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Andersson, Martin
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Publications (10 of 10) Show all publications
Andersson, M. G. I., Catalán, N., Rahman, Z., Tranvik, L. J. & Lindström, E. S. (2018). Effects of sterilization on dissolved organic carbon (DOC) composition and bacterial utilization of DOC from lakes. Aquatic Microbial Ecology, 82(2), 199-208
Open this publication in new window or tab >>Effects of sterilization on dissolved organic carbon (DOC) composition and bacterial utilization of DOC from lakes
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2018 (English)In: Aquatic Microbial Ecology, ISSN 0948-3055, E-ISSN 1616-1564, Vol. 82, no 2, p. 199-208Article in journal (Refereed) Published
Abstract [en]

Sterilization of dissolved organic carbon (DOC) is an essential step in research on interactions between DOC and organisms, for example where the effect of different microbial communities on DOC is studied or vice versa. However, few studies have gone beyond acknowledging that sterilization of DOC influences its characteristics. Here, we aimed to provide further knowledge that enables scientists to better tailor their sterilization methods to their research question. To meet this aim, we conducted a sterilization experiment with DOC from 4 boreal lakes treated with 4 sterilization methods, i.e. 2 filtrations (0.2 µm, 0.1 µm) and 2 autoclaving approaches (single and double autoclaving with a single pH adjustment). Quantity and spectroscopic properties of DOC, before and after sterilization, were studied, and DOC was further tested as a substrate for bacterial growth. We found that the filtration methods better preserved the different DOC measures. In contrast, autoclaving caused major inconsistent shifts in both qualitative and quantitative measures of DOC, as well as an increase of the maximum abundance of bacteria in growth experiments. Nonetheless, there remains a trade-off between retaining the quality of DOC and achieving sterile conditions. Therefore, the sterilization method of choice should be guided by the scientific question at hand.

Keywords
sterilization, autoclave, filtration, dissolved organic carbon, excitation emission matrices, parallel factor analysis
National Category
Biological Sciences
Research subject
Microbiology
Identifiers
urn:nbn:se:uu:diva-331676 (URN)10.3354/ame01890 (DOI)000454321300006 ()
Note

Title in Thesis list of papers: Effects of sterilization on composition and bacterial utilization of dissolved organic carbon

Available from: 2017-10-16 Created: 2017-10-16 Last updated: 2019-12-06Bibliographically approved
Onuţ-Brännström, I., Benjamin, M., Scofield, D. G., Starri, H., Andersson, M. G. .., Lindström, E. S. & Johannesson, H. (2018). Sharing of photobionts in sympatric populations of Thamnolia and Cetraria lichens: evidence from high-throughput sequencing. Scientific Reports, 8, Article ID 4406.
Open this publication in new window or tab >>Sharing of photobionts in sympatric populations of Thamnolia and Cetraria lichens: evidence from high-throughput sequencing
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2018 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 4406Article in journal (Refereed) Published
Abstract [en]

In this study, we explored the diversity of green algal symbionts (photobionts) in sympatric populations of the cosmopolitan lichen-forming fungi Thamnolia and Cetraria. We sequenced with both Sanger and Ion Torrent High-Throughput Sequencing technologies the photobiont ITS-region of 30 lichen thalli from two islands: Iceland and Öland. While Sanger recovered just one photobiont genotype from each thallus, the Ion Torrent data recovered 10–18 OTUs for each pool of 5 lichen thalli, suggesting that individual lichens can contain heterogeneous photobiont populations. Both methods showed evidence for photobiont sharing between Thamnolia and Cetraria on Iceland. In contrast, our data suggest that on Öland the two mycobionts associate with distinct photobiont communities, with few shared OTUs revealed by Ion Torrent sequencing. Furthermore, by comparing our sequences with public data, we identified closely related photobionts from geographically distant localities. Taken together, we suggest that the photobiont composition in Thamnolia and Cetraria results from both photobiont-mycobiont codispersal and local acquisition during mycobiont establishment and/or lichen growth. We hypothesize that this is a successful strategy for lichens to be flexible in the use of the most adapted photobiont for the environment.

