm sàng, việc bổ sung hai loại mẫu dò đề dò hai vi khuẩn Campylobacter jejuni và Yersinia enterocolitica O:8 gây bệnh đường ruột chủ yếu ở trẻ em, là cần thiết. Quy trình PCR-RDB được hoàn thiện trong nghiên cứu này vì vậy có khả năng phát hiện đồng thời 14 vi khuẩn gây bệnh đường ruột, một cách đặc hiệu, với độ nhạy đạt 10^2 bản sao/ml, đã được thử nghiệm trên 30 mẫu phân, ghi nhận kết quả hoàn toàn khớp với kít thương mại PowerCheckTM 20 Pathogen Multiplex Real-time PCR Kit (Korea).

The Effect of Fe3+ on Microbial Growth and Physical and Chemical Properties of Activated Sludge

2013 ◽  
Vol 864-867 ◽  
pp. 1319-1322
Author(s):  
Shan Hong Lan ◽  
Rui Chen ◽  
Ping Ma ◽  
Cong Cong Li ◽  
Hui Xia Lan
Keyword(s):  
Activated Sludge ◽  
Microbial Growth ◽  
High Efficiency ◽  
Removal Rate ◽  
Chemical Properties ◽  
Lag Phase ◽  
Logarithmic Phase ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

The method of activated sludge has been widely used in the process of sewage treatment for its high-efficiency and low-consumption. The effect of Fe3+ on microbial growth and physical and chemical properties of activated sludge were studied to obtain relevant parameters for the running of activated sludge system in this paper. Firstly, study on the effect of Fe3+ on microbial growth was carried out. The experiment results showed that the lag phase of microbial growth was obviously reduced with the presence of Fe3+, obtaining advancing into the logarithmic phase. Whats more, the value of OD600 reached to the maximum of 0.615 at 12h when the concentration of Fe3+ was 30mg/L. Secondly, the effects of Fe3+ on the wastewater treatment and that of the performance index include SVI and MLSS were studied. The results indicated that SVI decreased with increasing the dosages of Fe3+,while MLSS and removal rate of COD obviously increased which reach to the maximum of 88.21% when the concentration of Fe3+ was 30mg/L.

Bacteriological and Color Changes in Modified Atmosphere-Packaged Refrigerated Channel Catfish

1994 ◽  
Vol 57 (8) ◽  
pp. 715-719 ◽  
Author(s):  
J. L. SILVA ◽  
T. D. WHITE
Keyword(s):  
Ictalurus Punctatus ◽  
Channel Catfish ◽  
Clostridium Botulinum ◽  
Initial Increase ◽  
Modified Atmosphere ◽  
Salmonella Spp ◽  
Color Changes ◽  
The Third ◽  
Plate Counts ◽  
Carbon Dioxide Co2

Channel catfish (Ictalurus punctatus) fillet strips were packaged under aerobic (AIR), 25% carbon dioxide (CO2) (LC) and 80% CO2 (HC) environments with the remainder being air; and stored at 2 and 8°C for 4 weeks. Aerobic plate counts (APC) for HC fish at 2°C declined from 6 log CFU/g to 1.4 log CFU/g after 2 weeks but increased to 5 log CFU/g by the third week. The HC-stored strips at 8°C had an initial increase in APC followed by a decline to 1.4 log CFU/g on the third week, and a rise to 9 log CFU/g by the fourth week. Aerobic plate counts in AIR- and LC-packed fish at either temperature increased steadily throughout storage. Fish surface pH declined in HC-packed product from 6.2 to 5.6 by the fourth week, but did not change in LC and AIR packs. Hunter L-values increased in CO2-packed products, while Hunter a-values decreased. Listeria monocytogenes was isolated from fish under LC and AIR at 8°C in the second and third weeks. Salmonella spp. was present in fish stored in all storage atmospheres at 8°C, but only in AIR-packed fish at 2°C. Clostridium botulinum was not found in product at any of the storage atmospheres at either temperature at any time. The best treatment was fish packed in HC and stored at 2°C.

