RESUMO
Solid-state cultivation is a promising technology for algal biomass production, achieving high productivities without the need for dewatering. However, such systems have suffered from high evaporation, and capital costs. Here is described a hydrogel photobioreactor (hPBR) with the aim of reducing water demand in solid-state cultivations. Two designs are described with "Design A" offering better humidity control overgrowth conditions. A biomass productivity of 2.41gm-2d-1, and 2.87gm-2d-1 when using physically crosslinked poly(vinyl alcohol) (pPVA) and chemically crosslinked PVA (cPVA) respectively were achieved with Chlorella vulgaris with a water demand around 0.44â¯kg g-1 of biomass. Over the 23â¯days of growth, the lipid content increased from 18.9â¯% to 56.6â¯% and 13.8â¯% to 43.2â¯% for pPVA and cPVA respectively, and the chlorophyll content decreased by more than 81â¯%. However, cell viability stayed high at over 98â¯% and surface coverage analysis showed good coverage of the gel surface.