LAUSR

Attached cultivation system has emerged as a cost-effective approach for the cultivation of microalgae. However, few microalgae species are still restricted to grow as biofilm due to the lack of adhesive element known as extracellular polymeric substance (EPS). The main objective of our study is to develop a novel attached cultivation strategy for EPS-lacking microalgae, Scenedesmus sp. DDVG I. We also aimed to identify cost-effective substratum showing good performance for biofilm growth. The approach was experimentally studied by conditioning a variety of substrata with EPS derived on varying days from cyanobacteria, Limnothrix sp. DDVG II. The EPS-coated substrata were used for the attached cultivation system of Scenedesmus sp. Additionally, we compared the biochemical properties of the EPS matrix derived on varying days using different extraction methods, their performance on adhesion strength, and microalgal growth. As a result, rough substrata were highly prone to the colonization of the EPS matrix than the normal one. The EPS derived from 12-day-old Limnothrix sp. culture (EPS-12) showed the highest potential on adhesion strength. Rough substrata coated with EPS-12 showed the maximum growth of Scenedesmus sp. DDVG I as a biofilm. Among the rough substrata, rough polylactic acid (rPLA) sheet coated with EPS-12 was found to be the best substratum showing the highest adhesion capability of 94.60 ± 4.2% and the maximum aerial biomass productivity of 31.6 ± 1.20 g/m2/day. The results indicate that EPS-lacking Scenedesmus sp. can be cultured with the attached cultivation technique to improve its biomass productivity.