On-line Monitoring of Biomass and PHB in Methanotrophic Cultivation via Dissolved Oxygen and pH Signals
- 발행기관 서강대학교 일반대학원
- 지도교수 나정걸
- 발행년도 2026
- 학위수여년월 2026. 2
- 학위명 석사
- 학과 및 전공 일반대학원 화공생명공학과
- 실제URI http://www.dcollection.net/handler/sogang/000000082647
- UCI I804:11029-000000082647
- 본문언어 영어
- 저작권 논문은 저작권에 의해 보호받습니다.
초록(요약문)
In bioprocess engineering, the ability to monitor microbial growth and products in real time is essential for maintaining stable operations and improving overall process performance. However, conventional analytical tools are often costly, require complex calibration, and rely on time-consuming analysis, limiting their use in typical fermentation systems. To address these limitations, we developed a soft-sensing strategy that estimates biomass concentration and polyhydroxybutyrate (PHB) accumulation using dissolved oxygen and pH-stat based base addition signals, both routinely recorded in aerobic bioreactors. The method was applied to methane-fed cultures of Methylocystis sp. MJC1. Total biomass and non-PHB biomass were estimated through material-balance calculations using DO signals and ammonia solution additions. By combining these two, intracellular PHB content could be inferred in real time. Across various cultivation conditions, the model exhibited consistently good performance, with the DO-based total biomass estimation particularly accurate and stable. The algorithm developed herein provides a simple, robust, and cost-effective alternative to conventional methods, offering broad applicability not only to methane-based fermentations but also to a wide range of aerobic bioprocesses.
more목차
Contents 6
Abstract 7
List of figures 8
List of tables 10
1. Introduction 11
2. Theoretical background 14
2.1. Estimation of total cell concentration using DO signal 14
2.2. Estimation of non-PHB cell concentration and PHB using base pump operation 16
3. Materials and methods 18
3.1. Strain, media, and cultivation conditions 18
3.2. Analysis of cell mass, off-gas, and PHB 19
3.3. Real-time monitoring and data acquisition 20
4. Results and Discussion 21
4.1. Estimation of total cell concentration 21
4.2. Estimation of non-PHB cell concentration 25
4.3. Real-time estimation of cell concentration and PHB accumulation 26
5. Conclusion 32
6. References 34
