Organic Wastes as Feedstocks for Non-Conventional Yeast-Based Bioprocesses

Abstract

Non-conventional yeasts are efficient cell factories for the synthesis of value-added compounds such as recombinant proteins, intracellular metabolites, and/or metabolic by-products. Most bioprocess, however, are still designed to use pure, ideal sugars, especially glucose. In the quest for the development of more sustainable processes amid concerns over the future availability of resources for the ever-growing global population, the utilization of organic wastes or industrial by-products as feedstocks to support cell growth is a crucial approach. Indeed, vast amounts of industrial and commercial waste simultaneously represent an environmental burden and an important reservoir for recyclable or reusable material. These alternative feedstocks can provide microbial cell factories with the required metabolic building blocks and energy to synthesize value-added compounds, further representing a potential means of reduction of process costs as well. This review highlights recent strategies in this regard, encompassing knowledge on catabolic pathways and metabolic engineering solutions developed to endow cells with the required metabolic capabilities, and the connection of these to the synthesis of value-added compounds. This review focuses primarily, but not exclusively, on Yarrowia lipolytica as a yeast cell factory, owing to its broad range of naturally metabolizable carbon sources, together with its popularity as a non-conventional yeast.

Yeast Diversity Associated with the Phylloplane of Corn Plants Cultivated in Thailand

“…In recent years, yeasts isolated from various natural habitats have been found to havepotential as effective producers of various biotechnological products worldwide. Various wild yeast species have been reported to have a vital role in modern industrial biotechnology, for example, for the production of citric acid [51], single cell proteins [52,53], ethanol [54,55], microbial oils [56][57][58], indole-3-acetic acid (IAA) [59], itaconic acid [60], glycolipid biosurfactants [49], arabitol [61], xylitol [62], erythritol and mannitol [63]. In this study, we isolated 217 yeast strains of 10 species in the Ascomycota and 35 species in the Basidiomycota.…”

Occurrence and Molecular Identification of Wild Yeasts from Jimma Zone, South West Ethiopia

“…The Saccharomyces cerevisiae, Yarrowia lipolytica, and Pichia kudriavzevii, recognized for industrial production of single-cell proteins and microbial oils, were isolated from Qilxuu barks. Besides, Yarrowia lipolytica is reported for industrial production of erythritol and mannitol [40], feedstock bioprocesses [41], and recombinant protein [42]. The genera Candida, Pichia, and Debaryomyces were recovered from different environmental sources and are utilized in biomass hydrolysates and production of l-or d-arabitol [43].…”

Engineering Yarrowia lipolytica for the Synthesis of Glutathione from Organic By-Products

“…Only a few processes have considered industrial by-products such as sugarcane molasses as alternative carbon sources [2,4].The yeast Yarrowia lipolytica is known for its high tolerance to heavy metals [5,6], and since this tolerance has been linked to GSH synthesis [1], we hypothesized here that Y. lipolytica could be a promising organism for GSH production. Moreover, this yeast is also considered to be a promising cell factory for the conversion of industrial by-products into compounds of biotechnological interest [7,8]. Recent metabolic engineering strategies have been developed to expand the capability of Y. lipolytica to hydrolyze di-and polysaccharides (i.e., sucrose, inulin or starch) or to improve the endogenous metabolism of naturally consumed carbon sources (i.e., glucose, glycerol, fructose and hydrophobic substrates) [7,9,10].The worldwide production of organic waste is increasing yearly, leading to serious environmental issues.…”

“…Recent metabolic engineering strategies have been developed to expand the capability of Y. lipolytica to hydrolyze di-and polysaccharides (i.e., sucrose, inulin or starch) or to improve the endogenous metabolism of naturally consumed carbon sources (i.e., glucose, glycerol, fructose and hydrophobic substrates) [7,9,10].The worldwide production of organic waste is increasing yearly, leading to serious environmental issues. However, organic waste from various industries is increasingly considered to be a substitution substrate to reduce the process costs [8]. For instance, glycerol-the main byproduct of the biodiesel industry-is used for the synthesis of biofuels and chemicals (for a review, see [11]).…”

“…The worldwide production of organic waste is increasing yearly, leading to serious environmental issues. However, organic waste from various industries is increasingly considered to be a substitution substrate to reduce the process costs [8]. For instance, glycerol-the main byproduct of the biodiesel industry-is used for the synthesis of biofuels and chemicals (for a review, see [11]).…”