3-Hydroxy-4,5-dimethyl-2(5H)-furanone (sotolone) and 3-amino-4,5-dimethyl-2(5H)-furanone, the postulated precursor of sotolone, were detected in hairy root cultures of Trigonella foenum-graecum (fenugreek) by GC-MS. The hairy root cultures in both conical flasks and airlift with mesh bioreactors were achieved from hypocotyl of seedling by infection with Agrobacterium rhizogenes. In flasks, the mathematical relationship between hairy root growth and conductivity was established and afterward used to evaluate the biomass evolution in bioreactor cultures due to the difficulty of obtaining direct biomass samples from the bioreactor. The GC-MS analyses of ethanolic extracts from hairy roots revealed the presence of two important compounds: sotolone (1.2% of the volatile fraction) and 3-amino-4,5-dimethyl-2(5H)-furanone (17% of the volatile fraction). These results point out that biotechnological production of sotolone in bioreactors is possible. Additionally, these hairy root cultures offer, for the first time, an excellent biological model to study the biosynthetic pathway of sotolone in fenugreek.

The use of agroindustrial wastes such as orange rind as an alternative in the production of riboflavin was evaluated in this study with Ashbya gossypii mutants. Ashbya gossypii mutants were obtained using 300 µg/mL of MNNG after an exposition period of 90 min with 2.3% of survival rate. A total of 11 mutant high yield strains of riboflavin were selected. Of these mutants, the most productive in YM medium were ASHLVII, ASHLX, ASHLXI and ASHLXV. Three additional different mutants were shown to be unsusceptible to inhibition by itaconate in the medium. When we used orange rind at 0.3% in YM medium without malt extract, the rate of riboflavin production was enhanced in the mutant strains producing 223 mg/L of this vitamin, an increase of 184% in the ASHLXI and ASHLXV mutants, as compared with the wild strain.