Life on earth is fueled by the powerful source of energy – the sun. But we may wonder how the deep sea communities make food in the absence of sunlight. Certain organisms are fueled not by the sun but by the oxidation of simple inorganic chemicals, such as sulfates or ammonia. These are referred to as chemosynthetic organisms.
Though different species use different ways, they all utilize energy released by chemical reactions to make food. Thus, chemosynthesis is a process of making food by which certain microbes create energy by some chemical reactions. Chemosynthesis is similar to photosynthesis in a way that both are processes by which organisms produce food. Thus chemosynthesis is the biological process of conversion of nutrients and carbon molecules into organic matter without using sunlight as source of energy.
Apart from the seafloor around hydrothermal vents found in the deep ocean floor, Chemosynthetic bacteria could be found in hot springs, cold seeps, whale carcasses and sunken ships. Some bacteria make organic matter by reducing sulphide or oxidizing methane. Bacteria at vent produce sugar, sulfur, and water by adding carbon dioxide and oxygen to oxidized hydrogen sulfide. Through process of chemosynthesis, carbohydrates are manufactured from carbon dioxide and water using chemical nutrients as energy source instead of sun light.
Many chemosynthetic micro-organs become food for other organisms in the ocean. Many often chemosynthetic micro-organisms are found to be in symbiotic relationships. Chemosynthesis indicates that not all food production depends on photosynthesis.