Integrated processing platform for the production, recovery and separation of bio-produced tellurium particles

• Te(IV) reduction maximized in TSB with late exponential phase addition. • Water:ethanol (1:1) mixture effectively separated TePs from cell debris. • The black layer exhibited high-purity Te (99%), confirmed by XRD. • TePs were monodisperse; particle size increased with incubation time. • A simple, eco-friendly platform integrates TePs production and recovery. In alignment with Circular Economy principles, the recovery and upcycling of Tellurium (Te) for the production of advanced sensors and particles for therapy and bioimaging bioimaging—particularly through bio-based strategies—has garnered significant interest. The bioproduction of tellurium-particles (TePs) offers an efficient and eco-friendly alternative to conventional hydrothermal and chemical processes. However, downstream processing (DSP), specifically the recovery and separation of TePs, remains a major challenge for the practical implementation of these biogenic approaches. Therefore, innovative, eco-friendly, and low-energy extraction are urgently needed to replace existing techniques that rely on energy-intensive processes or hazardous chemicals. This study presents a novel approach for the room-temperature biogenic production of TePs using strain Paenibacillus pabulis ALJ109b. The key lies in the process’s reliance solely on a nitrogen-enriched growth medium and the mid-to-late growth phase addition of Te(IV) to enhance TePs yields. Notably, our integrated and simple recovery strategy employs eco-friendly solvents for the efficient separation of TePs, ensuring a sustainable and scalable approach. Optimal bacterial growth and tellurite reduction were achieved with Trypticase Soy Broth when the metalloid was added during the late exponential phase (4 h), resulting in a 24 % reduction in Te(IV) concentration after 20 h. Various cell disruption methods were evaluated for the TePs recovery, with 3 min of sonication in water providing the most effective for particle release. Additionally, a 1:1 mixture of water and ethanol emerged as the most efficient solvent for separating TePs from cell debris. TePs recovered after 8 h of bacterial growth exhibited smaller and more stable aggregates compared to those recovered after 24 h. Low-intensity sonication had minimal effects on particle size and surface charge. These findings confirm the potential of P. pabulis ALJ109b for the biogenic production of TePs. Furthermore, the integration of low-cost and eco-friendly solvents in straightforward solid–liquid extraction processes provides a sustainable and efficient solution for cell lysis and recovering of these microparticles from bacterial biomass.