Microbial defense substances

Substances with antibiotic properties are easily detected by appropriate screening procedures. Many of the microbial secondary products were examined with these methods and about 4500 compounds with antibiotic properties are known today. Approximately 3000 of them are derived from different Actino-mycetales, about 90 % originating from Streptomyces species. About 1000 compounds with antibiotic properties come from different fungi and 500-600 are formed from various bacterial strains (including Pseudomonales). Under natural conditions, however, obviously only a few of these substances play an ecological role in microbial defense, as may be shown by the following facts ... 

Smital T, Luckenbach T, Sauerborn R, Hamdoun AM, Vega RL, Epel D (2004) Emerging contaminants - pesticides, PPCPs, microbial degradation products and natural substances as inhibitors of multixenobiotic defense in aquatic organisms. Mutat Res 552 101-117 Snyder MJ (2000) Cytochrome P450 enzymes in aquatic invertebrates recent advances and future directions. Aquat Toxicol 48 529-547... 

Activity Via the gas phase [ 10 nL ( )-( 1 )/L] it is a potent inducer of proteinase-inhibitor proteins in some species of Solanaceae and Fabaceae . After uptake in the cells it is presumably rapidly hydrolysed to jas-monic acid [C,2H,g03, Mr 210.27, viscous oil, bp. 125 °C (0.13 Pa)], a ubiquitous, intracellular, plant signal substance which stimulates the synthesis of special proteins and induces the plant s defensive reaction via a gene activation . De novo synthesis of (3/f,75)-(-t)-jasmonic acid and an increase in the intracellular concentration of (3/f,75)-(-F)-jasmonic acid from 1-10 ng/g (dry weight) by one to three orders of magnitude occur within a few minutes, e.g., after contact with microbial cell wallswounding, and in shoot spiralization Exogenous application of (methyl)jas-... 

Note that in the context of FIFRA, the EPA has required prior notice of small-scale testing on some microbial pesticides. 59 Fed. Reg. 45600 (Sept. 1, 1994). This notification is required before an EUP, and the EPA may determine that no EUP is necessary. Because the definition of pesticide is governed by the intent to use the substance as a pesticide, then the microbial pesticide notification should be a sufficient demonstration of intent to use as a pesticide. The EPA has not adopted this position for TSCA purposes. However, there may be good defenses to an enforcement action based on failure to comply with TSCA once a... 

Certain groups of secondary products protect animals against predation and microbial attack (Table 67). These substances may be either synthesized de novo in the animal body or are taken up with the food and are used directly or in a modified form. Some compounds are built, stored and secreted in special glands, e.g., the defense glands of insects and the skin glands of salamanders and toads. Others are constituents of blood or gut. Most of the toxins have a broad spectrum of activity against different kinds of predators or microorganisms. 

The defense compounds produced in higher plants, as well as the toxic microbial products may be detoxified by hydroxylation, conjugation etc. (E 1) by the invading microorganisms and the infected plants, respectively. Even degradation to substances of primary metabolism occurs. This complicated field of metabolism, however, as yet is poorly understood. 

Plants produce antibiotic substances to defense themselves from insect and microbial attack, such as nicotine from tobacco leaves [37], rotenone from derris tree roots [38], pyrethroids from chrysanthemum flowers [39], and triterpenoids from neem tress [40], Evidence indicated that ginsenosides are one of the phytoanticipins to protect the ginseng plant. 

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