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由化石型自养微生物主导，它们使用简单的化合物作为能源。然而，它们的异养能力的全面程度仍在探索中。生物加工行业迫切需要新的微生物解决方案，因为在该行业，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，已经开发了新型的原位培养箱并进行了测试，以确定使用来自木材加工行业的抗降解材料是否会导致高温海洋热液沉积物中微生物群落结构的变化。观察到微生物群落结构的差异取决于所使用的材料、海底以下的洞室深度和/或温度。16S rRNA扩增序列分析表明，与Thermotogale中的培养成员相关的异养微生物谱系比例很高。然而，也发现了相当大比例的以前未培养的和新的温特盖尔和拟杆菌。此外，还观察到了几个尚未培养的嗜热古生菌和细菌的新谱系。基于此，该项目的目标是从北极热液沉积物中培养和分离各种异养菌。用不同底物如纤维素和甲壳素的增菌培养物将被筛选，以确定在已有的元基因组中是否存在多糖降解酶。将实施有针对性的培养策略，以选择新的异养菌。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目标细菌在混合培养中的原位活性来识别和分离目标细菌。最后，将从形态、生理和基因组等方面对新型异养细菌进行详细的表征。在改进的培养条件下的变态翻译方法也将提供关于碳水化合物活性酶(CAZymes)的信息。我们将对这些问题进行更详细的调查和描述。因此，基于元基因组和元转录组，可以发现用于各种行业的新酶。这个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.