What is the relationship between temperature and fungal growth?
Most of the research on temperature relationships for the fungi has been done in the food industry where heat is commonly used to prevent fungal growth. Much of this research involves wet heat, which is more effective than dry heat.
What are the factors that affect fungi growth?
Of course, temperature is also a crucial factor. Most of the research on temperature relationships for the fungi has been done in the food industry where heat is commonly used to prevent fungal growth. Much of this research involves wet heat, which is more effective than dry heat.
Why are some fungi more abundant in dry climates?
In hot dry climates, fewer species of fungi are present, both because of the lack of water and the high temperatures. Thus, thermophilic and xerophilic (dry tolerant) fungi are likely to be more abundant than in cooler wetter environments.
Why do I have so many fungi in my house?
Most fungi are mesophilic, and have growth optima within the temperature range that people find comfortable. This is why so many fungi appear when moisture enters our homes, schools, and work environments. Because of air conditioning and heating, mesophilic fungi flourish in occupied environments in all climates.
How is thermal death point determined?
Based on the growth of the bacteria the thermal death point can be estimated. The quadrant in which there is no growth is the temperature and the time required to destroy the bacteria.
What is an example of an application of thermal death point?
Thermal death time is how long it takes to kill a specific bacterium at a specific temperature. It was originally developed for food canning and has found applications in cosmetics, producing salmonella-free feeds for animals (e.g. poultry) and pharmaceuticals.
What factors influence whether a bacteria is vegetative?
In addition, the survival or inactivation of vegetative bacteria exposed to thermal treatments is influenced by many factors, such as growth conditions (temperature, time, composition of the growth medium), previous exposure to stresses, physicochemical characteristics of the treatment medium, and environmental ...
How does heat control microbial growth?
Heat can kill microbes by altering their membranes and denaturing proteins. The thermal death point (TDP) of a microorganism is the lowest temperature at which all microbes are killed in a 10-minute exposure.
Which bacteria has highest thermal death point?
Whereas Escherichia coli populations will be readily killed within 10 minutes at 212°F (100°C), spores of bacteria such as Bacillus subtilus and Clostridium perfringens will have a higher thermal death point, because a higher temperature is required to kill spores within 10 minutes.
Why is Bacillus subtilis heat resistant?
For B. subtilis strains, it has been demonstrated that the presence of a Tn1546 transposon is responsible for high-level heat resistance of the spores (Berendsen et al., 2016a). The presence of the Tn1546 transposon was assessed in nine strains of B. amyloliquefaciens and nine strains of B.
Are all bacteria and fungi destroyed during heat treatment?
of most bacteria, including food pathogens, spoilage bacteria, and the lactic acid bacteria used in vegetable fermentations, are readily destroyed by heating to 160°F (71°C), especially when the pH is low.
Why are bacterial spores heat resistant?
The ability of bacterial spores to withstand heat is known to be associated with a lowering of their water content. This partial dehydration is considered to be produced by reverse osmosis, with the pressure being applied by the cortex as it is growing.