Collaborative Research: Microbial Interactions with Marine Plastic Debris: Diversity, Function and Fate

合作研究：微生物与海洋塑料碎片的相互作用：多样性、功能和命运

• 批准号: 1155571
• 负责人: Linda Amaral Zettler
• 金额: $ 50.62万
• 依托单位: Marine Biological Laboratory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1155571&HistoricalAwards=false
• 关键词: Collaborative; Research; Microbial; Interactions; Marine

Plastic marine debris is a recent introduction to marine ecosystems resulting from the widespread use of polymers in consumer goods after World War II. The current global annual production of plastic is 245 million tonnes or 35 kg of plastic for each of the 7 billion humans on the planet, rivaling the combined biomass of all humans. Drifter buoys and physical oceanographic models demonstrate that surface particles passively migrate from the coastline to the central gyres in less than 60 days, illustrating how quickly human-generated debris can impact the pristine gyre interiors, more than 1000 km from land. Plastic debris has been implicated as a vector for transportation of harmful algal species and persistent organic pollutants, and provides a substrate for microbes that moves between environments and lasts much longer than most natural floating substrates. Despite increases in plastic production no significant trend in plastic accumulation has been observed since 1985. Physical shearing and photodegradation are known mechanisms of plastic degradation, but microbial degradation has also been implicated. Unpublished data employing pyrotag amplicon sequencing targeting bacterial and eukaryotic small subunit ribosomal RNA gene sequences, together with Scanning Electron Microscopy (SEM) data are consistent with the notion that plastic debris harbors a unique association of microbes including members capable of degrading plastic. The term "Plastisphere" describes this unique microbial community attached to and surrounding marine plastic debris and distinct from microbes in the surrounding seawater and on natural substrates such as macroalgae.This project will: (1) characterize diversity through amplicon sequencing and comparative -omics combined with SEM and confocal microscopy to investigate the microbial composition of the Plastisphere; (2) describe function of the Plastisphere taking a cultivation-independent environmental DNA gene expression approach, as well as a cultivation-based approach to interrogate environmental clones and microbial isolates for the ability to degrade hydrocarbons; and (3) determine key biological factors that control the fate of plastic debris in the upper water column.Intellectual Merit. Plastic is now the most abundant form of marine debris. Gaining an understanding of how plastic is affecting the very foundation of the food web in delicate open ocean environments is a first order question that will be addressed in this proposal and provides a base for an emerging research topic that has been identified as a high-priority research area. Understanding how microbes interact with plastic debris that accumulates in the North Atlantic Subtropical Gyre and North Pacific Subtropical Gyre (two of the largest biomes on Earth) will provide a foundation for follow-up research questions such as: Do microbial biofilms provide sustenance for filter feeding zooplankton?; how is the abundance of plastic debris affecting the health of these delicate biomes?; and can a truly biodegradable plastic be formulated that will have minimal impact on the oligotrophic environment? With a growing human population and second and third world economic growth, it is inevitable that more plastic debris will find its way into the ocean and collect in convergence zones such as the gyres.Broader Impacts. The field component of this project is built around independent research projects by undergraduate students participating in Sea Education Association?s SEA Semester research cruises in the Atlantic and Pacific oceans. In addition to mentoring SEA Semester students who will be collecting samples and helping with this project throughout the year, the project will engage faculty and students from the Caribbean region who are studying at St. Georges University in Grenada. Underrepresented minorities in the US will be mentored through the Partnership Education Program (PEP) program, the WHOI minority fellowship program, and the MBL REU Site program in Biological Discovery in Woods Hole. Outreach to the general public and K-12 teachers and students will be delivered through a dedicated website for the "Plastics at SEA expedition" in 2010 by adding a section that specifically addresses microbial ecology and the role of plastic marine debris in open ocean marine ecosystems. All members of the research team will contribute to a newly developed undergraduate curriculum in "Marine Biodiversity and Conservation" via lectures and participation aboard ship.

塑料海洋垃圾是第二次世界大战后在消费品中广泛使用聚合物而导致的海洋生态系统的最新引入。目前，全球每年生产的塑料为2.45亿吨，即地球上70亿人每人生产35公斤塑料，相当于所有人的总生物量。漂流浮标和物理海洋学模型表明，表面颗粒在不到60天的时间内被动地从海岸线迁移到中心环流，这说明了人类产生的碎片可以多么迅速地影响距离陆地1000多公里的原始环流内部。塑料碎片被认为是有害藻类和持久性有机污染物运输的载体，并为微生物提供了在环境之间移动的基质，并且比大多数天然漂浮基质持续时间更长。尽管塑料产量有所增加，但自1985年以来没有观察到塑料积累的显著趋势。物理剪切和光降解是已知的塑料降解机制，但微生物降解也有牵连。未发表的针对细菌和真核生物小亚基核糖体RNA基因序列的热标记扩增子测序数据，以及扫描电子显微镜（SEM）数据，都与塑料碎片含有独特的微生物关联的观点一致，包括能够降解塑料的成员。“塑料球”一词描述了附着在海洋塑料碎片上和周围的独特微生物群落，与周围海水和大型藻类等自然基质上的微生物不同。本项目将：(1)通过扩增子测序和比较组学，结合扫描电镜和共聚焦显微镜研究塑料球的微生物组成，来表征多样性；(2)采用不依赖培养的环境DNA基因表达方法，以及基于培养的方法来询问环境克隆和微生物分离物降解碳氢化合物的能力，描述Plastisphere的功能；(3)确定控制上层水柱塑料碎片命运的关键生物因素。知识价值。塑料现在是海洋垃圾中数量最多的一种。了解塑料是如何影响脆弱的开放海洋环境中食物网的基础的，是本提案将解决的首要问题，并为一个新兴的研究课题提供基础，该课题已被确定为一个高优先级的研究领域。了解微生物如何与北大西洋亚热带环流和北太平洋亚热带环流（地球上最大的两个生物群落）中积累的塑料碎片相互作用，将为后续研究问题提供基础，例如：微生物生物膜是否为滤食性浮游动物提供营养？大量的塑料碎片如何影响这些脆弱的生物群落的健康？一种真正可生物降解的塑料能否被配制出来，对营养不良的环境影响最小？随着人口的增长和第二、第三世界的经济增长，越来越多的塑料碎片将不可避免地进入海洋，并在环流等汇聚区聚集。更广泛的影响。这个项目的实地部分是由参加海洋教育协会的本科生进行的独立研究项目。s SEA学期的研究巡航在大西洋和太平洋。除了指导SEA学期的学生全年收集样本并帮助完成该项目外，该项目还将吸引在格林纳达圣乔治大学学习的来自加勒比地区的教师和学生。美国未被充分代表的少数民族将通过伙伴关系教育计划（PEP）计划、WHOI少数民族奖学金计划和MBL REU网站计划在伍兹霍尔的生物发现得到指导。2010年，面向公众和K-12教师和学生的宣传活动将通过一个专门的网站进行，该网站将增加一个专门讨论微生物生态学和海洋塑料垃圾在开放海洋生态系统中的作用的部分。研究小组的所有成员都将通过船上的讲座和参与，为新开发的“海洋生物多样性与保护”本科课程做出贡献。