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Development and the Environment(环境与发展)

Development and the Environment(环境与发展)
Development and the Environment(环境与发展)

Development and the Environment(环境与发展)

Development and the Environment It is undeniable that the worsening environment has bee the biggest concern of the present-day world. Land resources are dwindling because of water loss and soil erosion. Waste gases poison the air we breathe. The rivers and lakes are polluted by waste dumped in them from factories. It is probably no exaggeration to say that deterioration of the quality of the environment threatens the existence of mankind itself. Some people are of the opinion that the environmental problem is the price we have to pay for economic development. But I do not think that this argument is valid. After all, what is the point of economic growth if people’s lives are adversely alfec ted by worsening environmental pollution? There is plenty of evidence to show that sustainable development can be achieved by balancing economic growth with protection of the environment. The key to achieving this is to make people aware of the seriousness of the problem. Both governments and ordinary citizens should join hands to make this world a better place to live in, not only for ourselves, but also for future generations.

环境与发展不可否认的是环境恶化已成为当今世界上人们最担心的事了。因为水资源的浪费和土壤被侵蚀,土地资源逐渐缩小。我们呼吸着有毒的空气,河流和湖泊也被附近的工厂里排放出来的废弃物严重污染了。不夸大其词地说,环境质量的恶化很可能威胁人类的生存。有些人说环境问题是我们为经济发展所付出的代价。对此,我不敢苟同。如果人类的生活被日益恶化的环境污染所影响的话,那么,经济发展的意义何在? 足够的证据表明:经济发展与环境保护的平衡可以实现可持续发展。关键是使人们意识到问题的严重性。政府和普通市民两方都应该携手使地球成为更适合人类居住的地方,这不仅是为我们自己,也是为我们的后代。

极端环境下微生物

列举五种极端环境下微生物及其应用 所谓极端环境是指高低温环境,高盐环境,高酸,高碱环境,高酸热环境,高压环境,还有其他特定环境如油田、矿山、火山地、沙漠的干旱地带、地下的厌气环境、原子炉等高放射能环境、高卤环境以及低营养环境等。能够在这些具有强烈限制性因子的环境下顽强生存的微生物,一般统称为极端环境微生物。 【1.极端嗜盐菌】人们发现在高浓度盐环境中,存在许多抗高渗压的微生物。我国从新疆和内蒙古的盐碱湖中分离出了一些极端耐盐菌。它们竟能在含0—15%Nacl的环境中生长。有些菌株可以在含5%—25%Nacl范围中生长。极端嗜盐微生物中唯一的真细菌是光合微生物的外硫红螺菌属;唯一的真核嗜盐微生物是杜氏藻类。微生物学家琼纳斯克在含盐量高达36%盐液中发现一种微生物,命名为Halophiles。还有地中海嗜盐杆菌等 应用:第一,医药工业:西班牙学者报道地中海嗜盐杆菌在高浓度NaCl介质中生长,聚B-羟基丁酸积累达细胞干重的45%,具有一定的应用前景。PHB能用于医学领域可降解生物材料的开发,如人造骨骼支架、药物微球体、外科手术以及裹伤用品等。此外,目前发现有些嗜盐菌素对去盐作用不敏感,所以可能有比较广泛的应用领域,筛选抑菌谱广、性质稳定的嗜盐菌素,在理论和实践中具有重要意义。第二,环境生物治理:嗜盐碱放线菌Nocardioidessp. M6能快速降解污染物2,4,6-三氯酚可应用于环境治理,利用其嗜盐特性除去工业废水中的磷酸盐,还可用于开发盐碱地等。由于bR蛋白具有质子泵作用,在未来的太阳能利用技术设备中,还可用作海水淡化和研制天然的太阳能电池。 【2.极端嗜碱菌】多生活在盐碱湖和盐池中,生活环境PH值可达11.5以上,最适PH值8

