Development of a Porous Ceramic Bioreactor for the Sterile and Efficient Production of Microbial Inoculants and the Advancement of Resilient and Sustainable Agriculture

• Grant number: 25/11884-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2026
• End date: December 31, 2027
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Cauê Ribeiro de Oliveira
• Grantee: Mariana Govoni Brondi Wolf
• Host Institution: Embrapa Instrumentação Agropecuária. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). São Carlos , SP, Brazil

Abstract

The industrial production of microbial inoculants via solid-state fermentation (SSF) presents several limitations that may compromise product quality, including a high incidence of contamination, low spore recovery efficiency, and ethical and socioeconomic concerns related to the use of food-grade substrates for microbial cultivation. To address these challenges, this postdoctoral research project proposes the development of a porous ceramic bioreactor for the sterile and efficient cultivation of spore-forming microbial inoculants. The system will be designed to operate with a range of microorganisms-here exemplified by the fungus Trichoderma harzianum and the bacterium Bacillus subtilis, selected as model organisms to validate the proposed concept-with potential adaptability to other species. Importantly, the cultivation process will not rely on food-based substrates. The bioreactor will consist of a hollow, porous ceramic filter housed within an isolated chamber under a controlled internal atmosphere. A nutrient medium composed of biopolymers, agro-industrial residues, and other additives will be applied to the external surface of the filter, where microbial growth will occur. Following cultivation, spores immobilized within the culture matrix-which will also serve as a protective barrier during storage, transport, and post-application in the field-will be recovered using a compressed air stream, generating a material with potential for direct application as a bioinoculant. The proposed system integrates principles of sustainability, biosafety, circular economy, and innovation in bioprocess engineering, and is aligned with the United Nations Sustainable Development Goals (SDGs). Expected outcomes include the development of a functional bioreactor prototype, production of biomass with high viability and virulence, reduction of cross-contamination risks, elimination of food-grade substrates as growth media, efficient system reuse, and the generation of technical and scientific knowledge applicable to sustainable agriculture.