scholarly journals Effect  of food matrix type on  growth characteristics and hemolysin production of Vibrio alginolyticus

2021 ◽  
Author(s):  
Rundong Wang ◽  
Xiaojun Hu ◽  
Yijia Deng ◽  
Ravi Gooneratne
Keyword(s):  
Freshwater Fish ◽  
Logistic Model ◽  
Goodness Of Fit ◽  
Gompertz Model ◽  
Primary Model ◽  
Current Belief ◽  
Thermostable Direct Hemolysin ◽  
Effect Of Food ◽  
Similar Growth ◽  
Modified Gompertz Model

The growth and hemolysin production of two V.   alginolyticus  strains (HY9901 and ATCC17749T) at 30 °C in briny tilapia, shrimp, scallop, oyster, pork, chicken, freshwater fish and egg fried rice were investigated. Bacterial counts were enumerated by plate counting. Hemolysin production was evaluated by blood agar and hemolytic titer tests. The two V.   alginolyticus  strains displayed similar growth and hemolysin production patterns in the foods. Based on the goodness of fit primary model statistics (R 2 , MSE, BF, AF), the modified Gompertz model was a better fit to V.   alginolyticus  growth in foods than the logistic model. Growth kinetic parameters of V.   alginolyticus  displayed a higher μ max and shorter λ in briny tilapia > shrimp > freshwater fish > egg fried rice > scallop > oyster > chicken > pork. It was notable that the V.   alginolyticus  counts were similar at the stationary phase, with no significant growth behavior difference between raw and cooked foods. Significantly higher (p < 0.05) thermostable direct hemolysin (TDH) activity was produced by V.   alginolyticus  in briny tilapia > freshwater fish > shrimp > chicken > egg fried rice > scallop > oyster > pork. But the hemolytic titer was not consistent with the TDH activity, being significantly higher (p < 0.05) in briny tilapia > egg fried rice > shrimp > freshwater fish > chicken > scallop > oyster > pork. Contrary to current belief, V.   alginolyticus  displayed a higher hemolysin production in some non-seafoods (freshwater fish, egg fried rice and chicken) than in scallop or oyster. This is the first report of growth and toxicity of V. alginolyticus  in different food matrices and confirmation that some non-seafood contaminated with V. alginolyticus  can be even more pathogenic. This study will enhance the awareness of non-seafood safety and improve the V.   alginolyticus  risk assessment accuracy.

scholarly journals Effect of food matrix type on growth characteristics and hemolysin production of Vibrio alginolyticus

2020 ◽  
Author(s):  
Xiaojun Hu ◽  
Rundong Wang ◽  
Yijia Deng ◽  
Qi Deng ◽  
Zhijia Fang ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Goodness Of Fit ◽  
Gompertz Model ◽  
Food Matrix ◽  
Microbial Risk Assessment ◽  
Microbial Risk ◽  
Primary Model ◽  
Thermostable Direct Hemolysin ◽  
Effect Of Food ◽  
Modified Gompertz Model

Abstract Background: The growth and hemolysin production of V. alginolyticus at 30 °C in briny Tilapia , shrimp, scallop, oyster, pork, chicken, freshwater fish and egg fried rice were investigated. Bacterial counts were enumerated by plate counting. Hemolysin production was evaluated by blood agar and hemolytic titer tests. Results: Based on the goodness of fit primary model statistics (R 2 , MSE, BF, AF), the modified Gompertz model was a better fit to V. alginolyticus growth in foods than the logistic model. Growth kinetic parameters of V. alginolyticus displayed a higher μ max and shorter λ in briny Tilapia > shrimp > freshwater fish > egg fried rice > scallop > oyster > chicken > pork. It was notable that the V. alginolyticus counts were similar at the stationary phase, with no significant growth behavior difference between raw and cooked foods. However, higher thermostable direct hemolysin activity and hemolytic titer were observed in briny Tilapia > egg fried rice > shrimp > freshwater fish > chicken > scallop > oyster > pork. Conclusion: V. alginolyticus growth was good in all food matrix types tested. Contrary to current belief, V. alginolyticus displayed a higher hemolytic activity in some non-seafoods (freshwater fish, egg fried rice and chicken) than in scallop or oyster. This is the first report of growth and toxicity of V. alginolyticus in non-seafood. This finding will significantly improve the accuracy of microbial risk assessment of V. alginolyticus in different food matrices especially during warmer climatic periods when it is most prevalent.

