Characterising the structure of photosynthetic biofilms using fluid dynamic gauging

Abstract

A new configuration of the fluid dynamic gauging technique for measuring soft layers on surfaces was used to monitor the growth of a cyanobacterium, Synechococcus sp. WH 5701, on stainless steel (SS), glass and an indium tin oxide (ITO) on a polyethylene terephthalate (PET) substratum. The biofilm thickness increased steadily over 4 weeks and exhibited noticeable changes in microstructure and strength. The biofilms all exhibited a two-layer structure, with a compact layer next to the substratum and a loose layer above. Biofilms on ITO or SS exhibited cohesive failure when removed by fluid shear whereas those on glass exhibited adhesive failure. The technique is able to elucidate various aspects of biofilm behaviour, as illustrated by the action of a biocide (NaOCl) on a mature biofilm.

Experimental investigation of interactions between the temperature field and biofouling in a synthetic treated sewage stream

“…Due to the difference in bacteria, nutrient, material, and particularly the temperature used in these other studies, no comparisons can be made beyond the order of magnitude. Observation of the biofilm structure at the microscopic level indicated that it consisted of a dense layer of organisms at the wall, with a softer, less-compacted layer beyond in contact with the flowing solution, similar to the structures reported by Salley et al (2012) for cyanobacterial biofilms growing on SS and other substrata.…”

Biophotovoltaics: oxygenic photosynthetic organisms in the world of bioelectrochemical systems

“…24 Conversely, DEET generally yields higher power densities than IEET-driven systems, but requires close physical contact between cellular components of the electron transfer pathway and the electrode. Cultivation of biolms directly onto electrode surfaces is critical for effectively exploiting DEET activities [39][40][41][42][43] and improving our understanding of the factors governing biolm generation and morphology will be very helpful in this regard.…”

Assessing the Impact of Germination and Sporulation Conditions on the Adhesion of Bacillus Spores to Glass and Stainless Steel by Fluid Dynamic Gauging

“…The FDG configuration used in this study is identical to that used by Salley and others () to investigate the strength and structure of photosynthetic biofilms. Detailed descriptions of the operation and analysis of FDG are given by Gordon and others () and Salley and others (). In brief, liquid is ejected from a vertical convergent nozzle located a small distance (the clearance, h , see Figure S2) above the test surface.…”