A new method for ethanol productivity determination

Summary A simple and easily applicable method for determination of the ethanol fermentation rate is described. The formulas to be used for the ethanol productivity calculation in the case of free and agar immobilized cells are given.     

A new colorimetric method for determination of creatine phosphokinase

A new colorimetric method has been developed for the determination of creatine phosphokinase (CPK). This method is based on the reaction of creatine, formed enzymatically from creatine phosphate and ADP, with p-nitrophenylglyoxal (PNPG) under alkaline conditions to produce a colored product which absorbs maximally at 480 nm. At 25 degrees C the reaction was complete after 10 min in 0.1 M sodium pyrophosphate, pH 12, containing 0.15 M sodium ascorbate. The colored product was stable for at least 24 h and obeyed Beer's law in the range 0.005-0.05 mM creatine. The color reaction was used to determine the activity of CPK in serum and tissue extracts. The results obtained by this method agreed well with the results obtained by other available methods for CPK determination. However, the PNPG method was more rapid and more sensitive than other colorimetric methods and required a single chromogenic reagent.