Chinese Name: Energy of Chemotactic Heterotrophic Microorganism: Carbon source produced by oxidative decomposition of organic matter: directly derived from organic carbon compounds, including introduction, classification and introduction of most bacteria in nature. The energy and carbon source of chemoheterotrophic microorganisms come from organic matter, energy comes from oxidative decomposition of organic matter, ATP is produced through oxidative phosphorylation, and carbon source comes directly from organic carbon compounds. It includes most bacteria in nature, all actinomycetes, fungi and protozoa. According to the classification of ecological habits, microorganisms can be divided into saprophytic and parasitic types. 1. Saprophytic type obtains nutrients from inanimate organic matter. Some molds and bacteria that cause food spoilage belong to this type. Such as Fusobacterium, Mucor, Rhizopus, Aspergillus, etc. Parasitic microorganisms are called parasites because they must live in living organisms and get nutrients from their hosts. Parasitism can be divided into absolute parasitism and facultative parasitism. If you can only live in living organisms, it is called absolute parasitism. They are pathogenic microorganisms that cause human, animal, plant and microbial diseases, such as viruses, phages and rickettsia. Some microorganisms can live on living organisms, grow on dead organic residues and grow on artificial media. Most pathogenic microorganisms belong to facultative parasitic microorganisms, such as Escherichia coli, which are ubiquitous in human and animal intestines. It is parasitic when living in human and animal intestines, excreted with feces, and saprophytic in water, soil and feces. Another example is that the mycelia of pythium melongena, which causes fruit rot, can invade the germ base of fruit tree seedlings for parasitism, or it can rot in the soil for a long time. The division of the above nutritional types is not absolute, but only determined according to the main aspects. Most heterotrophs can also absorb and utilize CO2, which can be added to pyruvic acid to generate oxaloacetic acid, which is a common reaction in heterotrophs. Therefore, the standard to distinguish heterotrophic microorganisms from autotrophic microorganisms is not whether CO2 can be used, but whether CO2 can be used as the only carbon source or the main carbon source. There are some transitional types between autotrophic and heterotrophic, and between light energy type and chemical energy type. For example, hydrogen bacteria is a facultative autotrophic microorganism, which lives autotrophic in a completely inorganic environment, obtains energy through hydrogen oxidation, and reduces CO2 to cellular substances. But if there is organic matter in the environment, it can be directly used for heterotrophic life.