Induced Biofilm Cultivation Enhances Riboflavin Production by an Intertidally Derived Candida famata

The aim of the investigation was to ascertain if surface attachment of Candida famata and aeration enhanced riboflavin production. A newly designed polymethylmethacrylate (PMMA) conico-cylindrical flask (CCF) holding eight equidistantly spaced rectangular strips mounted radially on a circular disk allowed comparison of riboflavin production between CCFs with hydrophobic surface (PMMA-CCF), hydrophilic glass surface (GS-CCF), and 500-ml Erlenmeyer flask (EF). Riboflavin production (mg/l) increased from 12.79 to 289.96, from 54.44 to 238.14, and from 36.98 to 158.71 in the GS-CCF, EF, and PMMA-CCF, respectively, when C. famata was grown as biofilm-induced cultures in contrast to traditional planktonic culture. Production was correlated with biofilm formation and planktonic growth was suppressed in cultivations that allowed higher biofilm formation. Enhanced aeration increased riboflavin production in hydrophilic vessels. Temporal pattern of biofilm progression based on two-channel fluorescence detection of extracellular polymeric substances and whole cells in a confocal laser scanning microscope followed by application of PHLIP and ImageJ volume viewer software demonstrated early maturity of a well-developed, stable biofilm on glass in contrast to PMMA surface. A strong correlation between hydrophilic reactor surface, aeration, biofilm formation, and riboflavin production was established in C. famata. Biofilm culture is a new-found means to improve riboflavin production by C. famata.