Application of purple phototrophic bacteria in a biofilm photobioreactor for single cell protein production: Biofilm vs suspended growth

Expanding mechanistic models to represent purple phototrophic bacteria enriched cultures growing outdoors

“…The obtained values (13-28 g COD•m -2 •d -1 considering only volatile solids) are in agreement with those commonly estimated from SCOD removal values (Hülsen et al, 2022b). These predicted productivities are difficult to determine experimentally if the wastewater has high solid contents, as additional measurements (e.g., pigments contents) are required to differentiate between solids as biomass and solids remaining from the influent (Hülsen et al, 2020). Therefore, the model predictions can be used to estimate the actual biomass fraction in the harvested solids, which in turn can be used to estimate the biomass composition and thus its final value (e.g., crude protein and ash contents when considering its application as SCP).…”

Potential of enriched phototrophic purple bacteria for H2 bioconversion into single cell protein

“…Journal Pre-proof contents in the biomass (showing the degree of biomass reduction) of 1.29±0.15 g COD biomass •g VSS -1 were obtained during the last five enrichment cycles, further confirming the culture stability. These values were slightly lower than those obtained in the parallel heterotrophic enrichment (1.48±0.10 g COD biomass •g VSS -1 ) and those previously reported for PPB with heterotrophic growth (1.35-1.96 g COD biomass •g VSS -1 ) (Alloul et al, 2019;Hülsen et al, 2020), but comparable with the degree of biomass reduction commonly reported for activated sludge biomass (1.2-1.6 g COD biomass •g -1 VSS) (Bullock et al, 1996). A stable N content (143±19 mg N•g VSS -1 ) was also observed during the last five enrichments.…”

Biotechnological Production of Sustainable Microbial Proteins from Agro-Industrial Residues and By-Products

“…Hülsen et al suggested using a biofilm photobioreactor to cultivate mixed culture phototrophic bacteria in pre-settled red meat processing wastewater as a potential way to reduce the harvesting cost substantially. Compared to suspended systems, the biofilm bioreactor's main disadvantage is its capital cost [67].…”