
Full text loading...
SUMMARY: An oligotrich protozoon identified as Eudiplodinium medium was separated in pure culture and inoculated into the rumen of an isolated ciliate-free buffalo (Bos bubalus L.) calf to act as a continuous source of the organism. Analysis of the protozoa showed that a single organism contained on average 3.35 + 0.003 μg. protein; the carbohydrate fraction (49.1% of dry matter) gave on hydrolysis 60.4% glucose. Growth rate of the protozoa in vitro was dependent on food concentration. The number of protozoa was doubled in 2 hr at a substrate concentration of 0.23 mg./protozoon; at lower concentrations the doubling time was greater; at higher concentrations (0.32 mg./protozoon) the organisms burst.
Eudiplodinium medium did not metabolize simple sugars; it utilized starch, amylopectin, amylose and showed highest activity with hemicelluloses. Xylans were degraded faster than arabans; xylans gave relatively lower amounts of volatile acids than did arabans; acetic and butyric acids predominated, formic acid and traces of propionic and lactic acids were found but no succinic acid. No cellulose digestion took place during incubation for 12 hr; with longer periods of incubation with cellulose the organisms died. Ammonium salts, urea and amino acids were not used by the protozoa; proteolytic activity was observed towards gelatin, casein and gluten in descending order of activity. Cell-free extracts of E. medium showed activities towards carbohydrates as did whole organisms; xylanase activity was greatest. This enzyme was purified 28-fold; it had an optimum pH of 7.5 and an optimum temperature of 43°.
Article metrics loading...
Full text loading...
References
Data & Media loading...