Sarahi Garcia

Sarahi Garcia

Stockholm University

Key publications

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

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 doi:10.1002/lno.11619

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 doi: 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 doi: 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. 2017. Contrasting patterns of genome-level diversity across distinct co-occurring bacterial populations. ISME J doi:10.1038/s41396-017-0001-0

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 doi: 10.1111/mec.13319

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

Research interests

– Uncover the principles of microbial interactions in aquatic environments and how those links have effects on the carbon cycle

My research interests lie on microbial interactions in aquatic environments and the effect of these interactions on carbon cycles. I am interested in auxotrophies, metabolic complementarities, metabolic handoffs, microbial market and any kind of microbial cooperation.

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 about 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 microorganism 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 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 are 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.

My research vision is to further our understanding of carbon cycle in aquatic environments by revealing the role of interactions and microbial and molecular diversity. To obtain a fundamental understanding of the carbon flow from carbon dioxide through cyanobacteria, to the diversity of dissolved organic carbon molecules and the bacterial heterotrophs that consume these organic nutrients. To use ecological principles to engineer biosystems to mitigate the global carbon balance dilemma.

Group members

  • Postdoctoral researcher Julia Nuy
  • PhD student Alejandro Rodriguez-Gijón


Sarah L. Garcia 
SciLifeLab Fellow 
Assistant Professor 

Stockholm University
Department of Ecology, Environment and Plant Sciences (DEEP) 

106 91 Stockholm

Phone: 08-16 12 11 

Gamma 5
Tomtebodavägen 23
Box 1031
171 21 Solna

Last updated: 2023-02-23

Content Responsible: Scilifelab Administration()