Methods for producing melanin and inorganic fertilizer from fermentation leachates

A method for producing a secondary leachate for use in producing inorganic fertilizer from the secondary leachate comprising the steps of:

• (a) providing a primary processing bioreactor, a fermentation medium and a microbial culture comprising microorganisms, wherein the microorganisms in the microbial culture comprise Lactobacillus bacteria;
• (b) fermenting the fermentation medium with the microbial culture in the primary processing bioreactor, thereby producing a primary leachate, wherein the primary leachate comprises microorganisms derived from the microbial culture and/or naturally occurring microorganisms acquired during the fermentation step;
• (c) isolating or removing the primary leachate from the primary processing bioreactor;
• (d) providing the primary leachate isolated or removed from the primary processing bioreactor, a secondary processing bioreactor, Hermetia illucens (black soldier fly) larvae (BSFL), and a cellulose-based substrate;
• (e) culturing the BSFL in an aerated culture with the primary leachate isolated or removed from the primary processing bioreactor and the cellulose-based substrate in the secondary processing bioreactor under suboptimal culture conditions for culture of the BSFL, thereby producing a secondary leachate, wherein the suboptimal culture condition is suboptimal temperature, high density, chemical stress, acidification, presence of toxic secondary metabolites, and/or nutrient starvation;
• and
• (f) isolating or removing the secondary leachate from the secondary processing bioreactor, wherein the secondary leachate from the secondary processing bioreactor comprises inorganic fertilizer;
• and
• (g) extracting or isolating the inorganic fertilizer from the primary and secondary leachate.