Chemosynthetic Autotrophs

Introduction

Chemosynthesis is a biological process in which molecules such as methane or carbon dioxide are converted into organic compounds such as hydrogen sulphide or hydrogen gas, which act as a source of energy. This process does not require sunlight. The microorganism which lives in dark areas uses chemosynthesis to produce their food. They are known as chemosynthetic autotrophs.

Chemosynthetic autotrophs are creatures that can synthesise their energy by the oxidation of inorganic chemicals such as sulphur nitrates, nitrites, and other similar compounds. The energy released through synthesis, during the oxidation step, is used to synthesise ATP molecules once more.

Chemosynthetic Organism

Chemosynthetic organisms are those which produce their food in the absence of light. Chemosynthetic organisms are of two types: chemosynthetic autotrophs and chemosynthetic heterotrophs.

Chemosynthetic heterotrophs are those organisms that cannot produce their own food. They obtain energy from the chemical processes which occur in their body. Good examples of chemosynthetic heterotrophs would be fungi, bacteria, humans and animals.

Chemosynthetic Autotrophs 

Chemosynthetic autotrophs are those organisms that produce their own food. These organisms include mostly bacteria such as Nitrosomonas, ferrooxidans, beggiatoa, T. novellus, T. neapolitanus.

Examples of Chemosynthetic Autotrophs

There are three types of chemosynthetic bacteria:

1. Nitrogen bacteria

Any bacteria that uses nitrogen molecules in their metabolic process is known as nitrogen bacterium. They use electrons of nitrogen molecules to make organic chemicals. The compounds they employ can have quite varied consequences on their habitat.

They are divided into three categories.

• Nitrifying bacteria- This bacteria lives in soils and converts ammonia into nitrites and nitrates. They are useful bacteria for the ecosystem because they convert ammonia into nitrate, which is essential for many plants because it produces amino acids
• Denitrifying bacteria- It consumes nitrate compounds to produce energy. These bacteria have a negative impact on the ecosystem, as they convert nitrate into a useless compound that cannot be consumed by animals or plants. They deplete the quality of the soil
• Nitrogen-fixing bacteria- it is an important bacterium for ecosystems, humans and agriculture. They convert atmospheric nitrogen into nitrates, which are used by plants to make proteins

1. Metal ion bacteria

These bacteria use metal to convert into organic matter for chemosynthesis, also known as iron bacteria. Bacteria consume metal ions dissolved in soil and water and convert them into insoluble matter, such as ferric ions.

1.  Sulphur bacteria

These bacteria consume hydrogen sulphide gas and produce sulphur elements as waste products.

Consumers of Chemosynthetic Bacteria

Chemosynthetic microorganisms can be found on or below the seafloor, as well as symbionts inside the bodies of other vent creatures. Snails, limpets, and scale worms feed in the microbial mat that covers the seafloor around vents, and other predators come to eat the grazers. Some crabs and fishes also eat these grazers, and these crabs and fishes are eaten by large fishes, octopuses, etc.

Importance of Chemosynthesis

Chemosynthesis is important for those who live in areas devoid of sunlight.

Chemosynthetic bacteria such as nitrogen-fixing bacteria are good for the ecosystem as they convert nitrogen gas into useful nitrates.

Chemoautotrophs convert non-living matter into living and useful matter.

Conclusion

Chemosynthesis and photosynthesis are two processes to produce food. Photosynthesis is a process used by photosynthetic organisms, which produce their food in the presence of sunlight. Chemosynthesis is a process of producing food by the process of oxidation in the absence of sunlight.

Chemosynthesis is done mostly by bacteria that live in extreme conditions and where sunlight cannot be reached. Examples of some bacteria are Nitrosomonas, Beggiatoa, etc. These are nitrogen-fixing bacteria, sulphur oxidising bacteria and iron-oxidising bacteria.