National Category
Ecology Evolutionary Biology
Identifiers
urn:nbn:se:uu:diva-319634 (URN)10.1038/s41598-018-22470-y (DOI)000427241500007 ()
Funder
Swedish National Infrastructure for Computing (SNIC), b2013277The Royal Swedish Academy of SciencesHelge Ax:son Johnsons stiftelse Lars Hierta Memorial FoundationSwedish National Infrastructure for Computing (SNIC), b2013277
Note

Title in thesis list of papers: Differential sharing of photobionts in sympatric populations of Thamnolia and Cetraria lichens: evidence from next generation sequencing

Available from: 2017-04-06 Created: 2017-04-06 Last updated: 2018-05-31Bibliographically approved
Andersson, M. (2017). Abundance data adaptation experiment. Uppsala
Open this publication in new window or tab >>Abundance data adaptation experiment
2017 (English)Data set, Primary data
Place, publisher, year
Uppsala: , 2017
National Category
Microbiology
Identifiers
urn:nbn:se:uu:diva-339089 (URN)
Available from: 2018-01-16 Created: 2018-01-16 Last updated: 2018-01-17Bibliographically approved
Andersson, M. (2017). Bacterial abundance data from sterilization experiment. Uppsala
Open this publication in new window or tab >>Bacterial abundance data from sterilization experiment
2017 (English)Data set
Place, publisher, year
Uppsala: , 2017
National Category
Microbiology
Identifiers
urn:nbn:se:uu:diva-339118 (URN)
Available from: 2018-01-16 Created: 2018-01-16 Last updated: 2018-01-17Bibliographically approved
Lindström, E. S. & Andersson, M. (2017). Effects of sterilization on composition and bacterial utilization of dissolved organic carbon.
Open this publication in new window or tab >>Effects of sterilization on composition and bacterial utilization of dissolved organic carbon
2017 (English)Data set, Primary data
National Category
Ecology
Research subject
Biology with specialization in Limnology
Identifiers
urn:nbn:se:uu:diva-336146 (URN)
Available from: 2017-12-12 Created: 2017-12-12 Last updated: 2018-12-03Bibliographically approved
Lindström, E. S. & Andersson, M. (2017). Effects of sterilization on composition and bacterial utilization of dissolved organic carbon.
Open this publication in new window or tab >>Effects of sterilization on composition and bacterial utilization of dissolved organic carbon
2017 (English)Data set, Primary data
National Category
Ecology
Research subject
Biology with specialization in Limnology
Identifiers
urn:nbn:se:uu:diva-342359 (URN)
Available from: 2018-02-20 Created: 2018-02-20 Last updated: 2019-12-06Bibliographically approved
Andersson, M. (2017). Extent and limitations of functional redundancy among bacterial communities towards dissolved organic matter. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>Extent and limitations of functional redundancy among bacterial communities towards dissolved organic matter
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

One of the key processes in the carbon cycle on our planet is the degradation of dissolved organic matter (DOM) in aquatic environments. The use of organic matter by bacteria links energy from DOM to higher trophic levels of the ecosystem when bacteria are consumed by other organisms. This is referred to as the microbial loop. In this thesis I examined if the communities were functionally redundant in their ability to utilize organic matter, or if variation in bacterial composition and richness is of importance. To test this overarching question several experiments were conducted that include methods such as illumina sequencing of the 16S rRNA gene for taxonomic identification of bacterial communities, flow cytometry to follow the growth of communities and spectroscopic measurement to describe the composition of the organic matter pool. Initially we demonstrated how to optimally sterilize organic matter for experimental studies in order to preserve its natural complexity. In further experiments we found that bacterial communities are redundant in their utilization of organic matter and can maintain optimal performance towards a range of organic matter pools. Related to this we found that pre-adaptation to organic matter played a small role as communities performed equally well regardless of their environmental history. We saw a small effect of richness and composition of bacterial communities on the efficiency of organic matter use, but conclude that this is of minor importance relative to abiotic factors. Still, we also show that organic matter can put strong selection pressure on bacterial communities with regards to richness and composition. Additionally we found that the supply rate of a carbon compound greatly influenced the energy utilization of the compound, i.e. a higher growth rate can be maintained if substrate is delivered in pulses relative to a continuous flow. Finally we conclude that the variation in bacterial communities is unlikely to have a major influence on carbon cycling in boreal lakes, but to enable a finer understanding, the genetics underlying the carbon utilization needs to be further explored. 

