A microbiologist is conducting a research project on chemolithoautotrophs. This means that the investigator is examining certain aspects of a bacterium that is a purple nonsulfur bacteria which depends on light. uses light as its energy source and carbon for organic compounds. can oxidize inorganic molecules such as ammonia and sulfur for energy. can use the energy from sunlight to build organic molecules from carbon dioxide. obtains carbon from organic molecules.

uses light as its energy source and carbon for organic compounds.

Explanation:

The purple non-sulfur bacteria which depends on light produces organic food  just like plants through the process of photosynthesis. The purple non-sulfur bacteria uses carbondioxide and water with sunlight produces oxygen and glucose which is an organic compound. So that's why purple non-sulfur bacteria is also known as phototrophic means organism that produces their own food through photosynthesis.

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.