XVI International Botanical Congess

Pitcher plants capture prey in water-filled pitfall traps or pitchers. To what extent are plant enzymes, as opposed to bacterial enzymes, responsible for digestion of prey? We measured acid phosphatase (AP) activity in pitcher fluid in the presence and absence of bacteria, with and without feeding the pitcher. Repeated, sterile sampling of the same pitcher increased likelihood of bacteria entering the pitcher. Bacteria derived from pitcher fluid were generally resistant to antibiotics used. Pitchers with bacteria were highly variable in AP activity. AP activity in pitchers without bacteria was a small fraction of maximum activity measured with bacteria. Fed pitchers exhibited higher levels of AP activity than unfed pitchers. With regard to acid phosphatase, bacteria contributed significantly to the digestion process in the pitcher.