Can Microplastic Pollution Change Important Aquatic Bacterial Communities?
摘要（ABSTRECT）
“科學(xué)家已經(jīng)發(fā)現(xiàn)，微塑料正在污染世界各地的環(huán)境，這包括我們的海洋以及沿海地帶。其中一些塑料會(huì)進(jìn)入一個(gè)尤為重要的環(huán)境——海岸沉積物中或水下的泥土層。這種沉積物是多種多樣的細(xì)菌的生活家園，這些細(xì)菌在生態(tài)系統(tǒng)的營(yíng)養(yǎng)物循環(huán)中發(fā)揮著重要的作用。這些細(xì)菌對(duì)營(yíng)造健康的環(huán)境至關(guān)重要，但也很容易受到環(huán)境污染的影響。不幸的是，人們對(duì)這些細(xì)菌是如何對(duì)微塑料污染做出反應(yīng)的仍知之甚少。我們研究了不同微塑料對(duì)生活在海底沉積物中的細(xì)菌的影響，也研究了之后其對(duì)營(yíng)養(yǎng)物循環(huán)的影響。我們首次發(fā)現(xiàn)，不同的微塑料可以顯著地改變這些細(xì)菌群落和碳循環(huán)，我們應(yīng)該對(duì)其做進(jìn)一步的研究，以了解其對(duì)我們自然環(huán)境帶來的持久影響。
Scientists have discovered that microplastics are polluting many environments worldwide, including our oceans and coastlines. Some of these plastics will make their way into a particularly important environment—coastal sediments, or the layer of mud below the water. This sediment is home to diverse bacterial life, which plays a key role in nutrient cycles of the ecosystem. These bacteria are critical for healthy environments, but are also easily affected by environmental pollution. Unfortunately, little is known about how the bacteria respond to microplastic pollution. We studied the effects of different microplastics on bacteria living in marine sediments, as well as the subsequent impacts on nutrient cycling. We found, for the first time, that different microplastics can significantly alter these bacterial communities and the nitrogen cycle, which should be studied further to understand lasting impacts on our natural environments.”
微塑料污染
MICROPLASTIC POLLUTION
你可能已經(jīng)聽說過微塑料，但你可能并不清楚它們是什么，也不知道為什么大家似乎都在談?wù)撍鼈儭Ｎ⑺芰鲜趾?jiǎn)單——它們是一些小型塑料，一般是5mm寬（大約是橡皮的大小）甚至更小。塑料可以被制造成微塑料般的大小，如添加到護(hù)膚品或牙膏中的小塑料珠。然而，在大多數(shù)情況下，微塑料來自于較大塑料塊的分解。在海洋環(huán)境中尤為如此，大量的塑料垃圾隨著時(shí)間的推移不斷積累，它們暴露在大風(fēng)、海浪和陽光下，最終形成微塑料。
You may have heard of?microplastics,?but you may not know what they are or why everyone seems to be talking about them. Microplastics are simple—they are small bits of plastic, generally 5 mm wide (about the size of a pencil eraser) or smaller. Plastics can be manufactured to be microplastic size, such as small beads that are added to skin care products or toothpaste. Most often, however, microplastics come from the breakdown of larger pieces of plastic. This is especially true in the ocean environment, where a lot of plastic trash accumulates over time and is exposed to wind, waves, and sunlight, eventually creating microplastics [1]!
盡管這聽起來十分簡(jiǎn)單，但環(huán)境中的微塑料是十分復(fù)雜的。這是因?yàn)榇嬖谥煌愋偷乃芰稀Ｈ魏嗡芰系臉?gòu)件和構(gòu)成的“脊梁”都被稱為聚合物。常見的塑料最常以其聚合物命名，如聚乙烯和聚氯乙烯。此外，還會(huì)經(jīng)常添加其他化學(xué)物品以幫助塑料產(chǎn)品達(dá)到所用目的。這些所謂的添加劑各種各樣，也可包括顏色燃料。因此，沒有兩塊塑料是完全相同的。
While this sounds simple, microplastics in the environment are extremely complex. This is because there are many different kinds of plastics. The building blocks or “backbone” of any plastic are called?polymers. Common plastics are most often named after their polymer, for example, polyethylene or polyvinyl chloride. In addition, other chemicals are often added to help a plastic product serve its purpose. These so-called additives vary, but can include color dyes, for example. As such, no two microplastics are identical to each other [2].
