Nutrition of bacteria
Nutrition is the process by which nutrients are acquired from the surrounding environment and are used in cellular activities. Bacteria need energy for their growth, maintenance and reproduction.
Bacterias are divided into two major groups on the basis of nutrition:
Heterotrophic bacteria
Autotrophic bacteria
Heterotrophic bacteria:
They cannot manufacture their food from simple inorganic substances. Most of the bacteria belong to this category.
There are following types of heterotrophic bacterias:
Saprophytic bacteria:
They get their food from the dead organic matter. Organic compounds are abundant in the soil in the form of dark colored material called humus. This material results from partial decay of plants and animals. Many soil-inhabiting bacteria have very extensive enzyme system, which is responsible for breakdown of complex substances of humus to simple substances. These simple substances are then absorbed by bacteria, which use them as a source of energy.
Parasitic bacteria:
They get their food from other living organisms. They may cause diseases in their host e.g., T.B. bacteria and typhoid bacteria.
Symbiotic bacteria:
They live in association with other organisms and both partners get benefit e.g., colon bacteria.
Autotrophic bacteria:
They can manufacture their food from simple inorganic substances. Some bacteria belong to this category. There are two types of autotrophic bacterias:
Photosynthetic bacteria
They have chlorophyll, which is different from the chlorophyll of green plants. It is dispersed in cytoplasm. During photosynthesis, these bacteria utilize hydrogen sulphids instead of water as a hydrogen source and release sulphur instead of oxygen.
Chemosynthestic bacteria
The oxidize inorganic compounds like ammonia, nitrate, sulphur or ferrous ions trap the energy produced during their activity.
Nutrition is the process by which nutrients are acquired from the surrounding environment and are used in cellular activities. Bacteria need energy for their growth, maintenance and reproduction.
Bacterias are divided into two major groups on the basis of nutrition:
Heterotrophic bacteria
Autotrophic bacteria
Heterotrophic bacteria:
They cannot manufacture their food from simple inorganic substances. Most of the bacteria belong to this category.
There are following types of heterotrophic bacterias:
Saprophytic bacteria:
They get their food from the dead organic matter. Organic compounds are abundant in the soil in the form of dark colored material called humus. This material results from partial decay of plants and animals. Many soil-inhabiting bacteria have very extensive enzyme system, which is responsible for breakdown of complex substances of humus to simple substances. These simple substances are then absorbed by bacteria, which use them as a source of energy.
Parasitic bacteria:
They get their food from other living organisms. They may cause diseases in their host e.g., T.B. bacteria and typhoid bacteria.
Symbiotic bacteria:
They live in association with other organisms and both partners get benefit e.g., colon bacteria.
Autotrophic bacteria:
They can manufacture their food from simple inorganic substances. Some bacteria belong to this category. There are two types of autotrophic bacterias:
Photosynthetic bacteria
They have chlorophyll, which is different from the chlorophyll of green plants. It is dispersed in cytoplasm. During photosynthesis, these bacteria utilize hydrogen sulphids instead of water as a hydrogen source and release sulphur instead of oxygen.
Chemosynthestic bacteria
The oxidize inorganic compounds like ammonia, nitrate, sulphur or ferrous ions trap the energy produced during their activity.
