In order to get food, some bacteria are autotrophs and can synthesize the food they need. Autotrophic bacteria make food in two ways. An autotrophic bacterium can use solar energy to synthesize food like a plant. Others, such as autotrophic bacteria living in the depths of the ocean, can't use solar energy, but can only use energy in the environment to make food. Autotrophic bacteria use one of the above two methods, namely solar energy or chemical energy, to synthesize the food they need.
Some bacteria belong to heterotrophs and get food by consuming autotrophs or other heterotrophs. Heterotrophic bacteria can consume all kinds of food, from your favorite milk and meat to rotting leaves in the Woods.
Bacteria, like other living things, need stable energy to perform their functions, and energy comes from food. The process by which bacteria break down food and get energy from it is called respiration.
Most bacteria, like many other organisms, need oxygen to break down food. But some bacteria don't need oxygen to breathe at all. In fact, once oxygen appears in their environment, their end will come. For them, oxygen is fatal.
Sometimes the surrounding environment will become unfavorable to the growth of bacteria. For example, when food sources are lost or wastes toxic to bacteria are produced in the environment, some bacteria will form endospore and survive in these harsh environments.
Endospore is a small, round, thick-walled dormant cell formed in bacterial cells, which contains the genetic material and part of cytoplasm. Endospore can survive for many years because of its cold tolerance, high temperature tolerance, drought tolerance and strong resistance to harsh environment.
Endospores are very light-a gust of wind can blow them up and send them to a whole new place. If endospore falls into the right environment, it will germinate, and then bacteria will start to grow and multiply.