| Congresso Brasileiro de Microbiologia 2023 | Resumo: 128-2 | ||||
Resumo:Buildings are continuously exposed to wear and tear from environmental factors and human activities. These pressures invariably lead to the formation of cracks that significantly reduce the lifespan of reinforced concrete structures. In response to this perennial challenge, advancements in the field of bioconcrete technologies have emerged. However, incorporating bacteria within the cementitious matrix, along with essential nutrients presents challenges. Bacteria viability is compromised when directly exposed to the matrix during production, and nutrients can interfere with cement hydration, weakening the matrix. To overcome these obstacles, an encapsulation approach is examined, involving the use of a protective delivery system for the bacteria and nutrients safeguarding them from the hostile environment inherent to the cementitious matrix. One potential delivery system is starch, which forms polymeric structures capable of trapping bacteria and nutrients for incorporation and serving as a carbon source for bacteria. This study aims to evaluate the potential of starch as a delivery system for bacteria and nutrients in cementitious matrices. Starch capsules were created using starch gel, starch powder, calcium nitrate, and bacterial spores, then dried overnight at 40°C. A thin layer of starch gel was applied to prevent hydration expansion. The rough and coated capsules had 5.4 mm and 5.5 mm of diameters, respectively, with a non-significant difference between the groups based on T-test analysis. Expansion evaluation over 20 hours showed a significant difference in area increase, with rough capsules demonstrating a 196.5% increase and coated capsules only 66.8%. Upon tearing, the coated capsules exhibited similar behavior to the rough capsules, indicating their potential for rapid crack filling within minutes, effectively preventing the ingress of deleterious compounds into the matrix. Notably, bacteria demonstrated consistent growth in the medium containing solely macerated capsules and the medium prepared with the same composition as the capsules. The coating gel layer proved efficient in preventing capsule expansion and releasing bacteria and nutrients during the concrete curing process, making it a viable and effective delivery system alternative. Overall, this work highlights the potential of starch as a promising delivery system for bacteria and nutrients in cementitious matrices, offering a solution to the challenges of direct incorporation. Palavras-chave: bioconcrete, starch capsules, encapsulation technology, delivery system Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Pesquisa e Desenvolvimento (CNPq) | |||||