Impact of heat and chloramphenicol pretreatments on sludge anaerobic bioconversion: Insights into physicochemical and microbial disruption

IF 3.7 3区生物学 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Biochemical Engineering Journal Pub Date : 2025-07-13 DOI:10.1016/j.bej.2025.109872

Anam Jalil , Hikmatullah Ahmadi , Chengyu Zhang , Xiangyang Wang , Zhisheng Yu

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Abstract

This study examines impact of heat and chloramphenicol pretreatments on sludge characteristics to improve anaerobic bioconversion under mesophilic conditions. Physicochemical, microbial, and biogas analyses were conducted to evaluate the effect of each pretreatment. Elemental composition analysis revealed that chloramphenicol pretreatment reduced the C/N ratio to 12.8 ± 0.18, whereas heat treatment maintained a more balanced ratio of 15.0 ± 0.12, compared to 13.83 in the control. Macromolecular analysis revealed extensive microbial lysis in chloramphenicol-treated sludge, reflected by significant increases in protein (43.5 ± 0.6 %) and lipid (12.0 ± 0.5 %) contents, whereas moderate changes were observed in heat-pretreated samples. The lowest VS/TS ratio (0.60 ± 0.02) in the chloramphenicol group indicated enhanced organic solubility. Biogas assays revealed that heat-pretreated sludge produced the highest cumulative yield (35.0 mL/g VS) and CH₄ content (61 %), while chloramphenicol treatment yielded slightly less gas (33.0 mL/g VS) but with an elevated H₂ content (18 %), higher than that of the control (20.4 mL/g VS). COD and TVFA reductions of 20.0 % and 77.8 %, respectively, were also notable under chloramphenicol stress. Microbial analysis revealed an enrichment of spore-forming Firmicutes following heat pretreatment and a hydrogenogenic shift toward Chloroflexi and Actinobacteriota under antibiotic stress. Overall, these findings demonstrated how targeted pretreatment alters sludge composition and microbial ecology to optimize biogas quality, particularly by enhancing hydrogen production for sustainable bioenergy recovery.

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热和氯霉素预处理对污泥厌氧生物转化的影响：对物理化学和微生物破坏的见解

本研究考察了热和氯霉素预处理对污泥特性的影响，以改善中温条件下的厌氧生物转化。进行了理化、微生物和沼气分析，以评估每种预处理的效果。元素组成分析显示，氯霉素预处理使C/N比降低至12.8 ± 0.18，而热处理使C/N比保持更为平衡，为15.0 ± 0.12，而对照组为13.83。大分子分析显示，氯霉素处理过的污泥发生了广泛的微生物裂解，蛋白质（43.5±0.6 %）和脂质（12.0±0.5 %）含量显著增加，而在热处理过的样品中观察到适度的变化。氯霉素组的VS/TS比最低（0.60 ± 0.02）表明有机溶解度增强。沼气试验表明，热处理污泥的累积产气量最高（35.0 mL/g VS），氯化铵含量最高（61 %），而氯霉素处理的产气量略低（33.0 mL/g VS），但H₂含量升高（18 %），高于对照组（20.4 mL/g VS）。在氯霉素胁迫下，COD和TVFA分别降低20.0 %和77.8 %。微生物分析显示，热预处理后形成孢子的厚壁菌门丰富，抗生素胁迫下产氢向氯氟菌门和放线菌门转移。总的来说，这些发现证明了有针对性的预处理如何改变污泥组成和微生物生态，以优化沼气质量，特别是通过提高氢气产量来实现可持续的生物能源回收。

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来源期刊

Biochemical Engineering Journal 工程技术-工程：化工

CiteScore

7.10

自引率

5.10%

发文量

380

审稿时长

34 days

期刊介绍： The Biochemical Engineering Journal aims to promote progress in the crucial chemical engineering aspects of the development of biological processes associated with everything from raw materials preparation to product recovery relevant to industries as diverse as medical/healthcare, industrial biotechnology, and environmental biotechnology. The Journal welcomes full length original research papers, short communications, and review papers* in the following research fields: Biocatalysis (enzyme or microbial) and biotransformations, including immobilized biocatalyst preparation and kinetics Biosensors and Biodevices including biofabrication and novel fuel cell development Bioseparations including scale-up and protein refolding/renaturation Environmental Bioengineering including bioconversion, bioremediation, and microbial fuel cells Bioreactor Systems including characterization, optimization and scale-up Bioresources and Biorefinery Engineering including biomass conversion, biofuels, bioenergy, and optimization Industrial Biotechnology including specialty chemicals, platform chemicals and neutraceuticals Biomaterials and Tissue Engineering including bioartificial organs, cell encapsulation, and controlled release Cell Culture Engineering (plant, animal or insect cells) including viral vectors, monoclonal antibodies, recombinant proteins, vaccines, and secondary metabolites Cell Therapies and Stem Cells including pluripotent, mesenchymal and hematopoietic stem cells; immunotherapies; tissue-specific differentiation; and cryopreservation Metabolic Engineering, Systems and Synthetic Biology including OMICS, bioinformatics, in silico biology, and metabolic flux analysis Protein Engineering including enzyme engineering and directed evolution.