[Khoa học & Ứng dụng] Máy đo Hoạt độ nước EZ-200 và các yếu tố ảnh hưởng tới sự phát triển Vi sinh trong thực phẩm

Microorganisms are similar to more complex organisms in that they need a variety of materials from their environment to function and accomplish two primary goals--supply enough energy to manage their processes and extract building blocks to repair themselves or procreate. In addition to what they take in, microorganisms also thrive in particular environments. These environments vary as much as the organisms do themselves, and even the amount and distribution of elements in any particular environment can be very important. Scientists use this information to grow microorganisms in laboratories for experimentation.

All microorganisms need food. The food sources can vary, but the organisms primarily extract carbon and nitrogen from substances such as proteins, fats and carbohydrates. Some microorganisms seek out and absorb such particles. Others may perform chemical reactions with surrounding elements such as carbon dioxide to gain what they need, while still others can produce their own simple sugars through photosynthesis similar to plants. Nitrogen, which is used to synthesize proteins, can be taken from the surrounding atmosphere or from other organic matter.

In general, the higher the temperature, the more easily microorganisms can grow up to a certain point. Very high and very low temperatures both obstruct the enzyme processes microorganisms depend on to survive, but individual species of microorganisms have grown to prefer different levels of temperature. Scientists usually divide them into three different groups: psychrophiles, mesophiles and thermophiles. Psychrophiles prefer temperatures from 0 to 5 degrees Celsius; mesophiles like it in the middle, 20-45 degrees Celsius; and thermophiles like it hot, thriving in temperatures around or above 55 degrees.

pH Levels

Moisture