Bacterial boundary—Actinomycete phylum
Actinobacteria is a class of gram-positive bacteria that inhabit water or on land, and although initially identified as soil fungi, species in freshwater may be more abundant than those on land, with branched fibers and spores that reproduce on spores and are ostensibly similar to fungi belonging to eukaryotes. Because of their morphology, it was thought that they were species somewhere between bacteria and mold, so they were originally classified as actinomycetes. But because actinomycetes do not have a nuclear membrane and the cell wall is made up of peptidoglycans, like other bacteria. Currently, through molecular biology methods, actinomycetes are identified as a large branch of bacteria. Actinomycetes stained with Gram can be stained purple (positive), and the gc content of actinomycetes is higher than that of another type of gram-positive bacteria, the pachychophyte phylum. But a 2012 study showed that some freshwater actinomycetes have lower GC levels, and the GC ratio of these freshwater actinomycetes can be as low as 42%.
The actinomycete phylum is one of the important bacterial phylums, which contains the largest genus, Streptomyces. Phylogenetic analysis can be sequenced in glutamine synthase.
While some of the largest and most complex bacterial cells are actinomycetes, actinomycetes living in the ocean have been described as prokaryotic cells with the smallest free life.
Important genera of actinomycetes are:
Actinomyces
Arthrobacter
Corynebacterium
Frankia
Micrococcus
Micromonospora
Mycobacterium
Nocardia
Propionibacterium
Streptomyces
Most of the actinomycetes are saprophytic bacteria, generally distributed in the soil, generally good gas, a few are symbiotic with some plants, there are also parasitic bacteria, can cause disease, parasitic bacteria are generally anaerobic bacteria. Actinomycetes have a musty smell of soil that makes water and food smelly, and some actinomycetes can also mold cotton wool products or paper like mold. The colonies formed by actinomycetes in the culture medium are relatively strong, and after the spores grow, the colonies have a powdery appearance of various colors, which are different from the colonies of bacteria, but cannot spread outward growth, and the mold is also different. Actinomycetes have hyphae, which are 1 μ in diameter and are similar in width to bacteria, but there is no transverse septum in the hyphae, which is different from mold. Actinomycetes can mainly promote the decay of animal and plant remains in the soil, and the most pathogenic actinomycetes are Mycobacterium tuberculosis and Mycobacterium leprosy, which can cause tuberculosis and leprosy in humans. The most important role of actinomycetes is to produce and refine antibiotics, at present, more than 2,000 kinds of antibiotics have been found in the world, about 56% of which are produced by actinomycetes (mainly streptomyces), such as streptomycin, oxytetracycline, tetracycline, gentamicin, etc. are produced by actinomycetes. In addition, some plant agricultural antibiotics and vitamins are also extracted from actinomycetes.
The special smell that appears in the air after rain has a lot to do with actinomycetes: moist air carries some of the spores of actinomycetes floating around, and people smell pleasant odors after inhalation. But in addition, the factors that affect the smell of the air after the rain are: the reaction of weakly acidic rainwater and the surface of the material may produce an aromatic odor, but it produces more unpleasant odors; the volatile essential oils of plants after the rain often make people smell fragrant.
Most medical or economic subclass actinomycetes play an important role in the order Actinomycetes. Of the many bacteria of this purpose, only Streptomyces is a notable source of antibiotics.
Among those bacteria of the actinomycete subgenus rather than actinomycetes, Gardner's is one of the most studied bacteria. The medical classification of Gardner's bacteria is controversial, and the medical subject word classifies it as a organism that is both a Gram-positive and a Gram-negative bacterium. Actinomycetes subclass, particularly Streptomyces, is recognized as the manufacturer of many biologically active metabolites that are medically useful to humans, such as antibacterial drugs, antifungals, antithrombotics, immunomodulators, antitumors, and enzyme inhibitors; in agriculture, its uses include insecticides, herbicides, fungicides, and plant and animal growth promoters. Antibiotics from important medically important sources of actinomycetes include aminoglycosides, anthracyclines, chloramphenicol, macrolides, tetracyclines, and so on.
Streptomyces and other actinomycete organisms mainly contribute to the biobuffing of soil and play a role in the decomposition and conduction of organic matter in crop production.
