8.13 菌类营养
章节大纲
-
So what do fungi "eat"?
::那么真菌吃什么?Just about anything. From dead plants to rotting fruit . Shown here are sprouting from dead material in the woods. Fungi perform an essential role in the decomposition of organic matter and have fundamental roles in nutrient cycling and exchange.
::从死植物到腐烂的果实。在这里展示的是树林中死物质的发芽。真菌在有机物质的分解中起着关键作用,在养分循环和交换方面起着根本作用。Nutrition
::营养营养营养Fungi get their nutrition by absorbing from the environment. Fungi are heterotrophic : they rely solely on carbon obtained from other organisms for their metabolism and nutrition. Fungi have evolved in a way that allows many of them to use a large variety of organic substrates for growth, including simple compounds such as nitrate, ammonia, acetate, or ethanol. Their mode of nutrition defines the role of fungi in their environment.
::菌类通过吸收环境来获得营养。 菌类是血化营养学:它们仅仅依靠从其他生物中获取的碳来进行新陈代谢和营养。 菌类的进化使得它们中的许多人能够使用多种有机基元素来进行生长,包括简单的化合物,如硝酸盐、氨、乙酸盐或乙醇。它们的营养模式决定了真菌在其环境中的作用。Fungi obtain nutrients in three different ways:
::菌类以三种不同的方式获得营养:-
They decompose dead organic matter. A
saprotroph
is an organism that obtains its nutrients from non-living organic matter, usually dead and decaying plant or
matter, by absorbing soluble organic compounds. Saprotrophic fungi play very important roles as recyclers in
energy
flow and
biogeochemical cycles
. Saprophytic fungi, such as shiitake (
Lentinula edodes
) and oyster
mushrooms
(
Pleurotus ostreatus
), decompose dead plant and animal
tissue
by releasing
from hyphal tips. In this way they recycle organic materials back into the surrounding environment. Because of these abilities, fungi are the primary
decomposers
in forests (see
Figure
).
::它们分解了死亡有机物。 衰变是一种有机体,通过吸收可溶性有机化合物,从非生物有机物(通常为死亡和腐烂的植物或物质)中获取养分,通过吸收可溶性有机物获得养分。 生化真菌在能源流动和生物地球化学循环中作为循环循环循环的回收者发挥着非常重要的作用。 生化真菌,如(Lentinula edodes)和牡蛎蘑菇(Pleurotus ostreatus),通过从催眠提示中释放来分解死亡植物和动物组织。 通过这种方式,它们把有机物循环回到周围环境。 由于这些能力,真菌是森林中主要的脱腐烂生物(见图 )。 -
They feed on living hosts. As
parasites
, fungi live in or on other organisms and get their nutrients from their
host
. Parasitic fungi use enzymes to break down living tissue, which may causes illness in the host. Disease-causing fungi are parasitic. Recall that
parasitism
is a type of symbiotic relationship between organisms of different
in which one, the parasite, benefits from a close association with the other, the host, which is harmed.
::寄生虫以活体宿主为食,作为寄生虫,真菌以其他生物为生,从宿主处获取养分。寄生虫真菌使用酶来分解活体组织,这可能造成宿主的疾病。引起病菌的寄生虫是寄生虫。请注意,寄生虫是不同生物体之间的一种共生关系,其中寄生虫从与宿主的紧密联系中受益,宿主则受到伤害。 -
They live mutualistically with other organisms. Mutualistic fungi live harmlessly with other living organisms. Recall that
mutualism
is an interaction between individuals of two different species, in which both individuals benefit.
::它们与其他生物体相互生活,相互性真菌与其他生物体无害地生活,回顾相互性是两种不同物种个人之间的一种互动,对两者都有利。
Both parasitism and mutualism are classified as symbiotic relationships, but they are discussed separately here because of the different effect on the host.
::寄生炎和相互性都被归类为共生关系,但由于对宿主的不同影响,此处分别讨论。Forest Decomposers. These forest mushrooms may look fragile, but they do a powerful job. They decompose dead wood and other tough plant material.
