<p>Phosphorus is an essential mineral for all living things, particularly plants. While phosphorus is a limited and non-renewable resource, global reserves of phosphorus are abundant. There are phosphate mines in more than 40 countries around the world, producing high-grade phosphate rock (27–36% P₂O₅), but low-grade phosphate rock (less than 27% P₂O₅) is neglected as phosphate rock waste (PRW). So, microbiological improvement of RPW grades is our main area of interest. Therefore, in <i>Vitro</i> biotreatment of RPW using <i>Streptomyces coelicoflavus</i> strain AUMC B- 535 was the main focus of this study. To improve the microbiological upgrade of RPW, the growth conditions of strain AUMC B- 535, including temperature, initial pH, incubation time, carbon source type, and UV radiation exposure time, were assessed. The strain grew well after 7&#xa0;days of cultivation in 1.0&#xa0;kg L⁻¹ of 14.9% P₂O₅ RPW using D-glucose as the carbon source. The optimal temperature was 35&#xa0;°C and the pH was 7 ± 0.2. UV rays with a wavelength of 254&#xa0;nm exposure for 3&#xa0;h leads to its activity. Biotreated RPW was found to contain six distinct layers under optimal growth conditions, whereas the control had only four layers. Also, the P₂O₅% rate increased by 14.9% to 15.38%. Technologies that are clean, efficient and affordable are in high demand worldwide. Green mineral beneficiation methods can benefit from the technology based on <i>Streptomyces</i> for treating PRW, as it can enhance the P₂O₅% grade of PRW by modifying the growth conditions of <i>Streptomyces</i>.</p>