**3.3 Photosynthetic bacteria**

Phototropic or photosynthetic bacteria are a group of self-supporting and independent microorganisms. By using soil heat and sunlight as a source of energy, these bacteria synthesize beneficial substances from harmful gases such as hydrogen sulphide and/or organic matter and root secretions. Plant development and growthpromoting substances such as nucleic acids, amino acids, sugars, and bioactive substances are all developed by these microbes. According to Prescott et al. [33], the metabolites developed by these microbes are absorbed directly into plants and act as substrates for increasing useful populations.
