RUI: Microbial Processes Facilitating Xylophagy in a Loricariid

这个项目关注的是一种令人着迷的长有装甲的叉尾鱼，这种叉尾属，其中包括能够通过吃木头生存和获取能量的成员。以木材为食，或以木质为食，是一种罕见的饮食策略，通常涉及复杂的肠道微生物群落。该项目的一个主要目标是确定以黑线木为食的木材的胃肠道(GI)中存在的微生物群落，并研究使这种以木质为食的生活方式得以实现的纤维素分解和固氮机制。将进行一项长期的饮食实验，以比较饲喂草本和纯木材饲料的鱼中的微生物群落。DNA测序和其他分子方法将能够描述不同饮食制度下鱼类中的微生物群落，并进一步比较鱼类GI区不同区域的微生物群落，精确定位涉及纤维素分解的关键区域。还将通过分离参与这一重要全球过程的基因，以及培养与Panaque GI区相关的固氮微生物来检验固氮。该项目的更广泛的科学影响包括加强我们对纤维分解和固氮基因多样性的了解，以及在食木鱼中微生物群落的重要性。纤维素是生物圈中含量最丰富的碳聚合物，然而，很少有降解途径被表征。由于纤维素是全球碳循环中的一种重要化合物，也是生物质燃料生产的潜在来源，因此更好地了解其在环境中的降解至关重要。此外，新途径的发现可能对生物燃料生产和全球碳和氮循环具有关键影响。教育影响包括在本研究项目期间对研究生和本科生的培训。计划与巴尔的摩市的一所小学开展一项外联活动，为3-8年级的儿童提供实践机会，目的是促进这些儿童将科学作为职业选择。

This project focuses on a fascinating group of fish - armored catfish, from the genus Panaque, which include members that are capable of surviving and obtaining energy by eating wood. Wood eating, or xylophagy, is a rare dietary strategy and often involves a complex intestinal tract microbial community. A major goal of this project is to identify the microbial communities present in the gastrointestinal (GI) tract of the wood eating Panaque nigrolineatus and examine the mechanisms used for cellulose decomposition and nitrogen fixation that enable this xylophagous lifestyle. A long-term dietary experiment will be performed to compare the microbial communities in fish fed an herbaceous diet to those fed a wood-only diet. DNA sequencing and other molecular methods will allow the description of microbial communities in fish subjected to different dietary regimes and furthermore, compare microbial communities in different regions of the fish GI tract, pinpointing key areas involved in cellulose breakdown. Nitrogen fixation will also be examined by isolating genes involved in this vital global process, and by culturing nitrogen fixing microorganisms associated with the Panaque GI tract. Broader scientific implications of this project include enhancing our knowledge of cellulolytic and nitrogen fixation gene diversity and the importance of the microbial community within xylophagous fish. Cellulose is the most abundant carbon polymer in the biosphere, yet, few degradation pathways have been characterized. As cellulose is an important compound in the global carbon cycle and a potential source for biomass fuel generation, gaining a better better understanding of its degradation in the environment is critical. Furthermore, discovery of novel pathways may have critical implications for biofuel production and the global carbon and nitrogen cycles. Educational impacts include the training of graduate and undergraduate students during this research project. An outreach activity with a Baltimore City elementary school is planned, enabling a hands-on opportunity for children in grades 3-8 with the goal of promoting science as a career choice for these children.