青年说 ‖ 李依静:自然知道答案

发表时间:2020-09-01 08:47


Li Yijing, female, a master student from eco-environmental sciences of Chinese academy of sciences, Sino-Danish Center of university of CAS, focus on environment microbiology.


My name is Li Yijing, I’m a master student from research center for eco-environmental sciences, Chinese academy of sciences. Currently, my study interest is environment microbiology, I mainly focus on biodegradation of environmental pollutants. I’m very happy to share my learning experience in the field of environment subject, by the platform of “popular eco-youth talk”.


In my middle school age, I watched a documentary named Ocean by chance, and deeply touched by the splendor and vast of the underwater world. After that, I begun to seek more information on that, however, I gradually found that there are so many potential risks covered under the beauty of the deep blue—ocean acidification, plastic pollution, over-fishing, discharge of pollutants, so many issues have been threatening the biodiversity and eco-balance of ocean. The more I knew about eco-environment issues, the stronger the impulsion to do something became. Thus, firmly, I chose environment engineering as my first volunteer subject in college entrance examination. Until now, I still feel happy and proud for studying and working in this field, and I am even more determined to engage in this career.


Because I’ve been always interested in biology, so I chose environmental microbiology as my study interest at the beginning. From marine hydrothermal whose temperature can be as high as 400℃, to the whole year frozen plateau glacier, microorganism are ubiquitous in environment. Microbes are highly diverse in phylogeny with various genetic information, they perform a wide range of metabolism and growth patterns, and form microbial communities with distinct compositions and structures, and play unique roles in different niches in consequence. Even nowadays, when the microbial cultivation and identification technology has developed into a new stage, the microbes we can cultivate in the labs only accounts for 1~10% of the total microorganisms in nature, the hidden resources of microorganisms are still there for further explorations.


In my bachelor period, I mainly studied on anaerobic ammonium oxidation. The bacteria (anaerobic ammonium oxidation bacteria, AAOB) proceeding this process is magical, they choose a harsh way to make livings, namely, using nitrate/nitrite to oxidize ammonium under anoxic condition, and grow on inorganic carbonate as carbon source, thus the doubling time of AAOB can be as long as two weeks. However, living such a struggling life, AAOB contribute to half nitrogen removal in marine environment, as well as shed the light on the energy-efficient technology of anaerobic wastewater denitrogenation, which is a milestone discovery in the field of environmental microbiology.


In my master period, I mainly focus on anaerobic biodegradation of environmental organic pollutants. With the development of technology, various organic compounds have been released into environment, such as polycyclic aromatic hydrocarbon, herbicides, antibiotics, which results in risks to human health and eco-environment safety, due to their toxicity. It has been widely reported that, the newly synthesized compounds could cause severe inhibition on local bacteria when they enter certain environment at the beginning, because there may be lack of relevant degraders due to their complicated and specific molecular structure. However, through the natural evolution of indigenous microbes, several weeks or thousand years, the “enemy” of this pollutant would appear, maybe a certain species who evolved and harbor the specific degrading genes targeted on this certain compound, may be multiple populations working in synergistic pattern as well. In the process of industrialization, due to the delay characteristic of environment problem, human beings have created countless compounds that even ourselves have no idea about how to deal with, but luckily, it seems that nature always prepare an answer for that, in silence, waiting for the discovery of human beings. That is the mission for environmental microbiologist, in my mind, to find out those hidden answers.

环境保护是一门要求理论与实践紧密结合的专业,所以在学习、科研之余,我也十分珍惜每一次的实习机会,从实践中总结经验。正是通过一次次的实践,我获得了对环境学科在深度和广度上的认识和见解。本科一年级时,我担任了湖南省环保NGO绿色潇湘“上游一公里”活动的讲解员,带领长沙市的小朋友们探访了长沙市的母亲河湘江,向小朋友们讲述了水质检测的相关知识。活动中小朋友们表现出的好奇心和对水源保护的关切深深打动了我,我越发感受到身为环境学子身上沉甸甸的责任。在本科三年级,我们深入大型冶炼企业进行了生产实习,期间深入了解了各个生产车间中每一道工序的运作原理、各个步骤的污染物产生情况及其配套的环保措施。通过身临其境的学习,我对实际工业过程的环境污染及控制状况有了十分直观细致的认知,同时也对产品全生命周期的污染控制有了更深刻的体会——单一污染物末端治理向清洁生产工艺应用的必要。在国科大中丹学院的研究生学习阶段,在Erik Jeppesen和刘正文教授的带领下,我和同学们在太湖进行了实地考察与调研,并结合历年太湖水质理化指标、浮游生物和鱼类的数据,深入研究了太湖富营养化问题的成因与修复情况。

Environment protection requires the combination of theory and practice, so I always cherish every opportunities of internship, and try to improve myself from practice experiences. By practice, I learn environmental knowledge both in depth and width. In my freshman year, I worked as a volunteer commentator in Green Hunan, the environment protecting NGO of Hunan province. I guided a group of children to visit Xiangjiang river, the mother river of Changsha city, and shared the knowledge about the test of water quality. The curiosity and deep concern on water resource protection shown by those children impressed me a lot, making me feel the responsibility of working as an environment protector. In my junior year, me and my classmates got the internship chance in large smelting companies, during that period, we went down to every workshop to learn the operating mechanism, the production of various pollutants in every unit and its relevant pollutant control strategies. Being personally on the scene, I obtained a deeper understanding on the pollutants production and control during the whole life cycle, and higher acknowledgement on the necessity of transformation to the clean production. When I studied in SDC of UCAS, under the guidance of professor Erik Jeppesen and Liu Zhengwen, I had an excursion to Taihu Lake, by combining the physiochemical water quality index with plankton and fish data over several years, I had deeper understanding on the eutrophication problem of Taihu.


—— 环保寄语 ——


Environment protection requires not only the update of technology and management, but also that everyone’s willingness to live a sustainable life despite the inconvenience may accompany.