Growing Ochromonas malhamensis Above 35°C.*

Abstract

SUMMARY. Ochromonas malhamensis (Pringsheim strain) can be grown above 35.5°C.; below 35°, the previous chemically defined medium supports dense growth. The B12 and thiamine requirements rise steeply with temperature, and growth promotion by folic acid emerges; folic acid spares the enhanced B12 requirement. B12 is spared also, perhaps wholly bypassed, by purines + pyrimidines + amino acids (below 35°, exogenous purines, pyrimidines, and folic acid have little effect). Requirements also emerge for glycine (spared by serine), valine and isoleucine (their ratio is critical; leucine and threonine assist in maintaining a good balance), and, at very slightly higher temperatures, phenylalanine, tryptophan, cystine, and lysine. Requirements for Mg, Fe, Zn, and Mn appear to rise steeply with temperature; metal toxicities have to be circumvented carefully. The proportion of histidine + arginine to carbohydrate has to be increased, and a Krebs‐cycle component such as succinic acid becomes stimulatory. At 36.3–36.7°, a further supplement of crude natural materials such as an autoclaved suspension of Ochromonas cells is needed. Relevance of these findings to fever stress in vertebrates, general mitochondrial function, and repair of radiation damage, is discussed.

Vitamin B12 and Marine Ecology: The Response of Monochrysis Lutheri

“…It is possible that if these barriers could be overcome Monochrysis might behave more like Ochromonas in its requirement for vitamin B 12 . The anomolous results in the 25 0 experiment invite further investigation along lines indicated by Hutner et al (1957) and Scher & Aaronson (1958) for Ochromonas and Euglena. On the other hand, extrapolation of Ford's curve to lower vitamin B 12 values brings it well below the level of the Monochrysis curve at the same values.…”

“…(2) Agreement in the calculated magnitude of requirement (3 molecules per /x 3 of alga) between different algae may be a matter of chance, the sample being too small. Furthermore, greatly enhanced requirement occurs under conditions of temperature stress in at least one species (Ochromonas malhamensis) (Hutner et al, 1957).…”

Vitamin requirements and induced nutritional imbalances as criteria in speciating psychrophobic yeasts

“…A feature common to all strains of C. sloo[]ii besides choline inhibition was the inhibition by ammonium citrate + metals (the mixture of Hutner et al, 1957, for growing Ochromonas malhamensis above 35 C) in a simple defined medium at pH 5.0. No such inhibition was observed in any other species investigated.…”

Inhibition of Algae by Nystatin

“…Media. (i) Nutrient broth (Difco) or agar containing 1% glucose (initial pH 6.8); (ii) the defined medium described by Arnow, Oleson, and Williams (1953), hereafter termed medium A; (iii) the defined medium used by Hutner et al (1957) for the growth of Ochromonas (medium 0); (iv) the Cyanophycean medium described by Starr (1960), to which was added 1 mg/ml L-arginine monohydrochloride and 0.01 % manganese sulfate (medium C); (v) the soil-extract medium described by Starr (1960), to which was added 1 mg/ml yeast extract, 1 mg/ml LAMPEN AND ARNOW L-arginine monohydrochloride, and 0.01 % manganese sulfate (medium S).…”