Heterotrophic microorganisms in Arctic hydrothermal sediments - the ecological roles and impact of their CAZymes repertoire

深海热液喷口是地球上最极端的生境之一，是海洋生物勘探和生物发现的有趣目标。深海热液喷口的微生物群落往往以化能自养微生物为主，它们利用简单的化合物作为能源。然而，其异养能力的全部范围仍在探索中。生物加工行业迫切需要新的微生物解决方案，其中复杂有机材料的降解通常是一个重大挑战。为了满足这些需求，已经开发并测试了新型原位培养器，以了解使用木材加工业的抗降解材料是否会导致海洋热液沉积物中微生物群落结构的变化。微生物群落结构的差异取决于所使用的材料，海底以下的腔室深度，和/或温度。16 S rRNA扩增子测序揭示了与Thermotogales内培养成员相关的异养微生物谱系的高比例。然而，以前未培养的和新的Thermotogales和拟杆菌的显着比例也被确定。此外，还观察到几个新的尚未培养的嗜热菌和细菌谱系。基于此，本项目的目标是从北极热液沉积物中培养和分离各种异养细菌。将筛选具有不同底物（例如纤维素和几丁质）的富集培养物，以确定在已经可用的宏基因组中鉴定的多糖降解酶的存在。将进行定向培养策略以选择新的异养细菌。不同代谢能力的基因组分析将支持这些。单细胞水平的功能分析将有助于根据目标细菌在混合培养物中的原位活性来鉴定和分离目标细菌。最后，新的异养细菌将在形态学，生理学和它们的基因组方面进行详细的表征。在改进的孵育条件下的元转录组学方法也将提供关于碳水化合物活性酶（CAZymes）的信息。这些将被调查和特点更详细。因此，基于宏基因组和元转录组，可以发现用于各种工业的新酶。该项目将揭示北极深海热液喷口微生物组的代谢秘密和能力。

Deep-sea hydrothermal vents are among the most extreme habitats on Earth and represent interesting targets for marine bioprospecting and biodiscovery. Microbial communities at deep-sea hydrothermal vents are often dominated by chemolithoautotrophic microorganisms that use simple chemical compounds as energy sources. However, the full extent of their heterotrophic capabilities is still being explored. New microbial solutions are urgently needed in the bioprocessing industry, where the degradation of complex organic materials is often a major challenge. To meet these needs, novel in situ incubators have already been developed and tested to see if the use of degradation-resistant materials from the wood processing industry causes changes in the microbial community structure in hot marine hydrothermal sediments. Differences in the microbial community structure were observed depending on the used material, chamber depth below the seafloor, and/or temperature. 16S rRNA amplicon sequencing revealed a high proportion of heterotrophic microbial lineages related to cultivated members within the Thermotogales. However, significant proportions of previously uncultured and novel Thermotogales and Bacteroidetes were also identified. In addition, several new lineages of not yet cultured thermophilic Archaea and Bacteria were observed. Based on this, the goal of the proposed project is to cultivate and isolate various heterotrophic bacteria from Arctic hydrothermal sediments. Enrichment cultures with different substrates such as cellulose and chitin will be screened for the presence of polysaccharide degrading enzymes identified in already available metagenomes. Targeted cultivation strategies will be performed to select the new heterotrophic bacteria. Genomic analyses for different metabolic capacities will support these. Functional analyses at the single cell level will help identify and isolate the target bacteria based on their in situ activity in mixed cultures. Finally, novel heterotrophic bacteria will be characterized in detail with respect to morphology, physiology and their genome. Metatranscriptomic approaches under modified incubation conditions will also provide information about the carbohydrate-active enzymes (CAZymes). These will be investigated and characterized in more detail. Thus, based on metagenomes and metatranscriptomes, new enzymes for various industries can be discovered. The metabolic secrets and the capacity of the microbiomes of hydrothermal vents in the Arctic deep-sea will be revealed within this project.