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2017. p. 41
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1578
Keywords
Dissolved organic matter, BCC, biodiversity, functional redundancy
National Category
Natural Sciences
Research subject
Microbiology
Identifiers
urn:nbn:se:uu:diva-331772 (URN)978-91-513-0112-9 (ISBN)
Public defence
2017-12-01, Friessalen, Norbyvägen 18, Uppsala, 09:00 (English)
Opponent
Supervisors
Available from: 2017-11-08 Created: 2017-10-17 Last updated: 2017-11-28Bibliographically approved
Ricão Canelhas, M., Andersson, M., Eiler, A., Lindström, E. S. & Bertilsson, S. (2017). Influence of pulsed and continuous substrate inputs on freshwater bacterial community composition and functioning in bioreactors. Environmental Microbiology, 19(12), 5078-5087
Open this publication in new window or tab >>Influence of pulsed and continuous substrate inputs on freshwater bacterial community composition and functioning in bioreactors
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2017 (English)In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 19, no 12, p. 5078-5087Article in journal (Refereed) Published
Abstract [en]

Aquatic environments are typically not homogenous, but characterized by changing substrate concentration gradients and nutrient patches. This heterogeneity in substrate availability creates a multitude of niches allowing bacteria with different substrate utilization strategies to hypothetically coexist even when competing for the same substrate. To study the impact of heterogeneous distribution of organic substrates on bacterioplankton, bioreactors with freshwater bacterial communities were fed artificial freshwater medium with acetate supplied either continuously or in pulses. After a month-long incubation, bacterial biomass and community-level substrate uptake rates were twice as high in the pulsed treatment compared to the continuously fed reactors even if the same total amount of acetate was supplied to both treatments. The composition of the bacterial communities emerging in the two treatments differed significantly with specific taxa overrepresented in the respective treatments. The higher estimated growth yield in cultures that received pulsed substrate inputs, imply that such conditions enable bacteria to use resources more efficiently for biomass production. This finding agrees with established concepts of basal maintenance energy requirements and high energetic costs to assimilate substrates at low concentration. Our results further imply that degradation of organic matter is influenced by temporal and spatial heterogeneity in substrate availability. 

National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-275178 (URN)10.1111/1462-2920.13979 (DOI)000418352800021 ()29124844 (PubMedID)
Funder
Swedish Research Council, 2012-3892
Available from: 2016-02-01 Created: 2016-02-01 Last updated: 2018-01-30Bibliographically approved
Andersson, M., Berga, M., Lindström, E. S. & Langenheder, S. (2014). The spatial structure of bacterial communities is influenced by historical environmental conditions. Ecology, 95(5), 1134-1140
Open this publication in new window or tab >>The spatial structure of bacterial communities is influenced by historical environmental conditions
2014 (English)In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 95, no 5, p. 1134-1140Article in journal (Refereed) Published
Abstract [en]

The spatial structure of ecological communities, including that of bacteria, is often influenced by species sorting by contemporary environmental conditions. Moreover, historical processes, i.e., ecological and evolutionary events that have occurred at some point in the past, such as dispersal limitation, drift, priority effects, or selection by past environmental conditions, can be important, but are generally investigated much less. Here, we conducted a field study using 16 rock pools, where we specifically compared the importance of past vs. contemporary environmental conditions for bacterial community structure by correlating present differences in bacterial community composition among pools to environmental conditions measured on the same day, as well as to those measured 2, 4, 6, and 8 d earlier. The results prove that selection by past environmental conditions exists, since we were able to show that bacterial communities are, to a greater extent, an imprint of past compared to contemporary environmental conditions. We suggest that this is the result of a combination of different mechanisms, including priority effects that cause rapid adaptation to new environmental conditions of taxa that have been initially selected by past environmental conditions, and slower rates of turnover in community composition compared to environmental conditions.

National Category
Ecology Microbiology
Identifiers
urn:nbn:se:uu:diva-207181 (URN)10.1890/13-1300.1 (DOI)000336740500003 ()
Available from: 2013-09-10 Created: 2013-09-10 Last updated: 2017-12-06Bibliographically approved
Andersson, M. (1987). Spectroscopic data / carbon quality measurements. Uppsala
Open this publication in new window or tab >>Spectroscopic data / carbon quality measurements
1987 (English)Data set
Place, publisher, year
Uppsala: , 1987
National Category
Microbiology
Research subject
Biology with specialization in Microbiology; Biology with specialization in Limnology
Identifiers
urn:nbn:se:uu:diva-339092 (URN)
Available from: 2018-01-16 Created: 2018-01-16 Last updated: 2018-01-17Bibliographically approved
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