3 5 dinitrosalycilic acid

Glucose, xylose, arabinose, sucrose, lactose, and glycerol were supplied from Bio Basic Canada Inc. Furfural, 5-hydroxymethyl Furfural (HMF), and 3,5-dinitrosalycilic acid were purchased from Sigma Chemical Co. (St. Louis, MO, USA). Agroindustrial by-products (wheat bran and sugarcane bagasse) were kindly provided by a local food processing industry (White-rose group, Sfax, Tunisia). Almond shell, date palm leaves, and Posidonia oceanica balls were collected locally. All lignocellulosic residues are conserved at 4°C until use.
The new oleaginous yeast strain Y-MG1, isolated from rotten fruit, was identified in our previous work based on its internal transcribed spacer (ITS) sequence [21 (link)]. Y-MG1 strain was identified as being Rhodotorula mucilaginosa and was submitted in the National Strains Collection of Centre of Biotechnology of Sfax, CBS, Tunisia, under the accession number CTM-30138. The ITS sequence of Y-MG1 was also submitted to GenBank under the accession number ID: KX347596.1. This strain was stored at −80°C in sterilized glycerol-enriched solution containing 2% (w/v) Glucose, 1% (w/v) yeast extract, 1% (w/v) bacto-peptone, and 20% (w/w) glycerol.

The content of reducing sugars was measured as described by Miller (1959 ). For each accession, 30 dry seeds were ground as previously described. The seed powder (0.5 g) was added to 5 ml of dH₂O, vortexed and incubated 2 h at 80°C in a water bath. After centrifugation at 1500 g for 15 min, the upper phase was transferred to new test tubes and the content of reducing sugars was quantified using DNS (3,5‐dinitrosalycilic acid, Sigma‐Aldrich) solution. Absorbance was read at 540 nm using a UV–visible spectrophotometer (UV‐1800, Shimadzu) and dH₂O as reference. Standard solutions of glucose in the range of 0.4–1.5 mg ml⁻¹ were used (Figure S1d).