scholarly journals Effect of food matrix type on growth characteristics and hemolysin production of Vibrio alginolyticus

2020 ◽  
Author(s):  
Rundong Wang ◽  
Xiaojun Hu ◽  
Yijia Deng ◽  
Qi Deng ◽  
Zhijia Fang ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Goodness Of Fit ◽  
Food Poisoning ◽  
Gompertz Model ◽  
Vibrio Alginolyticus ◽  
Food Matrix ◽  
Primary Model ◽  
Thermostable Direct Hemolysin ◽  
Effect Of Food ◽  
Modified Gompertz Model

Abstract Background: Vibrio alginolyticus is an important seafood-borne pathogen. There is increasing evidence that V.alginolyticus can also contaminate non-seafood by cross contamination and thereby cause food poisoning in humans. The growth and hemolysin production of V. alginolyticus at 30 °C in briny tilapia, shrimp, scallop, oyster, pork, chicken, freshwater fish and egg fried rice were investigated. Bacterial counts were enumerated by plate counting. Hemolysin production was evaluated by blood agar and hemolytic titer tests.Results: Based on the goodness of fit primary model statistics (R 2 , MSE, BF, AF), the modified Gompertz model was a better fit to V. alginolyticus growth in foods than the logistic model. Growth kinetic parameters of V. alginolyticus displayed a higher μ max and shorter λ in briny tilapia > shrimp > freshwater fish > egg fried rice > scallop > oyster > chicken > pork. It was notable that the V. alginolyticus counts were similar at the stationary phase, with no significant growth behavior difference between raw and cooked foods. However, higher thermostable direct hemolysin activity and hemolytic titer were observed in briny tilapia > egg fried rice > shrimp > freshwater fish > chicken > scallop > oyster > pork.Conclusion: V. alginolyticus growth was good in all food matrix types tested. Contrary to current belief, V. alginolyticus displayed a higher hemolytic activity in some non-seafoods (freshwater fish, egg fried rice and chicken) than in scallop or oyster. This is the first report of growth and toxicity of V. alginolyticus in different food matrices and confirmation that some non-seafood contaminated with V. alginolyticus can be even more pathogenic. This study will enhance the awareness of non-seafood safety and improve the V. alginolyticus risk assessment accuracy.

scholarly journals Comparative Analysis of the Amount of Biogas Produced by Different Cultures using the Modified Gompertz Model and Logistic Model

2020 ◽  
Vol 4 (4) ◽  
pp. em0141
Author(s):  
Srigan Moharir ◽  
Ameya Bondre ◽  
Salil Vaidya ◽  
Parth Patankar ◽  
Yashraj Kanaskar ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Logistic Model ◽  
Gompertz Model ◽  
Different Cultures ◽  
Modified Gompertz Model

scholarly journals Batch Anaerobic Co-Digestion and Biochemical Methane Potential Analysis of Goat Manure and Food Waste

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1952
Author(s):  
Ayobami Orangun ◽  
Harjinder Kaur ◽  
Raghava R. Kommalapati
Keyword(s):  
Food Waste ◽  
Gompertz Model ◽  
Water Displacement ◽  
Biochemical Methane Potential ◽  
Greenhouse Gasses ◽  
Nonlinear Regression Models ◽  
The Us ◽  
Methane Potential ◽  
Goat Manure ◽  
Modified Gompertz Model

The improper management of goat manure from concentrated goat feeding operations and food waste leads to the emission of greenhouse gasses and water pollution in the US. The wastes were collected from the International Goat Research Center and a dining facility at Prairie View A&M University. The biochemical methane potential of these two substrates in mono and co-digestion at varied proportions was determined in triplicates and processes were evaluated using two nonlinear regression models. The experiments were conducted at 36 ± 1 °C with an inoculum to substrate ratio of 2.0. The biomethane was measured by water displacement method (pH 10:30), absorbing carbon dioxide. The cumulative yields in goat manure and food waste mono-digestions were 169.7 and 206.0 mL/gVS, respectively. Among co-digestion, 60% goat manure achieved the highest biomethane yields of 380.5 mL/gVS. The biodegradabilities of 33.5 and 65.7% were observed in goat manure and food waste mono-digestions, while 97.4% were observed in the co-digestion having 60% goat manure. The modified Gompertz model is an excellent fit in simulating the anaerobic digestion of food waste and goat manure substrates. These findings provide useful insights into the co-digestion of these substrates.

