title: Effects of pH on the growth rate, motility and photosynthesis in Euglena gracilis.
abstract: The influence of pH 3-10 on the growth, motility and photosynthesis in Euglena gracilis was demonstrated during a 7-d cultivation. The cells did not survive at pH < 4 and > 8, highest growth rate being detected at pH 7. Motility followed a similar pattern as growth rate. Photosynthetic response curves were shown to be of the same type over the whole pH range. High respiration was characteristic for cells grown at pH 5 and 6, the lowest one at 7. At high and also at low pH more active respiration was found which can be considered as a protective response on proton stress. Respiration was not completely inhibited with potassium cyanide. Photosynthesis was the most effective at pH 6; lower and higher pH decreased photosynthetic efficiency. pH affected more the growth rate than the photosynthesis.
authors.affiliation: Department of Natural and Environmental Sciences, Mid Sweden University, 871 88 Härnösand, Sweden. roman.danilov@tnv.mh.se
authors.forename: R A
authors.initials: RA
authors.lastname: Danilov
authors.forename: N G
authors.initials: NG
authors.lastname: Ekelund
mesh_terms: D000818:Animals; D005056:Euglena gracilis / Q000254:growth & development / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D009068:Movement; D010101:Oxygen Consumption; D010788:Photosynthesis; D011190:Potassium Cyanide
chemical_list: D011190:Potassium Cyanide