Table 3.

Environmental studies performed on different biofilm platforms to evaluate the initial adhesion, biofilm formation, and treatment under defined shear conditions.

Platform	Field	Biofilm Stage	Study Aim	Hydrodynamics	Assay Time	Surface Material	Organisms	Concluding Remarks	References
Modified Robbins device	Drinking- water distribution systems	Biofilm formation	Investigate the combined impact of flow hydrodynamics and pipe material	0.13 and 0.24 Pa	100 days	Polyvinyl chloride Polypropylene Structured wall high-density polyethylene Solid wall high-density polyethylene	Natural flora present in drinking water	The biomass amount was greater for the biofilms formed at lower shear stress. The opportunistic pathogens have limited ability to propagate within biofilms under high shear conditions without protection (surface roughness).	[79]
	Water treatment	Biofilm formation	Evaluate the application of non-biocide release coatings as coated filters for biofouling prevention	Flow rate of 300 L h−1, corresponding to an average shear stress of 0.25 Pa	2 days	Polyurethane coating Polyurethane coating with incorporated Econea Polyurethane coating with grafted Econea	Enterococcus faecalis	Biocidal polyurethane-based surfaces were less prone to biofilm formation, with an average reduction of 60%, compared to pristine polyurethane.	[81]
Flow chamber	Man-made equipment (heat exchangers, ship hulls, and pipelines)	Biofilm formation	Study the influence of surface energy components on the adhesion and removal of fouling	9.8 × 10−4, 4.6 × 10−4, and 2.1 × 10−4 Pa	10 days	316 L Stainless steel Ni–P–TiO2–polytetrafluoroethylene nanocomposite coatings	Pseudomonas fluorescences Cobetia marina Vibrio alginolyticus	Coatings with the lowest ratio between the Lifshitz van der Waals apolar component and the electron donor component had the lowest bacterial adhesion or the highest bacterial removal.	[85,86]
Rotating cylinder reactor	Drinking- water distribution systems	Biofilm formation and treatment	Effect of chemical and mechanical stresses on single and dual- species biofilm removal	Biofilm formation: 1 Pa Treatment: 1–23 Pa	7 days	Polyvinyl chloride	Acinectobacter calcoaceticus Stenotrophomonas maltophilia	Dual species biofilms were the most susceptible to chemical and mechanical removal. Stenotrophomonas maltophilia biofilms demonstrated high tolerance to chemical and mechanical stress.	[80]
		Biofilm formation	Action of copper materials on biofilm formation and control by chemical and mechanical stress	0.1 Pa	7 days	Stainless steel Copper alloys (100, 96, and 57%)	Stenotrophomonas maltophilia	Chemical, mechanical, and combined shocks were not effective in biofilm control. Copper surfaces were found to reduce the number of non-damaged cells.	[87]
6-well microplates	Drinking- water distribution systems	Adhesion and biofilm formation	Influence of shear stress, temperature, and inoculation concentration on water-stressed Helicobacter pylori	0, 60, and 120 rpm corresponding to 0, 0.138, and 0.317 Pa	2, 6, 12, 24, 48, 96, and 192 h	304 stainless steel Polypropylene	Helicobacter pylori	High shear stresses negatively influenced the adhesion to the substrata. However, the temperature and inoculation concentration appeared to not affect adhesion.	[88]
12-well microplates	Marine environment	Biofilm formation	Effect of surface hydrophobicity on biofilm development by a filamentous cyanobacterium	Orbital shaking with a 25 mm diameter incubator at 185 rpm (average shear stress of 0.07 Pa)	3 weeks	Glass Perspex	Leptolyngbya mycoidea LEGE 06118	Higher biofilm growth was observed on perspex, the most hydrophobic surface.	[89]
