Aim: To measure the biological activities of extracts of fodder grasses Onobrýchis arenária, Galéga orientális and Rhaponticum carthamoides that are commonly planted in Europe, Middle East and eastern Africa.
Methods and results: Microbial test-systems based on Escherichia coli BW25113 that allow measurement of gene expression, growth and survival, biofilm formation (BF) in combination with the standard chemical procedures were used. The extracts studied had radical scavenging and metal-chelating activities and induced expression of antioxidant genes via generation of hydrogen peroxide. However, the extracts did not affect bacterial growth in planktonic cultures but dose-dependently inhibited BF.
Conclusions: The most remarkable effects were observed in G. orientalis, a high-yielding crop, rich in crude protein and fibres.
Significance and impact of the study: Taking into account the antibiofilm activities of the extracts, a perspective for decreasing colonization of ruminants' gut with pathogenic bacteria might be suggested in case of feeding with all the grasses studied.
Keywords: Escherichia coli; biofilm formation; fodder grasses; microbial test-systems; redox activity.
© 2021 The Society for Applied Microbiology.