Scaled-up bioconversion of fish waste to liquid fertilizer using a 5Â L ribbon-type reactor

► A scaled-up conversion process of fish waste to liquid fertilizer was performed in a 5 L ribbon-type reactor. ► Mixed microorganisms degraded approximately 430 g of fish waste for 96 h. ► The 96 h culture broth of fish waste possessed comparable fertilizing ability to commercial fertilizers. ► A more satisfactory fish waste degradation rate (3.61 g h−1) was obtained from the scaled-up production. ► The culture broth of fish waste at 25 °C was well preserved for 6 months by the addition of 1% lactate.