Microbial production and consumption of dissolved organic matter in glacial ecosystems on the Tibetan Plateau

TY - JOUR

T1 - Microbial production and consumption of dissolved organic matter in glacial ecosystems on the Tibetan Plateau

AU - Zhou, Lei

AU - Zhou, Yongqiang

AU - Hu, Yang

AU - Cai, Jian

AU - Liu, Xin

AU - Bai, Chengrong

AU - Tang, Xiangming

AU - Zhang, Yunlin

AU - Jang, Kyoung Soon

AU - Spencer, Robert G.M.

AU - Jeppesen, Erik

PY - 2019/9/1

Y1 - 2019/9/1

N2 - Dissolved organic matter (DOM) from alpine glaciers is highly biolabile and plays a vital role in the biogeochemical cycle of meltwater-impacted environments. To unravel the composition and interactions of DOM with the bacterial community in glacier and glacier meltwater, we conducted sampling of two different Tibetan Plateau glaciers and carried out laboratory bio-incubation experiments. The field data revealed that four protein-like components accounted for 86.0 ± 11.9% of the total variability of all six fluorescence components, which suggests a predominantly microbial source of glacial chromophoric DOM (CDOM). The ice and meltwater samples displayed major contributions of molecular formulae associated with lipids and proteins (i.e. high H/C) as revealed by ultrahigh resolution mass spectrometry. Multiple linear regression models revealed that the abundant phyla explain 64.2%, 61.3%, and 65.0% of the variability of microbial and terrestrial humic-like, and protein-like components, respectively. Correlation-based network analysis determined the metabolic niches of the bacterial community members associated with different fluorescence types in biogeochemical processes. Furthermore, laboratory DOM bio-incubation experiments confirmed that sub-components of the CDOM pool differentially participate in bacterial metabolism. We therefore conclude that the bacterial community interacted closely with the compositional variability of DOM in the investigated alpine glacial environments by both producing and consuming of DOM.

AB - Dissolved organic matter (DOM) from alpine glaciers is highly biolabile and plays a vital role in the biogeochemical cycle of meltwater-impacted environments. To unravel the composition and interactions of DOM with the bacterial community in glacier and glacier meltwater, we conducted sampling of two different Tibetan Plateau glaciers and carried out laboratory bio-incubation experiments. The field data revealed that four protein-like components accounted for 86.0 ± 11.9% of the total variability of all six fluorescence components, which suggests a predominantly microbial source of glacial chromophoric DOM (CDOM). The ice and meltwater samples displayed major contributions of molecular formulae associated with lipids and proteins (i.e. high H/C) as revealed by ultrahigh resolution mass spectrometry. Multiple linear regression models revealed that the abundant phyla explain 64.2%, 61.3%, and 65.0% of the variability of microbial and terrestrial humic-like, and protein-like components, respectively. Correlation-based network analysis determined the metabolic niches of the bacterial community members associated with different fluorescence types in biogeochemical processes. Furthermore, laboratory DOM bio-incubation experiments confirmed that sub-components of the CDOM pool differentially participate in bacterial metabolism. We therefore conclude that the bacterial community interacted closely with the compositional variability of DOM in the investigated alpine glacial environments by both producing and consuming of DOM.

KW - Bacterial community

KW - Chromophoric dissolved organic matter (CDOM)

KW - Glacier

KW - Network analysis

KW - Tibetan plateau

UR - http://www.scopus.com/inward/record.url?scp=85065908914&partnerID=8YFLogxK

U2 - 10.1016/j.watres.2019.05.048

DO - 10.1016/j.watres.2019.05.048

M3 - Journal article

C2 - 31129378

AN - SCOPUS:85065908914

SN - 0043-1354

VL - 160

SP - 18

EP - 28

JO - Water Research

JF - Water Research

ER -