Comparison on the growth heterogeneity of Vibrio parahaemolyticus coupled with strain sources and genotypes analyses in different oligotrophic conditions

2021 ◽  
Author(s):  
Jun Shi ◽  
Wei Zhao ◽  
Jing Xie ◽  
Yongheng Zhu ◽  
Yingjie Pan ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Specific Growth ◽  
Growth Curves ◽  
Gompertz Model ◽  
Growth Variability ◽  
Aquatic Products ◽  
Theoretical Support ◽  
Food Borne ◽  
Modified Gompertz Model

Vibrio parahaemolyticus is an important food-borne pathogen in aquatic products, which can survive long-term in an oligotrophic environment and maintain pathogenicity. In this study, the growth curves of 38 strains of V.parahaemolyticus (pathogenic and environmental strains) under different oligotrophic conditions (tryptone soy broth (TSB), TSB diluted 2, 4, and 6 times medium) were simulated and their growth heterogeneity was compared. The growth kinetic parameters (maximum specific growth rate ( µ max ) and lag time (LT)) were calculated by the modified Gompertz model. The results showed that oligotrophic conditions affected the growth variability of strains, and the coefficient of variation (CV) of all strains reached the maximum in the 4-fold dilution of TSB. Under different oligotrophic conditions, the LT of the pathogenic strains was shorter than that of the environmental strains, while the µ max of the environmental strains was greater. This indicated that pathogenic strains were more adaptable to the nutrient-deficient environment. The analysis of different genotypes revealed that the strains with genotype tlh + /tdh + /trh − showed a greater growth variability in oligotrophic environments. These results provided theoretical support for the accuracy of the risk assessment of aquatic products.

scholarly journals Isolation of A Molybdenum-reducing Bacillus sp. strain Zeid 15 and Modeling of its Growth on Amides

2021 ◽  
Vol 5 (2) ◽  
pp. 19-27
Author(s):  
I.M. Abu Zeid ◽  
M.F. Rahman ◽  
Mohd Yunus Shukor
Keyword(s):  
Heavy Metals ◽  
Specific Growth ◽  
Growth Parameters ◽  
Gompertz Model ◽  
Electron Donors ◽  
Bacillus Sp ◽  
Aquatic Life ◽  
Molybdenum Blue ◽  
Specific Growth Rates ◽  
Modified Gompertz Model

More and more people are looking at bioremediation as a cheaper option to physhiochemical techniques for cleaning up pollution from farming, mines, and other chemical industries. Toxic effects of molybdenum on spermatogenesis harm not only humans but also livestock and aquatic life. As a result, efforts are being made to remove it from the ecosystem. A microorganism that can convert soluble molybdenum into colloidal molybdenum blue has been discovered. Phosphate concentrations were optimum between 2.5 and 5, molybdate concentrations between 15 and 20, pH between 6, and temperature between 25 and 34 degrees Celsius for the bacteria to thrive. Absorption spectrum of Mo-blue shows a peak at 865 nm and a shoulder at 700 nm, which indicates that it is in fact reduced phosphomolybdate. Copper, mercury, silver, copper, and chromium are all hazardous heavy metals that hinder the synthesis of Mo-blue. Bacillus sp. strain Zeid 15 is the most likely candidate for the bacterium's identity. As part of our screening, we look for the bacterium's capacity to employ different nitriles and amides as potential electron donors for molybdenum reduction or as substrates for growth. A microplate format was used for the screening. The bacterium was able to use the amides acrylamide and propionamide as sources of electron donor for reduction. Mo-blue production was best supported by acrylamide between 750 and 1250 mg/L, and propionamide between 750 and 1000 mg/L. In addition, these amides including acetamide could support the growth of the bacterium. The modified Gompertz model was utilized to model the growth of this bacterium on amides. The model’s growth parameters obtained were lag periods of 1.372, 1.562 and 1.639 d and maximum specific growth rates of 1.38, 0.95 and 0.734 d-1, for acrylamide, acetamide and propionamide, respectively. The capacity of this bacterium to decontaminate simultaneously amides and molybdenum is a novel characteristic that will be very beneficial in bioremediation.

