A honeycomb-like hydrogel in-situ constructed by Streptococcus zooepidemicus and TOCN for the proliferation of bacteria

Abstract

Cellulose, as a significant natural carbohydrate polymer, can be transformed into polysaccharide nanofiber. A novel in-situ hydrogel was constructed using TEMPO-oxidized cellulose nanofiber (TOCN) and metabolites of Streptococcus zooepidemicus, such as hyaluronic acid (HA) and lactic acid (LA). In the presence of LA, HA underwent a gelation process, and S. zooepidemicus was embedded in the skeleton of the hydrogel network. This in-situ hydrogel accommodated the bacteria by providing a suitable environment for their growth and protecting them from external stress. The elastic modulus of the in-situ hydrogel was maintained at 4000 G′ in Pa, thus ensuring that it was protected from damage even after being immersed in the medium. The hydrogel continued to show normal fermentation activities upon being transferred into the seed or fermentation medium. These findings indicated that the in-situ hydrogel could act as a wellspring that spills out the scattered bacteria.