::森林分解者。这些森林蘑菇看起来可能很脆弱, 但他们的工作很有力。它们分解了枯木和其他坚硬的植物材料。Fungal hyphae are adapted to efficient absorption of nutrients from their environments, because hyphae have high surface area-to-volume ratios. These adaptations are also complemented by the release of hydrolytic enzymes that break down large organic molecules such as polysaccharides , , and into smaller molecules. These molecules are then absorbed as nutrients into the fungal . One enzyme that is secreted by fungi is cellulase , which breaks down the polysaccharide cellulose . Cellulose is a major component of plant cell walls . In some cases, fungi have developed specialized structures for nutrient uptake from living hosts, which penetrate into the host cells for nutrient uptake by the fungus.
::合合金合硫酸可以适应有效吸收其环境中的养分,因为合金的表面面积与体积比率较高。这些适应还辅之以释放液解酶,这些酶分解了大型有机分子,如聚沙焦化物,并形成小分子。这些分子随后作为养分被吸收到真金中。一种由真金分泌的酶是细胞酶,它分解了聚沙焦化纤维素。细胞素是植物细胞壁的主要组成部分。在某些情况下,真金从活体宿主那里开发了专门的养分吸收结构,这些结构渗透到宿主细胞中,供真金菌吸收养分。Fungal mycelia. Fungi absorb nutrients from the environment through mycelia. The branching mycelia have a high surface-area-to-volume ratio which allows for efficient absorption of nutrients. Some fungi digest nutrients by releasing enzymes into the environment.
::蘑菇菌通过微菌吸收环境中的养分。小菌菌的表面面积与体积比率较高,可以有效地吸收养分。一些真菌通过将酶释放到环境中来消化养分。Mycorrhiza
::脑膜炎A mycorrhiza (Greek for "fungus roots") is a symbiotic association between a fungus and the of a plant. In a mycorrhizal association, the fungus may colonize the roots of a host plant by either growing directly into the root cells, or by growing around the root cells. This association provides the fungus with relatively constant and direct access to glucose , which the plant produces by . The mycelia of the fungi increase the surface area of the plant’s root system . The larger surface area improves and mineral nutrient absorption from the soil .
::菌株(Greek for "fungus root")是真菌和植物之间的共生联系。在菌株协会中,真菌可能直接生长在根细胞中,或生长在根细胞周围,从而将宿主植物的根根殖民化。这个协会为真菌提供了相对固定和直接的获取葡萄糖的途径。真菌的神话增加了植物根系统的表面面积。更大的地表面积改善了土壤中的矿物养分和吸收。Summary
::摘要-
Fungi are heterotrophic. They get their nutrition by absorbing organic compounds from the environment.
::菌菌有血化营养,通过吸收环境的有机化合物获得营养。 -
Fungi, along with bacteria that are found in soil, are the primary decomposers of organic matter in terrestrial ecosystems.
::菌类以及土壤中发现的细菌是陆地生态系统有机物的主要分解物。
Review
::回顾-
Describe how fungi obtain nutrients.
::描述真菌如何获得养分。 -
Explain the role of saprotrophic fungi? Give an example of this role.
::解释一下预产期真菌的作用? -
What is a mycorrhiza? What are the advantages of a mycorrhiza?
::鼻血有什么好处呢 鼻血有什么好处吗
-
They decompose dead organic matter. A
saprotroph
is an organism that obtains its nutrients from non-living organic matter, usually dead and decaying plant or
matter, by absorbing soluble organic compounds. Saprotrophic fungi play very important roles as recyclers in
energy
flow and
biogeochemical cycles
. Saprophytic fungi, such as shiitake (
Lentinula edodes
) and oyster
mushrooms
(
Pleurotus ostreatus
), decompose dead plant and animal
tissue
by releasing
from hyphal tips. In this way they recycle organic materials back into the surrounding environment. Because of these abilities, fungi are the primary
decomposers
in forests (see
Figure
).
