Nucleic acids from agro-industrial wastes: a green recovery method for fire retardant applications

Two different agro-industrial biological wastes, namely spent brewer’s yeast and vegetable scraps have been considered as inexpensive sources of nucleic acids (NAs) to be employed for conferring flame retardant features to cotton fabrics. A simple, cheap and green extraction method has been set-up for each matrix. The yields, purity grades and molecular sizes have been assessed and compared with two different commercially available purified DNA. The developed extraction procedures have shown a high level of reliability for the recovery of nucleic acids from both agro-industrial wastes. The results of the flammability tests with the extracted NAs clearly indicated that, the add-on value on the fabrics being equal, the NAs extracted from spent brewer’s yeast cells are able to provide self-extinction to cotton and reproduce the fire behaviour obtained with highly expensive commercially purified DNAs. Thus, the proposed procedures may be applied for large-scale NA recovery from inexpensive agro-food wastes to obtain partially purified NA suitable for fire retardant applications. Moreover, the developed extraction procedures can be considered an addition to the growing body of more rational waste valorisation techniques within the bio-refinery approach and circular economy concept.