Culture medium optimization of fastidious Parvimonas micra

Abstract:

[Objective] To improve the culture medium components of Parvimonas micra, increase the number of live cells, and develop a demonstration method for culturing fastidious bacteria. [Methods] Biochemical analysis was conducted on a strain of P. micra to screen the potential substrates that could promote bacterial growth. A single-factor experiment was carried out for each substrate with three concentrations. The substrate with a significant bacterial enrichment effect was further optimized for concentration, and thus a new culture medium was obtained. [Results] The single-factor experiment results showed that the substrates with significant bacterial enrichment effects included l-serine, l-threonine, and glycyl-l-glutamine. In the medium with the addition of 4.8 g/L l-serine, the live cell count of P. micra reached 3.6×10⁸ cfu/mL, representing a 4.2-fold increase compared with that in the basic medium with tryptone soya broth (TSB) and fetal bovine serum (FBS). Furthermore, the improved culture medium was applied to the culture of another P. micra strain, demonstrating a significant growth-promoting effect. [Conclusion] This study proves that using biochemical identification plates to screen medium supplements is a fast and efficient method, providing a reference for the enlargement culture of fastidious bacteria.