[P003] Poster

12:10 PM - 1:00 PM JST(3:10 AM - 4:00 AM UTC)

[P02-261] Enhanced PHA Production from Waste Glycerol by Paraburkholderia sp. through Optimized Fed-Batch Strategies

○Gayeon Hwang^1,2, Hyun-Hee Cho¹, Tae-Rim Choi¹, Jong-Min Jeon¹, Sang-Hyoun Kim², Shin Sik Choi³, Jeong-Jun Yoon¹ (1. Korea Institute of Industrial Technology (Korea), 2. Yonsei University (Korea), 3. Elegslab (Korea))

Keywords:

Paraburkholderia,Polyhydroxyalkanoates,Waste glycerol,Fed-Batch,Biomass

The increasing consumption of petroleum-based plastics has intensified environmental concerns and accelerated the depletion of fossil resources, leading to growing interest in biodegradable bioplastics such as polyhydroxyalkanoates (PHA). However, the commercialization of PHA remains limited due to high production costs and low production efficiency. In particular, the cost of carbon sources represents a significant portion of the overall production cost. Waste glycerol, a byproduct generated during biodiesel production, has attracted attention as a low-cost carbon source that can potentially improve the economic feasibility of PHA production. In this study, the PHA-producing strain Paraburkholderia sp. was cultivated using pure glycerol and crude glycerol as carbon sources to evaluate PHA production under batch and fed-batch cultivation conditions. In flask-scale batch cultivation, after 48h of incubation, the strain produced 3.3g/L of dry cell weight (DCW) with 75.49% PHB content using pure glycerol, while crude glycerol resulted in 2.25g/L DCW with 78.32% PHB content. When flask-scale fed-batch cultivation was performed with additional glycerol feeding at 48 h and 72 h, biomass accumulation slightly increased while maintaining PHB accumulation, reaching 3.4 g/L DCW with 78.31% PHB using pure glycerol and 2.8g/L DCW with 78.95% PHB using crude glycerol. Scale-up cultivation in a 4L fermenter initially showed limited biomass accumulation, achieving 5.76g/L DCW with 74.03% PHB content after 48 h. To improve production performance, the culture medium and feeding strategy were redesigned, and a two-step fed-batch strategy separating the cell growth phase and the PHB production phase was implemented. As a result, high cell density fermentation was achieved after 72h, producing 37.2g/L DCW with 64.86% PHB content using pure glycerol and 24.66g/L DCW with 41.08% PHB content using crude glycerol. Under optimized fed-batch conditions, the process achieved a PHB titer of 24.1g/L, demonstrating a significant improvement in PHA productivity. These results demonstrate that optimizing fed-batch strategies can significantly enhance PHA production using waste glycerol and highlight the potential for converting biodiesel byproducts into value-added biopolymers, contributing to the development of economically feasible and sustainable bioplastic production processes. This work was supported by the Technology Innovation Program [grant number: RS-2025-02310257] funded by the Ministry of Trade, Industry & Resources (MOTIR, Korea), and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [RS-2026-25474153].