Studying effects of lecithin and glucose on the growth properties of Streptococcus pneumoniae strains

The article presents the results of evaluating the effect of the addition of glucose and lecithin to the culture medium (Brain Heart Infusion Broth) on the rate and accumulation of biomass of various Streptococcus pneumoniae strains: No. 3405, serotype 4 (K-4); No.16082, serotype 14 (K-14); No. 3391, unstable in capsule formation (R-form). There was an increase in the biomass accumulation of strain No. 3405 (K-4) by 10% in the variant with the addition of lecithin; an increase in biomass by 64% and an elongation of the stationary phase in strain No. 16082 (K-14) when grown with the addition of glucose. There was an increase in the biomass growth of strain No. 3391 (R-form) by 37.5% and an extended duration of the stationary phase occurred when grown with lecithin. Based on the results obtained, it can be noted that lecithin and glucose had different effects on the growth of the studied strains of pneumococcus. The obtained data showed that strain No. 16082 (K-14) was the most promising and technologically advanced. Strain No. 16082 (K-14) had a more stable growth during three passages and in all three cases was identified with a high score value (2>) by MALDI-TOF mass spectrometry, had a higher level of biomass accumulation, and possessed a denser sediment of biomass. The study resulted in the selection of strain, optimal composition of the growth medium and suitable cultivation conditions to obtain a higher yield of S. pneumoniae biomass.