极端温度微生物生存机理及应用研究进展

极端温度微生物生存机理及应用研究进展 李淼 (中山大学生命科学学院广东) 摘要:极端温度微生物是生物对极冷与极热环境适应的特殊种类,研究微生物对于极端温度环境的生存机理对探索生命的起源、微生物的育种及开发利用等具有重要意义。本文大致介绍了嗜热微生物、嗜冷菌和耐冷菌的生物类群,阐述了微生物在面临极端环境温度的适应机理多样性,总结其在环境应用的研究进展。最后旨在综合对比这两类极端微生物的生存机理和实际生产生活应用。 关键词:微生物;极端环境;生存机理;环境应用 极端微生物(extreme microorganism)是指一般生物无法生存的极端环境中(高温、寒冷、高盐、高压、高辐射等)能够正常生存的微生物群体的统称。一般把在高温环境中生长的微生物叫嗜热菌(thermophiles),包括一些细菌及古细菌。他们广泛分布在草堆、厩肥、温泉、火山地及海底火山附近等处。普通耐热菌的最高生长温度在45℃-55℃之间,低于30℃也能生长,而超嗜热菌最高生长温度可达80℃-110℃,最低生长温度也在55℃左右。同时,在地球这个大生态系统中也存在着广泛的低温环境。如占地球表面14%的两极地区及海洋深处(90%的海水其平均温度为5℃或更低)等[1],在这些特殊环境中生活着一类微生物即低温微生物(halophilic microorganism)。 极端高温与极端低温环境都会对生物膜结构以及蛋白质结构造成巨大的影响。了解高温微生物与低温微生物的生存机理,有助于人们开展深一层次的蛋白与膜分子结构研究。本文在目前已有的研究基础上,就高温微生物与低温微生物的生存机理以及在环境应用的最新进展做一简要对比综述,为进 一步研究提供参考。 1 高温微生物概述 通常把最适生长温度高于45℃的微生物称 为嗜热菌。嗜热菌并非单一的菌属或菌群, 其中有些嗜热细菌,其同届菌中皆为嗜热 菌,如红色嗜热杆菌(Rhodothermus)、嗜 热好氧杆菌(Thermoaerobium)、嗜热厌氧 杆菌(Thermoanaerobaeterium)、球杆菌(Sphaembaeter)等,也有高温菌及中温菌 并存的菌属,如芽孢杆菌、奇异球菌(Deincooccus)、假黄色单胞菌(Pseudoxanthomonas)等。嗜热菌按其生 长的耐热程度不同可分为5类(表1)[2]。目 前,对嗜热菌的耐热性主要从细胞壁的结 构、类脂的敏感性、DNA结构的稳定性以及 蛋白质的热稳定性等方面进行研究。 表1 嗜热菌的分类/℃ Tab.1 The classification of thermophiles /℃ 分类最适生长温度最高生长温度最低生长温度

environment

environment, circumstances, conditions, surroundings 四个“环境” 为便于讨论,我把这四个词分为两组: environment与surroundings一组, conditions与cirsumstances一组。 surroundings 偏重于生活、居住的周围环境, environment则指对人的成长、情感、观念、伦理、道德、品行等产生影响的环境。 优美的周边环境 beautiful surroundings; 幸福的家庭环境:happy home environment; 遗传和环境;发展与环境,其中的环境只能用 environment。 破坏环境,保护环境中的环境当然也是environment。 这词的使用范围比sorroundings宽泛得多,延伸到人类活动的各种领域,如political/economic/cultural/demographic/natural/social/technological /legal/macroeconomic/microeconomic marketing/investment/language/learning/Chinese speaking/bilingual/multilingual/operating/global/international environment etc. Conditions 虽有"环境"的含义,不过更接近汉语“条件”——泛指改变、限制性因素,也指影响生活质量的种种因素。 circumstances则相当于“形势、情况”,往往指人力无法控制、驾驭的事件和事态的总和, weather/working/living/housing/production/natural/financial conditions, 其中有些条件人们可以创造、改变,但人们无法改变、创造circumstances。 Don't judge the crime until you know the circumstances. 指时间、地点、条件、情况等细节,不能用conditions替换。circumstances 还有一层意思,便是境遇、财力、经济状况,如经济宽余、生活安 逸 (in good/easy/comfortable/flourishing circumstances),经济拮据、境遇不佳 (in bad/reduced/distressed/straitened circumstances)。两词有时也可通用,如 under present conditions/circumstances; national conditions/circumstances (国情)。 在习语中,词的搭配是固定的,不可互换,如in/under the circumstances, in/under no circumstances。中国政府在核武器问题上有句名言,不可不学:Time and again the Chinese government has solemnly declared thatat no time and under no circumstances will it be the first to use nuclear weapons。

