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Title: Isolation and screening of yeasts that ferment D-xylose directly to ethanol

Abstract

Natural habitats of yeasts were examined for the presence of strains able to produce ethanol from D-xylose. Black knots, insect frass, and tree exudates were screened by enrichment in liquid D-xylose-yeast extract medium. These and each D-xylose-assimilating yeast in a collection from cactus fruits and Drosophila spp. were tested for alcohol production from this sugar. Among the 412 isolates examined, 36 produced more than 1 g of ethanol liter/sup -1/ from 20 g of D-xylose liter/sup -1/, all under aerated conditions. Closer examination of the strains indicated that their time courses of D-xylose fermentation followed different patterns. Some strains produced more biomass than ethanol, and among these, ethanol may or may not be assimilated rapidly after depletion of D-xylose. Others produced more ethanol than biomass, but all catabolized ethanol after carbohydrate exhaustion. Ethanol production appeared best at low pH values and under mild aeration. Possible correlations between the nutritional profiles of the yeasts and their ability to produce ethanol from D-xylose were explored by multivariate analysis. D-Xylose appeared slightly better utilized by yeasts which rate poorly in terms of fermentation. The fermentation of D-glucose had no bearing on D-xylose fermentation. No specific nutritional trait could discriminate well between better D-xylosemore » fermentors and other yeasts.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Univ. of Western Ontario, London
OSTI Identifier:
6457633
Resource Type:
Journal Article
Journal Name:
Appl. Environ. Microbiol.; (United States)
Additional Journal Information:
Journal Volume: 50:6
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; ETHANOL; BIOSYNTHESIS; XYLOSE; FERMENTATION; YEASTS; PRODUCTIVITY; COMPARATIVE EVALUATIONS; ALCOHOLS; ALDEHYDES; BIOCONVERSION; CARBOHYDRATES; FUNGI; HYDROXY COMPOUNDS; MICROORGANISMS; MONOSACCHARIDES; ORGANIC COMPOUNDS; PENTOSES; PLANTS; SACCHARIDES; SYNTHESIS; 090222* - Alcohol Fuels- Preparation from Wastes or Biomass- (1976-1989); 140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)

Citation Formats

Nigam, J N, Ireland, R S, Margaritis, A, and Lachance, M A. Isolation and screening of yeasts that ferment D-xylose directly to ethanol. United States: N. p., 1985. Web.
Nigam, J N, Ireland, R S, Margaritis, A, & Lachance, M A. Isolation and screening of yeasts that ferment D-xylose directly to ethanol. United States.
Nigam, J N, Ireland, R S, Margaritis, A, and Lachance, M A. Sun . "Isolation and screening of yeasts that ferment D-xylose directly to ethanol". United States.
@article{osti_6457633,
title = {Isolation and screening of yeasts that ferment D-xylose directly to ethanol},
author = {Nigam, J N and Ireland, R S and Margaritis, A and Lachance, M A},
abstractNote = {Natural habitats of yeasts were examined for the presence of strains able to produce ethanol from D-xylose. Black knots, insect frass, and tree exudates were screened by enrichment in liquid D-xylose-yeast extract medium. These and each D-xylose-assimilating yeast in a collection from cactus fruits and Drosophila spp. were tested for alcohol production from this sugar. Among the 412 isolates examined, 36 produced more than 1 g of ethanol liter/sup -1/ from 20 g of D-xylose liter/sup -1/, all under aerated conditions. Closer examination of the strains indicated that their time courses of D-xylose fermentation followed different patterns. Some strains produced more biomass than ethanol, and among these, ethanol may or may not be assimilated rapidly after depletion of D-xylose. Others produced more ethanol than biomass, but all catabolized ethanol after carbohydrate exhaustion. Ethanol production appeared best at low pH values and under mild aeration. Possible correlations between the nutritional profiles of the yeasts and their ability to produce ethanol from D-xylose were explored by multivariate analysis. D-Xylose appeared slightly better utilized by yeasts which rate poorly in terms of fermentation. The fermentation of D-glucose had no bearing on D-xylose fermentation. No specific nutritional trait could discriminate well between better D-xylose fermentors and other yeasts.},
doi = {},
journal = {Appl. Environ. Microbiol.; (United States)},
number = ,
volume = 50:6,
place = {United States},
year = {1985},
month = {12}
}