Actinomycetes degradation

Parales RE, JE Adanus, N White, HD May (1994) Degradation of 1,4-dioxane by an actinomycete in pure cultures. Appl Environ Microbiol 60 4527-4530. 

The microbial activity in forest soils is much more intense in comparison with Tundra ecosystems. Fungi, bacteria and actinomycetes play a significant role in degradation of carbohydrates of forest litterfall (Box 1). 

In laboratory tests, several fungi and cultures of actinomycetes isolated from garden soil readily degraded disulfoton (Bhaskaran et al. 1973). In flooded soil under anaerobic conditions, the reduction of disulfoton sulfoxide to disulfoton was due to biological conversion (Tomizawa 1975). 

In general, microorganisms on/in solid phases can be viewed as a vast biological entity whose parts live in unison, with diverse capabilities for the degradation of all natural organics and many xenobiotics. The major characteristics and differences of bacteria, actinomycetes, and fungi are compared in Table 1. 

Soil The actinomycete Nocardiopsis sp. isolated from soil extensively degraded pure cis- and /ra/3s-chlordane to dichlorochlordene, oxychlordane, heptachlor, heptachlor e/ c/o-epoxide, chlordene chlorohydrin, and 3-hydroxy-traas-chlordane. Oxychlordane slowly degraded to 1-hydroxy-2-chlorochlordene (Beeman and Matsumura, 1981). In Hudson River, NY sediments, the presence of adsorbed chlordane suggests it is very persistent in this environment (Bopp et al., 1982). The reported half-life in soil is approximately 1 yr (Hartley and Kidd, 1987). 

Chacko et al. (1966) reported DDT dechlorinated to DDD by six actinomycetes Norcardiasp., Streptomyces albus, Streptomyces antibioticus, Streptomyces auerofaciens, Streptomyces cinna-moneus, Streptomyces viridochromogenes) but not by eight fungi. The maximum degradation observed was 25% in 6 d. 

Briglia, M. (1995). Chlorophenol-degrading actinomycetes molecular ecology and bioremediation properties. Ph.D. Thesis, Department of Applied Chemistry and Microbiology, University of Helsinki, Helsinki, Finland. 

Table 6.1 Comparison of Mechanisms of Keratin Degradation by a Dermatophyte Fungus with That of an Actinomycete...

Hemicelluloses, the second group of plant-cell constituents, are water-insoluble polysaccharides. During the first stage of attack, hemicelluloses disappear more rapidly than cellulose. Later, hemicelluloses slow down in degradation owing to their heterogeneity. Fungi, bacteria, and actinomycetes are able to break down hemicelluloses by... 

Jarerat, A. Tokiwa, Y. (2001a). Degradation of poly(tetramethylene succinate) by thermophilic actinomycetes. Biotechnology Letters, 23, 647-51. 

Anhker, R, Dvomik, D, Gubler, K, Heusser, H, Prelog, V, Metabolic products of actinomycetes V. The lactone of p-hydroxy-a,a,y-trimethylpimehc acid, a degradation product of narbomycin, picromycin, and methymycin, Helv. Chim. Acta, 39, 1785-1790, 1956. 

Soil microorganisms (fungi, bacteria and actinomycetes) play a major role in the degradation of organic matter, ultimately releasing nutrient elements— about 98% nitrogen, 5-60% phosphorus and 10-80% sulphur to the soil nutrient pool—along with micronutrients such as boron and molybdenum, into the soil for reuse by plants and animals. The role of biotic soils as sources of N and CH4... 

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