Conditions required for bacterial growth and therefore their reproduction are referred to as Extrinsic and Intrinsic factors. Bacteria can grow anywhere in the world including animals and plants, depending on their characteristic, type and so on.
Knowing that, it seems like bacteria can grow everywhere once they have correct conditions.
However there are a lot of factors that can affect bacterial growth. The factors affecting bacterial growth are the internal and external conditions of the bacterial host.
These factors are known as Extrinsic and Intrinsic factors.
Intrinsic factors
The factors inside of the food (i.e. whether food is a lemon or a piece of meat) in that dictate whether the bacteria might start to grow or not.
Intrinsic …show more content…
Therefore yeast and moulds spoil low pH foods such as fruits. [11]
2) Moisture Content Water is a very important factor in microbial growth, it is essential for microorganisms to grow in their preferable water content level. Different microorganisms need different water requirements which are described in terms of water activity (aw). e.g. yeast and moulds grow at aw of 0.80 and they grow at a higher range of aw than bacteria. [12]
3) Oxidation – reduction potential (Eh) This relates to a substrate loosing or gaining an electron (e-), therefore the Eh value is used to show how likely redox reaction will happen. Oxidation can be identified by more positive (+ve) electrical potential values, therefore reduction can be identified by more negative (-ve) electrical potential values. e.g. fruit juices Eh values reach + 300 (aerobic bacteria and moulds can spoil them) and rumen contents’ Eh value reaches about – 350 …show more content…
Mesophilic temperatures are perfect for human or animal parasites e.g. human parasites S.aureus or E.coli. [18] - Thermophilic temperatures relates to heat-loving microorganisms with a temperature range of 40 -85°C and the optimal temperature is 50°C. And the microorganisms associated with this group of temperature preferences would be those microorganisms present in canned foods e.g. Clostridium botulinum. [19]
2) Relative Humidity (R.H.) This factor refers to the water activity (aw) in the food or to the growth of microorganisms on the surface of the food. As the temperature reaches higher values, the R.H. value lowers down. [20]
3) The presence and the concentration of Gases in the environment There are four different classes of microorganisms that exist based on their need for oxygen (O2). - Aerobes are the class of microorganisms that need 21 % O2 to grow. e.g. Filamentous moulds, Legionella.
Knowing that, it seems like bacteria can grow everywhere once they have correct conditions.
However there are a lot of factors that can affect bacterial growth. The factors affecting bacterial growth are the internal and external conditions of the bacterial host.
These factors are known as Extrinsic and Intrinsic factors.
Intrinsic factors
The factors inside of the food (i.e. whether food is a lemon or a piece of meat) in that dictate whether the bacteria might start to grow or not.
Intrinsic …show more content…
Therefore yeast and moulds spoil low pH foods such as fruits. [11]
2) Moisture Content Water is a very important factor in microbial growth, it is essential for microorganisms to grow in their preferable water content level. Different microorganisms need different water requirements which are described in terms of water activity (aw). e.g. yeast and moulds grow at aw of 0.80 and they grow at a higher range of aw than bacteria. [12]
3) Oxidation – reduction potential (Eh) This relates to a substrate loosing or gaining an electron (e-), therefore the Eh value is used to show how likely redox reaction will happen. Oxidation can be identified by more positive (+ve) electrical potential values, therefore reduction can be identified by more negative (-ve) electrical potential values. e.g. fruit juices Eh values reach + 300 (aerobic bacteria and moulds can spoil them) and rumen contents’ Eh value reaches about – 350 …show more content…
Mesophilic temperatures are perfect for human or animal parasites e.g. human parasites S.aureus or E.coli. [18] - Thermophilic temperatures relates to heat-loving microorganisms with a temperature range of 40 -85°C and the optimal temperature is 50°C. And the microorganisms associated with this group of temperature preferences would be those microorganisms present in canned foods e.g. Clostridium botulinum. [19]
2) Relative Humidity (R.H.) This factor refers to the water activity (aw) in the food or to the growth of microorganisms on the surface of the food. As the temperature reaches higher values, the R.H. value lowers down. [20]
3) The presence and the concentration of Gases in the environment There are four different classes of microorganisms that exist based on their need for oxygen (O2). - Aerobes are the class of microorganisms that need 21 % O2 to grow. e.g. Filamentous moulds, Legionella.