A systematic study was conducted on the effects of specific concentrations of fermentation inhibitors acetic acid, 5-hydroxymethylfurfural (5-HMF), furfurals, and phenolics on the fermentation of xylose to xylitol and hexoses to ethanol by Candida guilliermondii in water-soluble fractions (hydrolysates) from steam-pretreated sugarcane bagasse, hybrid poplar, switchgrass, mixed wood, and giant reed. The influence of different inhibitor concentrations on the growth and fermentation abilities of C. guilliermondii cultivated in lignocellulosic hydrolysates was measured during liquid batch cultures. In the presence of up to8 g/Lof acetic acid along with furfural, 5-HMF, and phenolics (found in hybrid poplar hydrolysate and sugarcane bagasse), the ethanol and xylitol yields increased up to 140% and 88%, respectively, compared to a control containing no inhibitors(100% and 68, respectively). The highest ethanol but lowest xylitol yields compared to controls were measured in hybrid poplar hydrolysate,which was then selected forthesystematic study for production of specific concentrationsof the fermentation inhibitors to enhance ethanol and xylitol yields. For all six steam pretreatment severities tested for hybrid poplar, the presence of inhibitors caused the ethanol yield to be enhanced by as much as 22% compared to the control. However, the xylitol yield was negatively affected by the higher concentrations of inhibitors in the six hybrid poplar hydrolysates. Overall this study showed that fermentation inhibitors are not necessarily harmful compounds. At specific concentrations, acetic acid, furfural, 5-HMF, and phenolics might be called fermentation enhancers rather than inhibitors.
Get full access to this article
View all access options for this article.
References
1.
MosierN, WymanC, DaleB, et al.Features of promising technologies for pretreatment of lignocellulosic biomass. Bioresour Technol, 2005; 96(6):673–686.
BuraR, ChandraR, SaddlerJ. Influence of xylan on the enzymatic hydrolysis of steam-pretreated corn stover and hybrid poplar. Biotechnol Prog, 2009; 25(2):315–322.
4.
CarrascoC, BaudelH, PenarrietaM, et al.Steam pretreatment and fermentation of the straw material “paja brava” using simultaneous saccharification and co-fermentation. J Biosci Bioeng, 2011; 111(2):167–174.
5.
EwanickSM, BuraR, SaddlerJN. Acid-catalyzed steam pretreatment of lodgepole pine and subsequent enzymatic hydrolysis and fermentation to ethanol. Biotechnol Bioeng, 2007; 98(4):737–746.
6.
TengborgC, StenbergK, GalbeM, et al.Comparison of SO2 and H2SO4 impregnation of softwood prior to steam pretreatment on ethanol production. Appl Biochem Biotechnol, 1998; 70–72:3–15.
7.
OlssonL, Hahn-HägerdalB. Fermentation of lignocellulosic hydrolysates for ethanol production. Enzyme Microb Technol, 1996; 18(5):312–331.
8.
KumarP, BarrettDM, DelwicheMJ, StroeveP. Methods for pretreatment of lignocellulosic biomass for efficient hydrolysis and biofuel production. Ind Eng Chem Res, 2009; 48(8):3713–3729.
9.
WinkelhausenE, KuzmanovaS. Microbial conversion of D-xylose to xylitol. J Ferment Bioeng, 1998; 86(1):1–14.
10.
VajzovicA, BuraR, KohlmeierK, DotSL. Novel endophytic yeast Rhodotorula mucilaginosa strain PTD3 II: Production of xylitol and ethanol in the presence of inhibitors. J Ind Microbiol Biotechnol, 2012; 39:1453–1463.
11.
PalmqvistE, GalbeM, Hahn-HägerdalB. Evaluation of cell recycling in continuous fermentation of enzymatic hydrolysates of spruce with Saccharomyces cerevisiae and on-line monitoring of glucose and ethanol. Appl Microbiol Biotechnol, 1998; 50(5):545–551.
12.
