TY - JOUR
T1 - A strategic approach to apply bacterial substances for increasing metabolite productions of Euglena gracilis in the bioreactor
AU - Kim, Da Hee
AU - Kim, Jee Young
AU - Oh, Jeong Joo
AU - Jeon, Min Seo
AU - An, Hye Suck
AU - Jin, Cho Rok
AU - Choi, Yoon E.
N1 - Funding Information:
This study was supported by the Marine Biotechnology Program of the Korea Institute of Marine Science and Technology (KIMST) funded by the Ministry of Oceans and Fisheries (MOF) (No. 20170488). This work was also supported by NRF (National Research Foundation of Korea) Grant funded by the Korean Government (NRF-2019R1A2C2087449).
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2021/7
Y1 - 2021/7
N2 - Abstract: Bacterial extracellular polymeric substances (EPS) are promising materials that have a role in enhancing growth, metabolite production, and harvesting efficiency. However, the validity of the EPS effectiveness in scale-up cultivation of microalgae is still unknown. Therefore, in order to verify whether the bacterial metabolites work in the scale-up fermentation of microalgae, we conducted a bioreactor fermentation following the addition of bacterial EPS derived from the marine bacterium, Pseudoalteromonas sp., to Euglena gracilis. Various culture strategies (i.e., batch, glucose fed-batch, and glucose and EPS fed-batch) were conducted to maximize metabolite production of E. gracilis in scale-up cultivation. Consequently, biomass and paramylon concentrations in the continuous glucose and EPS-treated culture were enhanced by 3.0-fold and 4.2-fold (36.1 ± 1.4 g L−1 and 25.6 ± 0.1 g L−1), respectively, compared to the non-treated control (12.0 ± 0.3 g L−1 and 6.1 ± 0.1 g L−1). Also, the supplementation led to the enhanced concentrations of α-tocopherols and total fatty acids by 3.7-fold and 2.8-fold, respectively. The harvesting efficiency was enhanced in EPS-supplemented cultivation due to the flocculation of E. gracilis. To the best of our knowledge, this is the first study that verifies the effect of bacterial EPS in scale-up cultivation of microalgae. Also, our results showed the highest paramylon productivity than any other previous reports. The results obtained in this study showed that the scale-up cultivation of E. gracilis using bacterial EPS has the potential to be used as a platform to guide further increases in scale and in the industrial environment. Key points: Effect of EPS on Euglena gracilis fermentation was tested in bioreactor scale.EPS supplement was effective for the paramylon, α-tocopherol, and lipid production.EPS supplement induced the flocculation of E. gracilis.
AB - Abstract: Bacterial extracellular polymeric substances (EPS) are promising materials that have a role in enhancing growth, metabolite production, and harvesting efficiency. However, the validity of the EPS effectiveness in scale-up cultivation of microalgae is still unknown. Therefore, in order to verify whether the bacterial metabolites work in the scale-up fermentation of microalgae, we conducted a bioreactor fermentation following the addition of bacterial EPS derived from the marine bacterium, Pseudoalteromonas sp., to Euglena gracilis. Various culture strategies (i.e., batch, glucose fed-batch, and glucose and EPS fed-batch) were conducted to maximize metabolite production of E. gracilis in scale-up cultivation. Consequently, biomass and paramylon concentrations in the continuous glucose and EPS-treated culture were enhanced by 3.0-fold and 4.2-fold (36.1 ± 1.4 g L−1 and 25.6 ± 0.1 g L−1), respectively, compared to the non-treated control (12.0 ± 0.3 g L−1 and 6.1 ± 0.1 g L−1). Also, the supplementation led to the enhanced concentrations of α-tocopherols and total fatty acids by 3.7-fold and 2.8-fold, respectively. The harvesting efficiency was enhanced in EPS-supplemented cultivation due to the flocculation of E. gracilis. To the best of our knowledge, this is the first study that verifies the effect of bacterial EPS in scale-up cultivation of microalgae. Also, our results showed the highest paramylon productivity than any other previous reports. The results obtained in this study showed that the scale-up cultivation of E. gracilis using bacterial EPS has the potential to be used as a platform to guide further increases in scale and in the industrial environment. Key points: Effect of EPS on Euglena gracilis fermentation was tested in bioreactor scale.EPS supplement was effective for the paramylon, α-tocopherol, and lipid production.EPS supplement induced the flocculation of E. gracilis.
KW - Euglena gracilis
KW - Extracellular polymeric substances
KW - Fed-batch fermentation
KW - Harvesting
KW - Paramylon
UR - http://www.scopus.com/inward/record.url?scp=85108802380&partnerID=8YFLogxK
U2 - 10.1007/s00253-021-11412-w
DO - 10.1007/s00253-021-11412-w
M3 - Article
C2 - 34173846
AN - SCOPUS:85108802380
VL - 105
SP - 5395
EP - 5406
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
SN - 0175-7598
IS - 13
ER -
