Synergistic outcomes of Chlorella-bacterial cellulose based hydrogel as an ethylene scavenger

Increasing the freshness of vegetables requires the elimination of ethylene, which can be done through chemical methods. However, the development of eco-friendly approaches is required for environmental reasons. Chlorella vulgaris (C. vulgaris) was selected as a new biological material for demonstrating an excellent performance in ethylene removal. To support C. vulgaris, bacterial cellulose (BC) produced by Gluconacetobacter hansenii (G. hansenii) was chosen due to its high water content and biodegradability. To increase BC productivity, UV-induced mutant G. hansenii was isolated, and they produced high yields of BC (9.80 ± 0.52 g/L). Furthermore, comparative transcriptome analysis revealed metabolic flux changes toward UDP-glucose accumulation and enhanced BC production. BC-based hydrogels (BC hydrogels) were successfully prepared using a 2.4 % carboxymethyl cellulose (CMC) and 1 % agar mixture. We used Chlorella-BC hydrogels as an ethylene scavenger, which reduced 90 % of ethylene even when the immobilized C. vulgaris was preserved for 14 days at room temperature without media supplementation. We demonstrated for the first time the potential of BC hydrogels to integrate C. vulgaris as a sustainable ethylene absorber for green food packaging and biomass technology.