Assessment of the response of indigenous microflora and inoculated Bacillus licheniformis endospores in reconstituted skim milk to microwave and conventional heating systems by flow cytometry

2021 ◽  
Author(s):  
F. Li ◽  
E. Santillan-Urquiza ◽  
U. Cronin ◽  
E. O'Meara ◽  
W. McCarthy ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Bacillus Licheniformis ◽  
Skim Milk ◽  
Conventional Heating ◽  
Heating Systems ◽  
Indigenous Microflora

scholarly journals A COMBINED USE OF FDM AND DOE METHOD TO DERIVE A NEW TRANSIENT SIMPLIFIED SEMI-ANALYTICAL MODEL: A CASE STUDY OF ANHYDRITE RADIANT SLAB

2020 ◽  
Vol 330 ◽  
pp. 01002
Author(s):  
Abdelatif Merabtine ◽  
Abdelhamid Kheiri ◽  
Salim Mokraoui
Keyword(s):  
Surface Temperature ◽  
Analytical Model ◽  
Numerical Models ◽  
Thermal Response ◽  
Sensitivity Study ◽  
Conventional Heating ◽  
Heating Systems ◽  
Combined Use ◽  
Scale Test ◽  
Radiant Floor Heating

Radiant floor heating systems (FHS) are considered as reliable heating systems since they ensure maintaining inside air temperature and reduce its fluctuations more efficiently than conventional heating systems. The presented study investigates the dynamic thermal response of an experimental FHS equipped with an anhydrite radiant slab. A new simplified model based on an analytical correlation is proposed to evaluate the heating radiant slab surface temperature and examine its thermal behavior under dynamic conditions. In order the validate the developed analytical model, an experimental scenario, under transient conditions, was performed in a monitored full-scale test cell. 2D and 3D numerical models were also developed to evaluate the accuracy of the analytical model. The method of Design of Experiments (DoE) was used to both derive meta-models, to analytically estimate the surface temperature, and perform a sensitivity study.

scholarly journals Suboptimal Bacillus licheniformis and Bacillus weihenstephanensis Spore Incubation Conditions Increase Heterogeneity of Spore Outgrowth Time

2020 ◽  
Vol 86 (6) ◽  
Author(s):  
C. Trunet ◽  
N. Mtimet ◽  
A.-G. Mathot ◽  
F. Postollec ◽  
I. Leguerinel ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Flow Cytometry ◽  
Bacillus Licheniformis ◽  
Model Parameters ◽  
Vegetative Cells ◽  
Content Type ◽  
Bacillus Weihenstephanensis ◽  
Spore Outgrowth ◽  
Growth Limits ◽  
Kinetics Of

ABSTRACT Changes with time of a population of Bacillus weihenstephanensis KBAB4 and Bacillus licheniformis AD978 dormant spores into germinated spores and vegetative cells were followed by flow cytometry, at pH ranges of 4.7 to 7.4 and temperatures of 10°C to 37°C for B. weihenstephanensis and 18°C to 59°C for B. licheniformis. Incubation conditions lower than optimal temperatures or pH led to lower proportions of dormant spores able to germinate and extended time of germination, a lower proportion of germinated spores able to outgrow, an extension of their times of outgrowth, and an increase of the heterogeneity of spore outgrowth time. A model based on the strain growth limits was proposed to quantify the impact of incubation temperature and pH on the passage through each physiological stage. The heat treatment temperature or time acted independently on spore recovery. Indeed, a treatment at 85°C for 12 min or at 95°C for 2 min did not have the same impact on spore germination and outgrowth kinetics of B. weihenstephanensis despite the fact that they both led to a 10-fold reduction of the population. Moreover, acidic sporulation pH increased the time of outgrowth 1.2-fold and lowered the proportion of spores able to germinate and outgrow 1.4-fold. Interestingly, we showed by proteomic analysis that some proteins involved in germination and outgrowth were detected at a lower abundance in spores produced at pH 5.5 than in those produced at pH 7.0, maybe at the origin of germination and outgrowth behavior of spores produced at suboptimal pH. IMPORTANCE Sporulation and incubation conditions have an impact on the numbers of spores able to recover after exposure to sublethal heat treatment. Using flow cytometry, we were able to follow at a single-cell level the changes in the physiological states of heat-stressed spores of Bacillus spp. and to discriminate between dormant spores, germinated spores, and outgrowing vegetative cells. We developed original mathematical models that describe (i) the changes with time of the proportion of cells in their different states during germination and outgrowth and (ii) the influence of temperature and pH on the kinetics of spore recovery using the growth limits of the tested strains as model parameters. We think that these models better predict spore recovery after a sublethal heat treatment, a common situation in food processing and a concern for food preservation and safety.