极端环境微生物——台喜生

极端环境微生物研究进展 极端环境(extreme environment)泛指存在某些特殊物理和化学状态的自然环境,包括高温、低温、强酸、强碱、高盐、高压、高辐射和极端缺氧环境等,适合在极端环境中生活的微生物称为极端微生物(extremophiles)(Margesin and Schinner,2001; Rothschild and Mancinelli,2001; 陈骏等,2006;张敏和东秀珠,2006)。具有独特的基因类型、特殊生态群落、特殊生理机理和特殊代谢产物。 一、海洋极端环境微生物 1.海洋极端环境微生下微生物类型主要为细菌和古生菌,热泉微生物群落主要为异氧发酵菌、硫酸盐还原菌、产甲烷菌等;冷泉微生物群落主要为ANME-2族的厌氧甲烷氧化古生菌、硫酸盐还原细菌和ANME-1族厌氧甲烷氧化古菌,这些极端微生物利用CH4和H2S等气体进行能量固定,有较高的生物丰度和较低的分异度,具有垂向和水平分带性,并能营生一套独特的宏体生物(王家生等,2007)。 2.油气资源的形成和演化与时间、温度和有机质组成密切相关(Seewald,2003),油气的产生、运移、圈闭和后期改造过程也大多是在一些特殊环境中进行的,极端微生物活动可能参与了整个过程。 3.探索海洋极端环境下微生物活动,不仅在理论上可将其作为特定地质微生物标志(geomicrobiological signature),揭示现代和地史时期海洋环境变化和地质环境变迁(党宏 月等,2006)、探索生物圈与地圈之间协同演化、阐明生物多样性形成机制和认识生命极限等(汪品先,2003;中国大洋钻探学术委员会,2003),而且在实践中指导海洋深水油气田的开发和地史早期潜在烃源岩的寻找。 4.自第一个海底冷泉1984年首次报道后(Paull et al.,1984),迄今全球已至少发现共 24处海底冷泉。冷泉流体一般含有大量甲烷气体,在海底表面通常表现为泥火山,喷口附 近发育独特的营甲烷化能自养生物群落,下伏的沉积物中通常伴有天然气水合物,在更深部位则通常为油气藏。海底冷泉微生物以化能自养细菌和古生菌为主,它们能与冷泉中化学气体(甲烷、硫化氢等)发生化学反应,把碳氧化物还原成有机碳获得能源,它们通常贴附在沉积物表面形成细菌席,或与其他生物内共生。根据类脂生物标志化合物、16S rDNA分子 序列和DNA分子探针荧光原位杂交(FISH)分析,冷泉微生物主要是ANME-2族的厌氧甲烷氧化古细菌和硫酸盐还原细菌(脱硫八叠球菌属Desul fosarcina和脱硫球菌属Desul fococcus细菌)的共栖互养体(Syntrophism),其次为ANME-1族厌氧甲烷氧化古菌(Hinrich et al.,1999; Orphan et al.,2001,2002; Boetius and Suess,2004; Zhang and Lanoil,2004; 党宏月等,

环境类--雅思范文Environmental-problems

环境类--雅思范文 1. Environmental problems are too big for individual countries and individual people to address. We have reached the stage where the only way to protect the environment is to address it at an international level. To what extent do you agree or disagree? Nowadays, environmental problem has been the focus of a debate. Among these related problems, the issue of international efforts in combating environmental pollution is an extremely acute one. It is firmly believed that the benefits of large scale groups have remarkable impact on our society, especially on environment and animals aspects. First and foremost, environmental pollution is a problem that beyond national borders. This is because the destructive effects that it brought cannot be solved without the co-operation of all the countries in the world. A case in point is the occurrence of extreme weather condition, like La Nina in terms of heavy flood and drought; in addition to, global warming, acid rain that happen in many parts of the world. Due to its chronic and perpetual environment effect, it is necessary for the countries on the earth to form an association and join hands to protect our land from further environment deterioration. Another reason is that it is urgent to set up international alliance to prevent the shrinking space of animals' habitat. It is due to the fact that, local ecosystem has gradually been destroyed all over the world. For instance, Mountain Gorilla has loss its natural habitat to human beings, for being continually developing housing estate deep into the forest. Thus, the breaking down of ecosystem has pushed species closer to the brink of extinction. Hence, it is cleared that the prevention of declining the numbers of rare animals need the joint efforts from many administrative agencies in the world. In conclusion, I totally agree with the idea that international collaboration and cooperation in tackling environmental pollution is positively affects the sustainable development on earth. It is expected that environmental preservation can be greatly enhanced through cultivating environmental awareness around the people in every countries in the foreseeable future.

