Academic Journal

Changes in Activity and Community Composition Shape Bacterial Responses to Size-Fractionated Marine DOM

التفاصيل البيبلوغرافية
العنوان: Changes in Activity and Community Composition Shape Bacterial Responses to Size-Fractionated Marine DOM
المؤلفون: Marta M. Varela, Tamara Rodríguez-Ramos, Elisa Guerrero-Feijóo, Mar Nieto-Cid
المصدر: Frontiers in Microbiology, Vol 11 (2020)
بيانات النشر: Frontiers Media S.A., 2020.
سنة النشر: 2020
المجموعة: LCC:Microbiology
مصطلحات موضوعية: bacterial diversity, amplicon sequencing variants, flow cytometry, dissolved organic matter, DOM optical properties, tangential ultrafiltration, Microbiology, QR1-502
الوصف: To study the response of bacteria to different size-fractions of naturally occurring dissolved organic matter (DOM), a natural prokaryotic community from North Atlantic mesopelagic waters (1000 m depth) was isolated and grown in (i) 0.1-μm filtered seawater (CONTROL), (ii) the low-molecular-weight (1 kDa) and low-molecular-weight DOM fractions (H + L-DOM), to test the potential effect of ultrafiltration on breaking the DOM size continuum. Prokaryotic abundance and leucine incorporation were consistently higher in the H + L-DOM niche than in the L-DOM and CONTROL treatments, suggesting a different interaction with each DOM fraction and the disruption of the structural DOM continuum by ultrafiltration, respectively. Rhodobacterales (Alphaproteobacteria) and Flavobacteriales (Bacteroidetes) were particularly enriched in L-DOM and closely related to the colored DOM (CDOM) fraction, indicating the tight link between these groups and changes in DOM aromaticity. Conversely, some other taxa that were rare or undetectable in the original bacterial community were enriched in the H + L-DOM treatment (e.g., Alteromonadales belonging to Gammaproteobacteria), highlighting the role of the rare biosphere as a seed bank of diversity against ecosystem disturbance. The relationship between the fluorescence of protein-like CDOM and community composition of populations in the H + L-DOM treatment suggested their preference for labile DOM. Conversely, the communities growing on the L-DOM niche were coupled to humic-like CDOM, which may indicate their ability to degrade more reworked DOM and/or the generation of refractory substrates (as by-products of the respiration processes). Most importantly, L- and/or H + L-DOM treatments stimulated the growth of unique bacterial amplicon sequence variants (ASVs), suggesting the potential of environmental selection (i.e., changes in DOM composition and availability), particularly in the light of climate change scenarios. Taken together, our results suggest that different size-fractions of DOM induced niche-specialization and differentiation of mesopelagic bacterial communities.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 1664-302X
Relation: https://www.frontiersin.org/articles/10.3389/fmicb.2020.586148/full; https://doaj.org/toc/1664-302X
DOI: 10.3389/fmicb.2020.586148
URL الوصول: https://doaj.org/article/d0bb8542b9484c59bae8885c1db6927f
رقم الانضمام: edsdoj.0bb8542b9484c59bae8885c1db6927f
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:1664302X
DOI:10.3389/fmicb.2020.586148