TengborgC, GalbeM, ZacchiG. Reduced inhibition of enzymatic hydrolysis of steam-pretreated softwood. Enzyme Microb Technol, 2001; 28(9–10):835–844.
13.
LarssonS, ReimannA, NilvebrantNO, JönssonLJ. Comparison of different methods for the detoxification of lignocellulose hydrolyzates of spruce. Appl Biochem Biotechnol, 1999; 77(1):91–103.
14.
van ZylC, PriorBA, du PreezJC. Acetic acid inhibition of d-xylose fermentation by Pichia stipitis. Enzyme Microb Technol, 1991; 13(1):82–86.
15.
HyneNJ.Nontechnical Guide To Petroleum Geology, Exploration, Drilling, And Production. Pennwell Books, Tulsa, OK. 2001.
16.
MaddoxI, MurrayAE. Production of n-butanol by fermentation of wood hydrolysate. Biotechnol Lett, 1983; 5(3):175–178.
17.
AmarteyS, JeffriesT. An improvement in Pichia stipitis fermentation of acid-hydrolysed hemicellulose achieved by overliming (calcium hydroxide treatment) and strain adaptation. World J Microbiol Biotechnol, 1996; 12(3):281–283.
18.
PalmqvistE, Hahn-HägerdalB. Fermentation of lignocellulosic hydrolysates. I: Inhibition and detoxification. Bioresour Technol, 2000; 74(1):17–24.
19.
TaherzadehM, NiklassonC, LidenG. Conversion of dilute-acid hydrolyzates of spruce and birch to ethanol by fed-batch fermentation. Bioresour Technol, 1999; 69(1):59–66.
20.
PalmqvistE, AlmeidaJS, Hahn-HägerdalB. Influence of furfural on anaerobic glycolytic kinetics of Saccharomyces cerevisiae in batch culture. Biotechnol Bioeng, 1999; 62(4):447–454.
21.
BuraR, VajzovicA, DotySL. Novel endophytic yeast Rhodotorula mucilaginosa strain PTD3 I:Production of xylitol and ethanol. J Ind Microbiol Biotechnol, 2012; 39:1003–1011.
22.
SchmittE.2009. Life cycle assessment of converting lignocellulosic rich urban waste to ethanol. (MS thesis) Seattle, WA: University of Washington OCLC 499143352.
23.
PalmqvistE, GrageH, MeinanderNQ, Hahn-HägerdalB. Main and interaction effects of acetic acid, furfural, and p-hydroxybenzoic acid on growth and ethanol productivity of yeasts. Biotechnol Bioeng, 1999; 63(1):46–55.
24.
TaherzadehMJ, NiklassonC, LidénG. Acetic acid—Friend or foe in anaerobic batch conversion of glucose to ethanol by Saccharomyces cerevisiae. Chem Eng Sci, 1997; 52(15):2653–2659.
25.
LarssonS, PalmqvistE, Hahn-HägerdalB, et al.The generation of fermentation inhibitors during dilute acid hydrolysis of softwood. Enzyme Microb Technol, 1999; 24(3–4):151–159.
26.
GranstromTB, IzumoriK, LeisolaM. A rare sugar xylitol. Part II: Biotechnological production and future applications of xylitol. Appl Microbiol Biotechnol, 2007; 74(2):273–276.
27.
PrakashamRS, Sreenivas RaoR, HobbsP. Current trends in biotechnological production of xylitol and future prospects. Curr Trends Biotechnol Pharm, 2009; 3(1):8–36.
28.
GranstromTB, LeisolaM. Production and applications of xylitol. Agro Food Ind Hi-Tech, 2009; 20(3):32–35.
29.
GranstromTB, IzumoriK, LeisolaM. A rare sugar xylitol. Part I: The biochemistry and biosynthesis of xylitol. Appl Microbiol Biotechnol, 2007; 74(2):277–281.
30.
BuraR, EwanickS, GustafsonR.Assessment of arundo donax (giant reed) as feedstock for conversion to ethanol. Tappi J, 2012; 11(4).
