Evidence map›Paper›PMID 36310161›Full record

ArticleBiotechnology for biofuels and bioproducts2022

Water-soluble saponins accumulate in drought-stressed switchgrass and may inhibit yeast growth during bioethanol production.

Sarvada Chipkar, Katherine Smith, Elizabeth M Whelan, Derek J Debrauske, Annie Jen, Katherine A Overmyer, Andrea Senyk, Larkin Hooker-Moericke, Marissa Gallmeyer, Joshua J Coon and 3 more

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In one paragraph

Article in Biotechnology for biofuels and bioproducts, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.

0numbers the graph read from it
0cells of the map it votes in
6citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

6 citing papers in PubMed.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

13 authors.

Sarvada ChipkarDepartment of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI, USA.
Katherine SmithDepartment of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI, USA.
Elizabeth M WhelanDOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA.
Derek J DebrauskeDOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA.
Annie JenDOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA.
Katherine A OvermyerDepartment of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
Andrea SenykDepartment of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI, USA.
Larkin Hooker-MoerickeDepartment of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI, USA.
Marissa GallmeyerDepartment of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI, USA.
Joshua J CoonDepartment of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
A Daniel JonesRTSF Mass Spectrometry & Metabolomics Core, Michigan State University, East Lansing, MI, USA.
Trey K SatoDOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA.
Rebecca G OngDepartment of Chemical Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI, USA. rgong1@mtu.edu.

Funding

Great Lakes Bioenergy Research Center DE-SC0018409
6 · The paper itself

Abstract

backgroundDeveloping economically viable pathways to produce renewable energy has become an important research theme in recent years. Lignocellulosic biomass is a promising feedstock that can be converted into second-generation biofuels and bioproducts. Global warming has adversely affected climate change causing many environmental changes that have impacted earth surface temperature and rainfall patterns. Recent research has shown that environmental growth conditions altered the composition of drought-stressed switchgrass and directly influenced the extent of biomass conversion to fuels by completely inhibiting yeast growth during fermentation. Our goal in this project was to find a way to overcome the microbial inhibition and characterize specific compounds that led to this inhibition. Additionally, we also determined if these microbial inhibitors were plant-generated compounds, by-products of the pretreatment process, or a combination of both.

resultsSwitchgrass harvested in drought (2012) and non-drought (2010) years were pretreated using Ammonia Fiber Expansion (AFEX). Untreated and AFEX processed samples were then extracted using solvents (i.e., water, ethanol, and ethyl acetate) to selectively remove potential inhibitory compounds and determine whether pretreatment affects the inhibition. High solids loading enzymatic hydrolysis was performed on all samples, followed by fermentation using engineered Saccharomyces cerevisiae. Fermentation rate, cell growth, sugar consumption, and ethanol production were used to evaluate fermentation performance. We found that water extraction of drought-year switchgrass before AFEX pretreatment reduced the inhibition of yeast fermentation. The extracts were analyzed using liquid chromatography-mass spectrometry (LC-MS) to detect compounds enriched in the extracted fractions. Saponins, a class of plant-generated triterpene or steroidal glycosides, were found to be significantly more abundant in the water extracts from drought-year (inhibitory) switchgrass. The inhibitory nature of the saponins in switchgrass hydrolysate was validated by spiking commercially available saponin standard (protodioscin) in non-inhibitory switchgrass hydrolysate harvested in normal year.

conclusionsAdding a water extraction step prior to AFEX-pretreatment of drought-stressed switchgrass effectively overcame inhibition of yeast growth during bioethanol production. Saponins appear to be generated by the plant as a response to drought as they were significantly more abundant in the drought-stressed switchgrass water extracts and may contribute toward yeast inhibition in drought-stressed switchgrass hydrolysates.

Indexed as

DroughtFermentation inhibitionSaponinsSwitchgrassWater-extraction

Identifiers

PMID36310161
PMCPMC9620613

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.