Improving energy efficiency of Bacillus velezensis broth microfiltration in tubular ceramic membrane by air sparging and turbulence promoter

Abstract

© 2019 Society of Chemical Industry BACKGROUND: Popularity of biocontrol has increased due to the growing environmental concerns and the demand for organic products. It is considered as a sustainable practice for efficient agricultural production. Microbial biopesticides offer environment-friendly biotechnological alternative to chemical control of plant diseases and pests. Due to its advantages in cell separation cross-flow microfiltration has emerged as a powerful alternative to the conventional separation methods. However, the flux enhancement remains to be addressed. This study has estimated the use of flux improvement techniques for biomass harvesting by microfiltration using tubular ceramic membranes. Investigated methods for flux enhancement were turbulence promoter, i.e. Kenics static mixer, two-phase flow (air sparging) and the combination of these two methods. RESULTS: Significant flux improvement coincides with a reduction in specific energy consumption, while at the same time Bacillus velezensis cells have retained viability and antibacterial activity. The highest values of flux and corresponding improvement, compared to the microfiltration without enhancement techniques, are obtained in the case of combining Kenics static mixer and two-phase flow (133.4 L m−2 h−1 and 502%). Flux improvement for air sparging was 134%, for turbulence promoter alone flux increase was 434%. CONCLUSION: The methods proposed herein have achieved effective flux enhancement for cell harvesting. The obtained results also suggest encouraging basis to promote large-scale economical production of biomass for biocontrol application. © 2019 Society of Chemical Industry.