近些年來，科學(xué)家發(fā)現(xiàn)微塑料污染已十分普遍，而且是由于人口增長(zhǎng)以及塑料用量的增加而不斷增加的。在海洋、湖泊、河流和土壤中，在遙遠(yuǎn)的山頂上，在冰川的冰層里，都能找到微塑料，有些微塑料還懸浮在大氣中！在水生環(huán)境里，微生物在沉積物中積聚——沉淀在水底的泥土層中。許多不同的動(dòng)物生活在沉積物中，它們可能會(huì)與微塑料污染相互作用。科學(xué)家一直在竭力了解形形色色的微塑料可能對(duì)生物的影響。
In recent years, scientists have discovered that microplastic pollution is widespread, and is growing due to population rise and increasing plastic usage. Microplastics have been found in oceans, lakes, rivers, and soils, on remote mountain tops, inside glacier ice, and suspended in the air [1]! In aquatic environments, microplastics accumulate in?sediment—the layers of mud and dirt that settle to the bottom, below the water. Many different animals live in the sediment and may interact with the microplastic pollution. Scientists have been working to understand the effects that diverse microplastics might have on living things [1].
沉積物細(xì)菌群落
THE SEDIMENT BACTERIAL COMMUNITY
如果你對(duì)溪流、湖泊以及河流里對(duì)沉積物進(jìn)行探察，你會(huì)發(fā)現(xiàn)許多活生生的生物，舉幾個(gè)例子而言，就如蠕蟲、蛤蜊和螃蟹。但如果你用顯微鏡對(duì)沉積物進(jìn)行探察，你會(huì)發(fā)現(xiàn)還有豐富的微生物群落（即肉眼看不到的生物）。細(xì)菌是一種微生物，在沉積物中尤為豐富。成千上萬的細(xì)菌共存，形成了一個(gè)細(xì)菌群落，科學(xué)家們通過物種的種類以及每個(gè)物種存在的數(shù)量來描述沉積物的細(xì)菌群落。這些細(xì)菌群落對(duì)整個(gè)生態(tài)系統(tǒng)起著非常重要的作用。
If you explore sediments in streams, lakes, and rivers, you will discover many living organisms—worms, clams, and crabs, to name a few. But if you explore?sediment?with a microscope, you will see that there is also a rich community of microbes (i.e., organisms that cannot be seen with the naked eye)! Bacteria are a type of microbe that are very abundant in sediments. Thousands of species of bacteria co-exist, forming a?bacterial community. Scientists describe bacterial sediment communities by the kinds of species and how many of each species are present. These bacterial communities perform very important jobs for the entire ecosystem.
沉積物細(xì)菌群落的另一個(gè)作用就是轉(zhuǎn)化營(yíng)養(yǎng)物質(zhì)。植物和動(dòng)物（包括人類）需要營(yíng)養(yǎng)素來構(gòu)建必要的生物大分子，這些大分子包括蛋白質(zhì)和DNA。在你腸道里的細(xì)菌的幫助下，你可以從食物中攝取營(yíng)養(yǎng)物質(zhì)。當(dāng)你在吃東西時(shí)，消化道里的細(xì)菌會(huì)幫助身體消化食物，從而釋放出你身體所需的營(yíng)養(yǎng)素。沉積物細(xì)菌對(duì)水中的生物也起著同樣的作用。當(dāng)有機(jī)質(zhì)（如死去的生物和糞便）沉入沉積物時(shí)，大多數(shù)營(yíng)養(yǎng)物質(zhì)仍然會(huì)被困在里面，無法供其他生物體利用。沉積物里的細(xì)菌就會(huì)分解這些有機(jī)質(zhì)，從而為它們自身以及其他生物釋放出營(yíng)養(yǎng)素（圖1）。與此同時(shí)，它們還會(huì)確保任何一種營(yíng)養(yǎng)素都不會(huì)過多，因?yàn)檫^多可能會(huì)對(duì)它們?cè)斐蓚ΑＲ虼耍?xì)菌群落會(huì)影響那些可以生活在該環(huán)境的高等生物的類型與健康。
One of the roles of sediment bacterial communities is transforming nutrients. Nutrients are needed by plants and animals (including humans) to build essential biomolecules, including proteins and DNA. You get nutrients from food, with the help of bacteria inside your gut. When you eat food, bacteria in your digestive tract help process the food to release the nutrients that your body needs. Sediment bacteria do the same thing for organisms in the water. When organic material, such as dead organisms or feces, sink to the sediments, most nutrients are still trapped inside and not available for other living organisms to use. The bacteria in sediments break down organic material, releasing nutrients for themselves and for other organisms (Figure 1). At the same time, they also make sure there is not too much of any one nutrient, which may cause harm. Thus, the bacterial community affects the types and health of higher organisms that can live in that environment.