scholarly journals A generalized Gompertz growth model with applications and related birth-death processes

2020 ◽  
Author(s):  
Majid Asadi ◽  
Antonio Di Crescenzo ◽  
Farkhondeh A. Sajadi ◽  
Serena Spina
Keyword(s):  
Growth Model ◽  
Growth Curve ◽  
Goodness Of Fit ◽  
Gompertz Model ◽  
Death Process ◽  
Birth Process ◽  
Failure Data ◽  
First Case ◽  
Gompertz Growth Model ◽  
Birth Death

AbstractIn this paper, we propose a flexible growth model that constitutes a suitable generalization of the well-known Gompertz model. We perform an analysis of various features of interest, including a sensitivity analysis of the initial value and the three parameters of the model. We show that the considered model provides a good fit to some real datasets concerning the growth of the number of individuals infected during the COVID-19 outbreak, and software failure data. The goodness of fit is established on the ground of the ISRP metric and the $$d_2$$ d 2 -distance. We also analyze two time-inhomogeneous stochastic processes, namely a birth-death process and a birth process, whose means are equal to the proposed growth curve. In the first case we obtain the probability of ultimate extinction, being 0 an absorbing endpoint. We also deal with a threshold crossing problem both for the proposed growth curve and the corresponding birth process. A simulation procedure for the latter process is also exploited.

scholarly journals Optimizing anaerobic co-digestion of goat manure and cotton gin trash using biochemical methane potential (BMP) test and mathematical modeling

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Harjinder Kaur ◽  
Raghava R. Kommalapati
Keyword(s):  
Liquid Fraction ◽  
Gompertz Model ◽  
Biochemical Methane Potential ◽  
Methane Potential ◽  
Mathematical Equations ◽  
Goat Manure ◽  
Bmp Test ◽  
Batch Bioreactors ◽  
Modified Gompertz Model ◽  
Cotton Gin

AbstractAnaerobic co-digestion is widely adopted to enhance process efficacy by balancing the C/N ratio of the feedstock while converting organic wastes to biomethane. Goat manure (GM) and cotton gin trash (CGT) were anaerobically co-digested in triplicate batch bioreactors. The process was optimized and evaluated utilizing mathematical equations. The liquid fraction of the digestate was analyzed for nitrate and phosphate. The co-digestions with 10 and 20% CGT having the C/N ratios of 17.7 and 19.8 yielded the highest and statistically similar 261.4 ± 4.8 and 262.6 ± 4.2 mL/gvs biomethane, respectively. The biodegradability (BD) of GM and CGT was 94.5 ± 2.7 and 37.6 ± 0.8%, respectively. The BD decreased proportionally with an increase in CGT percentage. The co-digestion having 10% CGT yielded 80–90% of biomethane in 26–39 d. The modified Gompertz model-predicted and experimental biomethane values were similar. The highest synergistic effect index of 15.6 ± 4.7% was observed in GM/CGT; 30:70 co-digestion. The concentration of nitrate and phosphate was lower in the liquid fraction of digestate than the feedstocks, indicating that these nutrients stay in the solid fraction. The results provide important insights in agro-waste management, further studies determining the effects of effluent application on plants need to be conducted.

A Goodness of Fit Test for the Multilevel Logistic Model

2015 ◽  
Vol 45 (2) ◽  
pp. 643-659 ◽  
Author(s):  
A. A. P. N. M. Perera ◽  
M. R. Sooriyarachchi ◽  
S. L. Wickramasuriya
Keyword(s):  
Logistic Model ◽  
Goodness Of Fit ◽  
Goodness Of Fit Test ◽  
Multilevel Logistic Model

scholarly journals Applicability of Item Response Theory to the Korean Nurses' Licensing Examination

2005 ◽  
Vol 2 ◽  
pp. 23 ◽  
Author(s):  
Geum-Hee Jeong ◽  
Mi Kyoung Yim
Keyword(s):  
Rasch Model ◽  
Logistic Model ◽  
Goodness Of Fit ◽  
Item Analysis ◽  
Classical Test Theory ◽  
Test Theory ◽  
Classical Test ◽  
Licensing Examination ◽  
The Rasch Model ◽  
Two Parameter

