Effects of Cell Lysis Treatments on the Yield of Coenzyme Q 10 Following Agrobacterium tumefaciens Fermentation

The yield of CoQ₁₀, an intracellular product extracted from Agrobacterium tumefaciens cells is dependent on the effectiveness of cell lysis post fermentation. Various cell lysis approaches are investigated, including ultrasound, repetitive freezing/thawing, grinding and acid-heat treatment. The acid-heat combination using hydrochloric acid is found the most effective in releasing CoQ₁₀, followed by lactic, sulfuric, phosphoric and oxalic acids. The most significant processing parameters, namely the ratio of acid solution volume and bacteria weight (A/B ratio), incubation temperature and reaction time, are optimized by using the central composite design with a quadratic regression model built by response surface methodology. The highest CoQ₁₀ yield at 1.518 mg/g dry cell is attained using hydrochloric acid (3 mol/L) under optimal A/B ratio, temperature and time at 10.8 mL/g, 84.2 °C and 35.3 min, respectively.