圖1-沉積物中的細(xì)菌和你腸道中的細(xì)菌起著相類似的作用---幫助處理營(yíng)養(yǎng)物質(zhì)！左圖說明了這在水生環(huán)境中的作用，有機(jī)物（通常是死去的生物體和排遺廢物，但最近也有塑料）被沉積物中的細(xì)菌處理。
右圖將其比作你的腸道，腸道里的細(xì)菌幫助處理你每天攝入的有機(jī)物（即食物）！（用BioRender.com創(chuàng)建）。
Figure 1 - The bacteria in sediments and those in your gut serve similar roles—helping to process nutrients! The left side of the figure illustrates how this works in the aquatic environment, where organic matter (generally dead organisms and wastes, but more recently, plastic) is processed by bacteria in the sediments.
The right side compares this to your gut, where bacteria help process the organic matter (i.e., food) that you eat every day! (Created with BioRender.com).
沉積物中的氮循環(huán)
THE SEDIMENT NITROGEN CYCLE
沉積物細(xì)菌幫助調(diào)控的一個(gè)重要營(yíng)養(yǎng)素是氮。氮循環(huán)十分復(fù)雜，因此我們只需關(guān)注它的一些重要特征。在沉積物和水中，許多不同的物質(zhì)都含有氮元素，這包括銨鹽（NH4+）和硝酸鹽（NO3?）。不同的細(xì)菌可以將這些化合物從一種形式轉(zhuǎn)化到另一種形式。沉積物中的兩個(gè)非常重要的轉(zhuǎn)化是硝化作用和反硝化作用。這兩個(gè)過程可以結(jié)合在一起，即通過硝化作用可將銨鹽轉(zhuǎn)化為硝酸鹽，通過反硝化作用可將硝酸鹽轉(zhuǎn)化為氮?dú)猓∟2）（圖2）。
An important nutrient that sediment bacteria help regulate is?nitrogen. The nitrogen cycle is complex, so we will only focus on a few of its features. In sediments and water, many different chemicals contain nitrogen, including ammonium (NH4+) and nitrate (NO3?). Different bacteria can transform these compounds from one form to another. Two very important transformations in sediments are?nitrification?and?denitrification. Both processes can work in combination to convert ammonium to nitrate via nitrification, and nitrate to dinitrogen gas (N2) via denitrification (Figure 2A).
圖2-（A）水生沉積物中氮循環(huán)的關(guān)鍵組成部分
（B）我們?cè)趯?shí)驗(yàn)中看到的硝化作用（藍(lán)色）和反硝化作用（紅色）的變化，顯示了在容器中將每種類型的塑料添加到沉積物的微生態(tài)系統(tǒng)上面。聚乳酸和聚氨酯泡沫微塑料都增強(qiáng)了硝化作用和反硝化作用；聚氯乙烯減輕了這兩個(gè)過程；與沒有添加微塑料的對(duì)照組相比，聚乙烯沒有明顯改變?nèi)魏芜^程（用BioRender.com創(chuàng)建）。
Figure 2 -?(A)?Key components of the nitrogen cycle in aquatic sediments.
(B)?The changes to nitrification (blue) and denitrification (red) that we saw in our experiment are shown above the microcosms containing each type of plastic added to sediments. Both polylactic acid and polyurethane foam microplastics increased nitrification and denitrification; polyvinyl chloride decreased both processes; polyethylene did not significantly change either process compared to the control with no added microplastics (Created with BioRender.com).
