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This content will become publicly available on September 11, 2018

Title: Disposition and bioavailability of inulin and free sugar in untreated and dilute acid pretreated Agave tequilana leaves

Industrially, the Agave tequilana plant is most commonly associated with beverage production, which requires it to be grown for 8–10 year before harvesting. However, its robust growth characteristics and low water usage requirements suggest that it could also be utilized as a substrate for alternative fermentation processes that do not require such long crop turnover times. Therefore, a study was undertaken to characterize the feasibility of utilizing the leaves from two year-old plants as a microbial fermentation biomass substrate. Quantitative saccharification revealed the carbohydrate concentration of two year-old A. tequilana leaves to be 633 mg g -1 dry weight biomass. HPLC analysis identified the primary carbohydrates as glucans, with minor contributions from xylans, galactans, arabinanas, and mannans. Fructose was observed predominantly as inulin. The direct use of unpretreated A. tequilana leaf biomass as a sole carbon source could support yeast growth, however, dilute acid pretreatment removed sufficient levels of carbohydrates to prevent the growth of wild type or inulinase-expressing yeast strains. Up to 133.5 g kg -1 of soluble carbohydrates and 69.6 g kg -1 of soluble inulin were extracted in the pretreatment soakate and 4.0 g kg -11 of soluble carbohydrates and 1.3 g kg -1 of soluble inulinmore » remained in the biomass post processing. Ultimately, inulinase gene expression did not significantly improve yeast growth rates, but permitted up to 6.3 g kg -1 of the available soluble inulin from the dilute acid pretreatment soakate to be metabolized towards cellular growth.« less
Authors:
ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Biomass and Bioenergy
Additional Journal Information:
Journal Volume: 106; Journal ID: ISSN 0961-9534
Publisher:
Elsevier
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Laboratory Directed Research and Development (LDRD) Program
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; Inulin; Agave; Pretreatment; Fermentation; Biomass; Inulinase
OSTI Identifier:
1393806