scholarly journals Electrical Heating Emissions on the Island of Ireland

2018 ◽  
Vol 64 ◽  
pp. 07001
Author(s):  
D. Kerr William ◽  
M. Laverty David ◽  
J. Best Robert
Keyword(s):  
Dynamic Stability ◽  
Electric Heating ◽  
Electrical Heating ◽  
Conventional Heating ◽  
Heat Output ◽  
Demand Side ◽  
Heating Systems ◽  
Electrical Grid ◽  
Heating Source ◽  
Co2 Intensity

This paper shows the effect on household greenhouse gas emissions if standalone or supplementary electric heating was to replace conventional heating methods, based on the present day electrical grid. While having the capability to improve future grid effectiveness and dynamic stability through the potential incorporation of demand side management (DSM). The All-Ireland system has been used in this paper as an example of a network which has been experiencing a significant increase in renewable generation. To show the potential of the electric heating methods the characteristics of existing domestic heating systems will be discussed, in terms of their heat output against their exhaust emissions (gCO2e/kWh). This will then be compared to that of the grid CO2 Intensity, showing the frequency and duration of the possible emission savings involved when using electricity as a main or supplementary heating source.

Experimental Study on Radiant Floor Heating System

2015 ◽  
Author(s):  
C. C. Ngo ◽  
B. A. Alhabeeb ◽  
M. Balestrieri
Keyword(s):  
Heating System ◽  
Conventional Heating ◽  
Design Parameters ◽  
Piping System ◽  
Burial Depth ◽  
Heating Systems ◽  
Radiant Floor Heating System ◽  
Radiant Floor Heating ◽  
Floor Heating ◽  
Floor Temperature

Radiant floor heating systems have become popular due to their advantages over conventional heating systems in residential, commercial and industrial spaces. They are also used for snow and ice melting and turf conditioning applications. This paper presents a general study focuses on the design of radiant floor heating systems and investigates the effect of design parameters such as pipe spacing (ranging from 4 in. to 12 in.), pipe depth (ranging from 2.5 in. to 6.5 in.) and pipe temperature (45 °C, 65 °C and 85 °C) on the performance of radiant floor heating system embedded in different mediums (air, gravel and sand). The experimental results showed that a radiant heating system with pipes embedded at a shallow burial depth and placed closer together resulted with a more desired floor temperature distribution. The average floor temperature was also higher when the piping system was embedded in an air-filled space instead of a porous medium such as gravel or sand.

scholarly journals Death kinetics of Escherichia coli in goat milk and Bacillus licheniformis in cloudberry jam treated by ohmic heating

2007 ◽  
Vol 61 (2) ◽  
Author(s):  
R. Pereira ◽  
J. Martins ◽  
C. Mateus ◽  
J. Teixeira ◽  
A. Vicente
Keyword(s):  
Escherichia Coli ◽  
Bacillus Licheniformis ◽  
Ohmic Heating ◽  
Goat Milk ◽  
Conventional Heating ◽  
Decimal Reduction Time ◽  
Fold Reduction ◽  
Death Kinetics ◽  
D Values ◽  
Kinetics Of

AbstractThe influence of ohmic heating on the death kinetic parameters of Escherichia coli ATCC® 25922 in goat milk and spores of Bacillus licheniformis ATCC® 14580 in cloudberry jam was investigated and compared with that of conventional heating. Ohmic treatment of goat milk shortened the decimal reduction time D in comparison with the D values obtained at conventional treatment. Similarly, the z value, increase of temperature required for a ten-fold reduction of D, was also lower at ohmic treatment. The death kinetics of Bacillus licheniformis ATCC® 14580 spores in cloudberry jam was also studied employing both types of heat treatment. Similar conclusions were obtained for the D values as in the case of goat milk. However, the differences between the z values obtained for ohmic and conventional heating were not significant.

