Optimization of medium and cultivation conditions for capsular polysaccharide production by Streptococcus pneumoniae serotype 23F

Abstract

The influence of medium composition and culture conditions on Streptococcus pneumoniae serotype 23F cultivation was investigated in order to develop an industrial method for polysaccharide (PS) production. Acid-hydrolyzed casein (AHC) and dialyzed enzymatically hydrolyzed soybean meal (EHS) were investigated as nitrogen sources, and the vitamin solution of Hoeprich's medium and dialyzed yeast extract as vitamin sources. The influence of initial glucose concentration was also evaluated. In flask experiments, the best nitrogen source for PS production was AHC; EHS yielded small amounts of PS without interfering with bacterial growth. Dialyzed yeast extract provided an approximately 2-fold increase in PS production when compared to Hoeprich's vitamin solution. In a 5-l bioreactor, it was observed that the pneumococcus did not grow under aerobic conditions, CO(2) did not increase PS yield, glucose was inhibitory above 30 g l(-1), and the main glucose catabolism product was lactate, which had an inhibitory effect on cell growth. When anaerobic cultivation was performed under N(2) flow using the optimized medium, 240 mg l(-1) of soluble PS was obtained, which represents a 3-fold increase in yield as compared to that described in the published patent [Yavordios and Cousin (1983) European Patent 0 071515 A1]. Application of these results would considerably simplify upstream and downstream processes for PS production.

Capsular polysaccharide production by Streptococcus pneumoniae serotype 1: from strain selection to fed-batch cultivation

“…Acid-hydrolyzed casein (AHC)-based medium (Gonçalves et al 2002) was employed for screening the best PS1 producer strain. The composition of AHC-based medium per liter was the following: 30 g AHC (Bacto TM Casamino Acids, BD/ Difco, Sparks, MD, USA), 20 g ultrafiltered yeast extract (BD/Difco, Sparks, MD, USA), 20 g glucose, 5 g potassium phosphate dibasic, 1 g sodium bicarbonate, 0.1 g L-asparagine (Asn), 0.6 g L-glutamine (Gln), 0.01 g choline, 2 mL salt solution, and 1 mL 10 % thioglycolic acid.…”

“…However, S. pneumoniae is highly sensitive to the pH decrease that occurs in flasks, which can greatly affect its growth (Gonçalves et al 2002;Liberman et al 2008). Also, while S. pneumoniae is an anaerobe aerotolerant microorganism (Auzat et al 1999), oxygen above a certain level can be inhibitory (Gonçalves et al 2002;Carvalho et al 2013).…”

Optimal Conditions for Streptococcus pneumoniae Culture and for Polysaccharide Production for Vaccines

“…pneumoniae culture conditions are critical for the determination of time profiles of bacterial cell growth and polysaccharide production, which dictate optimal harvest time. Uniformity in the molecular weight distribution of the polysaccharides is desirable for consistency in the manufacture of conjugate vaccines [22,23].…”

The kinetics of <i>Escherichia coli</i> B growth and bacteriophage T4 multiplication in SM-1 novel minimal culture medium

“…Glucose or glycerol are often used as carbon sources. Whereas nitrogen and amino acid sources are different extracts such as beef or yeast extract, caseine hydrolysates, ammonium salts or nitrates (Durnin et al, 2009;Gonçalves et al, 2002;Kim and Gadd, 2008). The presence or absence of various bacterial growths is dependent on the occurrence of mineral salts, or specific elements in the culture medium, such as Zn, Cu or Se, that regulate the activity of several, metabolic enzymes (Blencowe and Morby, 2003;Ding et al, 2010).…”