Saprolegnia

The full details of the conversion of cycloeucalenol into [19- H]obtusifoliol by the microsomes of Zea mays in DjO have appeared (see Vol. 7, p. 135). The formation of a A intermediate in the enzymatic cleavage of the cyclopropane ring is excluded by the incorporation of only one deuterium atom. Both cyclo-artenol and lanosterol are converted into normal sterols by Saprolegnia ferax and Chlorella ellipsoidea. ... 

Increased susceptibility to mycotic dernial infections by Saprolegnia parasitica LC50 (144 h)... 

Shirasaka, N., Yokochi, T., and Shimizu, S. 1995. Formation of a novel odd chain polyunsaturated fatty acid, 5,8,11,17,17-a i-nonadecapentaenoic acid, by an EPA-producing aquatic fungus, Saprolegnia sp. 28YTF-1. Biosci. Biotech. Biochem., 59, 1963-1965. 

Order 2.—Saprolegniales.—Water molds which attack fishes, frogs, water insects, and decaying plants and animals. Example Saprolegnia,... 

Examples of other antiviral crude extracts from the Anthemideae tribe included the ethanol extract of Santolina oblongifolia Boiss. [56], and the hot water extract from Stevia rebaudiana Bertoni which showed anti-human rotavirus activity [57]. Another Santolina species, Santolina etrusca (Lacaita) Marchi et Dam., was also active against Saprolegnia ferax [24]. 

Apart from the above mentioned enzymes, there also exist a few enzymes involved in PUFA metabolic pathways that have recently been found. One of them is a novel n-3 fatty acid desaturase, isolated from an EPA-rich fungus, Saprolegnia diclina [248]. The gene was isolated by PCR amplification from a fungus cDNA library and then, expressed in S. cerevisiae, which was cultured in the presence of several FA as substrates. The study showed that the recombinant protein could exclusively desaturase C20 n-6 PUFAs, with preference for AA which was converted into EPA. This represents a completely novel and different activity from any organism previously described, and its potential for use in EPA production in transgenic oilseed crops has been outlined. 

Information on the effects of UVR on parasites and diseases in aquatic systems is mainly restricted to viruses and Saprolegnia spp. As we have seen in section 15.5, the interaction among UVR, viruses, and their hosts is extremely complex including direct and indirect effects. The use of models may help to explore the response of this system under UV stress. For example, the time needed to... 

L. G. Willoughby (1989). Continued defense of salmonid fish against Saprolegnia fungus after its establishment, J. Fish. Dis., 12, 63-67. 

Fusarium, Pythium, Rhizoctonia, Rhizopus, Saccharomyces, Saprolegnia ... 

Some of the enzymes from lower fungi, investigated by L John, are modulated by purine nucleotides, but generally in a different way from the regulation of GDH s from animal sources for example, whereas GDH s from Achlya and Saprolegnia are only weakly affected by purine nucleotides at concentrations of about 1 mM, that from Pythium is completely inhibited, in the direction of oxidative deamination, by 1 mM AMP (25). 

Several oomycete species, for example, Py. insidiosum, A. invadans, A. astaci, and Saprolegnia sp. are also cause of life-threatening infections in animals, fishes, and humans [160,161], Although most of those organisms have limited host range, but chemical basis of their host-specificity is vastly unknown. Zoospores of those non-plant pathogens are also attracted to the... 

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