Design of a fermentation process for agave fructooligosaccharides production using endo-inulinases produced in situ by Saccharomyces paradoxus

•A methodology to evolve from spontaneous to directed fermentation is shown.•A stepwise methodology to designing feasible fermentation processes is proposed.•The importance of using native strains in the design of directed fermentation processes is confirmed.•Saccharomyces paradoxus as promising strain for producing endo-inulinases is proposed. Saccharomyces paradoxus, a native microorganism of the aguamiel, was used successfully for endoinulinase synthesis for agave fructooligasaccharide (FOS) production. We optimized the fermentation parameters to maximize the enzyme synthesis, and we performed enzyme kinetics studies to achieve agave fructans hydrolysis. The results showed that under constant operating conditions (pH 7.7, 40 °C, 175 rpm of agitation, and 0.005 VVM of aeration) results in the production of an enzymatic extract with 49.57 mg/L. This enzymatic extract, when mixed with an agave fructans solution containing 37.8 g/L, allowed us to obtain products with 18% more FOS content the original concentration. The mass spectrum plot shows that the hydrolyzed product contains FOS with a degree of polymerization from 5 to 9 hexose units. These results are promising because they show FOS production from agave and confirm that importance of using native strains in the design of directed fermentation processes.