Virus-bacteria-protist intercations under future ocean conditions

该项目旨在提高海洋生物对预期气候变化反馈的评估和可预测性。特别是，将从病毒导向的角度研究温带/北极远洋微生物食物网的潜在响应模式。为了获得对微生物组合的预期响应和结构机制的机制理解，将进行小尺度扰动实验，操纵各种相关的非生物气候变化应激源。在关注海洋变暖的同时，该项目将特别考虑与其他因素（如营养、盐度）结合的非线性响应模式和（交互）增效或拮抗效应。使用不同复杂性的微生物群落（例如原位样品的大小分馏，培养物/病毒-宿主系统），将研究生物相互作用（例如病毒裂解，原生生物捕食）对非生物强迫的反应。在社区生态框架内，实验将分析活动-多样性关系以及稳定性和弹性等特征。病毒、细菌和原生生物丰度的变化将被检测并与分子生物学群落分析和功能组合分析相结合。此外，这些研究将与Julia Wohlers博士的一个伙伴项目密切相关，该项目调查群落变化对相关生物地球化学循环和有机物的微生物处理的最终后果。

This project aims at improving the assessment and predictability of ocean biology feedbacks to expected climate change. In particular, the potential response patterns of temperate/arctic pelagic microbial food webs will be studied from a virus-oriented perspective. In order to obtain a mechanistic understanding of prospective responses and structuring mechanisms in microbial assemblages, small-scale perturbation experiments will be performed manipulating various relevant abiotic climate change stressors. While focusing on ocean warming, this project will particularly account for non-linear response patterns and (interactive) synergistic or antagonistic effects of warming in combination with other factors (e.g. nutrients, salinity). Using microbial communities of different complexity (e.g. size-fractionated in situ samples, cultures/virus-host systems), responses in biotic interactions (e.g. viral lysis, protist predation) to abiotic forcing will be investigated. Within a community ecological framework, experiments will analyse activity-diversity relationships and features such as stability and resilience. Changes in viral, bacterial and protist abundances will be detected and combined with molecular biological community analyses and a functional assemblage profiling. Moreover, these studies will be closely linked to a partner project of Dr. Julia Wohlers investigating the ultimate consequences of community changes for the associated biogeochemical cycling and microbial processing of organic matter.