Actinomycetes in Environmental Applications

Abstract

The presence of soil actinomycetes induces plant health by persuading plant growth and development by producing phytohormones. Endophytic actinobacteria such as Actinoplanes, Micromonospora, and Nocardiopsis are the major producers of important phytohormones like indole-3-pyruvic acid (IPYA) and indole-3-acetic acid, whose main function lies in controlling gene regulation and in coordinating cell growth. Describing the microbially produced phytohormone is extremely difficult compared to the phytohormones produced by the host organisms. However, in vitro produced compounds by root colonizing actinobacteria dictate which microorganism is suitable to maintain plant health. Soil actinomycetes, especially Streptomyces, usually enhance the nutrient absorption capabilities of plants along with the growth of rhizobia provided with the soil nutrients. Composting with biomass enzymatic hydrolysis may help to alter the physicochemical and biological properties of the soil's nature. This compost can be easily prepared using consortia of microorganisms, and the process involves rapid mixing of different groups of organisms, especially bacteria belonging to actinomycetes. Other unique environments where actinobacteria occur include fungus-farming ants, beewolf wasps offspring protection, and bioweathering of rock minerals. The examples presented illustrate how diverse actinobacteria can occur in different environments. Genetic methods have also revealed that only a small fraction of these actinbacterial functions are known.