The uptake of bacteria and amino acids by Ophryoscolex caudatus, Diploplastron affine and some other rumen Entodiniomorphid protozoa

摘要

The rate of uptake of mixed rumen bacteria and free amino acids by washed suspensions of seven species of rumen ciliate protozoa has been followed. By assuming that the behaviour of these protozoa was the same under these conditions as during growth it was shown thatOphryoscolex caudatuscould obtain the amino acids for growth by the engulfment of rumen bacteria. However, all the cellulolytic protozoa studied(Diploplastron affine, Diplodinium anacanthum, Diplodinium anisacanthum, Enoploplastron triloricatum, Eremoplastron bovisandOstracodinium obtusum bilobum)were unable to obtain sufficient amino acids from either source to grow at even 25 of the maximum rate and it is postulated that they might utilize plant protein.O. caudatusgrownin vitrodid not engulfKlebsiella aerogenesorEscherichia colibut took up other bacteria and a rumen yeast at rates of up to 54000 organisms/protozoon/h from a population density of 109/ml. When grownin vivoit was more selective and engulfed mixed rumen bacteria at only 10 of the rate obtained with protozoa grownin vitro. D. affinegrownin vitrodid not engulfBacteroides ruminicola, Esch. coli, Kl. aerogenesorProteus mirabilisbut took up mixed rumen bacteria from a population of 109/ml at a rate of 2200 bacteria/ protozoon/h.