Foodborne and Waterborne Disease in Canada - 1976 Annual Summary

1981 ◽  
Vol 44 (10) ◽  
pp. 787-795 ◽  
Author(s):  
E. C. D. TODD
Keyword(s):  
Staphylococcus Aureus ◽  
Vibrio Parahaemolyticus ◽  
Clostridium Botulinum ◽  
Bakery Products ◽  
Foodborne Disease ◽  
Salmonella Spp ◽  
Fermented Sausages ◽  
Bacillus Spp ◽  
Foodborne Outbreaks ◽  
Mold And Yeast

Data on foodborne disease in Canada in 1976 were compared with data for 1975. A total of 858 incidents, comprising 752 outbreaks and 106 single cases, causing illness in 5367 persons were reported for 1976. The number of outbreaks increased by 5.9% over those for 1975, but the total number of cases decreased by 24.5%. As for previous years, Staphylococcus aureus was responsible for more incidents (27) than any other agent. Other incidents were caused by Salmonella spp. (25), Clostridium perfringens (19) suspect mold and yeast (17), Bacillus spp. (10), Clostridium botulinum (4) and suspect Pseudomonas aeruginosa (4). Seven incidents of trichinosis occurred. Chemicals implicated in causing illness included metals, rancid compounds, a pesticide and solvents. The deaths of five persons were attributed to foodborne disease. About 35% of incidents and 41% of cases were associated with meat and poultry. Bakery products, vegetables, fruits and Chinese food continued to play a prominent role in the spread of foodborne disease, as in previous years. Mishandling of food took place mainly in foodservice establishments (18.9% of incidents, 52.7% of cases) or homes (10.5% of incidents, 6.8% of cases). However, mishandling by the manufacturer caused some problems, including three separate incidents involving fermented sausages. More than 60% of reported foodborne disease incidents occurred in Ontario and the number of incidents per 100,000 population was highest in Ontario and British Columbia. Narrative reports of foodborne outbreaks are presented. Relatively few illnesses resulted from consumption of, or contact with, water; a total of 9 incidents and 1476 cases occurred from ingestion of water and a further three incidents were recorded as a result of penetration of the skin by swimmers' itch parasite (many hundreds of cases) and invasion of wounds in swimmers by Vibrio parahaemolyticus.

scholarly journals Predictive Modeling for the Growth of Salmonella spp. in Liquid Egg White and Application of Scenario-Based Risk Estimation

2021 ◽  
Vol 9 (3) ◽  
pp. 486
Author(s):  
Mi Seon Kang ◽  
Jin Hwa Park ◽  
Hyun Jung Kim
Keyword(s):  
Predictive Model ◽  
Scenario Analysis ◽  
Specific Growth ◽  
Risk Estimation ◽  
Egg White ◽  
Lag Phase ◽  
Salmonella Spp ◽  
Baseline Model ◽  
Phase Duration ◽  
Root Model

The objective of the study was to develop a predictive model of Salmonella spp. growth in pasteurized liquid egg white (LEW) and to estimate the salmonellosis risk using the baseline model and scenario analysis. Samples were inoculated with six strains of Salmonella, and bacterial growth was observed during storage at 10–37 °C. The primary models were developed using the Baranyi model for LEW. For the secondary models, the obtained specific growth rate (μmax) and lag phase duration were fitted to a square root model and Davey model, respectively, as functions of temperature (R2 ≥ 0.98). For μmax, the values were satisfied within an acceptable range (Af, Bf: 0.70–1.15). The probability of infection (Pinf) due to the consumption of LEW was zero in the baseline model. However, scenario analysis suggested possible salmonellosis for the consumption of LEW. Because Salmonella spp. proliferated much faster in LEW than in egg white (EW) during storage at 20 and 30 °C (p < 0.01), greater Pinf may be obtained for LEW when these products are stored at the same conditions. The developed predictive model can be applied to the risk management of Salmonella spp. along the food chain, including during product storage and distribution.

scholarly journals Quantitative Interaction Effects of Carbon Dioxide, Sodium Chloride, and Sodium Nitrite on Neurotoxin Gene Expression in Nonproteolytic Clostridium botulinum Type B

