Integration of feather waste hydrolysis, enzyme production, and cultivation of Spirulina (Limnospira platensis) and its potential economic and environmental benefits.

Abstract

In this study feather hydrolysate served as the sole nitrogen source for the cultivation of Spirulina (Limnospira platensis) replacing nitrate used in the standard medium. Although Spirulina is well known for its excellent nutritional content ideal for food and animal feed application and it allows a climate smart production system, its wide use remains limited because of high production cost. The growth medium used for cultivation where nitrate serves as the nitrogen source has significant contribution to the high production cost. Therefore, the use of cheaper growth substrates could help lower production cost and make Spirulina biomass accessible to most users. The feather hydrolysate used in this study was prepared through microbial solubilization which also resulted in the production of a protease that has properties suitable for different industrial applications. The whole feather hydrolysate and the enzyme-free feather hydrolysate obtained after recovery of the enzyme supported good growth of Spirulina equivalent to nitrate in the standard medium. Currently the poultry industry releases huge quantities of feather as waste posing serious risks of environmental pollution. The results of this study, therefore, indicate that feather could serve as a cheap substrate to produce an industrially important enzyme while the enzyme free hydrolysate serve as a substrate for the cultivation of Spirulina. This process, in addition to lowering production costs, could help to reduce environmental pollution. Therefore, integration of feather hydrolysis, enzyme production, and Spirulina cultivation could lead to a circular bioeconomy offering huge environmental and economic benefits.