Title
Onion waste valorization for bacterial cellulose-based vegan leather production via sustainable cultivation
Authors
SO YEON WON, SEONG MIN KIM, WONYI JUNG, DAEUN YEO, ANKUR SOOD, MADURU SUNEETHA and SUNG SOO HAN

Received August, 4, 2025
Published Volume 60 Issue 3-4 March-April
Keywords sustainable materials, bacterial cellulose, agricultural waste, leather substrate

Abstract
This study examined the possibility of utilizing onion waste extract as a substitute for the conventional culture medium for bacterial cellulose (BC) production by Gluconacetobacter hansenii. The nutrient components present in the onion waste extract were identified as fermentable sugars and other low-molecular-weight nutrients essential for BC biosynthesis. Essential bioactive compounds in onion waste were effectively recovered using hot water extraction, which was further confirmed using ¹H NMR spectroscopy with distinct peaks at 3.2-4.2 ppm for carbohydrates, 0.8-2.5 ppm for aliphatic amino acids, and minor peaks at 6.0-8.0 ppm for aromatic compounds. BC production by G. hansenii was successfully achieved when the waste onion extracts were used as the culture medium. The Fourier transform infrared and X-ray diffraction analyses verified the retention of the cellulose I crystal structure for BC produced from the waste onion extracts, as evidenced by the presence of similar characteristic peaks. The mechanical properties of BC and OBC also showed some differences, as the OBC material had higher stiffness and tensile strength, while the material produced from the waste onion extracts had lower elongation and toughness. The thermal stability of the BC and OBC materials also showed a decrease for the BC produced from the waste onion extracts. In vitro cytocompatibility tests with NIH 3T3 cells indicated the cell viability on BC and OBC surfaces. The results demonstrate the potential of onion extract as a nutrient substitute for BC production, while impacting the BC property–structure relationship. The paper presents experimental results for the valorization of agricultural waste materials for the production of microbial cellulose biosynthesis.