擁有適量的合適細(xì)菌可以確保生態(tài)系統(tǒng)中存在著適量的銨鹽和硝酸鹽。如果這個(gè)平衡發(fā)生錯(cuò)亂，生態(tài)系統(tǒng)就會(huì)發(fā)生改變或受到傷害。特別的，應(yīng)該要有足夠的細(xì)菌來完成硝化作用和反硝化作用，從而除去多余的銨鹽（這些多余的銨鹽對(duì)環(huán)境有害），但又不能完全去除銨鹽（適量的銨鹽是供其他生物體生命活動(dòng)的重要營(yíng)養(yǎng)物質(zhì)）。所有對(duì)氮循環(huán)的不同步驟起著重要作用的細(xì)菌物種都有著不一樣的遺傳密碼。科學(xué)家可以解讀這些密碼來了解存在的細(xì)菌物種有哪些，以及它們?cè)跔I(yíng)養(yǎng)物循環(huán)中起著怎樣的作用。我們決定利用這個(gè)手段提出兩個(gè)問題。
Having the right bacteria in the right amounts ensures that the correct level of ammonium and nitrate are present in an ecosystem. If the balance is wrong, the ecosystem can be changed or harmed. Specifically, there should be sufficient bacteria that complete nitrification and denitrification to remove excess ammonium (which can harm the environment), but not too much to completely remove ammonium (which, in the right amount, is an important nutrient for other organisms). All bacterial species that are important for different steps of nitrogen cycling have a different genetic code. Scientists can read this code to see which bacterial species are present and what roles in the nutrient cycle they perform. We decided to use this tool to ask two important questions.
我們的實(shí)驗(yàn)
OUR EXPERIMENT
我們提出的兩個(gè)問題是：沉積物中不同的微塑料是否會(huì)改變細(xì)菌群落的組成成分？如果是這樣的話，這是否會(huì)影響氮元素轉(zhuǎn)化的進(jìn)程？為了回答這些問題，我們?cè)O(shè)立了一個(gè)實(shí)驗(yàn)！我們從當(dāng)?shù)氐囊粋€(gè)沼澤中收集了一些沉積物，并把這些沉積物分散裝在多個(gè)容器中，然后加水，從而創(chuàng)造出一個(gè)生態(tài)系統(tǒng)的小型復(fù)制品，我們把這稱為“微觀生態(tài)環(huán)境”，我們往不同容器里的沉積物中添加了四種不同類型的微塑料，分別是聚乙烯、聚氯乙烯、聚氨酯泡沫和聚乳酸。這些微塑料是通過在一個(gè)專門的研磨機(jī)中研磨較大的塑料塊制成的。因此它們含有不同的聚合物和添加劑，對(duì)細(xì)菌群落產(chǎn)生的影響也各不相同。我們也弄了一個(gè)沒有添加任何微塑料的容器，以代表正常情況。我們把這稱為對(duì)照。我們對(duì)這些容器進(jìn)行了超過16天的觀察。
Our two questions were: Do different microplastics in sediments change the bacterial community composition? And if so, does this also affect nitrogen-transforming activities? To answer these, we set up an experiment! We collected sediment from a local marsh, distributed it into containers, and added water to create smaller replicas of the natural ecosystem, called?microcosms. We added four different types of microplastics to the sediments in the different containers: polyethylene, polyvinyl chloride, polyurethane foam, and polylactic acid. These microplastics were made by grinding larger pieces of plastic in a specialized grinder. These microplastics are used for different purposes, so they contain different polymers and additives that could affect the bacterial community differently. We also made one container with no added microplastics, to represent a normal situation. This is called a control. The containers were monitored over 16 days.
通過解讀每個(gè)微觀生態(tài)環(huán)境中存在的細(xì)菌的遺傳密碼，我們分析了實(shí)驗(yàn)前、實(shí)驗(yàn)中和實(shí)驗(yàn)后的沉積物中的細(xì)菌群落。首先，我們利用這些信息來描述細(xì)菌群落的特征——存在的物種有哪些？它們的豐裕度如何？緊接著，我們專門尋找了負(fù)責(zé)硝化作用和反硝化作用的遺傳密碼。我們對(duì)比了不同微生態(tài)環(huán)境中所看到的結(jié)果，以了解微塑料是否改變了細(xì)菌群落的氮循環(huán)。
We analyzed the bacterial communities in the sediments before, during, and after the experiment by reading the genetic codes of the bacteria present in each microcosm. First, we used this information to characterize the bacterial community—what species are present and how abundant are they? Then, we specifically looked for the parts of the genetic code responsible for nitrification and denitrification. We compared our findings between the different microcosms, to see if the microplastics changed the bacterial community or nitrogen cycling.
