Long‐term biofouling formation mediated by extracellular proteins in Nannochloropsis gaditana microalga cultures at different medium N/P ratios

• Published in: Biotechnology and bioengineering Vol. 118; no. 3; pp. 1152 - 1165
• Main Authors: Soriano‐Jerez, Y., López‐Rosales, L., Cerón‐García, M. C., Sánchez‐Mirón, A., Gallardo‐Rodríguez, J. J., García‐Camacho, F., Molina‐Grima, E.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.03.2021
• Subjects: Adhesion; Algae; Algal Proteins - chemistry; Algal Proteins - metabolism; Aquatic microorganisms; Biofouling; Borosilicate glass; Bovine serum albumin; Cell adhesion; Cell adhesion & migration; Cell culture; Coated Materials, Biocompatible - chemistry; Coatings; extracellular organic substances; extracellular proteins; Hydrogels; Hydrogels - chemistry; Hydrophobicity; Macromolecules; microalgae; Microalgae - growth & development; N/P ratio; Nannochloropsis gaditana; Nanoparticles; Polyethylene; Polyethylene terephthalate; Polymethyl methacrylate; Polymethylmethacrylate; Polystyrene; Polystyrene resins; Proteins; Release agents; Serum albumin; Serum Albumin, Bovine - chemistry; Stramenopiles - growth & development; Surface Properties; N/P ratio; microalgae; extracellular proteins; extracellular organic substances; cell adhesion
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.27632

Biofouling represents an important limitation in photobioreactor cultures. The biofouling propensity of different materials (polystyrene, borosilicate glass, polymethyl methacrylate, and polyethylene terephthalate glycol‐modified) and coatings (two spray‐applied and nanoparticle‐based superhydrophobic coatings and a hydrogel‐based fouling release coating) was evaluated by means of a short‐term protein test, using bovine serum albumin (BSA) as a model protein, and by the long‐term culture of the marine microalga Nannochloropsis gaditana under practical conditions. The results from both methods were similar, confirming that the BSA test predicts microalgal biofouling on surfaces exposed to microalgae cultures whose cells secrete macromolecules, such as proteins, with a high capacity for forming a conditioning film before cell adhesion. The hydrogel‐based coating showed significantly reduced BSA and N. gaditana adhesion, whereas the other surfaces failed to control biofouling. Microalgal biofouling was associated with an increased concentration of sticky extracellular proteins at low N/P ratios (below 15).