<P><B>Abstract</B></P> <P>Anaerobic digestion is an established technology to produce renewable energy as methane-rich biogas for which microalgae are a suitable substrate. Besides biogas production, anaerobic digestion of microalgae generates an effluent rich in nutrients, so-called digestate, that can be used as a growth medium for microalgal cultures, with the potential for a closed nutrient loop and sustainable bioenergy facility. In this study, the methane potential and nutrient mobilization of the microalga <I>Scenedemus dimorphus</I> was evaluated under continuous conditions. The suitability of using the digestate as culture medium was also evaluated. The results show that <I>S. dimorphus</I> is a suitable substrate for anaerobic digestion with an average methane yield of 199 mL g<SUP>−1</SUP> VS. The low level of phosphorus in digestate did not limit algae growth when used as culture medium. The potential of liquid digestate as a superior culture medium rather than inorganic medium was demonstrated.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A closed nutrient loop for microalgal biogas and biomass production was developed. </LI> <LI> Up to 199 mL methane g<SUP>−1</SUP> VS was achieved without any pre-treatment of algal feed. </LI> <LI> Nutrient-rich digestate was effectively recycled for repeat algal biomass production. </LI> <LI> 36× dilution of liquid digestate achieved best results, superior to inorganic medium. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>