Author(s)

Taoufik Hakim¹, Souad Lekchiri¹, Hassan Latrache^1*, Mohamed El Amine Afilal², Abdeslam Jaafari¹, Safae Tankiouine¹, Mostafa Ellouali¹, Hafida Zahir¹

¹Bioprocess and Biointerfaces Laboratory, Faculty of Sciences and Techniques, Sultan Moulay Slimane University, Beni Mellal, Morocco.
²Biochemistry and Biotechnology Laboratory, Mohamed First University, Oujda, Morocco.

To improve the start-up speed and efficiency of bioreactors, biofilm technology is sometimes used. This technology uses various types of materials to facilitate the adhesion of microorganisms. In this study, the surface characteristics of inert substrates and substrates after olive oil-mill wastewater (OMWW) conditioning film were evaluated to understand the impact of OMWW on adhesion as well as the most suitable material to optimize bacterial adhesion. Three common substrates made of different polymers were tested for bacterial adhesion before and after treatment with OMWW: PP (polypropylene), PET (Polyethylene terephthalate), and PVC (polyvinyl chloride). The surfaces’ physicochemical characteristics were studied by measuring the contact angle for the studied bacteria strain and the supports, before and after treatment with OMWW. Results of initial adhesion tests for untreated and treated supports showed differences in how bacterial cells adhered to substrates. Before treatment with OMWW, PVC and then PP showed a significant adhesion capacity, double that of PET [PVC: 1.58 × 10⁵ CFU/cm², PP: 1.48 × 10⁵ CFU/cm² and PET: 0.72 × 10⁵ CFU/cm²]. After treatment with OMWW, initial bacterial adhesion increased by 10⁶ (from 10⁵ CFU/cm² for untreated supports to 10¹¹ CFU/cm² for treated supports), and PET followed by PP demonstrated the highest adhesion capacity, 2 and 1.7 times more than PVC, respectively [PET: 1.39 × 10¹¹ CFU/cm², PP: 1.15 × 10¹¹ CFU/cm² and PVC: 0.67 × 10¹¹ CFU/cm²]. OMWW conditioning film affects the physicochemical characteristics of plastic supports, especially the donor electron character, and improves the initial adhesion of bacteria to substrates (10⁵ to 10¹¹ CFU/cm²). Therefore, surfaces’ physicochemical characteristics were important in the initial adhesion of the bacteria onto the support before and after treatment.

Conditioning Film, Initial Adhesion, Olive Oil-Mill Wastewater, Physicochemical Properties

Hakim, T. , Lekchiri, S. , Latrache, H. , El Amine Afilal, M. , Jaafari, A. , Tankiouine, S. , Ellouali, M. and Zahir, H. (2020) Study of Initial Adhesion of a Bacterium to Different Support Materials before and after Conditioning Film of Olive Oil-Mill Wastewater. Advances in Bioscience and Biotechnology, 11, 391-404. doi: 10.4236/abb.2020.118027.