Ochromonas

Semple KT, RB Cain (1996) Biodegradation of phenols by the alga Ochromonas danica. Appl Environ Microbiol 62 1265-1273. 

Until recently, the only marine example of cycloartenol (32) production was in the chrysophyte Ochromonas sp. [20], A survey, documenting the products of squalene oxide (37) cyclization (see Scheme 3) using crude enzyme preparations of various algal phyla has recently been reported [21]. Interestingly, while all... 

Freshwater diatom, Nitzschia palea-, 5 pg/L Alga, Ochromonas danica... 

Piccinni, E. and O. Coppellotti. 1982. Response to heavy metals in organisms-II. Effects of physiological metals on Ochromonas danica. Comp. Biochem. Physiol. 71C 135-140. 

The inoculum for the assay is prepared by growing Ochromonas for 4-6 days in the basal medium supplemented with 10 m ig/ml of thiamine. The culture is then diluted 1 100 with basal medium a drop of this dilution serves as an inoculum for each assay flask. There is no... 

Medium for Thiamine Assay with Ochromonas malhamensisa... 

Fig. 1. Typical growth curve in thiamine assay with Ochromonas malhamensis [Baker et al. (B15)].

Nutritional and cultural techniques for growing Ochromonas danica in light and darkness have been described (A2, H18). It was grown under constant illumination from five 40-watt warm-white fluorescent lights, ca. 1.0 m from the cultures. Transfers were made weekly in 10 ml of maintenance medium 1ml was used for transfer (Table 6). 

Basal Medium for Ochromonas danica in Biotin Assay ... 

Fig. 2. Typical biotin curve for Ochromonas danica [Baker et al. (B3b)].

Knowledge of the coenzyme forms of vitamin Bi2 has increased steadily. The first coenzyme of Bi2 isolated from bacteria had similarities to pseudovitamin Bi2 it contained adenylic acid instead of 5,6-dimethyl-benzimidazole, but differed in lacking cyanide and having an extra molecule of adenine which was assumed to be bound to the cobalt atom by the coordination site, often occupied by cyanide (B24). This coenzyme, adenylcobamide, was completely inactive for Ochromonas malhamensis, but active for Escherichia coli 113-3. 

Ochromonas malhamensis responds to vitamin Bi2, but not to pseudovitamin Bi2 E. coli responds to both forms. Later other coenzymes were isolated (B25). One contained benzimidazole (BC), the other... 

Although B12 can be assayed biologically in mice, chicks, and rats, especially with the use of radioactive cobalt, the microbiologic method of assay is preferred because it is economical and sensitive. One serious drawback of bacterial Bi2 assay procedures is the lack of specificity and sensitivity. The extreme sensitivity (1 X 10 12 g) and relative freedom of stimulation in blood, serum, and urine make protozoa the choice assay tools (B17, F3, H19). The most specific is O. malhamensis (B17, F3) Euglena is known to be stimulated by pseudo-B12 (F2). Serum and blood from normal subjects have a growth-promoting effect on Euglena (M12) above that seen with Ochromonas. The reason for such... 

F2. Ford, J. E., Microbiological assay of vitamin B12. The specificity of the requirement of Ochromonas malhamensis for cyanocobalamin. Brit. J. Nutrition 7, 299-306 (1953). 

Kl. Kamikubo, J., and Oguni, Y., Microbiological determination of vitamin B12 with Ochromonas malhamensis. J. Vitaminol. 5, 51-60 (1959). 

The physiological functions of isofloridoside in algae have been shown to be (a) a carbohydrate reserve, and (b) a factor involved in controlling the osmotic balance in, for example, Ochromonas malha-men.st.s.242 244-247-249 Ochromonas is a green-brown alga that lacks a cell... 

Patni, N.J. Aaronson, S. (1974). Partial characterization of the intra-and extracellular acid phosphatase of an alga, Ochromonas dancia. Journal of General Microbiology 83, 9-20. 

Rothhaupt, K. O. 1996. Utilization of substitutable carbon and phosphorus sources by the mixotrophic chrysophyte Ochromonas sp. Ecology 77 706—715. 

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