2.1.2 Actinomycete phylum
2.1.2.1 Actinomycetes
2.1.2.1a Acid microbacterium suborder
2.1.2.1a.1 Acid microbial order
2.1.2.1a.1a Acid microbacterium suborder
2.1.2.1a.1a.1 Acid microbial family
2.1.2.1b Actinomycetes suborder
2.1.2.1b.1 Actinomycetes
2.1.2.1b.1a Actinomycetes suborder
2.1.2.1b.1a.1 Actinomycetes
2.1.2.1b.1b Suborder Corynebacterium
2.1.2.1b.1b.1 Corynebacterium family
2.1.2.1b.1b.2 Ditzellaceae
2.1.2.1b.1b.3 Mycobacteriaceae
2.1.2.1b.1b.4 Nocardia family
2.1.2.1b.1b.5Zukamura Clan Mycology
2.1.2.1b.1c Suborder Frankella
2.1.2.1b.1c.1 Acid thermidocyctics
2.1.2.1b.1c.2 Frankella family
2.1.2.1b.1c.3 Phyllobacteriaceae
2.1.2.1b.1c.4 Sporeaceae
2.1.2.1b.1d Glucosinomycete suborder
2.1.2.1b.1d.1 Glycodermae
2.1.2.1b.1e Micrococcus suborder
2.1.2.1b.1e.1 Acquired in the Family Of Themicaceae
2.1.2.1b.1e.2 Bogoria Lake Mycosidae
2.1.2.1b.1e.3 Bulbophyllaceae
2.1.2.1b.1e.4 Cellulosemonas
2.1.2.1b.1e.5 Micrococcus family
2.1.2.1b.1f Micromonas suborder
2.1.2.1b.1f.1 Micromonasporaceae
2.1.2.1b.1 g of propionic acid bacillus suborder
2.1.2.1b.1g.1 Nocardiaceae
2.1.2.1b.1g.2 Propionatecilli family
2.1.2.1b.1h Suborder Streptomyces
2.1.2.1b.1h.1 Streptomyces
2.1.2.1b.1i Suborder Streptomyces
2.1.2.1b.1 Bifidobacterium
2.1.2.1b.1.1 Bifidobacterium family
2.1.2.1c Erythropodidae suborder
2.1.2.1c.1 Order Erythrophoridae
2.1.2.1c.1a Erythrophoridae suborder
2.1.2.1c.1a.1 Erythrophoridae
2.1.2.1d Red Bacillus suborder
2.1.2.1d.1 Order Red Bacillus
2.1.2.1d.1a Suborder Red Bacillus
2.1.2.1d.1a.1 Red Bacillus family
2.1.2.1 e-Coccidioides suborder
2.1.2.1e.1 Bulbophyllum
2.1.2.1e.1a Suborder Spheroides
2.1.2.1e.1a.1 Bulbophyllaceae
Mycobacterium is a genus under the phylum Actinomycetes and is the only genus in the mycobacteriaceae family.
The genus includes many pathogens known to cause serious disease in mammals, including mycobacterium tuberculosis and mycobacterium leprae.
Species in this genus are aerobic bacteria and are inactive bacteria (with the exception of Mycobacterium marine, which can move within macrophages) and are acid-fast bacteria. Mycobacteria do not form endospores or pods, so they are often identified as gram-negative bacteria. Mycobacteria are not stained with crystal violet on gram staining, so they cannot be classified as gram-positive or negative bacteria.
Although the genus does not produce spores, two species appear to be exceptions: mycobacterium marinum and mycobacterium bovine (m. marinum). bovis）。 But further research sparked controversy.
Mycobacterium is characterized by its thicker cell walls than other species, waxy hydrophobicity, and large amounts of mycolic acids. Polysaccharides pull together the mycobacterial acid layer and peptidoglycan layer, making the cell wall very tough. If the biosynthetic pathways of its cell wall can be interfered with, drugs to treat tuberculosis may be developed.
Mycobacteria can be infected by mycobacterium phages, a bacterial virus that could be used in the future to treat tuberculosis and related diseases through phage therapy.
Streptomyces, also known as streptocetes, is a large genus of actinomycete phylum, with about a thousand species.
Streptocetes are good, most of them are saprophytic, their matrix hyphae are not broken, aerobacterial hyphae differentiate into straight, curved or spiral-shaped spore filaments, and mature spores generate chain-like conidia, so they are called streptocetes. Colonies are small, dense, difficult to pick, and have a powdery, velvet-like surface and come in a variety of colors.
In the process of metabolism, the secondary metabolites of many strains of Streptomyces are antibiotics, such as streptomycin, tetracycline, erythromycin, kanamycin and chympromycin; some strains can produce proteases and glucose isomerases.
It is commonly found in soil and decaying plants and generally smells of earth. Streptomyces spp. multiplyes more slowly than other strains, but because antibiotics in metabolic processes can inhibit the growth of other strains, Streptomyces will become the dominant species on the territory over time.
Streptomyces species mostly have the property of exchanging rna between the same genus, so new Streptomyces species continue to be discovered.
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