Partial depolymerization of capsular polysaccharides isolated from Streptococcus pneumoniae serotype 2 by various methods

• Published in: Carbohydrate research Vol. 512; p. 108503
• Main Authors: Gaikwad, Walmik Karbhari, Jana, Swapan K., Dhere, Rajeev M., Ravenscroft, Neil, Kodam, Kisan M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.02.2022
• Subjects: Acid hydrolysis; acid treatment; bioactive properties; Capsular polysaccharide; cell walls; depolymerization; high performance liquid chromatography; industry; Microwave; nuclear magnetic resonance spectroscopy; Partial depolymerization; polysaccharides; S. pneumoniae serotype 2; serotypes; Streptococcus pneumoniae; Thermal; ultrasonic treatment; Ultrasonication; vaccines; S. pneumoniae serotype 2; Ultrasonication; Acid hydrolysis; Partial depolymerization; Microwave; Capsular polysaccharide; Thermal
• ISSN: 0008-6215; 1873-426X; 1873-426X
• DOI: 10.1016/j.carres.2022.108503

Partial depolymerization of bacterial capsular polysaccharides (CPS) is an essential process carried out before its use as an antigenic preparation in a vaccine industry. Choice of CPS depolymerization methods depends on the process robustness, reproducibility, yield, retention of CPS bioactivity, etc. Partial depolymerization methods based on chemicals, enzymes, mechanical, thermal, etc. have been subject of many investigations before. Partial depolymerization of Streptococcus pneumoniae serotype 2 purified CPS was conducted by methods such as acid hydrolysis, microfluidization, ultrasonication, thermal and microwave. Partial depolymerization of the CPS was evaluated by size exclusion high performance liquid chromatography, whereas structural identity and conformity of CPS was ensured by 1H NMR spectroscopy. The antigenicity of CPS was assessed by bead based competitive inhibition assay. Microwave and thermal methods effectively depolymerized CPS and reduced the concentration of cell wall polysaccharide (CWPS) impurity, but both methods have a negative impact on the antigenicity of CPS. Whereas the trifluoroacetic acid treatment not only depolymerized the CPS but completely removed the CWPS while retaining the antigenicity of 92 ± 4% and this method is advantageous over other methods. [Display omitted] •Depolymerization challenges in production of bacterial CPS conjugate vaccine.•Various physiochemical methods were comparatively studied.•Partially depolymerized CPS evaluated by suitable analytical methods.•Acid hydrolysis were found to be most suitable for depolymerization.•Antigenic property of CPS retained after depolymerization by TFA.