Screening of Aeromonas hydrophila W-02 with High Polysaccharide Hydrolases Activity and Its Application in Alginate Preparation

Alginate is the main structural polysaccharide in brown algal cell walls and is widely used in pharmaceuticals, textiles, cosmetics, feed, and other fields. Its tradition production methods feature low yield, high water consumption and environmental pollution, which need industrial upgrading. In this study, Aeromonas hydrophila W-02, a bacterial strain capable of simultaneously producing high levels of cellulase, pectinase, and glucanase, was isolated and identified from kelp humic liquid. Genome sequencing revealed that it has 5781 genes, 116 of which are related to glycoside hydrolysis. When A. hydrophila W-02 was applied to kelp for alginate extraction, the optimized bacterial method achieved a 38.21% yield, four times that of the traditional acid coagulation–acidification method (8.12%). Alginate was used to prepare alginate fiber and its performance indices were compared with those of commercial fibers. Scanning electron microscopy and mechanical properties analysis revealed no significant difference between alginate fibers from this novel process and commercial alginate. This study provides an efficient and green approach for alginate preparation and provides data to support the industrialization of high-efficiency bio-based alginate extraction.