Comparative study of the bioconversion process using R-(+)- and S-(–)-limonene as substrates for Fusarium oxysporum 152B

•Complete process comparison of R-(+)- and S-(–)-limonene fungal bioconversion.•Characterisation of the bioconversion of S-(–)-limonene into limonene-1,2-diol.•One of the highest concentrations obtained of α-terpineol and limonene-1,2-diol.•First report to characterise the bioconversion using ultra-structural analysis. This study compared the bioconversion process of S-(–)-limonene into limonene-1,2-diol with the already established biotransformation of R-(+)-limonene into α-terpineol using the same biocatalyst in both processes, Fusarium oxysporum 152B. The bioconversion of the S-(−)-isomer was tested on cell permeabilisation under anaerobic conditions and using a biphasic system. When submitted to permeabilisation trials, this biocatalyst has shown a relatively high resistance; still, no production of limonene-1,2-diol and a loss of activity of the biocatalyst were observed after intense cell treatment, indicating a complete loss of cell viability. Furthermore, the results showed that this process can be characterised as an aerobic system that was catalysed by limonene-1,2-epoxide hydrolase, had an intracellular nature and was cofactor-dependent because the final product was not detected by an anaerobic process. Finally, this is the first report to characterise the bioconversion of R-(+)- and S-(–)-limonene by cellular detoxification using ultra-structural analysis.