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栖息地之一，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通常以化学岩石自养微生物为主，它们以简单的化合物作为能量来源。然而，它们的异养能力的全部程度仍在探索中。生物加工行业迫切需要新的微生物解决方案，复杂有机材料的降解往往是一个重大挑战。为了满足这些需求，已经开发并测试了新的原位孵育器，以观察使用木材加工业的抗降解材料是否会导致热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。16S rRNA扩增子测序显示，在热菌群中与培养成员相关的异养微生物谱系比例很高。然而，也发现了大量以前未培养的新型热菌和拟杆菌门菌。此外，还观察到一些尚未培养的嗜热古细菌和细菌的新谱系。基于此，拟建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。不同底物（如纤维素和几丁质）的富集培养物将被筛选是否存在已在宏基因组中发现的多糖降解酶。通过有针对性的培养策略筛选新的异养菌。对不同代谢能力的基因组分析将支持这些观点。单细胞水平的功能分析将有助于根据混合培养中的原位活性识别和分离目标细菌。最后，新型异养细菌将在形态学，生理学和基因组方面进行详细的表征。改良孵育条件下的超转录组学方法也将提供有关碳水化合物活性酶（CAZymes）的信息。这些将被更详细地研究和描述。因此，基于宏基因组和亚转录组，可以发现各种行业的新酶。该项目将揭示北极深海热液喷口微生物群的代谢秘密和能力。

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.