Heterotrophic Pioneers Facilitate Phototrophic Biofilm Development

Abstract

Phototrophic biofilms are matrix-enclosed microbial communities, mainly driven by light energy. In this study, the successional changes in community composition of freshwater phototrophic biofilms growing on polycarbonate slides under different light intensities were investigated. The sequential changes in community composition during different developmental stages were examined by denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments in conjugation with sequencing and phylogenetic analysis. Biofilm development was monitored with subsurface light sensors. The development of these biofilms was clearly light dependent. It was shown that under high light conditions the initial colonizers of the substratum predominantly consisted of green algae, whereas at low light intensities, heterotrophic bacteria were the initial colonizers. Cluster analysis of DGGE banding patterns revealed a clear correlation in the community structure with the developmental phases of the biofilms. At all light intensities, filamentous cyanobacteria affiliated to Microcoleus vaginatus became dominant as the biofilms matured. It was shown that the initial colonization phase of the phototrophic biofilms is shorter on polycarbonate surfaces precolonized by heterotrophic bacteria.

Diversity and biomass accumulation in cultured phototrophic biofilms

“…The fast-growing green algae, Chlorococcum, Desmodesmus and Scenedesmus, are probably responsible for the shorter lag phase in biofilms grown at higher irradiances. This confirms findings from Roeselers et al (2007) on the pioneering role of Scenedesmus attachment to polycarbonate substrata in parallel experiments on Fiumicino WWTP biofilms.…”

Advanced nutrient removal from surface water by a consortium of attached microalgae and bacteria: A review

“…2a) (Ramanan et al, 2016). Roeselers et al (2007) reported that substrate precolonization by Betaproteobacteria accelerated the growth and adhesion of Microcoleus vaginatus to polycarbonate surfaces. Similarly, Park et al (2008) found that the addition of Brevundimonas sp.…”

Influence of phosphorus availability on the community structure and physiology of cultured biofilms

“…in the mid and late stages of biofilm colonization. It was likely that early colonizers changed the environmental conditions in the biofilms, and this change could facilitate the attachment of filamentous cyanobacteria (Roeselers et al, 2007). Previous studies also reported that filamentous cyanobacteria frequently prevailed in the cyanobacteria communities in low nutrient availability (Rejmankova and Komarkova, 2000) and extreme environments (Vincent et al, 1993).…”