31.
EwanickSM, BuraR. The effect of biomass moisture content on bioethanol yields from steam pretreated switchgrass and sugarcane bagasse. Bioresour Technol, 2011; 102(3):2651–2658.
32.
SchmittE, BuraR, GustafsonR, CooperJ, VajzovicA. Converting lignocellulosic solid waste into ethanol for the state of Washington: An investigation of treatment technologies and environmental impacts. Bioresour Technol, 2012, 1; 104(0):400–409.
33.
AinsworthEA, GillespieKM. Estimation of total phenolic content and other oxidation substrates in plant tissues using Folin-Ciocalteu reagent. Nat Protoc, 2007; 2(4):875–877.
34.
KeatingJD, RobinsonJ, CottaMA, SaddlerJN, MansfieldSD. An ethanologenic yeast exhibiting unusual metabolism in the fermentation of lignocellulosic hexose sugars. J Ind Microbiol Biotechnol, 2004; 31(5):235–244.
35.
KastnerJR, RobertsRS. Simultaneous fermentation of D-xylose and glucose by Candida shehatae. Biotechnol Lett. 1990; 12(1):57–60.
36.
OverendR, ChornetE. Fractionation of lignocellulosics by steam-aqueous pretreatments. Phil Trans Roy Soc London A, 1987; 30; 321(1561):523–536.
37.
ChumH, JohnsonD, BlackS. Organosolv pretreatment for enzymatic-hydrolysis of poplars. 2. Catalyst effects and the combined severity parameter. Ind Eng Chem Res, 1990; 29(2):156–162.
38.
RabeloSC, Vaz RossellCE, de Moraes RochaGJ, ZacchiG. Enhancement of the enzymatic digestibility of sugarcane bagasse by steam pretreatment impregnated with hydrogen peroxide. Biotechnol Prog, 2012;(5):1207–1217.
39.
YangG, PidkoEA, HensenEJM. Mechanism of bronsted acid-catalyzed conversion of carbohydrates. Journal of Catalysis. 2012; 295:122–132.
40.
TaherzadehMJ, EklundR, GustafssonL, NiklassonC, LidénG. Characterization and fermentation of dilute-acid hydrolyzates from wood. Ind Eng Chem Res, 1997; 36(11):4659–4665.
41.
SeneL, ConvertiA, ZilliM, FelipeM, SilvaS. Metabolic study of the adaptation of the yeast Candida guilliermondii to sugarcane bagasse hydrolysate. Appl Microbiol Biotechnol, 2001; 57(5):738–743.
42.
LimaLHA, FelipeMDD, VitoloM, TorresFAG. Effect of acetic acid present in bagasse hydrolysate on the activities of xylose reductase and xylitol dehydrogenase in Candida guilliermondii. Appl Microbiol Biotechnol, 2004; 65(6):734–738.
43.
LeeH, SopherCR, YauYF. Induction of xylose reductase and xylitol dehydrogenase activities on mixed sugars in Candida guilliermondii. J Chem Technol Biotechnol, 1996; 65(4):375–379.
44.
PalmqvistE, Hahn-HägerdalB. Fermentation of lignocellulosic hydrolysates. II: Inhibitors and mechanisms of inhibition. Bioresour Technol, 2000; 74(1):25–33.
45.
PereiraRS, MussattoSI, RobertoIC. Inhibitory action of toxic compounds present in lignocellulosic hydrolysates on xylose to xylitol bioconversion by Candida guilliermondii. J Ind Microbiol Biotechnol, 2010;(38):71–78.
46.
KellyC, JonesO, BarnhartC, LajoieC. Effect of furfural, vanillin and syringaldehyde on Candida guilliermondii growth and xylitol biosynthesis. Appl Biochem Biotechnol, 2008; 148(1–3):97–108.
47.
Morales VeraR.2015. Bioconversion of heterogeneous lignocellulosic biomass for sugar production. (Doctoral dissertation) Seattle, WA: University of Washington. AAT 3688949.