To test the applicability of item response theory (IRT) to the Korean Nurses' Licensing Examination (KNLE), item analysis was performed after testing the unidimensionality and goodness-of-fit. The results were compared with those based on classical test theory. The results of the 330-item KNLE administered to 12,024 examinees in January 2004 were analyzed. Unidimensionality was tested using DETECT and the goodness-of-fit was tested using WINSTEPS for the Rasch model and Bilog-MG for the two-parameter logistic model. Item analysis and ability estimation were done using WINSTEPS. Using DETECT, Dmax ranged from 0.1 to 0.23 for each subject. The mean square value of the infit and outfit values of all items using WINSTEPS ranged from 0.1 to 1.5, except for one item in pediatric nursing, which scored 1.53. Of the 330 items, 218 (42.7%) were misfit using the two-parameter logistic model of Bilog-MG. The correlation coefficients between the difficulty parameter using the Rasch model and the difficulty index from classical test theory ranged from 0.9039 to 0.9699. The correlation between the ability parameter using the Rasch model and the total score from classical test theory ranged from 0.9776 to 0.9984. Therefore, the results of the KNLE fit unidimensionality and goodness-of-fit for the Rasch model. The KNLE should be a good sample for analysis according to the IRT Rasch model, so further research using IRT is possible.

scholarly journals Prediction of growth kinetics of Pseudomonas spp. in meat products under isothermal and non-isothermal storage conditions

2021 ◽  
Vol 7 (3) ◽  
pp. 194-202
Author(s):  
Fatih Tarlak
Keyword(s):  
Goodness Of Fit ◽  
Storage Temperature ◽  
Food Products ◽  
Storage Conditions ◽  
Chicken Meat ◽  
Lag Phase ◽  
Phase Duration ◽  
Pseudomonas Spp ◽  
Primary Model ◽  
One Step

The main objective of the present study was to develop and validate a new alternative modelling method to predict the shelf-life of food products under non-isothermal storage conditions. The bacterial growth data of the Pseudomonas spp. was extracted from published studies conducted for aerobically-stored fish, pork and chicken meat and described with two-step and one-step modelling approaches employing different primary models (the modified Gompertz, logistic, Baranyi and Huang models) under isothermal storage temperatures. Temperature dependent kinetic parameters (maximum specific growth rate ‘µmax’ and lag phase duration ‘λ’) were described as a function of storage temperature via the Ratkowsky model integrated with each primary model. The Huang model based on the one-step modelling approach yielded the best goodness of fit results (RMSE = 0.451 and adjusted-R2 = 0.942) for all food products at isothermal storage conditions, therefore, was also used to check it’s the prediction capability under non-isothermal storage conditions. The differential form of the Huang model provided satisfactorily statistical indexes (1.075 > Bf > 1.014 and 1.080 > Af > 1.047) indicating reliably being able to use to describe the growth behaviour of Pseudomonas spp. in fish, pork and chicken meat subjected to non-isothermal storage conditions.

scholarly journals Theoretical and Experimental Results on the Recovery of Potato Processing Residuals by Anaerobic Digestion

2019 ◽  
Vol 70 (7) ◽  
pp. 2524-2529 ◽  
Author(s):  
Andreea D. Dima ◽  
Carmen Mateescu ◽  
Oana C. Parvulescu ◽  
Eduard M. Lungulescu ◽  
Nicoleta O. Nicula
Keyword(s):  
Anaerobic Digestion ◽  
Gompertz Model ◽  
Economic Feasibility ◽  
Potato Processing ◽  
Biomethane Potential ◽  
Potato Waste ◽  
Cone Model ◽  
Treatment Technologies ◽  
Negative Environmental Impact ◽  
Modified Gompertz Model

Anaerobic digestion of organic matter with high moisture content has proven to be a suitable method for disposal of wet organic residuals with several advantages compared to other treatment technologies. This paper aimed at evaluating the theoretical and experimental biomethane potential of food processing residuals that are responsible for negative environmental impact, with exemplification for the potato processing waste. The biomethane potential is a useful parameter to assess the economic efficiency of anaerobic digestion processes as it can considerably influence the efficiency and the economic feasibility of the energy recovery technologies. Both experimental and theoretical biomethane potentials of potato waste in mesophilic anaerobic digestion as well as biodegradability of the substrate were estimated. Moreover, effects of microalgal extract addition on the digestion of potato waste were examined in an attempt to stimulate the anaerobic digestion. Cone model and a modified Gompertz model were used to predict the dynamics of biomethane production.

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