RUI: Physiological heterogeneity of plastic-associated microbial communities in freshwater Lake Lacawac

微塑料是一种尺寸小于5毫米的塑料颗粒，是一种常见的污染物，自第二次世界大战以来在环境中广泛积累。因为微塑料是固体，它们代表了微生物可以定居的独特表面。在海洋环境中，研究表明，这些与塑料相关的微生物群落与栖息在水柱中的微生物群落不同。然而，淡水环境中与塑料相关的微生物群落普遍存在，但受到的关注相对较少，尽管微生物在所有生态系统的营养循环中都是必不可少的。这项研究将是同类研究中首次探讨微塑料积累在改变淡水环境中微生物群落和基本代谢过程中可能发挥的作用。该项目将支持三名本科生在两个夏季的暑期实地研究经历。这些野外体验将在宾夕法尼亚州的拉卡瓦克保护区生物野外站和环境教育中心进行，这是全球公认的淡水研究地点。此外，学生将获得分析微生物群落的最先进软件程序的经验，并学习用于统计分析的关键编程语言。大量的两种微塑料（聚苯乙烯和聚对苯二甲酸乙二醇酯）以及天然凋落叶将被放置在以宾夕法尼亚州拉卡瓦克湖地表水为原料的生物反应器中。本科生研究人员将在24周内每周监测生物反应器中的溶解氧、pH值、温度和电导率。为了研究塑料相关微生物群落的组成与自然碎片上的微生物群落的组成有何不同，学生们将每三周从每个生物反应器中收集微塑料、凋落叶和水的样本，持续24周。从每个样本中提取DNA，研究人员将使用通用（细菌/古细菌）引物扩增16S rRNA基因序列。将对这些扩增子进行测序，并使用先进的统计软件确定每个群落的系统发育组成。学生们将根据他们的数据撰写报告，并在地区和国家会议上做研究报告，这将激励他们考虑未来的研究生学习。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Microplastics, which are plastic particles less than 5 millimeters in size, are a common pollutant that have seen widespread accumulation in the environment since World War II. Because microplastics are solid, they represent a distinct surface that microorganisms can colonize. In marine environments, studies have shown that these plastic-associated microbial communities are distinct from those that inhabit the water column. However, plastic-associated microbial communities in freshwater environments are ubiquitous but have received considerably less attention even though microorganisms are essential players in nutrient cycles in all ecosystems. This study will be the first of its kind to investigate what role microplastic accumulation may play in altering microbial communities and, by extension, essential metabolic processes, in freshwater environments. This project will support summer field research experiences for three undergraduate students per summer for two summers. These field experiences will take place at the Lacawac Sanctuary Biological Field Station and Environmental Education Center in Pennsylvania — a globally recognized location for freshwater research. In addition, students will gain experience with state-of-the-art software programs for analyzing microbial communities as well as learn critical programming languages used for statistical analyses.Quantities of two microplastics (polystyrene and polyethylene terephthalate) along with natural leaf litter will be placed within bioreactors fed with surface water from Lake Lacawac, Pennsylvania. Undergraduate researchers will monitor dissolved oxygen, pH, temperature, and conductivity in the bioreactors on a weekly basis for 24 weeks. To investigate how the composition of plastic-associated microbial communities differs from those found on natural debris, students will collect samples of microplastics, leaf litter, and water from each bioreactor every three weeks for 24 weeks. DNA will be extracted from each of these samples and the investigators will amplify the 16S rRNA gene sequences using universal (bacterial/archaeal) primers. These amplicons will be sequenced and the phylogenetic composition of each community will be determined using advanced statistical software. Students will produce reports from their data and make research presentations at regional and national conferences, which will inspire them to consider graduate studies in the future.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.