Ca2+ increases the specific coenzyme Q10 content in Agrobacterium tumefaciens

Area of Science:

• Microbiology
• Biotechnology
• Biochemistry

Background:

• Coenzyme Q10 (CoQ10) is a vital antioxidant and electron carrier.
• Optimizing CoQ10 biosynthesis in microbial hosts is crucial for industrial applications.
• Agrobacterium tumefaciens is a model organism with potential for CoQ10 production.

Purpose of the Study:

• To investigate the effect of various metal ions on CoQ10 production in Agrobacterium tumefaciens.
• To determine the optimal conditions for enhancing CoQ10 biosynthesis using calcium.
• To validate the findings at a pilot scale for industrial relevance.

Main Methods:

• Screening of multiple metal ions (Ca2+, Cr3+, Cu2+, Fe2+, Mg2+, Mn2+, Ni2+, Zn2+) at 1 mM concentration.
• pH-stat fed-batch fermentation with CaCO3 supplementation.
• Pilot-scale fermentation (300 L) to assess scalability.
• Measurement of CoQ10 content and assessment of cell growth and oxidative stress.

Main Results:

• Only calcium (Ca2+) significantly increased CoQ10 content without inhibiting cell growth.
• Supplementation with 40 mM CaCO3 in fed-batch culture enhanced specific CoQ10 content by 22.4% and oxidative stress by 48%.
• The positive effect of Ca2+ on CoQ10 production was confirmed in a 300 L pilot-scale fermentor.

Conclusions:

• Calcium is a key factor in enhancing CoQ10 biosynthesis in Agrobacterium tumefaciens.
• Increased oxidative stress induced by Ca2+ may stimulate CoQ10 production as a protective mechanism.
• These findings provide a foundation for optimizing industrial CoQ10 production through biological processes.