Arthrospira platensis Cultivation in a Bench-Scale Helical Tubular Photobioreactor

Alessandro Alberto Casazza,Leonie Asfora Sarubbo,Ricardo Pinheiro De Souza Oliveira,Milena Fernandes Da Silva,Charles Bronzo Barbosa Farias,Carlo Solisio,Attilio Converti

doi:10.3390/app12031311

Abstract

Cultivations of Arthrospira platensis were carried out to evaluate the CO2 capture capacity of this cyanobacterium under bench-scale conditions. For this purpose, the influence of light intensity on the microbial growth and the photosynthetic efficiency has been investigated in a helical photobioreactor. Five cultivations were performed at different photosynthetic photon flux densities (23 ≤ PPFD ≤ 225 µmol photons m−2 s−1) by fed-batch pulse-feeding pure carbon dioxide from a cylinder into the helicoidal photobioreactor. In particular, a range of PPFD (82–190 µmol photons m−2 s−1) was identified in which biomass concentration reached values (9–11 gDW L−1) significantly higher than those reported in the literature for other configurations of closed photobioreactors. Furthermore, as A. platensis suspensions behave as Newtonian and non-Newtonian (pseudoplastic) fluids at very low and high biomass concentrations, respectively, a flow analysis was carried out for evaluating the most suitable mixing conditions depending on growth. The results obtained in this study appear to be very promising and suggest the use of this helicoidal photobioreactor configuration to reduce CO2 emissions from industrial gaseous effluents.

Highlights

Nowadays, microalgal mass cultivation in closed photobioreactors has attracted much interest [1]
It was possible to verify the influence of this variable on both the start-up profile and the pseudo-steady state biomass concentration (Xm ), cell productivity (PX ), and photosynthetic efficiency (PE) of this system
The results obtained in this study appear very promising and suggest the use of this helical photobioreactor configuration to reduce CO2 emissions from industrial gaseous effluents

Summary

Introduction

Microalgal mass cultivation in closed photobioreactors has attracted much interest [1]. A substantial portion of them deals with “Arthrospira platensis cultivation and closed photobioreactors” (215 scientific articles). Since this topic is an active and expanding field of research, targeted studies in this area deserve further investigation. In this regard, intense research has been carried out on plant engineering to optimize the production system as well as on microbiological aspects to improve culture productivity through the isolation, selection, and genetic transformation of strains, with the goal of expanding the range of competitive high-value microalgal compounds [2,3,4,5]. The achievement of high productivity in microalgal mass with minimum operating costs is, fundamental to reduce the cost of valuable products and to broaden the commercial utilization of microalgae [6]

Methods

Results

Conclusion