Microorganisms (bacteria, archaea, fungi, and protists) form complex relationships among themselves and play an important role in shaping the physical environment in which they (and we) dwell. On the other hand, environmental variables such as light, temperature, and nutrients determine the composition, abundance, and "well-being" of microbial communities. To gain insights into the interplay between the biotic and abiotic parts of the earth, I employ and develop laboratory (e.g. mass spectrometry, microbial cultivation), field sampling (e.g. open ocean, estuaries), and computational (e.g. bioinformatics, numeric modeling) methods.