The Microbial Metagenome of the Termite Hindgut

白蚁以木头为食，具有惊人的生存能力。从一个角度来看，这可能是一个大问题，需要花费数十亿美元修复人造建筑和根除白蚁。另一方面，这也是一个了解如何有效地从木材中提取能量的机会。白蚁依靠其后肠中复杂的微生物群落来分解木材并为自己提供能量。然而，其中许多微生物的身份，以及它们在木材消化中扮演的具体角色，仍然是未知的。本研究以一种具有高度侵袭性和破坏性的地下白蚁为研究对象，旨在确定其相关微生物的群落多样性，并了解其在木材消化过程中的具体作用。这在一定程度上可以通过基因组测序来实现，因为每个微生物的代谢能力都可以从其基因组序列中预测出来。这些信息对科学和社会至关重要，因为它可以探索生物白蚁控制以及生物燃料和生物材料生产的替代方法。除了为学生提供研究培训外，该项目还为K-12学生开发了一个互动推广模块，以帮助激发学生对科学、技术和工程研究的欣赏。它们的基因组尚未被探索，但预计会非常大，需要进行深度测序。后肠群落还包括细菌、古菌和病毒，丰度变化很大。为了对生命的每个“区域”中的微生物进行充分的测序，在测序之前将进行浓缩步骤，即分离超乳杆菌核、分离病毒颗粒和滚动扩增丰度较低的细菌基因组。组装的微生物基因组将通过16S或18S核糖体RNA基因进行鉴定，从而将碳水化合物活性酶基因分配到微生物物种。固氮能力也将通过nifH基因的实时定量聚合酶链式反应来推断。对于最丰富的细菌，它们的共生状态(外共生体、内共生体或自由游动)将通过荧光原位杂交来确定。通过识别和推断后肠生物反应器中每个微生物的代谢能力，该项目将为更深入地理解高效的木材消化奠定基础。该奖项反映了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。

Termites have the remarkable ability to survive on a diet of wood. From one perspective, this can be a big problem, costing billions in damage repair to man-made structures and termite eradication. On the other hand, it is also an opportunity to understand how energy can be efficiently extracted from wood. Termites rely on a complex community of microorganisms in their hindgut to break down wood and provide energy for themselves. However, the identity of many of these organisms, and the specific roles they each play in wood digestion, are still unknown. This research focuses on a highly invasive and destructive subterranean species of termite, and aims to identify the community diversity of their associated microorganisms and to understand their specific roles in the wood digestion process. This can be achieved in part through genome sequencing, as each microorganism's metabolic capabilities can be predicted from its genome sequence. This information is fundamentally important for science and society as it may enable exploring alternative approaches to biological termite control as well as biofuel and biomaterial production. In addition to providing research training for students, this project also develops an interactive outreach module for K-12 students to help spark appreciation for science, technology, and engineering research.The Coptotermes formosanus hindgut community includes large, complex eukaryotic microbes called hypermastigotes. Their genomes are unexplored but are expected to be very large, necessitating deep sequencing. The hindgut community also includes bacteria, archaea, and viruses, at highly variable abundances. To adequately sequence microbes from each of these "domains" of life, enrichment steps will be performed before sequencing, namely isolation of hypermastigote nuclei, isolation of viral particles, and rolling-circle amplification of lower abundance bacterial genomes. Assembled microbial genomes will be identified by 16S or 18S ribosomal RNA genes, so that carbohydrate active enzyme genes can be assigned to microbial species. Nitrogen fixing capability will also be inferred by quantitative real-time PCR of nifH genes. For the most abundant bacteria, their symbiotic status (ectosymbiont, endosymbiont, or free swimming) will be determined through fluorescent in-situ hybridization. By identifying and inferring the metabolic capabilities of each microbe in the hindgut bioreactor, this project will lay the groundwork for a deeper understanding of efficient wood digestion.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.