Isolation and in vitro cultivation of the fibrolytic rumen ciliate Eremoplastron (Eudiplodinium) dilobum

The rumen ciliate Eremoplastron dilobum was isolated from sheep rumen fluid and cultivated in vitro as a species population. Four different salt solutions were used to prepare the culture media. However, only the “Artificial rumen fluid” composed of (g/L): K2HPO4-3.48, NaHCO3-2.1, NaCl-0.76, CaCl2 × 6H2O-0.33, CH3COONa-6.12, MgCl2 × 6H2O-0.3, Na2HPO4-1.71, NaHPO4 × H2O-1.01 and distilled water enabled cultivation of this species for over 56 weeks. The protozoa were able to grow in a medium consisting of culture salt solution and powdered meadow hay (0.6 mg/ml per d). The addition of wheat gluten did not increase the population density of E. dilobum whereas the supplemented crystalline cellulose and/or barley flour improved the growth of ciliates (P < 0.05). The influence of xylan depended on its dose. The enzymatic studies confirmed the fibrolytic and amylolytic abilities of ciliates. Neither the solubility nor the increase of the supplemented dose of purified protein influenced the density of the ciliate population. The recommended food consisted of meadow hay, wheat gluten, crystalline cellulose and barley flour when supplied in the proportions of 0.6, 0.16, 0.12 and 0.12 mg/mL per day. We observed morphological variation of the ciliates, involving partial or complete reduction of the caudal lobes.