음식물 쓰레기 유래 분리 미생물의 내산성 기반 바이오수소 생산성 향상 연구 = Enhancement of biohydrogen production based on acid tolerance of microorganisisms isolated from food waste

다국어 초록 (Multilingual Abstract)

Biohydrogen generation from food waste leachate (FWL) was investigated using microbial strains inherently tolerant to environments abundant in volatile fatty acids (VFAs), salts, and diverse inhibitory compounds. Strains were isolated from the anaerobic digesters of large-scale food waste treatment facilities (>100 tons/day) across South Korea to ensure exposure to representative food waste characteristics rather than the site-specific, varied characteristics of smaller plants.
Taxonomic identification revealed four isolated strains (IS): Paraclostridium bifermentans (IS #1), Clostridium perfringens (IS #2), Clostridium beijerinckii (IS #3), and Clostridium butyricum (IS #4). Among the four strains, P. bifermentans and C. beijerinckii exhibited 28% and 18% higher hydrogen production, respectively, than their type strains when cultivated with FWL. When FWL instead of reinforced clostridial medium (RCM) was used, the FWL-derived isolates showed 54% and 16% reductions in the inhibitory rates of hydrogen production compared to the Clostridium butyricum inoculum, indicating markedly enhanced resistance to inhibitory substrates. Subsequently, the best performing strain, P. bifermentans (IS #1), was selected for the acid-tolerance assays. Acid-tolerance assays using simulated FWL (0–50 g/L VFAs) confirmed its superior performance, with hydrogen productivity improvements of 244%, 145%, 171%, 260% at concentrations of 0, 30, 35, and 40 g/L, respectively.
The results demonstrated that microbial adaptation through evolutionary engineering enhances tolerance and productivity, providing a cost-effective strategy for scaling organic-waste-derived hydrogen production and offering a practical pathway for the commercialization of sustainable waste-to-energy technologies.

목차 (Table of Contents)

• ABSTRACT
• 1. Introduction 1
• 2. Materials and Methods 4
• 2.1. Isolation of strains from FWL 4
• 2.2. Batch test 7
• 2.3. Comparison of hydrogen productivity using FWL as the substrate 7
• 2.4. Comparison of acid tolerance under high volatile fatty acid (VFA) conditions 8
• 2.5. Metabolite analysis 9
• 3. Results and Discussion 10
• 3.1. Isolation and identification of hydrogen-producing strains from FWL 10
• 3.2. Comparative hydrogen productivity of the four ISs 13
• 3.3. Comparison of acid tolerance between the ISs and the TS 28
• 4. Conclusions 37
• 4.1. Conclusions 37
• 4.2. Further research 37
• 5. References 39
• 국문초록 45