Energy and economic comparisons of a heat pump/heat store with conventional heating systems in the British climate

1988 ◽  
Vol 30 (3) ◽  
pp. 197-208 ◽  
Author(s):  
P.P. Votsis ◽  
C.J. Marquand ◽  
S.A. Tassou ◽  
D.R. Wilson
Keyword(s):  
Heat Pump ◽  
Conventional Heating ◽  
Heating Systems ◽  
Heat Store

scholarly journals Improvement of Bacillus licheniformis MZK05 by mutation for increased production of keratinase

2015 ◽  
Vol 24 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Serajus Salaheen ◽  
Md Arafat Al Mamun ◽  
Shakila Nargis Khan ◽  
Md Mozammel Hoq
Keyword(s):  
Bacillus Licheniformis ◽  
Large Scale ◽  
Skim Milk ◽  
Shake Flask Culture ◽  
Scale Production ◽  
Feather Meal ◽  
Carbon And Nitrogen ◽  
Enhanced Production ◽  
Large Scale Production ◽  
Improved Strain

Bacillus licheniformis MZK05 was subjected to mutation by ultraviolet radiation for enhanced production of keratinase. Of 750 isolates from irradiated plates, 200 colonies that showed zone of casein hydrolysis on Skim Milk Agar were cultured in liquid Feather Meal Medium containing digested feather as carbon and nitrogen source in shake culture at 37ºC. The mutant B. licheniformis MZK05M9 (BlM9) exhibited highest enzyme activity of 170 ± 5.63 U/ml as compared to 74 ± 5.29 U/ml by the wild MZK05. Both the strains were examined for the presence of gene encoded for keratinase (kerA gene) by PCR using primer which showed the product sizes 1156 bp and 520 bp, respectively for MZK05 and BlM9. The keratinase from both strains exhibited a thermal stability of about 97% for 2 hrs at 40°C whereas the keratinase of the mutant strain showed less stability (55%) at 50°C. The BlM9 while cultivated in batch culture in 7 litre bioreactor for production of the keratinase in the Feather Meal Medium, the productivity was found to be double (17,608 U/L/hr) than that of in the shake flask culture (8,525 U/L/hr). This improved strain thus will be very useful for large scale production of keratinase enabling its technical applications in industry. Dhaka Univ. J. Biol. Sci. 24(1): 17-23, 2015 (January)

scholarly journals Effect of a Sustainable Air Heat Pump System on Energy Efficiency, Housing Environment, and Productivity Traits in a Pig Farm

2020 ◽  
Vol 12 (22) ◽  
pp. 9772
Author(s):  
Myeong Gil Jeong ◽  
Dhanushka Rathnayake ◽  
Hong Seok Mun ◽  
Muhammad Ammar Dilawar ◽  
Kwang Woo Park ◽  
...  
Keyword(s):  
Heat Pump ◽  
Electricity Consumption ◽  
Heating System ◽  
Conventional Heating ◽  
Growth Stages ◽  
Pump System ◽  
Average Growth ◽  
Heating Systems ◽  
Housing Environment ◽  
Significant Difference

High electricity consumption, carbon dioxide (CO2), and elevated noxious gas emission in the global livestock sector have a negative influence on environmental sustainability. This study examined the effects of a heating system using an air heat pump (AHP) on the energy saving, housing environment, and productivity traits of pigs. During the experimental period of 16 weeks, the internal temperature was found to be higher (p < 0.05) in the AHP house than in the conventional house. Moreover, the average electricity consumption and CO2 emission decreased by approximately 40 kWh and 19.32 kg, respectively, in the AHP house compared to the house with the conventional heating system. The average NH3 and H2S emissions were significantly lower in the AHP house (p < 0.05) during the growth stages. The AHP and conventional heating systems did not have a significant influence (p > 0.05) on the average ultra-fine dust (PM2.5) and formaldehyde level fluctuations. Furthermore, both heating systems did not show a significant difference in the average growth performance of pigs (p > 0.05), but the weight gain tended to increase in the AHP house. In conclusion, the AHP system has great potential to reduce energy consumption, greenhouse gas (GHG) emissions, and noxious gas emissions by providing economic benefits and an eco-friendly renewable energy source.

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