RUI: Collaborative: A REAL Approach to Investigating Bacterial Degradation of PET Plastic Waste

减少、再利用和回收计划很重要，但不足以解决我们地球面临的巨大塑料污染问题，因此这项研究集中在我们环境中发现的塑料的生物降解上。为了创造更循环的塑料经济，调查人员之前分离出了一个细菌物种联合体，总共五种，它们能降解塑料水瓶所用的材料聚对苯二甲酸乙二酯(PET)。总体而言，联合体的生长速度更快，产生的塑料降解酶活性也比单独的联合体或物种更多。研究人员将确定这些观察的遗传和生化基础。该合作项目将为本科生和高中生提供研究机会，旨在实现项目--S的目标。第一代和代表不足的少数族裔学生将被招募到这套令人兴奋的项目中，并为暑期研究提供资金，并在学年继续努力。细菌降解PET的遗传基础也将在普通微生物学课程的实验室部分进行研究，丰富课程内容。土壤细菌对PET塑料的协同降解尚未被探索，但有可能帮助去除目前存在于我们环境中的估计63亿吨中的一部分。假单胞菌3株，芽孢杆菌2株。通过对与塑料降解有关的脂肪酶活性的筛选，从德克萨斯州休斯顿附近的石油污染土壤中分离到一株。五个细菌物种的联合作用是协同作用的，产生更多的脂肪酶活性，并比单个联合或菌株更快地降解PET塑料。研究人员将挖掘这五种细菌的基因组，以了解在KEGG路径数据库的帮助下，PET生物降解所需的代谢路径，并将使用核磁共振来识别副产品，将这些数据与遗传信息相关联。分泌的酶将使用光谱分析技术进行鉴定。转座子突变，一种无偏见的方法，将确定表达和分泌脂肪酶、酯酶和PET降解所需生物膜的遗传基础。研究人员还将使用RNA测序，剖析酯键断裂和单体对苯二甲酸和乙二醇完全降解所需的联合细菌的遗传调控网络，最终目标是减少陆地和海洋中的PET废物。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Reduce, reuse and recycle programs are important, but are not enough to address the massive plastic pollution problem facing our planet, and thus this research is focused on the biodegradation of plastics found in our environment. Toward creating a more circular plastic economy, investigators previously isolated a consortium of bacterial species, five in total, that degrade polyethylene terephthalate (PET), the material used to make plastic water bottles. Collectively, the consortium grew faster on, and produced more plastic-degrading enzyme activity than individual consortia or species alone. Researchers will determine the genetic and biochemical basis for these observations. The collaborative project will provide undergraduate and high school students research opportunities aimed at accomplishing the project?s goals. First generation and underrepresented minority students will be recruited for this exciting set of projects, with funding for summer research, and continued effort during the academic year. The genetic basis for bacterial degradation of PET also will be investigated in the laboratory portion of a general microbiology course, enriching the curriculum. Synergistic degradation of PET plastic by soil bacteria is unexplored, but has the potential to aid in the removal of a portion of the estimated 6.3 billion metric tons that currently exist in our environment. Three Pseudomonas and two Bacillus spp. were isolated from petroleum polluted soils near Houston, TX, by screening for lipase activity, which has been associated with plastic degradation. The consortium of five bacterial species act synergistically, producing more lipase activity and degrading PET plastic faster than individual consortia or strains. Investigators will mine the genomes of the five bacteria to understand the metabolic pathways necessary for biodegradation of PET, aided by the KEGG pathways database, and will use NMR to identify byproducts, correlating these data with genetic information. Secreted enzymes will be identified using spectrometry techniques. Transposon mutagenesis, an unbiased approach will determine the genetic basis for expression and secretion of lipases, esterases, and biofilm formation necessary for PET degradation. Investigators will also dissect the genetic regulatory network, using RNA sequencing, of the consortium bacteria required for ester bond cleavage and the complete degradation of the monomers terephthalic acid and ethylene glycol, with the ultimate goal of reducing PET waste on land and in our oceans.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.