Escherichia coli K-12 was exposed to Quillaja saponaria saponins from various commercial firms (Sigma, Roth and Nor-feed) and to an extract of Yucca schidigera plant powder (DK Sarsaponin 30) at different concentrations (0.05-1.0% w/v). A concentration-dependent response was observed. Quillaja saponaria saponins from Sigma increased growth up to 0.1% (w/v) level, whereas Nor-feed and Roth saponins produced maximum growth at a much higher level (0.5 and 0.75%, w/v, respectively). These results suggest that quillaja saponins from various sources differ in their biological activity, although all three saponins had the same content of vanillin-sulphuric acid reactive moieties. The lyophilized water extract from the DK Sarsaponin powder showed maximum growth at 0.1% (w/v) level. The levels at which maximum growth was observed did not change on subjecting the quillaja or yucca saponins to heat treatment in an autoclave (121 degrees C for 30 min). All the saponins and the plant extract increased growth of Escherichia coli up to a certain concentration and thereafter decreased growth. In spite of the decreased growth at higher levels of saponins, it was higher compared to the control (without saponin) up to levels of 1% (w/v) for all saponins except Quillaja saponins from Sigma, for which the growth was lower at levels of 0.25% (w/v) and higher. Saponins have the potential to modulate microbial growth in natural and artificial fermenters.
No takes yet. Share an insight, caveat, or question.
Sen et al. (1998) studied this question.