Abstract: In order to develop marine biomass resources, seaweed organic liquid fertilizer was prepared by biological method with macroalgae as raw material. Compound enzymolysis coupled microbial fermentation method was used. The factors affecting enzymatic hydrolysis efficiency, such as pH, temperature, enzyme dosage and reaction time, were studied. The optimum technological parameters were obtained by orthogonal experiment. In order to further improve the release of bioactive substances in seaweed cells, the optimal fermentation conditions were obtained by further fermentation of seaweed hydrolysate with microbial agents. The results showed that the optimal enzymolysis conditions for the preparation of seaweed fertilizer by compound enzymolysis coupled with microbial fermentation were as follows： pH 6.5, enzymolysis temperature 65 ℃, enzyme dosage 5%, enzymolysis time 8 h. The optimal fermentation conditions were as follows： fermentation time 36 h, inoculation amount of microbial agent 0.3%, bottling amount 40 mL/100 mL, fermentation temperature 45 ℃, initial fermentation pH 6.5. Through seed germination test, seaweed liquid fertilizer prepared by compound enzyme hydrolysis coupled with microbial fermentation can significantly improve seed germination rate.

Key words: macroalgae, complex enzymatic hydrolysis, microbial fermentation, coupling process, seaweed organic liquid fertilizer