微生物实验报告:环境中微生物

实验四环境中微生物的检测和分离纯化 一、实验目的 1.熟悉常用微生物培养基的配置方法。 2.学习并掌握各种无菌操作技术,并用此技术进行微生物稀释分离、划线分离接种。 3.用平板划线法和稀释法分离微生物。 4.认识微生物存在的普遍性,体会无菌操作的重要性。 二、实验原理 土壤中有数量巨大、种类丰富的微生物,可以从中分离、纯化得到许多有价值的菌株。从混杂的微生物群体中获得只含有某一种或某一株微生物的过程称为微生物的分离与纯化。常用的是平板分离法。 平板菌落计数法是将待测样品经适当稀释,使其中的微生物充分分散成单个细胞,取一定量的稀释样液接种到平板上,经过培养,由每个单细胞生长繁殖而形成肉眼可见的菌落,即一个单菌落应代表原样品中的一个单细胞。统计菌落数,根据其稀释倍数和取样接种量即可换算出样品含菌数。 三、实验器材 土样10g,牛肉膏蛋白胨培养平板20个,未知菌种平板,当天降雪; 平皿,涂棒,接种环,无菌200ul, 1000ul吸头,记号笔,酒精灯,取液器:1000ul 、200ul 各一支,培养箱; 0.9% 无菌生理盐水,250ml三角瓶中装99ml生理盐水,每瓶加约20粒玻璃珠,250ml 三角瓶中99ml生理盐水,作100倍稀释用。 四、实验步骤 1.配置培养基:取牛肉膏5g,蛋白胨10g,NaCl5g,蒸馏水1000ml配置培养基,调 pH至7.2,灭菌。于讲课前倒板20块。 2.采集野外样品:选择肥沃土壤,去表层土,挖5~20cm深度的土壤数10g,装入烧杯,带 回实验室;取校河水装入烧杯,带回实验室;取新积雪中间层转入烧瓶,带回实验 室。 3.制备土壤稀释液:称取土样1.0g,放入盛99ml无菌水并带有玻璃珠的三角瓶中, 用手振荡5min使土壤均匀分散成为土壤悬液(10-2)。用200ul的无菌吸头从中吸 取0.1ml土壤悬液,注入事先分装有0.9ml无菌水的试管中,吹吸3次,摇匀(10-3)。 类推制得10-4、10-5的土壤悬液。 4.涂板: 1)土壤稀释液(9块):用无菌吸头,分别吸取10-3、10-4、10-5浓度土壤稀释液100ul,较均匀地放入已写好稀释度的牛肉蛋白胨培养基平板上,用无菌玻璃 涂棒涂匀。每个浓度做3个平板。 2)单菌落划线(4块):用接种环挑取未知平班上的菌落,做单菌落划线分离,每人2板。 3)手指(1块):分别用未洗过的手指头, 用自来水打湿的手指头,用自来水洗过的手指头,用肥皂洗过的手指头和用酒精棉球擦过的手指头(不用毛巾擦)在同 一平板的不同分区涂抹(用力一致)。