我們發(fā)現(xiàn)添加了微塑料的容器中的細(xì)菌群落確實(shí)與對(duì)照組存在差異，且聚合物的類型導(dǎo)致了它們的千變?nèi)f化！我們也發(fā)現(xiàn)微塑料會(huì)影響氮循環(huán)，即它們改變了能夠進(jìn)行硝化和反硝化作用的細(xì)菌的物種豐度。我們發(fā)現(xiàn)，經(jīng)過聚氯乙烯處理的沉積物在實(shí)驗(yàn)結(jié)束時(shí)細(xì)菌群落的變化最大，在含有聚氯乙烯微塑料的沉積物中，細(xì)菌的硝化作用和反硝化作用明顯受到抑制。然而在含有聚乳酸和聚氨酯泡沫微塑料的微生態(tài)環(huán)境中，硝化作用和反硝化作用得到了提升。含有聚乙烯的微生態(tài)環(huán)境與我們的對(duì)照組結(jié)果相近，這揭示了這種塑料沒有像其他塑料那樣對(duì)沉積物細(xì)菌群落影響那么大（圖2B）。這個(gè)實(shí)驗(yàn)告訴我們環(huán)境中的微生物污染可能會(huì)影響關(guān)鍵的細(xì)菌群落和氮循環(huán)。
We discovered that the communities containing added microplastics were indeed different from the control, and the polymer types resulted in different changes! We also found that the microplastics affected nitrogen cycling activities; i.e., they altered the abundance of species capable of performing nitrification and denitrification. We found that polyvinyl chloride-treated sediments had the biggest change in the bacterial community at the end of the experiment. In sediments with polyvinyl chloride microplastics, nitrification and denitrification were significantly reduced. In the microcosms with polylactic acid and polyurethane foam microplastics, however, nitrification and denitrification were elevated. The microcosms with polyethylene microplastics were similar to our control, suggesting this plastic did not affect the sediment bacterial community as much as the other plastics (Figure 2B). This experiment told us that microplastic pollution in the environment may affect key bacterial communities and the nitrogen cycle.
為何如此重要？
WHY DOES THIS MATTER?
科學(xué)家們?cè)缫阎溃诩?xì)菌的驅(qū)動(dòng)下，沉積物在營(yíng)養(yǎng)物循環(huán)中發(fā)揮著重要作用。營(yíng)養(yǎng)物循環(huán)對(duì)生活在沉積物里的生物至關(guān)重要，且對(duì)覆蓋在上層水和其他地方的生物也是如此。科學(xué)家們最近了解到，大量的微塑料正在污染全球的水生沉積物，而我們的研究正是第一個(gè)關(guān)于微塑料可以影響沉積物細(xì)菌群落，從而影響其氮循環(huán)活動(dòng)的報(bào)告。沉積物中氮循環(huán)的平衡使?fàn)I養(yǎng)物質(zhì)保持在合適的水平，以保證現(xiàn)存動(dòng)物的健康，這些動(dòng)物包括蠕蟲、魚類、浮游植物和水生草類！有了這些知識(shí)，我們可以跟進(jìn)研究上的一些重要問題。哪些類型的塑料所造成的有害影響最大？這些危害是由聚合物還是由添加劑造成的？這些沉積物中必須含有多少塑料才能影響細(xì)菌群落？當(dāng)我們有了這些知識(shí)，科學(xué)家可以與決策者合作，幫助保護(hù)沿海地區(qū)免受微塑料污染的有害影響。
Scientists have long known that sediments play an important role in nutrient cycles, driven by the bacteria. Nutrient cycles are critical to organisms living in the sediments, but also those in the overlying water and beyond. Scientists have recently learned that large amounts of microplastics are polluting aquatic sediments globally, and our research is the first report that microplastics can affect the sediment bacterial community, and therefore affect their nitrogen-cycling activities. The balance of the nitrogen cycle in sediments keeps the nutrients at the right levels for the health of the animals present, including worms, fish, phytoplankton, and aquatic grasses! With this knowledge, we can follow up with important research questions: Which types of plastic cause the most harmful effects? Is that harm caused by the polymer or the additives? And how?much plastic must be in those sediments to affect the bacterial community? When we have this knowledge, scientists can work with policy makers to help protect coastal zones from the harmful effects of microplastic pollution.
