Effects of Different Light Treatments on a Microbial Mat Photobioreactor

Abstract

One of the most exciting scientific innovations in fish feed and waste remediation systems has been the use of microbial mats for biomass production. This study aimed to improve productivity of biomass in an open microbial mat bioreactor. Biomass production was compared under fluorescent and light emitting diodes (LEDs) using 24 h photoperiod and similar radiance. Although the biomass production was similar under both treatments (1.8–2.0 g m-2 d-1) the power consumption of LED light treatment was 58.5% lower compared to fluorescent light treatment. The biomass productivity decreased significantly (0.5 g m-2 d-1) when pulsed LED lights were used. In addition, the effect of the different light regimes on microbial matt biodiversity was analyzed using phylogenetic analysis. In this open system, no significant differences were found at the class level. Overall, LED could potentially replace fluorescent lights in the production of microbial mats reducing annual costs significantly.