极端环境微生物的适应机制及利用

极端环境微生物的适应机制及利用 摘要:极端环境微生物是指生活于极端环境中的微生物,它们定义了生命的边界。对极端环境微生物适应机制的研究以及新的极端酶的发现,使得解决工业生产的苛刻条件与蛋白酶易变性的矛盾成为可能。本文分别对嗜热菌、嗜冷菌、嗜酸菌、嗜碱菌、嗜盐菌、嗜压菌 6 种极端微生物的适应机制和应用进行了总结。 关键词:极端微生物,适应机制,应用随着人类对生存家园地球乃至整个宇宙的探索开发,人们对原本被视为生命禁区内的生命 (极端环境微生物)产生了极大的好奇心。极端环境微生物( extremophiles) 是指在一般生 物无法生存的高温、低温、高酸、高碱、高盐、高压、高辐射、太空等异常环境中生存的微生物群体的统称[1],例如嗜热菌( Thermophiles ) 、嗜冷菌( Psychrophiles ) 、嗜碱菌( Alkali- philes)、嗜酸菌( Acidophiles) 、嗜盐菌( Halophiles) 、嗜压菌( Piezophiles) 等。由极端环境微生物适应极端环境所形成的特殊生理特性以及代谢产物,在基础研究、环境保护、食品化工及医学等多个领域中都有巨大应用潜力。本文分别对嗜热菌、嗜冷菌、嗜酸菌、嗜碱菌、嗜盐菌、嗜压菌 6 种极端微生物的适应机制和应用进行了简要概述。 1. 嗜热微生物 一般把最适生长温度高于45 ℃的微生物称为嗜热微生物。另外,还可根据它们的最适生长温度将其划分为嗜热微生物( 45℃ -60℃)、极端嗜热微生物( 60℃ -80℃)和超嗜热微生物( >80℃)。目前发现的嗜热菌大都来自热泉、海底热液口、堆肥、火山等极端环境中,它们中大多数属于古细菌。目前发现的生命最高生存温度为121-122 ℃ [2]。

法律术语:Environmentprotection环境保护.doc

法律术语:Environment protection 环境保 护 1.An act that is destructive to the environment may be criminalized by statute. 破坏环境之行为可以被法律规定为犯罪。 2.Discharge pipes directly take pollutants away from the plant into the river. 排泄管道直接将污染物从工厂排入河流。 3.Environmental impact reports are required under many circumstances by federal and state law. 根据联邦和州的法律规定,在许多情况下都要求提供环境影响报告书。

4.Environmental law heavily intertwined with administrative law. 环保法与行政法紧密联系在一起。 5.Environmental problems directly affect the quality of people's lives. 环境问题直接影响人们的生活质量。 6.In 1970, a federal agency was created to coordinate governmental action to protect environment. 1970年,成立了一个联邦机构以协调政府的环保行为。 7.Most environmental litigation involves disputes with governmental agencies. 许多环保诉讼都涉及与政府机构的争端。

environment,环境,英语演讲

开场白:Morning, everyone. Today I will share something about the environment with you. 1、Look at this picture. Does it remind you of anything? You see that river, gently flowing by; you notice the leaves, rusting with the wind; you hear the birds; you hear the frogs; in the distance, you hear a cow, you feel the grass, the mud gives a little bit on the river bank. It‘s quiet, it‘s peaceful. And all of a sudden, it’s a great shift inside you, and it’s like taking a deep breath and going, (深吸一口气)oh, yeah, I almost forgot about this. 2、This is a picture of the earth from space that any of us ever saw; it was taken on Christmas Eve, 1968, during the Apollo8 mission. We can see the earth within relatively comfortable boundaries. But we are filling up that thin shell of atmosphere with pollution. 3、This is the central park of Bit. I took it by myself on November, 1, 2013. On the picture, we see the whole park is covered with heavily thick smog. It was right on that evening, I had been playing the badminton outside with my friends for three solid hours. Thank god, I’m still alive. Do you feel a little frustrated just the same as me? Yes, we are always missing something only when we do not own it anymore. 4、It comes to me another well-known wisdom that what gets us into trouble is not what we don’t know; it’s what we know for sure that just ain’t so. ----Mark Twain This is actually an important point believe it or not, because there is an assumption that a lot of people have in their mind right now about the air pollution. They just think so, the assumption sounds like this, the earth is so big, we can’t possibly have any lasting harmful impact on the earth environment. Maybe that was true at one time, but it’s not anymore. And one of the reasons it is not true anymo re is that the most vulnerable part of the earth ecological system is the atmosphere. Vulnerable, because it’s so thin. That is to say, anything what we had done can truly make a big difference to the environment. This is meant to be the end but we won’t end it here. 5、It’s so lucky for me that I toke this picture at the right same spot after I finished the preparation for today’s presentation. You see the blue sky; and the central park is filled up with warm sunshine and fresh air. Sometimes you feel some soft wind from nowhere. (放出第二张图片)Is it not beautiful? 结束语:thank you for listening.