Development and Validation of Growth Model for Yersinia enterocolitica in Cooked Chicken Meats Packaged under Various Atmosphere Packaging and Stored at Different Temperatures

2001 ◽  
Vol 64 (7) ◽  
pp. 987-993 ◽  
Author(s):  
Q. K. WEI ◽  
T. J. FANG ◽  
W. C. CHEN
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Yersinia Enterocolitica ◽  
Specific Growth ◽  
Modified Atmosphere Packaging ◽  
Growth Curves ◽  
Gompertz Model ◽  
Lag Time ◽  
Bias Factor ◽  
Different Temperatures

Mathematical models that can predict the growth of Yersinia enterocolitica in chicken meats were evaluated in this study. The growth curves for Y. enterocolitica in chicken meats variously packaged (air, vacuum, and modified atmosphere packaging [MAP]) and stored at various temperatures (4, 10, 16, 22, 28, and 34°C) were constructed. The Gompertz model was applied to fit each of the experimental curves for the conditions mentioned above. The variations in the parameters, including lag time (λ) and specific growth rate (μ), at various temperatures were then described by the following models: the variations in lag time were described by the Adair and Smith models and the variations in the specific growth rate were described by the Ratkowsky and Zwietering models. The various models were then compared using graphical and mathematical analyses such as mean square error (MSE), regression coefficient (r2), bias factor, and accuracy factor. The results indicate that the mean r values in the Gompertz model for chicken meats packaged in air, vacuum, and MAP were 0.99, 0.99, and 0.95, respectively. The lag time modeled with the Adair and Smith functions exhibited a greater variance and demonstrated larger errors. The MSEs were 0.0015 and 0.0017 for Ratkowsky and Zwietering models, respectively. The r2 values in the Ratkowsky and Zwietering models were both 0.99. The bias factor was 1.017 for the Ratkowsky model and 1.096 for the Zwietering model. The accuracy factor of the Zwietering model was 1.174, which was lower than that in the Ratkowsky model (1.275), indicating that the former model was more accurate than the latter in predicting the specific growth rate of Y. enterocolitica in chicken meats.

Antifungal Activity Evaluation of Mexican Oregano (Lippia berlandieri Schauer) Essential Oil on the Growth of Aspergillus flavus by Gaseous Contact

2011 ◽  
Vol 74 (12) ◽  
pp. 2192-2198 ◽  
Author(s):  
AÍDA GÓMEZ-SÁNCHEZ ◽  
ENRIQUE PALOU ◽  
AURELIO LÓPEZ-MALO
Keyword(s):  
Antifungal Activity ◽  
Essential Oil ◽  
Aspergillus Flavus ◽  
Growth Curves ◽  
Gompertz Model ◽  
Model Parameters ◽  
Oregano Essential Oil ◽  
Independent Variables ◽  
Oil Concentration ◽  
Modified Gompertz Model

The antifungal activity of Mexican oregano (Lippia berlandieri Schauer) essential oil by gaseous contact on the growth of Aspergillus flavus at selected essential oil concentrations (14.7, 29.4, 58.8, or 117.6 μl of essential oil per liter of air) and temperatures (25, 30, or 35°C) was evaluated in potato dextrose agar formulated at water activity of 0.98 and pH 4.0. Mold growth curves were adequately fitted (0.984 < R2 < 0.999) by the modified Gompertz model. The effect of the independent variables (concentration of essential oil and temperature) on the estimated model parameters (reciprocal of growth rate [1/νm] and lag time [λ]) were evaluated through polynomial equations. Both νm and λ were significantly (P < 0.05) affected by the independent variables; νm decreased and λ increased as essential oil concentration increased and temperature decreased, which suggests that Mexican oregano essential oil retards or inhibits mold germination stage. Further, minimum fungistatic and fungicide essential oil concentrations at 30 and 35°C were determined. Mexican oregano essential oil applied in gas phase exerts important antifungal activity on the growth of A. flavus, suggesting its potential to inhibit other food spoilage molds.

