Neutralization study of L. lactis strain 3107 infection by phage TP901-1 in the presence of nanobodies. (A) OD at 500 nm of the culture in the presence of 105 pfu TP9010-1 and BppL VHH2, -11, -17, and -19 across the concentration range of 0.05–50 µg/mL after 7 h coincubation at 30 °C. (B) The same conditions were applied with Tal VHH11, -18, and -41. Controls of uninfected and infected culture in the absence of nanobodies were included, and all results are the average of at least triplicate assays.