Experiments with haliscomenobacter hydrossis in continuous culture without and with zoogloea ramigera

A study has been made of the sheath-forming bacterium Haliscomenobacter hydrossis, by growing the organism in continuous culture. Glucose together with components from trypticase soy broth/yeast extract were used as the energy source. At low dilution rates glucose was a more important energy source than components from trypticase soy broth/yeast extract. H. hydrossis was unable to produce large amounts of reserve material even in the presence of an excess of glucose. The minimum doubling time was approximately 13 h in the complex medium. The uptake sequence of amino acids derived from the trypticase soy broth yeast extract was found to be as follows: glutamic acid, glycine, methionine, tryptophan, lysine and arginine were easily consumed by the micro-organism, whereas the other amino acids were taken up mainly at low dilution rates.Competition experiments were carried out with H. hydrossis and Z. ramigera at two different dilution rates (0.016 and 0.005 h^-t). At both dilution rates Z. ramigera was dominantly present in the cultures.Finally the glucose respiration and glucose uptake of a washed cell suspension of H. hydrossis was studied. The oxygen uptake rate increased only very slightly upon addition of glucose. The difference between endogenous respiration and oxygen uptake rate in the presence of glucose was increased when the washed cells had been aerated a period of time.