环境微生物

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1 环境污染Preserve the environment A:A few days ago, I read a piece of news which made me considerable astonishment, our environments is in danger. At the same time, people are becoming more and more worried about the environment problems that are endangering ourselves. In your opinion, which problem will cause the worst damage to our environments? B: once our environment is very beautiful. The air was fresh, the water was clean, the sky was blue, and so on. But today, everything is different. The air in our cities is becoming more polluted, which I think will cause the worst damage. cars are still a major source of emission of air pollutants. What is about you? C: To our knowledge, Water is the source of life. Therefore, In all of the pollutions, I think Water pollution makes the most damage. Factories in the towns and cities drained waste liquid to the lakes, rivers and seas, which made the water becoming more polluted. D:I don’t agree with you. the global warming is a significant problem. The impacts will be felt around the world. The greenhouse effect is causing the earth’s temperature to rise. For example, the influence of it is the rising sea level on nature. There are lots of coastal city will submerged. How terrible! E:The biggest issue is Depletion of the ozone layer, which is a part of the atmosphere that protects the earth from dangerous radiation. Increased ultraviolet [?ltr?'va??l?t] radiation will lead to a growing number of skin cancers , cataracts ['k?t?r?kt], also reduce the ability of people's immune systems to respond to infection . F: However, Human population growth may be seen to be the root of virtually all of the world's environmental problems. Therefore, I think it makes the most damage. Population growth will lead to the energy crisis. These changes not only destroyed the original balance of ecosystems, but also triggered[?triɡ?] a number of natural disasters. A: Yes, I agree. Protecting environment, everybody has a responsibility! B:Me too , but also has how many people to have this consciousness ! if our survival environment is destructed, the consequence can be imagined, but also lives gets down? C:First, the government and the media should let people fully realize the importance of environmental protection through education. Second, much more efforts should be made to put the population planning policy into practice. D: And those who destroy the environment intentionally should be severely punished. We should

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极端环境微生物的研究进展

[摘要]极端微生物通常分为六个类群:嗜热微生物、嗜冷微生物、嗜酸微生物、嗜碱微生物、嗜盐微生物、嗜压微生物。极端环境中的微生物为了适应生存,逐步形成了独特的结构和生理机能,以适应环境。因此,研究适应机理并利用其特殊生理机能具有重要的理论和实际意义,极端微生物能产生多种极端酶和其他生物活性物质,极端微生物资源的开发利用有着广阔的前景。 极端环境(extreme environment) 泛指存在某些特殊物理和化学状态的自然环境,包括高温、低温、强酸、强碱、高盐、高压、高辐射和极端缺氧环境等,适合在极端环境中生活的微生物称为极端微生物(extremophiles)( Margesin and Schinner,2001【1】; Rothschild and Mancinelli,2001【2】;骏等,2006【3】;敏和东秀珠,2006【4】).海洋极端环境一般是指与正常海洋环境绝然不同的物理化学环境,主要包括海底热泉、海底冷泉和泥火山环境,其次还包括高盐度(卤水)、强酸化、缺氧和滞流等海洋环境。海洋极端微生物通常为化能自养生物(chemoautotroph),在分类体系上属于细菌和古细菌类,生活在无光、无氧或少氧环境,能利用一些海底热催化反应过程中产生的还原性小分子(H2、H2S和CH4 等)合成能量进行有机碳固定和新代,具有独特的基因类型、特殊生态群落、特殊生理机理和特殊代产物,有些属于共生生物(endosymbiont)。 一、极端微生物的种类及其生理特点 1.1 极端嗜热菌(Thermophiles) 一般最适生长温度在90℃以上的微生物,被称做极端嗜热菌【5,6】。已发现的极端嗜热菌有20多个属,大多是古细菌,生活在深海火山喷口附近或其周围区域【7】。如斯坦福大学科学家发现的古细菌,最适生长温度为100℃,8O℃以下即失活;德国的斯梯特(K Stette)研究组在意大利海底发现的一族古细菌,能生活在110℃以上高温中,最适生长温度为98℃,降至84℃即停止生长;美国的巴罗斯(J.Baroos)发现一些从火山喷口中分离出的细菌可以生活在250℃的环境中,嗜热菌的营养围很广。多为异养菌,其中许多能将硫氧化以取得能量。 1.2 极端嗜酸菌(Acidophiles) 一般指生活环境pH值在1以下的微生物,往往生长在火山区或含硫量极为丰富的地区。多为古细菌,其体环境保持pH值7左右。能氧化硫,硫酸作为代产物排出体外。嗜酸菌往往也是嗜高温菌。 1.3 极端嗜盐菌(Extremehalophiles)