大多數(shù)的微塑料是由較大的塑料塊在環(huán)境中分解后形成的。因此，如果我們想阻止微塑料污染，我們必須杜絕塑料污染！盡管塑料污染并不僅僅發(fā)生在我們亂扔垃圾的時(shí)候。有時(shí)人類產(chǎn)生了大量的塑料垃圾，在到達(dá)垃圾填埋場(chǎng)之前，它們就已經(jīng)逃到了環(huán)境中。這可能是由于垃圾桶溢出，垃圾袋從卡車上飄出，或垃圾被風(fēng)暴卷走，到達(dá)當(dāng)?shù)氐暮恿鳌⒑椿蚝Ｑ蟆Ｈ绻覀儨p少塑料垃圾，就會(huì)有更少的垃圾泄露在環(huán)境中。你可能會(huì)想到一些可以減少你每天產(chǎn)生塑料垃圾的方法，或者可以尋找到泄漏到環(huán)境中的塑料碎片的地方。這兩點(diǎn)都是減少微塑料污染的關(guān)鍵步驟!
Most microplastics are formed when bigger pieces of plastic break down in the environment. So, if we want to stop microplastic pollution, we must stop plastic pollution! Plastic pollution does not only happen when we litter, though. Humans produce a lot of plastic trash and, sometimes, it escapes into the environment before it reaches the landfill. This can happen because of an overflowing trash can, a trash bag being lost off a truck, or trash that is swept away in a storm and reaches a local river, lake, or ocean. If we reduce our plastic waste, there will be less that can leak into the environment. You may think of some ways that you can reduce the plastic trash you generate every day, or places where plastic debris leaking into the environment could be captured. Both are critical steps toward reducing microplastic pollution!
Glossary?術(shù)語表
Microplastic:?↑?A plastic particle that is <5 mm in the longest direction, often formed by the breakdown of larger pieces of plastic in the environment.
微塑料：小于5毫米的塑料顆粒，通常由環(huán)境中較大的塑料碎片分解形成
Polymer:?↑?Large chemicals that form the building blocks of plastics, often called the plastic “backbone.”
聚合物：構(gòu)成塑料構(gòu)件的大分子化學(xué)物質(zhì)，通常稱為塑料的"骨架"。
Sediment:?↑?The layers of mud and sand that settle below the water.
沉積物：沉淀在水底的泥土層和沙層
Bacterial Community:?↑?A group of different species of bacteria that live in the same environment.
微生物群落：一組生活在同一環(huán)境中的不同種類的細(xì)菌。
Nitrogen:?↑?An essential element that is used to build many of the compounds that living things need to survive.
氮：一種不可或缺的元素，用于構(gòu)建生物體生存所需的許多化合物。
Nitrification:?↑?A process that converts one form of nitrogen, ammonium (NH4+), to another form, nitrate (NO3?), which is made possible by microbes.
硝化作用：將一種形式的氮，即銨鹽（NH4+）轉(zhuǎn)化為另一種形式的硝酸鹽（NO3-）的過程，這是通過微生物完成的。
Denitrification:?↑?A process that converts one form of nitrogen, nitrate (NO3?), to another form, nitrogen gas (N2), which is made possible by microbes.
反硝化作用：?將一種形式的氮，即硝酸鹽（NO3-），轉(zhuǎn)化為氮?dú)猓∟2）的過程，這是通過微生物完成的。
Microcosm:?↑?A small replica of a natural environment, used by scientists to answer research questions about how different things may change that environment.
微生態(tài)環(huán)境：一個(gè)自然生態(tài)環(huán)境的小型復(fù)制品，科學(xué)家用它來解答關(guān)于不同事物如何改變?cè)摥h(huán)境的研究性問題。
附上作者信息
翻譯者小婧嘮叨幾句：
太久沒更新啦，最近發(fā)生太多事情，也比較忙吧...之后還有不到一個(gè)月的時(shí)間期末考試，期末考試后就步入高三了，至于翻譯吧，我還是會(huì)盡我所能更新的！
個(gè)人認(rèn)為這篇文章真的很不錯(cuò)，在給我們介紹了微生物污染的同時(shí)還通過設(shè)計(jì)實(shí)驗(yàn)讓我們明白了不同塑料對(duì)沉積物細(xì)菌群落的影響。其實(shí)設(shè)計(jì)實(shí)驗(yàn)真的很重要，現(xiàn)在考試也是經(jīng)常考的，是考察一個(gè)人實(shí)驗(yàn)?zāi)芰Φ捏w現(xiàn)，而多看這方面的文章可以不斷培養(yǎng)這方面的能力，這是一個(gè)不斷積累的過程。
也沒那么多時(shí)間細(xì)細(xì)審稿了，文章有筆誤之處或翻譯的有瑕疵之處還望海涵！
