Biosynthesis of 1-octen-3-ol and 10-oxo-trans -8-decenoic acid using a crude homogenate of Aqaricus bisporus: Reaction scale up

The enzymatic reaction that produces 1-octen-3-ol and 10-oxo-trans-8- decenoic acid was successfully scaled up from a 1-L to a 10-L bioreactor using a crude mushroom homogenate of Agaricus bisporus. For this non-Newtonian reaction broth, the agitation rate was considered the most important controlling factor for the scale up. An agitation rate of 600 rpm, for an aeration rate of 0.44 m³/m³/h, was found to be the minimum to maintain the yield constant for the 1-L reactor. Subsequently, the agitation rate for the 10-L reactor was determined using 2 different approaches: a constant power per volume of liquid and a constant volumetric mass transfer coefficient (k_La). The constant power per volume of liquid approach predicted an agitation rate of 364 rpm that resulted in being too low to maintain the same yield obtained with the 1-L reactor. Measurement of the k_La for the 10-L reactor, at 364 rpm and an aeration of 0.44 m³/m³/h, produced a value of 11.7/h, thus confirming that the reaction in the larger reactor was oxygen-deprived. Therefore, the use of constant volumetric mass transfer coefficient (k_La) strategy was used instead. k_La was experimentally determined at different agitation rates for the 10-L reactor. It was found that 750 rpm produced a k_La of 40.2/h. Confirmatory reactions were run in both reactors with the same batch of mushrooms, and the results were equivalent, thus indicating that was a good criterion for scaling up this process.