Development of a strategy induction AOX1 promoter methylotrophic yeast Komagataella phaffii

Currently, there is a significant increase in interest in the industrial production of enzyme preparations (and other recombinant proteins) using various microorganisms, including methylotrophic yeasts such as Komagataella phaffii. At the same time, the most significant productivity of the target proteins is achieved by methanol induction of heterologous genes cloned under the control of the AOX1 promoter. Thus, the efficiency of biosynthesis is largely determined by the metabolism of methanol. In this connection, the aim of the work is to develop an optimal strategy for methanol induction of the AOX1 promoter of Komagataella phaffii. The object of the study is the culture of the recombinant phospholipase A2 producing strain Komagataella phaffii. The studies were carried out in a laboratory fermenter Infors Minifors (Switzerland) on a liquid nutrient medium BSM (Basal Salt Medium) We used the generally accepted methods of studying the characteristics of metabolic activity, including the calculation of specific characteristics and productivity of the strain. The result of the study is the determination of the specific rate of consumption of methanol used as a carbon source, which was 19.2±1.8 mg/g*h. Also, the specific growth rate of Komagataella phaffii was determined and amounted to 0.24 h-1.Based on the data obtained during the research, a strategy for the induction of the AOX1 promoter in the cultivation of the methylotrophic yeast Komagataella phaffii was developed by maintaining the methanol concentration in the range of 0.6 to 2% based on the concentration of dissolved oxygen in the medium. The developed strategy of induction of the AOX1 promoter made it possible to obtain at least 1.87 g / l of recombinant protein (phospholipase A2) during cultivation of Komagataella phaffii for 96 h, which is 3.7 times higher than the known results.