Development of microfluidic systems for lipase production by Bacillus subtilis immobilized on alginate microparticles

Author(s)

Aline Furtado Oliveira

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2018-05-03

Examining board members

Lucimara Gaziola de la Torre; Rosiane Lopes da Cunha; Mariana Altenhofen da Silva; Juliana de Novais Schianti

• Advisor: Lucimara Gaziola de la Torre; Reinaldo Gaspar Bastos

Abstract

mmobilization methods of biocatalyst are important strategies for improving the bioprocess productivity. However, heterogeneous particles productions from conventional methods and the diffusional limitations from polymeric matrix are some points could be optimized in these systems. Microfluidics is a technology that can contribute on this area due to the monodisperse microparticles productions and the possibility to investigate the cellular responses into the microparticles. Therefore, the purpose of this project was to use the microfluidics for encapsulating and investigating the cell behavior of Bacillus subtilis inside of alginate microparticles. As challenge, to investigate the potential of these cells on lipase production, an enzyme of relevant biotechnological interest was selected. Thus, strategies for microchannels geometries, composition of continuous and dispersed phase for droplet generation and alginate gelation methods were studied for Bacillus subtilis encapsulation on microparticles. On these studies, an efficient encapsulation process was obtained using a cross-flow microfluidic system, with fluorocarbon oil to generate the droplets and alginate cross-linking via internal gelation. The bacteria growth in perfusion microbioreactor shows that microparticles alginate conditions were favorable, resulting in a high cell density that can be stimulated by the cell protection. In order to apply these microparticles on a laboratory scale, a double droplet microfluidic system allowed us to investigate lipase productivity between the cultivate manners with free cell, encapsulated by the conventional and microfluidics methods. Thus, the cultivation with immobilized bacteria in alginate microparticle showed a high cell density, the lipase productivity by this system was almost 3 times higher than the conditions of free and encapsulated cells by conventional method. Therefore, the microfluidic technology was efficient to encapsulate and investigate of cell behavior on alginate microparticles and apply them on submerged cultivate, which may contribute to the increase of productivity in bioprocesses (AU)

• FAPESP's process: 14/26814-7 - Encapsulation of microbial cells in microfluidic system aiming at development of biotechnological processes
• Grantee: Aline Furtado Oliveira
• Support Opportunities: Scholarships in Brazil - Doctorate