Pre_GI: SWBIT SVG BLASTP

Query: NC_016582:7699420 Streptomyces bingchenggensis BCW-1 chromosome, complete genome

Lineage: Streptomyces bingchenggensis; Streptomyces; Streptomycetaceae; Actinomycetales; Actinobacteria; Bacteria

General Information: Streptomyces bingchenggensis BCW-1 was isolated from a soil sample collected in Harbin, China. This species produces milbemycins, a family of macrocyclic lactones widely used in human health, animal health, and crop protection. The characteristic earthy smell of freshly plowed soil is actually attributed to the aromatic terpenoid geosmin produced by species of Streptomyces. There are currently 364 known species of this genus, many of which are the most important industrial producers of antibiotics and other secondary metabolites of antibacterial, antifungal, antiviral, and antitumor nature, as well as immunosuppressants, antihypercholesterolemics, etc. Streptomycetes are crucial in the soil environment because their diverse metabolism allows them to degrade the insoluble remains of other organisms, including recalcitrant compounds such as lignocelluloses and chitin. Streptomycetes produce both substrate and aerial mycelium. The latter shows characteristic modes of branching, and in the course of the streptomycete complex life cycle, these hyphae are partly transformed into chains of spores, which are often called conidia or arthrospores. An important feature in Streptomyces is the presence of type-I peptidoglycan in the cell walls that contains characteristic interpeptide glycine bridges. Another remarkable trait of streptomycetes is that they contain very large (~8 million base pairs which is about twice the size of most bacterial genomes) linear chromosomes with distinct telomeres. These rearrangements consist of the deletion of several hundred kilobases, often associated with the amplification of an adjacent sequence, and lead to metabolic diversity within the Streptomyces group. Sequencing of several strains of Streptomyces is aimed partly on understanding the mechanisms involved in these diversification processes.

Subject: NC_007333:1457000 Thermobifida fusca YX, complete genome

Lineage: Thermobifida fusca; Thermobifida; Nocardiopsaceae; Actinomycetales; Actinobacteria; Bacteria

General Information: Produces thermostable enzymes. Members of this genus are distinguished from most actinomycetes by their ability to form clustered spores that attach directly to the substrate mycelia, and not to the aerial mycelia. Moreover, these bacteria do not produce aerial mycelia at all. M. fusca is the most thermophilic, with some growth detectable at up to 75 degrees C. The natural habitat of Thermobifida is self-heated organic materials, like rotting hay, compost, manure or urban waste piles, etc., which they share with other thermophilic and thermotolerant actinomycetes. Biological and physiological features of these bacteria are accordingly adapted to the conditions of such environments, namely the high temperatures and the presence of abundant plant materials and other bio-polymer substrates of natural origin. Actinomycetes are well suited for this environment because they generally grow as branching hyphae and are well adapted to penetration and degradation of insoluble substrates such as lignocellulose. Spores of Thermobifida are known to cause allergic respiratory diseases called mushroom worker disease and farmer's lung, which develop in agricultural workers who by the nature of their work happen to breathe in significant amounts of actinomycete spores from hay, compost, etc. Some isolates of this organism are able to mineralize plastic disposals and other anthropogenic xenobiotics. Thermobifidaare of particular interest because they produce multiple thermostable enzymes involved in the degradation of lignocellulose.