The rare habitats and microbial communities found at Laugarvik (LV) and Yngingarlindir (YL) offer highly unique study sites accessible for study of microbial communities in extreme and dynamic environments. The main objectives of the project are to describe the microbial communities at two hot extreme intertidal thermal and saline habitats and determine their value as new natural biotechnological resources throughout their metagenomic analysis. The work proposed will result in an increased understanding of intertidal, geothermal, microbial mat communities and the effects of variable environmental factors on these ecosystems. The potential use of the results will be to improve the efficiency and the profitability of the use of extremophiles in biotechnology. The donor partner has an extensive expertise in prokaryotic organisms and the project promoter is an expert in eukaryotic extremophiles. Although the research methodologies used by both partners involved are similar, the processing of the data could be quite different. These makes the collaboration extremely complementary and both partners will be learning from each other.
Summary of project results
Biodiversity and photosynthetic behaviour of five cyanobacteria microbial mats from a hot intertidal extreme environment (SW, Iceland) has been analysed. Partners studied the effects of natural solar radiation during daily cycles at different periods of the year, from May to July by in situ pulse-amplitude modulated (PAM) fluorometry and pigment composition. In vitro experiments regarding temperature and salinity photosynthetic response were also carried out. The microbial mats were mainly formed by cyanocateria. A total of ten taxa were identified, being Cyanobacterium aponinum and Geitlerinema sp. the most abundant species. Microbial mats showed a remarkable trend in terms of diary and seasonally adaptation of photosynthesis to solar radiation and temperature. For ali microbial mats, rETRmax values were decreasing from May to July, while Fv/Fm remained constant in terms of absolute values. Although high light during June and July affects photosynthesis causing photoinhibition, tbis phenomenon can be revoked by high temperatures (between 40-SOºC), which supports that temperature is a determinant factor in the photosynthetic performance of these cyanobacterial mats. Our results showed a significant increase in the Chl a-b and phycobiliproteins content from June to October, as well as a significant decrease in total carotenoids content. Little is known about the microbial ecology and physiology of thermophilic intertidal cyanobacterial microbial mats. Results showed a remarkable ratio of novel species/genera, when compared to studies from other geothermal sampling sites. These results regarding biodiversity, therefore strongly confirm the uniqueness of these intertidal microbial habitats. Additionally, the work presented here shows a remarkable trend in terms of diary and seasonally adaptation of photosynthesis to solar radiation and temperature. In this regard, although high light affects photosynthesis causing photoinhibition, this phenomenon can be revoked by high temperatures (between 40-50ºC), which supports that temperature is a determinant factor in the photosynthetic performance of these cyanobacterial mats. Results of this project will increase our understanding of intertidal geothermal microbial mat communities and the effects of variable environmental factors on these ecosystems. Furthermore, this work has resulted in the identification of several novel microbial species which could be biotechnologically useful.
Summary of bilateral results
Dr. Hreggviósson research group, has contributed an extensive experience in the development and evaluation of extremophiles biotechnological utilities. Thus, the Division of Biotechnology and Biomolecules at MATIS pursues research on bioactive substances and enzymes with the goal of producing marketable products. The division has great expertise and decades of experience working with novel raw materials, ingredients and organisms, including unique extremophile microorganisms and a vast array of marine based raw materials. Partners involved in the project (Dr. Aguilera and Dr. Hreggviósson research group) provide an extensive expertise in extreme environments, with more than 15 years of experience in this field, mostly related to molecular taxonomy and phylogeny related to extreme environments as well as isolation and cultivation of extremophiles. Besides, their institutions provide strong genomic and bioinformatics facilities and experience. What make the project a real collaborative association is the fact that Dr. Aguilera is an expert in eukaryotic extremophiles while Dr. Hreggviósson and his research group has an extensive expertise in prokaryotic organisms. Although the methodologies to be used with both type of organisms are similar, the processing of the data could be quite different. These makes the collaboration extremely complementary and both partners had leamed from each other. Additionally, sampling methodology, geochemical, physicochemical analysis and environmental modelling skills were given by Dr Aguilera, since she has more than 10 years of experience in leading field work expeditions carried out in extreme environments, not only Arctic and Antarctic but acidic hydrothermal areas (Iceland, Kamchatka, Argentina) or high altitude acidic and hypersaline habitats (Perú, Bolivia). She is also in charge for the manuscripts publication as well as for two of the grants proposed, being the IP. During this time, partners have sent four proposals to different national calls in collaboration with researchers from MATIS Ltd. and other related institutions, this will allow partners to continue collaboration if any of these grants resulted funded.