Biofilm development by Listeria innocua in turbulent flow regimes

Chemostat-cultured cells of L. innocua were continuously recirculated through a stainless steel tubes at Reynolds numbers ranging from 9,500 to 16, 500 for 7 days. Samples of the tubes were removed by a special method and were examined using SEM. Biofilm formation had occurred after only 1 day at Reynolds numbers of 9,500 and 11,500 and the extent of coverage increased with time. At the higher Reynolds numbers (13,000 and 16,500) only individual cells were evident after 1 day, but these developed to form microcolonies. After 7 days biofilms had become established at all four Reynolds numbers.