Establishment of Multiple-PCR for Diagnosing Three Food-Borne Pathogenic Bacteria in Aquatic Products

2012 ◽  
Vol 554-556 ◽  
pp. 1029-1032
Author(s):  
Hui Li Xia ◽  
Hui Zheng ◽  
Jin Jun Zhang
Keyword(s):  
Listeria Monocytogenes ◽  
Multiplex Pcr ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Pcr Amplification ◽  
National Standard ◽  
Aquatic Products ◽  
Gene Coding ◽  
Food Borne ◽  
Pcr Method

A rapid multiplex-PCR method was established in order to detect three foodborne pathogenic bacteria including Salmonella typli，Vibrio parahaemolyticus and Listeria monocytogenes in aquatic products. Three pairs of oligonucleotide primers were designed for multiplex-PCR amplification according to gene coding invasion protein A of Salmonella typli，gene coding immune response of Vibrio parahaemolyticus and regulation histone gene of Listeria monocytogenes. The amplified fragment sizes of these three bacteria were 213 bp, 369 bp and 517bp, respectively．The specificity of the multiplex- PCR was high and the minimum detection limit reached 103 CFU/mL. The multiplex-PCR method was used to analyze three aquatic product samples compared with national standard methods, the coincidence rate of two methods reached 100%. The method developed in this study had high sensitivity and specificity, which could be applied for the rapid detection and molecular epidemiology survey of food-borne pathogenic bacteria in aquatic products．

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 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.

scholarly journals The structure of a GFP-based antibody (fluorobody) to TLH, a toxin fromVibrio parahaemolyticus

2015 ◽  
Vol 71 (7) ◽  
pp. 913-918 ◽  
Author(s):  
Yaoguang Chen ◽  
Xiaocheng Huang ◽  
Rongzhi Wang ◽  
Shihua Wang ◽  
Ning Shi
Keyword(s):  
Crystal Structure ◽  
Green Fluorescent Protein ◽  
Vibrio Parahaemolyticus ◽  
Fluorescent Protein ◽  
Hybrid Molecule ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Food Borne ◽  
Vapour Diffusion ◽  
Green Fluorescent

A fluorobody is a manmade hybrid molecule that is composed of green fluorescent protein (GFP) and a fragment of antibody, which combines the affinity and specificity of an antibody with the visibility of a GFP. It is able to provide a real-time indication of binding while avoiding the use of tags and secondary binding reagents. Here, the expression, purification and crystal structure of a recombinant fluorobody for TLH (thermolabile haemolysin), a toxin from the lethal food-borne disease bacteriumVibrio parahaemolyticus, are presented. This is the first structure of a fluorobody to be reported. Crystals belonging to space groupP43212, with unit-cell parametersa=b= 63.35,c = 125.90 Å, were obtained by vapour diffusion in hanging drops and the structure was refined to anRfreeof 16.7% at 1.5 Å resolution. The structure shows a CDR loop of the antibody on the GFP scaffold.

scholarly journals A Rapid and Sensitive Europium Nanoparticle-Based Lateral Flow Immunoassay Combined with Recombinase Polymerase Amplification for Simultaneous Detection of Three Food-Borne Pathogens

2021 ◽  
Vol 18 (9) ◽  
pp. 4574
Author(s):  
Kai Chen ◽  
Biao Ma ◽  
Jiali Li ◽  
Erjing Chen ◽  
Ying Xu ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Simultaneous Detection ◽  
Lateral Flow ◽  
Recombinase Polymerase Amplification ◽  
Quantitative Detection ◽  
Bacterial Strains ◽  
Food Borne Pathogens ◽  
Food Borne

Food-borne pathogens have become an important public threat to human health. There are many kinds of pathogenic bacteria in food consumed daily. A rapid and sensitive testing method for multiple food-borne pathogens is essential. Europium nanoparticles (EuNPs) are used as fluorescent probes in lateral flow immunoassays (LFIAs) to improve sensitivity. Here, recombinase polymerase amplification (RPA) combined with fluorescent LFIA was established for the simultaneous and quantitative detection of Listeria monocytogenes, Vibrio parahaemolyticus, and Escherichia coliO157:H7. In this work, the entire experimental process could be completed in 20 min at 37 °C. The limits of detection (LODs) of EuNP-based LFIA–RPA were 9.0 colony-forming units (CFU)/mL for Listeria monocytogenes, 7.0 CFU/mL for Vibrio parahaemolyticus, and 4.0 CFU/mL for Escherichia coliO157:H7. No cross-reaction could be observed in 22 bacterial strains. The fluorescent LFIA–RPA assay exhibits high sensitivity and good specificity. Moreover, the average recovery of the three food-borne pathogens spiked in food samples was 90.9–114.2%. The experiments indicate the accuracy and reliability of the multiple fluorescent test strips. Our developed EuNP-based LFIA–RPA assay is a promising analytical tool for the rapid and simultaneous detection of multiple low concentrations of food-borne pathogens.

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