Conversion of cardoon crop residues into single cell oils by Lipomyces tetrasporus and Cutaneotrichosporon curvatus: process optimizations to overcome the microbial inhibition of lignocellulosic hydrolysates

Cutaneotrichosporon oleaginosus: A Versatile Whole-Cell Biocatalyst for the Production of Single-Cell Oil from Agro-Industrial Wastes

“…The complex structure of lignocellulosic biomass and its innate recalcitrance to chemical and/or biological depolymerisation require multistep processes in order to convert the starting biomass into added-value products. The most common biorefinery schemes are based on the initial pretreatment of lignocellulosic biomass in order to deconstruct the lignocellulose matrix and make it more prone to subsequent chemical or biological hydrolysis [4,7,15,92,93]. Table S1 in Supplementary Materials shows a short list of the most common pretreatment approaches of lignocellulosic biomass together with a brief description of their main advantages and disadvantages.…”

“…Part of the most innovative biorefinery schemes is focused on the production of biofuels [2,6]. In the literature, several studies reported various chemical and/or biological catalytic approaches for the production of liquid bio-based fuels [7][8][9]. Among biofuels, biodiesel is one of the most promising for transporting since it does not require dedicated technology or engines, with this being a point of difference from bio-based ethanol [10].…”

“…Oleaginous microorganisms are characterised by the ability to accumulate high concentrations of lipids into their cells as energy storage. Several studies demonstrated the potential use of SCO as a good alternative to vegetable oil to produce new-generation biodiesels and other bioproducts [3,7,17,18], such as biosurfactants, biopolymers, cosmetics and animal feed (e.g., fish cultures) [14,19,20].…”

“…A crucial aspect to guarantee the economic sustainability of yeasts oil production is represented by the use of low-or negative-value carbon sources deriving from secondgeneration biomasses and/or agro-industrial side-streams [22]. For example, the use of sugar-containing hydrolysates from lignocellulosic crops is one the most common approaches [3,4,7,23,24]. However, the quality of biomass hydrolysates is essential for good production of TAGs, as the presence of furanic compounds deriving from the degradation of sugars, such as furfural and 5-hydroxymethylfurfural, can significantly alter yeast growth and oil yield [25,26].…”

“…In fact, some organic compounds, such as furaldehyde, formaldehyde, phenols, aliphatic acids, vanillic acid, uronic acid, 4-hydroxybenzoic acid, acetic acid and cinnamaldehyde, can act as inhibitors for different metabolic activities of oleaginous yeasts [27,28]. The susceptibility of microorganisms to inhibitors strictly depends on the strain they belong to, so it is necessary to adapt the fermentation process to the type of microorganism used, in order to increase the cell biomass and lipid production [4,7,17].…”