DR. JARONE PINHASSI

CENTRE FOR ECOLOGY AND EVOLUTION IN MICROBIAL MODEL SYSTEMS- EEMIS, LINNAEUS UNIVERSITY

I do research on bacterioplankton community structure and function in the marine environment. This includes spatiotemporal studies of bacterial diversity and gene expression (metatranscriptomics) in different seas, like the Baltic Sea, NW Atlantic and the Mediterranean Sea. Investigating the ecology and physiology of rhodopsin photoheterotrophy represents an important line of research. Analyses of the biodiversity of marine planktonic bacteria and their metabolism are essential to quantitatively asses the critical role bacteria play in carbon and nutrient turnover and energy flow through the marine ecosystem.

Key words: Ocean microbiome, Marine bacteria, Population dynamics, Biogeography, Ecophysiology, Rhodopsin photoheterotrophy

Theme leader for: Microbial biogeography across and within aquatic biomes

Clara Perez-Martinez, PhD Student

My research focuses on marine microbial ecology, diversity and function. I am interested in bacterial community responses to environmental changes as well as how bacteria influence their environment, with particular focus on organic and inorganic nutrient cycling. My analyses are based on state of the art methods in microbial ecology, such as metagenomics and metatranscriptomics.

Key words: Marine Microbial Ecology, Environmental Genomics, Metatranscriptomics, Vitamins, Nutrients, Climate Change

Theme: 2, Functional Diversity

BENJAMIN PONTILLER, PHD STUDENT, LINNAEUS UNIVERSITY

Benjamin Pontiller is a microbial ecologist with a special interest in aquatic ecosystems. He received his BSc in Biology with a specialization in microbiology. His curiosity and interest about the paramount role of the “unseen majority” in the global carbon cycle led him to continue in the field of microbial ecology before eventually obtaining his MSc from the University of Vienna. After his graduation, he moved on to Sweden and accepted a PhD position at the Linnaeus University in Kalmar under the supervision of Professor Jarone Pinhassi. He is now working intensively on the interaction between bacteria and dissolved organic matter (DOM), a critical component in the earth’s carbon cycle. The main focus of Ben's research is to investigate the functional role of marine bacterioplankton in carbon cycling by deciphering the genetic basis for organic carbon utilization. Dissolved organic carbon (DOC) derived from phytoplankton photosynthesis represents the main biologically available organic carbon pool in the ocean. The uptake and utilization of organic carbon compounds are mainly determined by the metabolic potential encoded in the genomes of marine bacteria. However, detail on the underlying molecular mechanisms and how they impact the cycling of organic matter remain largely unknown. Ben's research is based on field studies and experiments with natural marine bacterial assemblages. His current work focuses on elucidating the functional dynamics of heterotrophic bacteria in the degradation of ecologically relevant sources of organic compounds by applying state-of-the-art techniques currently used in microbiology, microbial ecology and molecular biology.

Keywords: Meta(omics), bacterioplankton, Baltic Sea, climate change, DOM

ANABELLA AGUILERA, POSTDOCTORAL FELLOW, LINNAEUS UNIVERSITY

My research encompasses aquatic microbiology, phytoplankton ecology and physiology, with emphasis in cyanobacteria. It merges field studies with laboratory assays and omics approaches aiming to better understand cyanobacterial responses to biotic and abiotic factors and their role in phytoplankton dynamics.

My PhD work focused on the taxonomy of native bloom-forming cyanobacteria and the environmental factors that promote their dominance in shallow lakes. The work combined morphological and ecological studies of natural populations with molecular characterization of native strains. Currently, as a postdoctoral fellow, I am part of a larger group working on biosilicification and its evolution through Earth’s history. I am focusing on the role that picocyanobacteria have on biosilicification and, ultimately, in the global biogeochemical silica cycle.

Keywords: Harmful algal blooms, cyanobacteria, silica, picophytoplankton, biosilicification

Evangelia Charalampous

My research focuses on the base of the marine food webs, the phytoplankton communities, and specifically, I use trait-based approaches, focusing on the “master” trait cell size, to understand complex ecological processes. Reorganization of phytoplankton communities under global change can change community interactions and energy flows through the whole marine food web. I am interested in the potential of cell size to be used as indicator trait for phytoplankton community responses to several environmental drivers. With this approach it will be possible to establish an intermediate level of complexity between the almost unachievable goal of reconstructing community behavior from single species and the overly simplistic approach of reducing phytoplankton to a single functional category. Currently, I am focusing on diatoms and the effect of their evolution on the silica cycle in the ocean. Specifically, using experiments and molecular tools I will try to disentangle the evolution of silica biomineralization ability of diatoms while in competition with other organisms. My work is part of the combined effort of a larger group to understand the interactions between biosilicification in organisms and the oceans and how these interactions have evolved through Earth’s history until today. 

Key words: phytoplankton ecology, cell size, traits, silicon, competition