BioEnergy Research

, Volume 9, Issue 1, pp 239–247

Reduction of Ethanol Yield from Switchgrass Infected with Rust Caused by Puccinia emaculata

  • Virginia R. Sykes
  • Fred L. Allen
  • Jonathan R. Mielenz
  • C. Neal StewartJr.
  • Mark T. Windham
  • Choo Y. Hamilton
  • Miguel RodriguezJr.
  • Kelsey L. Yee
Article

DOI: 10.1007/s12155-015-9680-4

Cite this article as:
Sykes, V.R., Allen, F.L., Mielenz, J.R. et al. Bioenerg. Res. (2016) 9: 239. doi:10.1007/s12155-015-9680-4
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Abstract

Switchgrass (Panicum virgatum) is an important biofuel crop candidate thought to have low disease susceptibility. As switchgrass production becomes more prevalent, monoculture and production fields in close proximity to one another may increase the spread and severity of diseases such as switchgrass rust caused by the pathogen Puccinia emaculata. The objective of this research was to examine the impact of rust on ethanol yield in switchgrass. In 2010 and 2012, naturally infected leaves from field-grown ‘Alamo’ and ‘Kanlow’ in Knoxville, TN (2010, 2012) and Crossville, TN (2012) were visually categorized as exhibiting low, medium, or high disease based on the degree of chlorosis and sporulation. P. emaculata was isolated from each disease range to confirm infection. Samples from 2010 were acid/heat pretreated and subjected to two runs of simultaneous saccharification and fermentation (SSF) with Saccharomyces cerevisiae D5A to measure ethanol yield. Near-infrared spectroscopy (NIRS) was used to estimate ethanol yield for 2012 samples. SSF and NIRS data were analyzed separately using ANOVA. Disease level effects were significant within both models (P < 0.05) and both models explained a large amount of variation in ETOH (SSF: R2 = 0.99, NIRS: R2 = 0.99). In the SSF dataset, ethanol was reduced by 35 % in samples exhibiting medium disease symptoms and by 55 % in samples exhibiting high disease symptoms. In the NIRS dataset, estimated ethanol was reduced by 10 % in samples exhibiting medium disease symptoms and by 21 % in samples exhibiting high disease symptoms. Results indicate that switchgrass rust will likely have a negative impact on ethanol yield in switchgrass grown as a biofuel crop.

Keywords

NIRS Rust Puccinia emaculata Switchgrass Ethanol SSF Panicum virgatum 

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Virginia R. Sykes
    • 1
  • Fred L. Allen
    • 1
  • Jonathan R. Mielenz
    • 2
    • 5
  • C. Neal StewartJr.
    • 1
    • 2
  • Mark T. Windham
    • 3
  • Choo Y. Hamilton
    • 2
    • 6
  • Miguel RodriguezJr.
    • 2
    • 4
  • Kelsey L. Yee
    • 2
    • 7
  1. 1.Department of Plant SciencesUniversity of TennesseeKnoxvilleUSA
  2. 2.Bioenergy Science CenterOak Ridge National LaboratoryOak RidgeUSA
  3. 3.Department of Entomology and Plant PathologyUniversity of TennesseeKnoxvilleUSA
  4. 4.Bioconversion Science & Technology BioSciences DivisionOak Ridge National LaboratoryOak RidgeUSA
  5. 5.White Cliff BiosystemsRockwoodUSA
  6. 6.Center for Renewable CarbonKnoxvilleUSA
  7. 7.Genomatica Inc.San DiegoUSA