2004 ◽  
Vol 70 (5) ◽  
pp. 2928-2934 ◽  
Author(s):  
Maria Lövenklev ◽  
Ingrid Artin ◽  
Oskar Hagberg ◽  
Elisabeth Borch ◽  
Elisabet Holst ◽  
...  
Keyword(s):  
Gene Expression ◽  
Carbon Dioxide ◽  
Growth Rate ◽  
Sodium Chloride ◽  
Optical Density ◽  
Sodium Nitrite ◽  
Clostridium Botulinum ◽  
Lag Phase ◽  
Type B ◽  
Phase Duration

ABSTRACT The effects of carbon dioxide, sodium chloride, and sodium nitrite on type B botulinum neurotoxin (BoNT/B) gene (cntB) expression in nonproteolytic Clostridium botulinum were investigated in a tryptone-peptone-yeast extract (TPY) medium. Various concentrations of these selected food preservatives were studied by using a complete factorial design in order to quantitatively study interaction effects, as well as main effects, on the following responses: lag phase duration (LPD), growth rate, relative cntB expression, and extracellular BoNT/B production. Multiple linear regression was used to set up six statistical models to quantify and predict these responses. All combinations of NaCl and NaNO2 in the growth medium resulted in a prolonged lag phase duration and in a reduction in the specific growth rate. In contrast, the relative BoNT/B gene expression was unchanged, as determined by the cntB-specific quantitative reverse transcription-PCR method. This was confirmed when we measured the extracellular BoNT/B concentration by an enzyme-linked immunosorbent assay. CO2 was found to have a major effect on gene expression when the cntB mRNA levels were monitored in the mid-exponential, late exponential, and late stationary growth phases. The expression of cntB relative to the expression of the 16S rRNA gene was stimulated by an elevated CO2 concentration; the cntB mRNA level was fivefold greater in a 70% CO2 atmosphere than in a 10% CO2 atmosphere. These findings were also confirmed when we analyzed the extracellular BoNT/B concentration; we found that the concentrations were 27 ng · ml−1 · unit of optical density−1 in the 10% CO2 atmosphere and 126 ng · ml−1 · unit of optical density−1 in the 70% CO2 atmosphere.

scholarly journals A Bayesian approach to analyzing phenotype microarray data enables estimation of microbial growth parameters

2016 ◽  
Vol 14 (03) ◽  
pp. 1650007 ◽  
Author(s):  
Matthias Gerstgrasser ◽  
Sarah Nicholls ◽  
Michael Stout ◽  
Katherine Smart ◽  
Chris Powell ◽  
...  
Keyword(s):  
High Throughput ◽  
Bayesian Approach ◽  
Microarray Data ◽  
Time Course ◽  
Microbial Growth ◽  
Mcmc Methods ◽  
Lag Phase ◽  
Maximum Output ◽  
Phenotype Microarray ◽  
Phenotype Microarrays

Biolog phenotype microarrays (PMs) enable simultaneous, high throughput analysis of cell cultures in different environments. The output is high-density time-course data showing redox curves (approximating growth) for each experimental condition. The software provided with the Omnilog incubator/reader summarizes each time-course as a single datum, so most of the information is not used. However, the time courses can be extremely varied and often contain detailed qualitative (shape of curve) and quantitative (values of parameters) information. We present a novel, Bayesian approach to estimating parameters from Phenotype Microarray data, fitting growth models using Markov Chain Monte Carlo (MCMC) methods to enable high throughput estimation of important information, including length of lag phase, maximal “growth” rate and maximum output. We find that the Baranyi model for microbial growth is useful for fitting Biolog data. Moreover, we introduce a new growth model that allows for diauxic growth with a lag phase, which is particularly useful where Phenotype Microarrays have been applied to cells grown in complex mixtures of substrates, for example in industrial or biotechnological applications, such as worts in brewing. Our approach provides more useful information from Biolog data than existing, competing methods, and allows for valuable comparisons between data series and across different models.

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