Fungal EPS extraction and packaging film application
A biogenic material technology that uses extracellular polymeric substances (EPS) extracted from Rhodotorula mucilaginosa via a combined heating and NaCl addition method to produce biodegradable packaging films for food preservation and shelf-life extension.
Overview
This research proposes a sustainable approach to food packaging by leveraging extracellular polymeric substances (EPS) produced by the fungus Rhodotorula mucilaginosa. EPS are biogenic materials composed of proteins, polysaccharides, nucleic acids, humic substances, and lipids, offering high specific surface area, abundant functional groups, and natural biodegradability. These properties make EPS well-suited for semi-transparent packaging films that help prevent microbial contamination and food spoilage, addressing growing demand for eco-friendly alternatives to conventional plastic packaging.
Technical specifications
- Efficient extraction method: A combination of heating at 70 °C in water with NaCl addition significantly boosts EPS yield while minimizing DNA leakage from cell rupture.
- Yield improvements: Protein content increased from approximately 300 to 650 mg/L, and polysaccharide content rose from 1700 to 2010 mg/L after the optimized extraction process.
- Low contamination profile: DNA leakage under the heating method remains below 2 mg/L, compared to over 6 mg/L with conventional CER (cation exchange resin) treatment.
- Material diversity: Three-dimensional excitation-emission matrix spectra confirm two characteristic peaks at 280/300 and 280/350 nm, indicating rich organic matter composition suitable for film formation.
- Film design pipeline: Extracted EPS is formulated into packaging films with planned testing for barrier properties, mechanical strength, and biodegradability.
Technology readiness level
The extraction methodology has been validated in laboratory settings, demonstrating reproducible improvements in EPS yield and quality. The research team has confirmed biodegradability of the extracted EPS. Future work from October 2023 through March 2025 will focus on scaling EPS extraction, designing the packaging film, testing material properties, and iterating on the formulation to optimize performance for real-world packaging applications.
About Nanjing Agricultural University
Nanjing Agricultural University is a public research university with an agricultural focus in Nanjing, advancing national and regional priorities through integrated basic-to-applied research and field training. Industry engages through experimental farms, field stations, controlled-environment facilities, and pilot processing spaces for prototyping and scale‑up. An industry liaison team supports sponsored research, testing services, and joint labs, while regional demonstration sites speed on‑farm trials across the Yangtze River Delta. Research is supported by national and provincial programs, including the National Natural Science Foundation of China and the Ministry of Science and Technology. A technology transfer office manages IP, licensing, and startup incubation.
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