| abstract |
Melanin or inorganic fertilizers are produced from fermentation leachates or from low-cost nutrient-rich solutions. The method for producing the melanin or inorganic fertilizer comprises repetitive trophic cycling in the controlled conditions of primary and secondary bioreactors. Nutrients are cycled between microorganisms such as bacteria, yeast and fungi and black soldier fly larvae, Hermetia illucens . Polysaccharides are partly converted into natural melanins or inorganic fertilizer, which are difficult to biodegrade and hence accumulate in the bioreactors. The method can employ, as a source of nutrients, leachates produced from food waste or from sugar-rich liquid waste of the food industry. These leachates can be used raw or can be augmented with low-cost sugar-rich solutions such as molasses, hydrolyzed cellulose or starch. The method is inexpensive and does not require the use of expensive chemically-defined culture media. |