Early colonization stages of fabric carriers by two Chlorella strains

Microalgal biofilms are increasingly attracting attention as a cultivation platform for different biotechnological purposes. The initial adhesion of algae to a surface, one of the key factors for the formation of a biofilm, was analyzed by coupling image analysis techniques and mathematical modeling. Two isolated microalgae, Chlorella vulgaris ACUF_809 and Chlorella sp. ACUF_802, were identified by molecular techniques. Their health condition and biomass growth were measured using pulse amplitude modulated (PAM) fluorometry; the carrier colonization was studied by imaging analysis (Weka Segmentation) and measuring the green tones of the biofilm through CIELAB colorimetry. Structural features and biofilm vertical distribution were determined by multichannel confocal laser scanning microscopy (CLSM), and some parameters were aligned to the Gompertz model. Chlorella vulgaris ACUF_809 showed good adaptation to form biofilm on cotton fabric measured as high biomass growth reflected in the high F0 (0.42) and biofilm colonization through the CIELAB colorimetry (a*− 9.3), coverage area 32.3%, and average biofilm thickness (106.37 ± 47 μm). This work demonstrated the feasibility of C. vulgaris ACUF_809 and Chlorella sp. ACUF_802 biofilm formation on cotton fabric which potentially provides an alternative for cultivating and producing microalgae biomass.