15N‐ and 2H proteomic stable isotope probing links nitrogen flow to archaeal heterotrophic activity. (20th May 2014)

• Record Type: Journal Article
• Authors: Justice, Nicholas B.; Li, Zhou; Wang, Yingfeng; Spaudling, Susan E.; Mosier, Annika C.; Hettich, Robert L.; Pan, Chongle; Banfield, Jillian F.
• Is Part Of: Environmental microbiology. Volume 16:Number 10(2014:Oct.)
• Page Start: 3224
• Page End: 3237
• Publication Date: 2014-05-20
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1462-2920.12488
• Languages: English
• ISSNs: 1462-2912

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Understanding how individual species contribute to nutrient transformations in a microbial community is critical to prediction of overall ecosystem function. We conducted microcosm experiments in which floating acid mine drainage (AMD) microbial biofilms were submerged – recapitulating the final stage in a natural biofilm life cycle. Biofilms were amended with either <sup>15</sup>NH<sub>4</sub><sup>+</sup> or deuterium oxide (<sup>2</sup>H<sub>2</sub>O) and proteomic stable isotope probing (SIP) was used to track the extent to which different members of the community used these molecules in protein synthesis across anaerobic iron‐reducing, aerobic iron‐reducing and aerobic iron‐oxidizing environments. <italic>S</italic><italic>ulfobacillus</italic> spp. synthesized <sup>15</sup>N‐enriched protein almost exclusively under iron‐reducing conditions whereas the <italic>L</italic><italic>eptospirillum</italic> spp. synthesized <sup>15</sup>N‐enriched protein in all conditions. There were relatively few <sup>15</sup>N‐enriched archaeal proteins, and all showed low atom% enrichment, consistent with <italic>A</italic><italic>rchaea</italic> synthesizing protein using the predominantly <sup>14</sup>N biomass derived from recycled biomolecules. In parallel experiments using <sup>2</sup>H<sub>2</sub>O, extensive archaeal protein synthesis was detected in all conditions. In contrast, the bacterial species showed little protein synthesis using <sup>2</sup>H<sub>2</sub>O. The nearly exclusive ability of <italic>A</italic><italic>rchaea</italic> to synthesize proteins using <sup>2</sup>H<sub>2</sub>O may be due to archaeal heterotrophy, whereby <italic>A</italic><italic>rchaea</italic> offset deleterious effects of <sup>2</sup>H by accessing <sup>1</sup>H generated by respiration of organic compounds.</p> </abstract>