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托福听力背景知识:生物膜

2017-04-17 11:13:07来源：新东方在线整理

　　Eukaryotic biofilms[edit]See also phototrophic biofilms.

　　Along with bacteria, biofilms are often initiated and produced by Eukaryotes. The biofilms produced by eukaryotes is usually occupied by bacteria and other Eukaryotes alike, however the surface is cultivated and EPS is secreted initially by the Eukaryote.[41][40][72] Both fungi and microalgae are known to form biofilms in such a way. Biofilms of fungal origin are important aspects of human infection and fungal pathagenicity, as the fungal infection is more resistant to antifungals.[73][74]

　　In the environment, fungal biofilms are an area of ongoing research. One key area of research are fungal biofilms on plants. For example, in the soil, plant associated fungi including mycorrhiza have been shown to decompose organic matter, protect plants from bacterial pathogens.[75]

　　Biofilms in aquatic environments are often founded by diatoms. The exact purpose of these biofilms is unknown, however there is evidence that the EPS produced by diatoms facilitates both cold and salinity stress.[76][42] These Eukaryotes interact with a diverse range of other organisms within a region known as the phycosphere, but importantly are the bacteria associated with diatoms, as it has been shown that although diatoms excrete EPS, they only do so when interacting with certain bacteria species.[77][78]

　　Biofilms in aquaculture[edit]In shellfish and algae farms, biofouling species tend to block nets and cages and ultimately outcompete the farmed species for space and food.[79] Bacterial biofilms start the colonization process by creating microenvironments that more favorable for biofouling species. In the marine environment, biofilms could reduce the hydrodynamic efficiency of ships and propellers, lead to pipeline blockage and sensor malfunction, and increase the weight of appliances deployed in seawater.[80] Numerous studies have shown that biofilm can be a reservoir for potentially pathogenic bacteria in freshwater aquaculture.[81][82][83][84] As mentioned previously, biofilms can be difficult to eliminate even when antibiotics or chemicals are used in high doses.[85][86] The role that biofilm plays as reservoirs of bacterial fish pathogens regarding has not been explored in detail but it certainly deserves to be studied.

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本文关键字: 2017年4月15日托福 托福听力背景资料

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