Next Article in Journal
Bacterial Microbiota of Rice Roots: 16S-Based Taxonomic Profiling of Endophytic and Rhizospheric Diversity, Endophytes Isolation and Simplified Endophytic Community
Next Article in Special Issue
Core Sulphate-Reducing Microorganisms in Metal-Removing Semi-Passive Biochemical Reactors and the Co-Occurrence of Methanogens
Previous Article in Journal
Responses of an Agricultural Soil Microbiome to Flooding with Seawater after Managed Coastal Realignment
Previous Article in Special Issue
Relationship among Phosphorus Circulation Activity, Bacterial Biomass, pH, and Mineral Concentration in Agricultural Soil

Biomarkers’ Responses to Reductive Dechlorination Rates and Oxygen Stress in Bioaugmentation Culture KB-1TM

School of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
Author to whom correspondence should be addressed.
Present Addresses: Floyd|Snider, Inc., Seattle, WA, USA.
Present Addresses: Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.
Present Addresses: Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA.
Present Addresses: Department of Genetics, Stanford University, Stanford, CA, USA.
Present Addresses: Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA.
Microorganisms 2018, 6(1), 13;
Received: 20 November 2017 / Revised: 25 January 2018 / Accepted: 5 February 2018 / Published: 8 February 2018
(This article belongs to the Special Issue Microorganisms for Environmental and Industrial Applications)
Using mRNA transcript levels for key functional enzymes as proxies for the organohalide respiration (OHR) rate, is a promising approach for monitoring bioremediation populations in situ at chlorinated solvent-contaminated field sites. However, to date, no correlations have been empirically derived for chlorinated solvent respiring, Dehalococcoides mccartyi (DMC) containing, bioaugmentation cultures. In the current study, genome-wide transcriptome and proteome data were first used to confirm the most highly expressed OHR-related enzymes in the bioaugmentation culture, KB-1TM, including several reductive dehalogenases (RDases) and a Ni-Fe hydrogenase, Hup. Different KB-1™ DMC strains could be resolved at the RNA and protein level through differences in the sequence of a common RDase (DET1545-like homologs) and differences in expression of their vinyl chloride-respiring RDases. The dominant strain expresses VcrA, whereas the minor strain utilizes BvcA. We then used quantitative reverse-transcriptase PCR (qRT-PCR) as a targeted approach for quantifying transcript copies in the KB-1TM consortium operated under a range of TCE respiration rates in continuously-fed, pseudo-steady-state reactors. These candidate biomarkers from KB-1TM demonstrated a variety of trends in terms of transcript abundance as a function of respiration rate over the range: 7.7 × 10−12 to 5.9 × 10−10 microelectron equivalents per cell per hour (μeeq/cell∙h). Power law trends were observed between the respiration rate and transcript abundance for the main DMC RDase (VcrA) and the hydrogenase HupL (R2 = 0.83 and 0.88, respectively), but not transcripts for 16S rRNA or three other RDases examined: TceA, BvcA or the RDase DET1545 homologs in KB1TM. Overall, HupL transcripts appear to be the most robust activity biomarker across multiple DMC strains and in mixed communities including DMC co-cultures such as KB1TM. The addition of oxygen induced cell stress that caused respiration rates to decline immediately (>95% decline within one hour). Although transcript levels did decline, they did so more slowly than the respiration rate observed (transcript decay rates between 0.02 and 0.03 per hour). Data from strain-specific probes on the pangenome array strains suggest that a minor DMC strain in KB-1™ that harbors a bvcA homolog preferentially recovered following oxygen stress relative to the dominant, vcrA-containing strain. View Full-Text
Keywords: organohalide respiration; Dehalococcoides; trichloroethene; biomarkers; Geobacter; proteomics organohalide respiration; Dehalococcoides; trichloroethene; biomarkers; Geobacter; proteomics
Show Figures

Figure 1

MDPI and ACS Style

Heavner, G.L.W.; Mansfeldt, C.B.; Debs, G.E.; Hellerstedt, S.T.; Rowe, A.R.; Richardson, R.E. Biomarkers’ Responses to Reductive Dechlorination Rates and Oxygen Stress in Bioaugmentation Culture KB-1TM. Microorganisms 2018, 6, 13.

AMA Style

Heavner GLW, Mansfeldt CB, Debs GE, Hellerstedt ST, Rowe AR, Richardson RE. Biomarkers’ Responses to Reductive Dechlorination Rates and Oxygen Stress in Bioaugmentation Culture KB-1TM. Microorganisms. 2018; 6(1):13.

Chicago/Turabian Style

Heavner, Gretchen L.W., Cresten B. Mansfeldt, Garrett E. Debs, Sage T. Hellerstedt, Annette R. Rowe, and Ruth E. Richardson 2018. "Biomarkers’ Responses to Reductive Dechlorination Rates and Oxygen Stress in Bioaugmentation Culture KB-1TM" Microorganisms 6, no. 1: 13.

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Back to TopTop