There is no self-acceptance in the barren cold of providence, so it is absolutely gorgeous to break Ling Jing.
Try to escape from the mouth of the urn to comfort the dog flies in the sand head.
Qiao Dazhuang at the end of the Qing Dynasty: "it is not cold to visit Zigui and see Jiangmei blooming in the snow on the shore."
Greater Cold is not only the last solar term in winter, but also the last solar term in 24.Greater Cold's solar terms often coincide with the time at the end of the year, and people are busy getting rid of the old and welcoming the new and preparing for the New year.
This solar term popular science will introduce to youDiversity and influence of Fungi in Nature.
What is a fungus?
Fungi are a kind of eukaryotes with absorption as the main nutrition, with cell wall, no chlorophyll, and most of them reproduce sexually or asexually by spores.
Fungi are a large biological population, and it is conservatively estimated that there are more than 1 million species of fungi in the world. About 150000 species have been described and recognized, including molds, yeasts and macrofungi (such as mushrooms).
The mycelium of typical fungi
Source: Microbiology: Principles and Explorations
Fungi are widely distributed all over the world, mainly in terrestrial, desert, saline-alkali and other extreme environments. Fungi have three forms of nutrition:Saprophytic, parasitic and symbiotic.
Most fungal parasites or saprophytes have no strict boundaries, some are mainly saprophytic, some are mainly parasitic, some are also engaged in saprophytic life, and some can establish symbiotic relationships with different biological groups, such as fungi and algae symbiosis to form lichens.
Classification of fungi
There are many systems for the classification of fungi, and most of them use Ainsworth's classification system. The fungal phylum can be divided into five subphyla: ascomycetes, flagellates, zygotes, basidiomycetes and demi-mycetes.
Some typical fungi
Source: Microbiology: Principles and Explorations
#1
Ascomycetes subphylumIt is the largest subphylum of fungi. In addition to yeast as a single cell, most of the vegetative bodies have developed mycelium, which have transverse septum and produce sexual spores (ascospores). The most familiar are Neurospora and Saccharomyces.
Flagellate subphylumIt produces asexual spores with flagella and exists as a single-celled individual or hyphae without diaphragm. The typical representative is Phytophthora infestans.
#2
#3
Half-known subphylumThe vegetative structure is unicellular or septate hyphae, and asexual reproduction is carried out by conidia. The representative bacteria in this subphylum are Penicillium and Aspergillus.
Subphylum zygomycetesIt can produce non-swimming asexual spores (zygotic spores), and the hyphae have no septum. The important representative bacteria are saprophytic bacteria in the soil, such as Rhizopus and Mucor.
#4
#5
Basidiomycetes subphylumVegetative bodies are unicellular or septate hyphae that produce sexual spores (basidiospores). Most of the familiar edible fungi belong to basidiomycetes.
Utilization of fungi
EdibleMany macrofungi are nutritious edible fungi, such as Lentinus edodes, Tremella fuciformis, boletus, Morchella and hericium Erinaceus.
Medicinal useFungi such as Cordyceps sinensis, Poria cocos, Polyporus umbellatus and Ganoderma lucidum can be used as drugs. Medicinal fungi can produce enzymes, proteins, amino acids, peptides, polysaccharides, alkaloids, sterols, terpenes, glycosides and vitamins during growth and development. The mycelium, sclerotia or fruiting body of fungi can be used directly, or the effective substances isolated from fungi can be used.
Industrial useIn the brewing industry, yeast is used to make wine and noodles, and Rhizopus and Mucor are used to make soy sauce, fermented bean curd and sauces.
In the petroleum industry, yeast is often used for oil dewaxing in recent years to reduce the freezing point of oil.
Industrial production, using fungi to produce ethanol, glycerol and enzyme preparations (cellulase, amylase) on a large scale through fermentation process; using fungi to produce organic acids (citric acid, Gallic acid), some drugs (ergoxin, cortisone), antibiotics (penicillin, griseofulvin) and immunosuppressive drug cyclosporine, etc.
Fungi are also used in other chemical, paper, leather and other industries.
Other applicationsIn agriculture, Beauveria bassiana and Trichoderma viride are used as biological insecticides and plant disease control agents.
In scientific research, fungi are an important research tool to study basic biological processes.
Fungi are also important decomposers in the ecosystem. Hyphae can secrete a variety of enzymes and can degrade macromolecular organic matter into small molecular substances in the environment.
The harm of fungi
Some fungi will be parasitic on the body surface or body of people or animals, from which they absorb nutrients, causing diseases such as tinea Manus, tinea pedis and so on.Accidental consumption of poisonous mushrooms can lead to poisoning and even death.Saprophytic fungi can cause food decay and produce toxins in the process of decomposing food, such as aflatoxins, aflatoxins can cause liver cancer in animals or humans.
Many forest plant and crop diseases are also caused by fungi. Thousands of fungi are known to attack plants and crops, such as wheat leaf rust, rice blast, potato late blight and so on.
Although fungi play an important role in the ecosystem, their parasitic and saprophytic characteristics will also bring a lot of harm. Therefore, we should fully understand fungi, make rational use and prevent them.
Science popularization of Henning's "24 solar terms"It is a popular science column about microorganisms launched by Hanning Chemistry. We will regularly launch popular science essays on topics related to microbiology, taking the traditional Chinese solar terms of 24 as the timeline."the four seasons are orderly, everything is sometimes", let's "send knowledge in the season"To explore the microbial world together. Henning will make an appointment with you at the right time and never part until we see you again.