			Effect of different marine coatings on biofilm formation by microfoulers	Orbital shaking with a 25 mm diameter incubator at 185 rpm (average shear rate of 40 s−1)	7 weeks	Epoxy-coated glass Silicone hydrogel coating	Cyanobium sp. LEGE 10375 Pseudoalteromonas tunicata (marine bacterium)	Epoxy-coated surface was effective in inhibiting biofilm formation at the initial stages, while silicone coating showed high antibiofilm efficacy during maturation. Silicone coating was less prone to biofilm formation. The efficacy of silicone may be dependent on the organism, while the performance of epoxy-coated surface was strongly influenced by a combined effect of surface and microorganism.	[82]
			Effect of different materials on biofilm structure		7 weeks	Glass Perspex Polystyrene Epoxy-coated glass Silicone hydrogel coating	Synechocystis salina LEGE 00041 Cyanobium sp. LEGE 06098 Cyanobium sp. LEGE 10375	Silicone coating was effective in inhibiting cyanobacterial biofilm formation. Cyanobacterial biofilms formed on silicone coating showed a lower percentage and size of empty spaces among all surfaces.	[70]
			Study the environmental compatibility of an innovative biocidal foul-release multifunctional coating		7 weeks	Polydimethylsiloxane Polydimethylsiloxane coating with grafted Econea	Pseudoalteromonas tunicata	Polydimethylsiloxane coating with grafted Econea was more effective in inhibiting biofilm formation than the bare polydimethylsiloxane (reductions of 77%, 60%, and 73% on biovolume, thickness, and substratum coverage, respectively). Long-lasting antifouling performances were observed in simulated and real scenarios.	[22]
			Effect of shear forces on biofilm development by filamentous cyanobacteria	Orbital shaking with a 25 mm diameter incubator at 40 rpm (average shear rate of 4 s−1) and 185 rpm (average shear rate of 40 s−1)	7 weeks	Glass Perspex	Nodosilinea sp. LEGE 06020 Nodosilinea sp. LEGE 06022 Unidentified filamentous Synechococcales LEGE 07185	Biofilm formation was higher under low shear conditions. The hydrodynamics was more effective on biofilm maturation than during initial cell adhesion. Different shear rates affected biofilm architecture.	[71]
			Effect of shear forces and surface hydrophobicity on biofilm development by coccoid cyanobacteria with different biofilm formation capacities		6 weeks	Glass Epoxy-coated glass	Synechocystis salina LEGE 00041 Cyanobium sp. LEGE 06097	Biofilms developed in both surfaces at lower shear conditions had a higher number of cells, wet weight, thickness, and chlorophyll a content. The impact of hydrodynamics was generally stronger than the impact of surface hydrophobicity. The antibiofilm performance of the polymeric coating was confirmed.	[90]
			Qualitative proteomic analyses of filamentous cyanobacterial biofilms formed under different shear rates		7 weeks	Glass Perspex	Nodosilinea sp. LEGE 06145 Nodosilinea sp. LEGE 0611	Biofilm formation was higher under low shear conditions. Biofilm development of Nodosilinea sp. LEGE 06145 was higher than LEGE 06119, but no significant differences were found between surfaces.	[91]
		Adhesion and biofilm formation	Potential of adhesion assays on the estimation of biofilm development behavior at different hydrodynamic conditions		Adhesion: 7.5 h Biofilm: 6 weeks	Glass Epoxy-coated glass	Synechocystis salina LEGE 00041 Synechocystis salina LEGE 06155 Cyanobium sp. LEGE 06097	For both adhesion and biofilm assays, the number of adhered cells was higher under low shear conditions. Higher biofilm development at 4 s−1 was confirmed by biofilm wet weight, thickness, and chlorophyll a content. Initial adhesion assays can be used to estimate marine biofilm development.	[92]
			Quantitative proteomic analyses of biofilms formed on different surfaces		7 weeks	Glass Perspex	Unidentified filamentous cyanobacterium LEGE 06007	After 7 weeks, high biofilm thickness was observed in biofilms formed at 4 s−1 on glass when compared to perspex. Differences in protein expression were more noticeable in biofilms formed under low shear conditions. Proteomic analysis revealed differentially expressed proteins between surfaces.	[93]