TY - JOUR
T1 - Comparison of batch, fed-batch and continuous operation modes for scalable polyhydroxyalkanoate (PHA) production and carbon sequestration from phenol
AU - Tao, Qiuyue
AU - Huang, Heyun
AU - Yang, Mingfeng
AU - Zou, Yuqi
AU - Harder, Marie K.
AU - Yan, Qun
AU - Liang, Bo
AU - Ntaikou, Ioanna
AU - Antonopoulou, Georgia
AU - Lyberatos, Gerasimos
AU - Zhang, Yi
N1 - Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/3/15
Y1 - 2024/3/15
N2 - Polyhydroxyalkanoates (PHA) are biodegradable intracellular polymers, and a renewable alternative to conventional plastics. To reduce PHA's cost, this study combined an unconventional carbon source, i.e. a toxic aromatics phenol, with an acclimated consortium, to develop a scalable PHA production process. The resultant process performance was systematically compared across three operational modes: batch, fed-batch, and continuous. Phenol toxicity caused inhibition in the batch mode, reducing the PHA synthesis rate but resulting in a high PHA content in cells (PHA% > 50 %). Fed-batch feeding alleviated such inhibition, facilitating a high PHA titer and yield from the substrate. Interestingly, a higher feeding rate in the fed-batch reactor improved its performance, probably by providing a suitable food-to-microbe ratio for the biomass. Using a continuous mode also reduced phenol toxicity, but resulted in more synthesis of non-PHA cellular materials (NPCM). The difference might have been caused by different metabolic states and the presence of intermediates in the reactors. Comparing all 14 conditions under the three modes, feeding phenol more gradually tended to channel substrate away from PHA to NPCM synthesis. The volumetric productivity generally ranged from 3 to 12 mg L−1 min−1, while the biomass productivity was between 2 and 11 mg g initial CDW−1 min−1. A 3-stage, production-harvest and starvation-production process was then designed to simulate real industrialized manufacturing, where the operational modes had a long-term effect on biomass' productivity. Fed-batch mode performed the best, as it fixed 1/3 of phenol's organic carbon in PHA product, suggesting high potential for future application.
AB - Polyhydroxyalkanoates (PHA) are biodegradable intracellular polymers, and a renewable alternative to conventional plastics. To reduce PHA's cost, this study combined an unconventional carbon source, i.e. a toxic aromatics phenol, with an acclimated consortium, to develop a scalable PHA production process. The resultant process performance was systematically compared across three operational modes: batch, fed-batch, and continuous. Phenol toxicity caused inhibition in the batch mode, reducing the PHA synthesis rate but resulting in a high PHA content in cells (PHA% > 50 %). Fed-batch feeding alleviated such inhibition, facilitating a high PHA titer and yield from the substrate. Interestingly, a higher feeding rate in the fed-batch reactor improved its performance, probably by providing a suitable food-to-microbe ratio for the biomass. Using a continuous mode also reduced phenol toxicity, but resulted in more synthesis of non-PHA cellular materials (NPCM). The difference might have been caused by different metabolic states and the presence of intermediates in the reactors. Comparing all 14 conditions under the three modes, feeding phenol more gradually tended to channel substrate away from PHA to NPCM synthesis. The volumetric productivity generally ranged from 3 to 12 mg L−1 min−1, while the biomass productivity was between 2 and 11 mg g initial CDW−1 min−1. A 3-stage, production-harvest and starvation-production process was then designed to simulate real industrialized manufacturing, where the operational modes had a long-term effect on biomass' productivity. Fed-batch mode performed the best, as it fixed 1/3 of phenol's organic carbon in PHA product, suggesting high potential for future application.
KW - Consortium
KW - Operation mode
KW - Phenol
KW - Polyhydroxyalkanoate (PHA)
KW - Productivity
UR - http://www.scopus.com/inward/record.url?scp=85187992028&partnerID=8YFLogxK
U2 - 10.1016/j.jwpe.2024.105147
DO - 10.1016/j.jwpe.2024.105147
M3 - Article
AN - SCOPUS:85187992028
SN - 2214-7144
VL - 60
JO - Journal of Water Process Engineering
JF - Journal of Water Process Engineering
M1 - 105147
ER -