A Comprehensive Review on Valorization of Agro-Food Industrial Residues by Solid-State Fermentation

Abstract

Agro-food industrial residues (AFIRs) are generated in large quantities all over the world. The vast majority of these wastes are lignocellulosic wastes that are a source of value-added products. Technologies such as solid-state fermentation (SSF) for bioconversion of lignocellulosic waste, based on the production of a wide range of bioproducts, offer both economic and environmental benefits. The versatility of application and interest in applying the principles of the circular bioeconomy make SSF one of the valorization strategies for AFIRs that can have a significant impact on the environment of the wider community. Important criteria for SSF are the selection of the appropriate and compatible substrate and microorganism, as well as the selection of the optimal process parameters for the growth of the microorganism and the production of the desired metabolites. This review provides an overview of the management of AFIRs by SSF: the current application, classification, and chemical composition of AFIRs; the catalytic function and potential application of enzymes produced by various microorganisms during SSF cultivation on AFIRs; the production of phenolic compounds by SSF; and a brief insight into the role of SSF treatment of AFIRs for feed improvement and biofuel production.

A Comparative Study of the Influence of Various Fungal-Based Pretreatments of Grape Pomace on Phenolic Compounds Recovery

“…Filippi et al [ 29 ] conducted their studies on a GP with a lignin content of 34.79%, and Teles et al [ 12 ] on a GP with a lignin content of 40.24%. However, the lignin content in GP can range from 11.6% to 41.3% depending on the grape variety [ 18 ]. To better understand the process of biological treatment and to see which components are actually degraded, it is important to present the data as absolute values using dry matter data.…”

“…Overall, SSF can be an effective technology for the recovery phenolic compounds, because during this process, microorganisms synthesize a complex system of enzymes involved in the degradation of the complex structure of heterogeneous substrates such as GP and lignocellulosic substrates in general [ 18 ]. This can lead to the release of phenolic compounds from the lignocellulosic structure, resulting in an increase in the content of phenolic compounds, usually due to hydrolytic enzymes [ 12 ], or degraded by enzymatic hydrolysis, leading to a decrease in the content of phenolic compounds [ 60 ].…”

“…Pretreatment of lignocellulosic materials is carried out by physical, chemical, biological methods, and by a combination of these methods [ 17 ]. Biological methods such as solid-state fermentation (SSF) provide an alternative to the recovery of natural phenolic compounds and are a useful technique and an environmentally friendly bioprocess that can yield high-value products with potential industrial applications [ 18 ]. Filamentous fungi are the most commonly used microorganisms for SSF, capable of synthesizing enzymes involved in the degradation of complex lignocellulosic material and the release of phenolic compounds.…”

The Potential of Brewer’s Spent Grain in the Circular Bioeconomy: State of the Art and Future Perspectives

“…The use of BSG as fermentation medium component typically results in high xylanase activities, which is to be expected considering that hemicellulose represents the largest portion of all polymers in BSG. In addition, many other enzymatic activities are involved in the complex degradation of lignocellulosic material (Šelo et al, 2021;Chilakamarry et al, 2022) e.g., various glucanases, cellobiohydrolases, esterases and pectinases.…”

Polymeric Compounds of Lingonberry Waste: Characterization of Antioxidant and Hypolipidemic Polysaccharides and Polyphenol-Polysaccharide Conjugates from Vaccinium vitis-idaea Press Cake

“…Recycling of agro-food wastes is the focus of scientists who are interested in eco-friendly technologies for waste processing, which is an important problem of modern life [ 2 ]. The problem of fruit processing is of interest to many scientists, but insufficient attention is paid to berry industry waste [ 3 ]; at best, this type of waste is composted, and at worst, it is simply thrown away [ 4 ]. Among the processed berries, the least attention is paid to hard-skinned berries derived from Vaccinium and Ribes species, which is explained by the impossibility of its transformation into a puree or a homogeneous mass, despite the use of heat treatment methods [ 5 ].…”