Biomanufacturing of value-added bioproducts from liquid digestate of POME (LDP)-based media using Haematococcus lacustris (Girod-Chantrans) rostafinski

Massive palm oil production leads to the accumulation of liquid digestate of POME (LDP), which contains high levels of COD and other organic compounds. One potential alternative approach to treating this issue is through phycoremediation using Haematococcus lacustris , the highest producer of astaxanthin. Astaxanthin is a high-value keto-carotenoid pigment due to its notable antioxidant activity. However, cultivating this microalga is highly challenging, as determined by the stress applied. Therefore, in this study, we evaluated the effects of adding 1 g/L NaCl and high light intensities in H. lacustris cultivated in LDP-based media under continuous three stage cultivation system. Based on our study, low light intensity (3500 lux) produced higher biomass and carbon fixation rate than the other treatments (59.37 gCO/L/year). The treatment exposed to 10,000 lux yielded the highest cell density, carbohydrate content, chlorophyll-a, chlorophyll-b, total chlorophyll (90.17 ± 9.95 10´ cells/mL, 0.51 ± 0.03 g/L, 1.09 ± 0.14 mg/L, 0.48 ± 0.09 mg/L, and 1.57 ± 0.23 mg/L). Meanwhile, under 20,000 lux, it produced higher astaxanthin content than the other treatments (6.05 ± 0.68 mg/L, 6.72 ± 0.76 mg/g, and 0.67 ± 0.08). The growth pattern was also consistent with the kinetics modelling using Logistic, Richards, and Gompertz models. Moreover, based on microbial quality analysis, the biomass complies with the standards with TPC values <5 10· CFU/g and YMC <5 10µ CFU/g. Thus, the findings indicate that LDP-based cultivation of H. lacustris holds significant promise for further exploration to provide sufficient biomass for bioindustries applications integrated with wastewater remediation. © 2026 The Authors.