Microorganisms and Fungi

The flora of raw cotton in the field is different from that of raw baled cotton. Some data from the literature are summarized in Table III. Field-grown cottons and their plant parts contain many more gram-negative microorganisms and fungi than do green-house-grown cottons. The weeds that contaminate the cotton crop... 

Microorganisms and fungi are an especially rich source of isoprenoids of the most diverse structures. Among these products one may find powerful toxins, compounds with antitumor and anti-inflammatory activity or antibiotics. Very little is known about their role in the host organisms. However, the broad spectrum of the observed biological activity could be taken as at least circumstantial evidence to indicate the existence of some function mediated by these products and essential to their producers. 

Anthranilic acid and indole are precursors of tryptophan in numerous microorganisms and fungi (e.g., 5, 263, 264, 602, 741, 783, 785, 816, 854, 855, 876), and it is probable that anthranilic acid is derived, with intermediate steps, from the common precursor, CP of diagram 1. The conversion of anthranilic acid to indole and tryptophan has been shown unambiguously in Neurospora with the use of isotopic techniques (93, 663). There may, however, be other pathways for tryptophan biosynthesis (45, 702). Tryptophan can, for example, be formed by transamination of indolepyruvic acid (e.g., 470, 912), which might be formed other than via anthranilic acid. Thus aromatic-requiring mutants have been found which accumulate unidentified indole compounds (307). 

Calcium oxalate minerals were found oidy in the rhizosphere soil. In soil, oxalates come from the acid dissociation of oxalic acid produced during the decomposition of organic matter or by the metabolism of microorganisms and fungi (Cromack et al., 1979 Malajczuk and Cromack, 1982 Fox, 1995 Jones, 1998 Caviglia and Modenesi, 1999 Tail et al., 1999). Plant roots can also excrete oxalic acid to increase the availability of Fe and P (Graustein et al., 1977 Jurinak et al., 1986 Bar-Yosef, 1991 Staunton and Leprince, 1996) or to inactivate toxic elements (Kochian, 1995). Once released, oxalic acid participates in mineral alteration (Shotyk and Nesbitt, 1992 Jones, 1998). The observation that at Mount... 

Chitin, the second most abundant natural polysaccharide, is widely distributed in nature as the principal component of exoskeletons of crustaceans and insects as well as of cell walls of some bacteria and fungi. Like cellulose, it is a glucose-based unbranched polysaccharide. Partial deacetylation of chitin results in the production of chitosan, which is a polysaccharide comprising copolymers of glucosamine and N-acetyl glucosamine. It is also naturally present in some microorganisms and fungi. 

Soil contaminated with TNT, RDX, HMX, or picric acid (ammonium picrate) can be bioremediated. One method involves composting the soil by mixing it with manure, sawdust, and so on. The same microorganisms and fungi that cause organic material to rot will eat the explosive contamination. The soil-manure mixture must be stirred and watered every few days to bring in oxygen. Some methods lay down perforated pipes and pile the mixture on top. 

An important established fact especially regarding the susceptibility of thermoplastic polymers is that while special-purpose additives in these polymers (such as plasticizers, stabilizers, fillers, dyes) can serve as nutrient sources to microorganisms and fungi, the degree of attack also depends on factors such as the lengths of the macromolecule chains, that is, polyethylene, polyvinylchloride, and polystyrene. Biodeterioration of polymers by microorganisms can be considered to be via two processes ... 

Biologically Active Peptides from Microorganisms and Fungi... 

Benzoquinone carbon atoms can be derived from acetic acid (acetyl-CoA in polyketide quinones) or from glucose (via shikimic acid in microorganisms and fungi). Terpenoid side chains are biosynthesised in the mevalonate (terpenoid) pathway. 

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