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Enhanced Biomethane Conversion and Microbial Community Shift Using Anaerobic/Mesophilic Co-Digestion of Dragon Fruit Peel and Chicken Manure
by
, ,
Xiaojun Zheng
1,2, 
Suyun Liu
1,
Shah Faisal
3
,
Adnan Khan
4,
Muhammad Ihsan Danish
5,
Abdul Rehman
1,* and
Daolin Du
6,* 
1
School of the Environment and Safety Engineering, Key Laboratory of Zhenjiang, Jiangsu University, Zhenjiang 212013, China
2
Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou 215009, China
3
Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, China
4
Co-Innovation Center for Sustainable Forestry in Southern China, College of Life Sciences, Nanjing Forestry University, Nanjing 210037, China
5
Department of Environmental Science, Shaheed Benazir Bhutto University, Sheringal, Dir Upper 18000, Khyber Pakhtunkhwa, Pakistan
6
Jingjiang College, Institute of Environment and Ecology, School of the Environment and Safety Engineering, Key Laboratory of Zhenjiang,School of Emergency Management, School of Agricultural Engineering, Jiangsu University, Zhenjiang 212013, China
*
Authors to whom correspondence should be addressed.
Biology 2026, 15(1), 83; https://doi.org/10.3390/biology15010083
Submission received: 18 November 2025
/
Revised: 15 December 2025
/
Accepted: 29 December 2025
/
Published: 31 December 2025
(This article belongs to the Section Biotechnology)
Simple Summary
The traditional perspective of waste disposal is no longer appropriate, as the circular economy recognizes organic waste as a key potential for both nutrition and energy recovery. Anaerobic digestion has proved high efficacy as a sustainable technique for acquiring energy from organic wastes with fewer adverse environmental effects. Chicken manure rich in organic matter is a significant agricultural pollutant associated with greenhouse gas emissions and water pollution. Due to the low carbon-nitrogen ratio of chicken manure, acidification could quickly occur in the anaerobic digestion process, reducing anaerobic digestion efficiency. Therefore, the application of chicken manure for anaerobic digestion has become a hot topic. The study was designed to improve the biogas/methane production and enhance the core microbial interaction of anaerobic digestion. The addition of dragon fruit peel as a co-substrate was suggested to determine the optimal ratio that reduces the low carbon nitrogen ratio and improves methane potential. The co-substrate dragon fruit peel at an optimal ratio maximizes the biogas/methane yields up to 411.1 and 180.2 mL/g VS, respectively. The study findings contribute to a deeper understanding and the approach of dragon fruit peel as a co-substrate for methane recovery from anaerobic digestion of chicken manure.
Abstract
Biogas and methane generated from the anaerobic digestion (AD) of organic waste present a highly effective alternative to fossil fuels. The study assessed using dragon fruit peel (DFP) as a co-substrate to enhance chicken manure (CM) biodegradability and stabilize the AD process for methane during co-digestion. The biochemical methane potential assays were conducted at mono-controls (CM and DFP) and co-digestion at CM-75:DFP-25, CM-50:DFP-50, and CM-25:DFP-75. Compared to the controls, mono-digestion produced 103.3 mL/g of volatile solids (VSs) of CM and 34.6 mL/g VS of DFP, while all treatment groups of co-digestion exhibited an increase in methane production. The highest yield was 180.3 mL/g VS at CM-25:DFP-75 (74.6% and 421.1% increase relative to mono-digestions of CM and DFP, respectively), followed by 148.3 mL/g VS at CM-50:DFP-50 (43.6% higher than CM) and 116.7 mL/g VS at CM-75:DFP-25 (13% higher than CM). Process stability at the optimal DFP co-substrate ratio (CM-25:DFP-75) was confirmed by total volatile fatty acid (VFA) conversion, as below 0.5 g/L VFAs were observed at the end of incubation, indicating highly acceptable performance. The relative abundance of Bacteroidetes and Bacillota in the treatment groups was higher as compared to the control reactors, correlating with enhanced substrate hydrolysis and VFA production. Moreover, the enrichment of acetoclastic methanogens Methanosarcina and Methanosaeta in co-digesters at CM-25:DFP-75 was associated with the efficient degradation of acetic acid and propionic acid, which aligns with the observed increase in methane yield. The study enhances the understanding of DFP as a co-substrate for optimizing methane recovery from AD of CM.
