Studying methods for extracting intracellular polysaccharide derived from cariogenic bacteria

The contribution of intracellular polysaccharide (IPs) on caries development is not well established since their extraction protocol is on debate. The aim of the work is to compare different forms to extract IPs from cariogenic bacteria. IPs from cariogenic biofilm were extracted by the following protocols: a) incubation at 100°C, 1M NaOH, 15 minutes (standard protocol); b) incubation at 100 °C, 1 M NaOH, 5 or 10 minutes; c) incubation at 100 °C, 0.5 M NaOH, 5, 10 or 15 minutes; d) sonication with water or saline with 1 pulse of 15 s and amplitude 20, 30 or 40%. The IPs were quantified and the results suggest the standard methodology can extract more carbohydrate than alternative protocols. However, IPs were analyzed by the total carbohydrate methodology, which does not specify the type of carbohydrate extracted. Monosaccharide composition studies are required to solve this issue.