Rumen oligotrich protozoa, namely some species of Entodinium, were successfully cultured in vitro on a salt medium containing whole egg protein, proteose-peptone, rice starch, yeast extract, cellulose powder, and white clover juice. Of these constituents proteose-peptone, yeast extract, and cellulose powder could be omitted, but omission of the clover juice resulted in the death of the protozoa. Attempts to replace the clover juice by known compounds were unsuccessful. Entodinia were maintained for over 10 months on a medium of rice starch and finely ground white clover at population densities of 2-10×104/ml. On the two media described above populations up to 2-3×105/ml were obtained by using a simple apparatus. On the latter medium, the ciliates were maintained at a mean density of nearly 2×105/ml for more than 50 days. Entodinium caudatum, starting from a single cell, multiplied with the average division rate of approximately once per day during the initial 4 weeks. The clone was maintained for over 3 months with active multiplication. Morphological variation was observed in these clonal cultures.
L-Arginine-producing mutants were found in mutants resistant to various amino acid analogs including canavanine and antimetabolites derived from glutamic acid-producing bacteria such as Brevibacterium flavum, Corynebacteriumlilium, Microbacterium ammoniaphilum, Arthrobacter paraffineus, and Brevibacterium ketoglutamicum. L-Arginine producers could also be obtained by random isolation from cells treated with N-methyl-N′-nitro-N-nitrosoguanidine. The best producer, strain No. 352, was isolated as a 2-thiazolealanine-resistant mutant from a guanine auxotroph of Brevibacterium flavum. Strain No. 352 produced 34.8mg/ml of L-arginine in a medium containing 13% of glucose. L-Citrulline was also produced by this strain in the same medium.
Nineteen cultures, which belong to the genera Schizosaccharomyces and Endomyces, were examined for the Co-Q system. The Co-Q system of the genus Endomyces was found to be Q9. The four species hitherto described in the genus Schizosaccharomyces were, on the other hand, discriminated from each other on the basis of the quinone system; Co-Q10 in the pombe-malidevorans group and Co-Q9 in the octosporus-japonicus group. The results obtained are discussed in connection with other criteria such as antigenic structure, PMR spectra of cell wall galactomannans, and DNA base composition. The discussion is also made concerning the genus Octosporomyces KUDRIAVZEV separated from the genus Schizosaccharomyces.
It has been known that age 0 cells of Saccharomyces cerevisiae, lacking any bud scar, hardly form any spore, while the cells of age 1 or more sporulate abundantly. Based on this finding we attempted to elucidate at what stage of cell age the age 0 cells acquire sporulation activity. Aliquots of the synchronous culture started from small age 0 cells were transferred to sporulation media at time intervals and sporulation in each culture was examined. Results showed that age 0 cells were endowed with the sporulating ability just before the first bud initiation. The sporulation ability decreased after the first budding and increased again at the stage of the second budding. The fluorescent staining of the resultant asci revealed that most asci derived from cultures just before the initiation of the first budding carried neither bud nor bud scar. It was also observed that the number of spores per ascus changed with the cellular age. Cells in synchronous culture of large cells, most of which bear more than one bud scar showed similar changes in the sporulating ability during their cell cycle. Addition of tomato juice to the culture media preceding sporulation stimulated the sporulating ability.
1) Liver extract of a marine gastropod, Turbo cornutus, destroyed the pyocin-R receptor activity of the lipopolysaccharide of sensitive Pseudomonasaeruginosa. 2) The extract contained at least two factors, probably proteins, attacking the receptor; one attacking below pH 4 inactivated the receptor immediately and the other with optimum pH 6.2 inactivated the receptor gradually. The latter was partially purified and its properties are described. It was strongly inactivated by acetate buffer.
When a water-soluble polymer ("Carbopol") was added to the growth medium of Aspergillus niger, significant enhancement in the rates of cellular growth and amylase production were observed. The role of the polymer additive in the system was not due to its utilization as a source of energy, neither to removal of toxic metabolic byproduct. Furthermore, it did not alter the respiratory quotient nor did it affect the overall enzyme system for respiration. Gross morphological changes from discrete pellets to filamentous growth was the only accountable parameter for yield enhancement.