Question

Short / Long answer type questions.
Write a short note on bacterial nutrition.

Answer 1

The bacterial structure is lack chlorophyll and unable to synthesize organic compounds which they need as food from simple inorganic substances. They obtain these from the external sources.

Hence the bacteria comes under the category of heterotrophic plants. However, there are some bacteria which are able to synthesize organic compounds necessary for their structure and metabolism from simple inorganic compounds, these are called Autotrophic bacteria. The latter live on a strictly inorganic diet. The autotrophic bacteria resemble green plants in their mode of nutrition but with a difference.

The green plants utilize water as one of the raw materials in photosynthesis (food manufacturing process). The autotrophic bacteria, in contrast, use other compounds of hydrogen such as hydrogen sulfide (H${}_2$S) and methane (CH${}_4$) and not water with the result that no oxygen is evolved as a by-product in the bacterial food manufacturing process.

The energy used in this case in either obtained from the sunlight (photosynthetic bacteria) or chemically by the oxidation of some inorganic substances present in the environment such as iron, sulfur, nitrogen compounds (Chemosynthetic bacteria).