极端环境微生物16S rRNA测序

ORIGINAL ARTICLE Contemporary environmental variation determines microbial diversity patterns in acid mine drainage Jia-Liang Kuang1,Li-Nan Huang1,Lin-Xing Chen,Zheng-Shuang Hua,Sheng-Jin Li, Min Hu,Jin-Tian Li and Wen-Sheng Shu 1State Key Laboratory of Biocontrol and Guangdong Key Laboratory of Plant Resources,School of Life Sciences,Sun Yat-sen University,Guangzhou,People’s Republic of China A wide array of microorganisms survive and thrive in extreme environments.However,we know little about the patterns of,and controls over,their large-scale ecological distribution.To this end,we have applied a bar-coded16S rRNA pyrosequencing technology to explore the phylogenetic differentiation among59microbial communities from physically and geochemically diverse acid mine drainage(AMD)sites across Southeast China,revealing for the first time environmental variation as the major factor explaining community differences in these harsh environments. Our data showed that overall microbial diversity estimates,including phylogenetic diversity, phylotype richness and pairwise UniFrac distance,were largely correlated with pH conditions. Furthermore,multivariate regression tree analysis also identified solution pH as a strong predictor of relative lineage abundance.Betaproteobacteria,mostly affiliated with the‘Ferrovum’genus,were explicitly predominant in assemblages under moderate pH conditions,whereas Alphaproteobac- teria,Euryarchaeota,Gammaproteobacteria and Nitrospira exhibited a strong adaptation to more acidic environments.Strikingly,such pH-dependent patterns could also be observed in a subsequent comprehensive analysis of the environmental distribution of acidophilic microorgan- isms based on16S rRNA gene sequences previously retrieved from globally distributed AMD and associated environments,regardless of the long-distance isolation and the distinct substrate types. Collectively,our results suggest that microbial diversity patterns are better predicted by contemporary environmental variation rather than geographical distance in extreme AMD systems. The ISME Journal advance online publication,22November2012;doi:10.1038/ismej.2012.139 Subject Category:microbial population and community ecology Keywords:acid mine drainage;biogeography;contemporary environmental variation;geographical distance;microbial diversity;pyrosequencing Introduction Microbial biogeography is increasingly becoming an exciting topic in microbial ecology and a growing number of researches are addressing the spatial scaling and distribution pattern of microorganisms in the environment(Martiny et al.,2006;Green et al., 2008).Despite their tremendous potential for global dispersal,there is accumulating evidence that free-living microorganisms exhibit nonrandom distribu-tion patterns across diverse habitats at various spatial scales.Niche-based processes have been implied as the primary drivers for the widely observed environ-ment-dependent diversity patterns and environmen-tal variables such as salinity(Lozupone and Knight,2007;Auguet et al.,2010),pH(Fierer and Jackson, 2006;Lauber et al.,2009;Rousk et al.,2010;Griffiths et al.,2011)and C:N ratio(Bates et al.,2011) identified as the major determinants of microbial community composition.However,there is also evidence that spatial distance,which may be seen as a proxy variable that represents differential com-munity dynamics related to the past historical events and disturbances(Ramette and Tiedje,2007),have a role in structuring natural microbial assemblages(Cho and Tiedje,2000;McAllister et al.,2011;Martiny et al.,2011).These studies of biogeography have provided initial insights into the processes that generate diversity patterns and improved our under-standing of why organisms live where they do and how they will respond to environmental change. However,systematically exploring the microbial geographical patterns by considering both contem-porary environmental variations and spatial distance simultaneously is limited(Ramette and Tiedje,2007; Ge et al.,2008),and the relative importance of these factors in shaping microbial communities in natural environments remains largely unsolved. Correspondence:W-S Shu,School of Life Sciences,Sun Yat-sen University,No.135,Xin-Gang-Xi Road,Guangzhou510275, People’s Republic of China. E-mail:shuws@https://www.doczj.com/doc/dd3258958.html, 1The first two authors contributed equally to this work. Received3July2012;revised1October2012;accepted1October 2012The ISME Journal(2012),1–13 &2012International Society for Microbial Ecology All rights reserved1751-7362/12 https://www.doczj.com/doc/dd3258958.html,/ismej

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