RAPID LARGE-SCALE GROWTH OF HELICOBACTER-PYLORI IN FLASKS AND FERMENTERS

We developed procedures for large-scale cultivation of Helicobacter py lori in flasks and fermentors. Flasks incubated closed under a microae rophilic gas phase with a cotton plug covered by a plastic bag, follow ed by removal of the bag after 8 h, gave excellent growth. Growth in a 10-liter fermenter led to excessive foaming if the medium was sparged with gas; silicone- or polyglycol-based antifoaming agents were sever ely inhibitory. Use of fermenter surface gassing, first with a microae rophilic 6% oxygen gas mixture, then with air, and then with 95% oxyge n, allowed the culture to grow to an A(600) of 2.5 in <24 h. This meth od was modified for scale-up to a 100-liter fermenter.