Innovative Production of Bioproducts From Organic Waste Through Solid-State Fermentation

Abstract

Solid-state fermentation (SSF) is, by definition, a technology carried out in absence or near absence of free water. Therefore, it allows the use of solid materials as substrates for further biotransformation. SSF has gained attention in the last years being reported as a promising eco-technology that allows obtaining bioproducts of industrial interest using solid biomass (wastes and by-products). Main advantages over conventional submerged fermentation rely on the lower water and energy requirements, which generate minimum residual streams. However, drawbacks related to poor homogeneity and energy and mass transfer often appear, hindering the process yield and the downstream of the produced bioproducts. Despite the difficulties, many successful processes have been reported on the production of a variety of bioproducts such as hydrolytic enzymes, mostly carbohydrases for bioethanol production, and to a lesser extent, aromas, biosurfactants, biopesticides, bioplastics, organic acids or phenolic compounds. Most of the reported research focuses on process development at small scale; however, the main challenges to overcome in SSF are related to the upscaling and the development of a consistent and continuous operation. In this work, the main advances for the production of valuable/innovative bioproducts are presented and discussed.

Biodegradation of Wasted Bioplastics in Natural and Industrial Environments: A Review

“…Other carbon sources used for synthesizing PHAs by microbes can include waste frying or cooking oil, coffee waste, crude glycerol, molasses, and wastewater [67][68][69][70]. Industrial and municipal wastewater sludge, agricultural, and food waste were used to produce PHB through SSF [71,72].…”

Solid-state fermentation technology and innovation for the production of agricultural and animal feed bioproducts

“…Solid-state fermentation exerts a positive effect on biofungicide development considering that the mostly used solid organic wastes resemble the microorganisms' natural habitat and help them thrive [81,82]. However, besides being able to grow on domestic and agro-industrial wastes, an inert solid material impregnated with a proper liquid medium can also be used as a substrate for colonization and spore production [83,84].…”

Xylan Decomposition in Plant Cell Walls as an Inducer of Surfactin Synthesis by Bacillus subtilis

“…In this study, we used B. subtilis 87Y previously isolated from soilworm Eisenia fetida [15] We decided to use the SSF process, which provides many benefits. Compared to liquid state fermentation, SSF requires lower energy, produces less wastewater, is environment-friendly, and most importantly, it resolves the huge problem of solid waste or by-product disposal [16,17]. It also better reflects the natural environmental conditions of the B. subtilis interaction with plant material, i.e., the degradation of plant debris in the soil.…”