Sarahi GarciaBiträdande lektor

Om mig

My research interests focus on microbial interactions in aquatic environments and the effect of these interactions on the carbon cycle. 

My research vision is to further our understanding of the carbon cycle in aquatic environments by revealing the role of microbial and molecular diversity as well as microbial interactions. I further want to use this ecological knowledge in biotechnological applications to strategically develop a more sustainable economy and society.

Microorganisms are the most phylogenetically diverse and abundant taxa on Earth, and their functions are indispensable in regulating global elemental cycling, bioremediation, human health, and other processes. The microbial world can be studied using cultivation-based or cultivation-independent techniques. Cultivation-independent techniques include holistic approaches, such as full community analysis of environmental samples, as well as reductionist approaches, such as single-cell genomics. These methodologies have greatly contributed to our current understanding of indispensable microbial functions and their immense diversity. With my research, I have integrated these holistic and reductionist strategies, and leveraged an intermediate approach, such as model communities, allowing me to address new ecological questions about microbial interactions.

The biogeochemical cycling of carbon is central in the modulation of Earth's global temperature and climate by controlling the amount of carbon dioxide and other greenhouse gases in the atmosphere. Global estimates indicate that photosynthetic microorganisms in aquatic environments are responsible for approximately half of the carbon dioxide fixed on Earth. A large part of this primary production is due to the activity of aquatic cyanobacteria that are globally ubiquitous and essentially the most abundant photosynthetic organisms on Earth. These microorganisms transform carbon from the atmosphere into more than a thousand different organic compounds that are then released in aquatic environments for heterotrophic bacteria to consume. Despite the central role in the global carbon cycle, many aspects of the cross-talk between cyanobacteria and associated heterotrophs are still poorly understood. Some of my research focus will study aquatic microorganisms to shed light on the role of the interactions between cyanobacteria and their heterotrophic partners. Moreover, the focus of my work is aquatic microbial communities in the context of the carbon cycle. The knowledge generated from my research is fundamental to aquatic ecology and also holds the potential to improve climate change models and design biotechnological tools for a biologically based economy and environmental stewardship.

Group members

Publications

2022

Rodríguez-Gijón, A., Nuy, J.K., Mehrshad, M., Buck, M., Schulz, F., Woyke, T., Garcia, S.L. 2021. A genomic perspective across Earth’s microbiomes reveals that genome size in Archaea and Bacteria is linked to ecosystem type and trophic strategy. Frontiers in Microbiology 10.3389/fmicb.2021.761869

2021

Martin, G., Rissanen, A.J., Garcia, S.L., Mehrshad, M., Buck, M., Peura, S. 2021 Candidatus Methylumidiphilus drives peaks in methanotrophic relative abundance in stratified lakes and ponds across Northern landscapes. Frontiers 10.3389/fmicb.2021.669937

Buck, M., Garcia,S.L., Fernandez V., L., Martin, G., Martínez R., G.A., Saarenheimo, J., Zopfi, J., Bertilsson, S., Peura, S. 2021. Comprehensive dataset of shotgun metagenomes from oxygen stratified freshwater lakes and ponds. Scientific data 10.1038/s41597-021-00910-1

Garcia, S.L., Mehrshad, M., Buck, M., Tsuji, J.M., Neufeld, J.D., McMahon, K.D., Bertilsson, S., Greening, C., Peura, S. 2021. Freshwater Chlorobia exhibit metabolic specialization among cosmopolitan and endemic populations. mSystems 10.1128/mSystems.01196-20

2020

Nayfach, S., Roux, S., Seshadri, R. et al. 2020. A genomic catalog of Earth’s microbiomes. Nat Biotechnol 10.1038/s41587-020-0718-6

Patriarca, C., Sedano-Nunez, V.T., Garcia, S.L., Bergquist, J., Bertilsson, S., Sjoberg, P.J.R., Tranvik, L.J., Hawkes, J.A. 2020. Character and environmental lability of cyanobacteria-derived dissolved organic matter. Limnol Oceanogr 10.1002/lno.11619

Mondav, R., Bertilsson, S., Buck, M., Langenheder, S., Lindstrom, E.S., Garcia, S.L. 2020. Streamlined and abundant bacterioplankton thrive in functional cohorts. mSystems 10.1128/mSystems.00316-20

2019 and before

Garcia, S.L., Szekely, A., Bergvall, C., Schattenhofer, M., Peura, S. 2019. Decreased snow cover stimulates under ice primary producers, but impairs methanotrophic capacity. mSphere 10.1128/mSphere.00626-18

Garcia, S.L., Buck, M., Hamilton, J., Wurzbacher, C., McMahon, K.D., Grossart, H.P., Eiler, A., 2018. Model communities hint at promiscuous metabolic linkages between ubiquitous free-living freshwater bacteria. mSphere 10.1128/mSphere.00202-18

Garcia, S.L., Stevens, S., Crary, B., Martinez-Garcia, M., Stepanauskas, R., Woyke, T., Tringe, S., Andersson, S., Bertilsson, S., Malmstrom, R., McMahon, K.D. 2018. Contrasting patterns of genome-level diversity across distinct co-occurring bacterial populations. ISME J 10.1038/s41396-017-0001-0

Garcia, S.L., 2016. Mixed cultures as model communities: hunting for ubiquitous microorganisms, their partners, and interactions. Aquat Microb Ecol 10.3354/ame01789

Garcia, S.L., Buck, M., McMahon, K.D., Grossart, H.P., Eiler, A., Warnecke, F., 2015. Auxotrophy and intra-population complementary in the ‘interactome’ of a cultivated freshwater model community. Mol Ecol 10.1111/mec.13319