Autotrophic type refers to the metabolic type in which organisms can directly convert inorganic substances absorbed from the external environment into their own substances and store energy during assimilation. Heterotrophic type refers to the metabolic type in which organisms can not produce their own organic matter during assimilation, but can only absorb ready-made organic matter to maintain their lives.
Autotrophic species
An organism that can obtain nutrients and energy needed for its own life activities from the process of synthesizing organic matter from inorganic substances. Green plants, such as algae, mosses, ferns and seed plants, rely on their unique chloroplasts and use solar energy to synthesize organic substances from CO2 and water to feed themselves.
Some chemically synthetic bacteria, such as nitrifying bacteria, sulfur bacteria, iron bacteria, etc. , can oxidize inorganic substances, using the energy released by oxidation to make the required nutrients.
Heterotrophic aerobic type
This kind of bacteria is the main member of the bacterial family, with the largest variety and quantity, such as Bacillus subtilis, common pathogenic bacteria and most other bacteria. From the aspect of assimilation, it can be divided into saprophytic and parasitic according to its habitat and the way of obtaining nutrients.
There are intermediate types between saprophytic and parasitic, which can be saprophytic or parasitic. For example, there are two stages in the life cycle of B. Bacteriouorus: parasitism and saprophy.
From the perspective of alienation, this kind of bacteria is aerobic and must live in an aerobic environment. Molecular oxygen is the final electron acceptor in the process of productivity metabolism, and carries out aerobic respiration. Vibration, stirring or ventilation are needed to provide sufficient oxygen during culture.