Characteristics of marine actinomycetes Classification Distribution Habits Research status

One of the most prominent properties of actinomycetes is that they can produce a large number and variety of antibiotics

1. Actinomycete is a class of terrestrial prokaryotes that mainly grow in mycelial form and reproduce with spores. It gets its name because it grows radially on a solid medium.

2. Most have well-developed branched hyphae. The hyphae are slender, nearly as wide as rod-shaped bacteria, about microns. It can be divided into:

Vegetative hyphae, also known as matrix hyphae, have the main function of absorbing nutrients, and some can produce different pigments, which is an important basis for the identification of strains; Aerial hyphae, superimposed on vegetative hyphae, are also known as secondary hyphae.

3. Actinomycetes are widely distributed in nature, mainly in the form of spores or hyphae in soil, air and water, especially in the soil with low water content, rich organic matter, neutral or slightly alkaline soil. Actinomycetes are only a morphological classification and belong to the phylum Actinomycetes in the bacterial kingdom. The earthy smell peculiar to the soil is mainly caused by the metabolites of actinomycetes.

4. Actinomycetes are gram-positive bacteria, the nucleus is not coated with nuclear membrane, and the content of cell DNA is high (>50%), and most bacteria grow slowly, producing vegetative hyphae that can penetrate deep into the medium and aerial hyphae growing on the surface, and form asexual spores. Due to the different colors of spores, aerial hyphae and vegetative hyphae, the front and back of the colony often appear different colors.

5. Most actinomycetes are easy to raise, and only some species are trace amounts of aerobic bacteria and anaerobic bacteria.

Actinomycetes morphologically differentiate into hyphae and spores and are similar to fungi in culture characteristics. However, it is studied with modern molecular biology methods.

The results showed that actinomycetes belonged to a class of bacteria with branched mycelium and were positive for Gram stain. The main basis is: the same genus guess clear prokaryotic microorganisms:

The nucleus has no nuclear membrane, the nucleolus and the true chromosome; The cytoplasm of celery lacks organelles such as mitochondria and endoplasmic reticulum; Ribosomes for 70s; The cell structure and chemical composition are similar: the cell has a cell wall, the main component is peptidoglycan, and contains DPA; The diameter of actinomycete hyphae is basically the same as that of bacteria; The pH range of the optimal growth is basically the same as that of bacteria, and it is generally slightly alkaline; are susceptible to lysozyme and antibiotics, but not to antifungal drugs; The mode of reproduction is asexual reproduction, and the genetic characteristics are similar to those of bacteria.

Actinomycetes are widely distributed in nature, and silver buckets are mainly based on spores or hyphae.

The state is present in the soil, air, and water, especially the water content.

The amount of disturbance was the highest in the low, organic matter-rich, neutral or slightly alkaline brady-paced soils. Actinomycetes are only a morphological classification, not a term for biological classification, and some bacteria and fungi can also be classified as actinomycetes.