Thermoactinomyces sacchari competent strain: Isolation from compost, selection and characterization for biotechnological use

Composting is an uncontrolled process of converting organic waste into a beneficial soil conditioner for agriculture. During this process, a diverse community of micro-organisms, including thermophilic bacteria and actinomycetes, plays an essential role in organic matter decomposition. These micro-organisms are capable of thriving at high temperatures, and have therefore received increasing attention due to their potential industrial applications such as biotechnology and bioremediation.This study aims to isolate competent thermophilic actinomycetes to control and optimize composting process. Samples were taken during the three phases of composting process characterized by temperature fluctuations. Classical identification, morphological and biochemical, of thermophilic actinomycetes strains was carried out to distinguish strains with interesting metabolic power. Selection pressure exerted by different temperatures (50 °C, 55 °C and 60 °C) on six competents strains led to the selection of a strain best suited to extreme composting conditions. Its taxonomic position was verified using molecular tools.This study, developed within a biological engineering framework, highlights the role of using the composting process in a controlled bioreactor, which can standardize physico-chemical and nutritional conditions to ensure composting reproducibility. Thermophilic strains, including Thermoactinomycetes Sacchari, form a consortium well adapted to the conditions imposed by the bioreactor.Thus, this study highlights the role that certain strains can play in the success of the composting process, particularly those that are still present in the active composting population.The isolation of Thermoactinomycetes sacchari strain provides some clues to the phenomenon of controlled composting boosted by a competent strain under industrial conditions. Thanks to its resistance to high osmotic pressures (20–60 g/L), a wide range of hydronium potentials (pH 5–10) and high temperatures, Thermoactinomycetes sacchari strain is a candidate for producing enzymes of biotechnological interest that can be exploited under the most rigorous industrial conditions. This strain could be the subject of research and development on the molecules produced by this microorganism, which has a wide range of biological activities.