Agriculture plays a major role on society, especially in developing countries which rely on commodity exportation markets. To maintain high crop productivity, the use of agrochemicals was once employed as the main strategy, which in turn affected soil, water, and human health. In order to aid this issue, identifying some alternatives, such as the implementation of biofertilizers and inoculants as bioinputs in modern agriculture, are imperative to improve ecosystem quality. Among these bioinputs, a few bioproducts have shown good performances, such as phytohormones (e.g., auxins and giberellins), biosurfactants, and other enzymes; thus, it is extremely important to assure the quality and feasibility of their production in biorefinery scenarios. These bioproducts can be synthesized through fermentation processes through utilizing plant biomasses and agricultural byproducts as carbon sources. In this sense, to increase the tecno-economical availability of these processes, the implementation of solid-state fermentation (SSF) has shown great potential due to its ease of operation and cost-attractiveness. Therefore, this study aims to describe the main substrates used in SSF systems for the production of potential bioinputs; their associated operation hurdles, parameters, and conditions selection; the most suitable microorganisms; and the underlying mechanisms of these molecules in soil dynamics. Within this context, this study is expected to contribute to the development of new processes in modern biorefineries and to the mitigation of environmental impacts.

Lignocellulosic biomass (LCB) has remained a latent alternative resource to be the main substitute for oil and its derivatives in a biorefinery concept. However, its complex structure and the underdeveloped technologies for its large-scale processing keep it in a state of constant study trying to establish a consolidated process. In intensive processes, enzymes have been shown to be important molecules for the fractionation and conversion of LCB into biofuels and high-value-added molecules. However, operational challenges must be overcome before enzyme technology can be the main resource for obtaining second-generation sugars. The use of additives is shown to be a suitable strategy to improve the saccharification process. This review describes the mechanisms, roles, and effects of using additives, such as surfactants, biosurfactants, and non-catalytic proteins, separately and integrated into the enzymatic hydrolysis process of lignocellulosic biomass. In doing so, it provides a technical background in which operational biomass processing hurdles such as solids and enzymatic loadings, pretreatment burdens, and the unproductive adsorption phenomenon can be addressed.

Biosurfactants are amphipathic molecules produced by plants, animals, and microorganisms, that present emulsifying properties and may act reducing surface and interfacial tensions. When compared to synthetic surfactants, these biological analogues have high biodegradability potential, and may be produced from renewable raw materials within overall biotechnological processes involving low generation of residues. The production and application of microbial surfactants have been recently considered in several industrial sectors, as these low toxicity versatile compounds find applications in food, pharmaceutical, cosmetic, and petrochemical products, in nanotechnology and agriculture, and in the bioremediation of xenobiotic-contaminated areas. Herein, the main conceptual aspects and physicochemical properties, as well as the classifications of biosurfactants according to their origin and their chemical structures, are addressed. The production of microbial biosurfactants through sustainable processes are also described, with particular focus on new applications and on the increasing relevance of such bioproducts for the sustainable development of modern society.