Mycotoxin biosynthesis

FIGURE 3.1 Development of PCR-based detection systems for mycotoxin producing-fungi from 1996 until April 2007. First publication of a diagnostic primer pair was taken as the time mark for each species depicted. In many cases, more systems were published later for the same fungus. Mycotoxin biosynthesis genes used as sequence source are given in bold. 

Burow, G.B. T.C. Nesbitt J. Dunlap N.P. Keller. Seed lipxygenase products modulate Aspergillus mycotoxin biosynthesis. MPMI 997, 10, 380-387. 

FERNANDES, M., KELLER, N.P., ADAMS, T.H., Sequence-specific binding by Aspergillus nidulans AflR, a C zinc cluster protein regulating mycotoxin biosynthesis, Mo/. Microbiol, 1998, 28, 1355-1365. 

MCDONALD, T., DEVI, T., SHIMIZU, K., SIM, S.-C., KELLER, N. P., Signaling events connecting mycotoxin biosynthesis and spomlation in Aspergillus and Fusarium spp., 2004, in press. 

Mycotoxins—Synthesis. 2. Metabolism, Secondary. 3. fungi—Physiology. I. Steyn, Pieter S. [DNLM 1. Mycotoxins—Biosynthesis. QW630 B615J... 

The main concern regarding the utilization of Monascus pigments relates to the production of the citrinin mycotoxin in Monascus cultures. Several methods for controlling the mycotoxin production were proposed, including selection of non-toxinogenic strains, control of citrinin biosynthesis, and modifications of culture conditions. Despite their wide and traditional food applications in Asian countries, Monascus pigments have not been approved for use in the United States or European Union. 

G.W. Kirby and D.J. Robins, in Biosynthesis of Mycotoxins. A Study in Secondary Metabolism, Academic Press, New York, 1980, 301-355. 

C domains can display functions that deviate from typical amide bond formation. Several C domains are postulated to act as ester synthases, catalyzing ester formation instead of amide formation. NRPS modules containing C domains that display this activity are present in the biosynthetic pathways for the kutznerides, cryptophycins, " cereulide, valinomycin, hectochlorin, and beauvericin. Each of these C domains likely utilizes a PCP-bound a-hydroxyl acceptor in the condensation reaction. Another NRPS C domain that catalyzes ester bond formation is involved in the biosynthesis of the polyketide-derived mycotoxins known as the fiimonisins. Du and coworkers have shown that a recombinant PCP-C didomain of an NRPS involved in the biosynthetic pathway of the fnmonisins can catalyze ester bond formation between hydroxyfumonisins and the A-acetylcysteamine thioester of tricarballylic acid, even though PCP-bound tricarballylic acid is not... 

Huff, W. E., and Hamilton, P. B. (1979). Mycotoxins - their biosynthesis in fungi Ochratoxins -metabolites of combined pathways. /. Food Prot. 42,815-820. 

Mothes, K. in "Secondary Plant Products" Encylopaedia of Plant Physiology New Series, Vol. 8 Ed. Bell, E.A. and Chari wood B.V. Springer-Verlag, Berlin, 1980, p. 1 Bu Lock, J.D. in "The Biosynthesis of Mycotoxins", Ed. Steyn, P.S., Academic Press, New York - London, 1980, p. 1 Janzen, K.H. in "Herbivores - Their Interactions with Secondary Metabolites" Ed. Rosenthal, G.A. and Janzen, D.H. Academic Press, New York - London, 1979, p. 331 Rhoades, D.F. in "Herbivores - Their Interactions with Secondary Metabolites" Ed. Rosenthal, G.A. and Janzen, D.H. Academic Press, Nre York - London, 1979, p. 3. 

In the first part of this chapter, we deal with insecticides including miticides and nematocides, which include very useful compounds such as avermectins and milbemycins, produced by bacteria and fungi. We list out microbial insecticides of importance and review the works mainly on the mode of action and biosynthesis of each metabolite. In the next part, major mycotoxins are listed and recent topics on them, especially on their biosynthesis, are described. Since contamination of two major mycotoxin groups, aflatoxins (AFs) and trichothecenes, in food and feed is a worldwide problem, they are treated in detail in the last part of this chapter. Recent studies on their biosynthesis, regulatory mechanism for their production, and inhibitors of their production are described. 

Citreoviridin (79), luteoskyrin (80), and cyclochlorotine (81) are historical mycotoxins studied in Japan. Citreoviridin was isolated as a toxin from Penicillium citreoviride associated with a disease called cardiac beriberi or shoshin kakke .164 Luteoskyrin and cyclochlorotine were isolated from Penicillium islandicum, which was infected into toxic yellowed rice.165 Genes responsible for biosynthesis of these compounds are not obtained. 

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