Mixotrophic Cultivation of Scenedesmus sp. in Rice Straw Hydrolysate for Protein-Rich Algal Biomass Production


  • Mai Huong T. Pham Faculty of Chemical Technology, Hanoi University of Industry (HaUI), 298 Cau Dien, Bac Tu Liem, Hanoi, Vietnam
  • Nham Tuat T. Nguyen Faculty of Natural Resources and Environment, Thai Nguyen University of Sciences (TNUS), Tan Thinh Ward, Thai Nguyen City, Thai Nguyen 250000, Vietnam
  • Van Gioi Ngo Faculty of Natural Resources and Environment, Thai Nguyen University of Sciences (TNUS), Tan Thinh Ward, Thai Nguyen City, Thai Nguyen 250000, Vietnam
  • Van Toan Lam Environment Faculty, Hanoi University of Natural Resource and Environment, No 41 A Phu Dien Road, Bac Tu Liem, Hanoi, Vietnam
  • Thu Uyen T. Bui Institute of Chemistry, Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam
  • Cam Van T. Do HaUI Institute of Technology, Hanoi University of Industry (HaUI), 298 Cau Dien, Bac Tu Liem, Hanoi, Vietnam
  • Thuan Dang Tran Institute of Chemistry, Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam




Scenedesmus sp., Rice straw, Carbon, Mixotrophic, Proteins


Rice straw is abundantly generated as a by-product of agriculture in Vietnam. However, the material mainly contains hemicellulose and cellulose, which can be hydrolyzed to reducing sugars as a carbon source for mixotrophic production of protein-rich microalgae biomass. In this study, rice straw was obtained from local farmer and transformed to hydrolysate via separated alkaline or acid and sequential alkaline-acid treatments to evaluate sugar conversion efficiency. The hydrolysate then was used as a carbon source for cultivation of Scenedesmus sp. via mixotrophic mode. Data revealed that pretreatment with H2SO4, NaOH and combined NaOH + H2SO4 yielded sugar conversion of 12 – 13%, 11 – 12% and 22%, respectively. Scenedesmus sp. displayed a good growth performance in both rice straw hydrolysates with and without supplement of nitrogen and phosphorous, reaching the maximal optical density of 1.5 Abs in culture medium of BG-11 with 10 – 50% v/v hydrolysate. The sugar utilization efficiency by Scenedesmus sp. was determined as 70 – 94%. The Scenedesmus sp. was assayed to be rich in protein with its content of up to 45% based on dry basis. The Scenedesmus sp. biomass is potential protein source for animal and aquafeed formulation. Our preliminary results demonstrated that recovery carbon from agricultural by-product for protein-rich material for novel food development in animal food and aquafeed industries is promising.


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