Kinetic Characteristics

With their respective natural substrates, type I BVMOs display kcat values of 520 s-1 while the apparent affinity is in the micromolar range. With these kinetic features, type I BVMOs display catalytic efficiencies that are typical for oxygenases [44]. Only for ethionamide monooxygenase have rather low kcat values been reported, which can be explained by the fact that the natural substrate for this monooxygenase is as yet unknown. The apparent affinity for molecular oxygen has been shown to be excellent for CHMO [30] and HAPMO (unpublished results) with apparent KM values of <25 |imol L-1. Effective consumption of oxygen within the cell by CHMO has recently been demonstrated through analysis of whole cell bioconversions [45]. However, cells used for whole cell bioconversions not only need oxygen for the targeted oxygenation reaction but also for coenzyme regeneration and cell maintenance. This sets a limit to the productivity of biocata-lytic applications based on whole cells as catalyst [44]. Nonetheless, it was recently shown that by optimizing the reaction conditions E. coli cells expressing CHMO can be used to perform Baeyer-Villiger oxidations at kilogram scale [46]. This study has illustrated that by careful tuning of reaction conditions (e.g. oxygen and glycerol feed, in situ substrate feeding and product removal) whole cells can effectively be exploited as catalyst.

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Heal Yourself With Qi Gong

Qigong also spelled Ch'i Kung is a potent system of healing and energy medicine from China. It's the art and science of utilizing breathing methods, gentle movement, and meditation to clean, fortify, and circulate the life energy qi.

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