Solid state fermentation of aquatic macrophytes for crude protein extraction

Aquatic macrophytes such as Elodea nuttalli, Vallisneria natans, Alterranthera philoxerides that are widely distributed in water environments of Lake Taihu basin were used as substrate of solid state fermentation to produce crude protein extraction. The effects of single-strain fermentation and mixed strains fermentation of aquatic macrophytes on the production of crude protein extraction and cellulase activity are analyzed, respectively. The experimental results showed that the crude protein content of products with mixed strains fermentation is higher than that with single-strain fermentation. The crude protein content of V. natans fermented by Aspergillus niger and Candida utilis is the highest among the aquatic macrophytes examined in this study. V. natans is used as the substrate to be fermented by C. utilis and A. niger; their ratio is 1:1 at 28 ± 1 °C for 72 h. The crude protein of fermented V. natans is as high as 49.54%, with 128.82% of its increase rate. The cellulose activity reaches a maximum of 4.21 μ/ml at 84 h of fementation of V. natans. Thus, the solid state fermentation of aquatic macrophytes to produce crude protein extraction is promising, which make aquatic macrophytes a potential resource and thus is beneficial to the long-term ecological restoration of eutrophic lakes.