Exogenous L-proline Increases Stress Tolerance of Yeast Pichia kudriavzevii Against Inhibitors in Lignocellulose Hydrolysates and Enhances its Ethanol Production

2nd International Conference on Biosciences

Astuti, R.I.^1 ; Nurhayati, N.^1 ; Ukit^1 ; Alifiyanti, S.^1 ; Sunarti, T.C.^2 ; Meryandini, A.^1

Department of Biology, Faculty of Mathematics and Natural Science, Bogor Agricultural University, West-Java, Bogor

16680, Indonesia^1

Department Department of Agroindustrial Technology, Faculty of Agricultural Technology, Bogor Agricultural University, West-Java, Bogor

16680, Indonesia^2

关键词: Dose-dependent manner;    Ethanol fermentation;    Fermentation substrates;    Future applications;    Lignocellulose hydrolysates;    Pichia kudriavzevii;    proline;    Stress response;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/197/1/012052/pdf
DOI  :  10.1088/1755-1315/197/1/012052

来源: IOP

【 摘 要 】

Three ethanologenic yeast isolates (E, R and T) capable to use both pentose and hexose sugars as substrate for ethanol fermentation was isolated. Thus, suggesting its potential for 2nd generation of ethanol production by using lignocellulose hydrolysate. Based on ITS sequence, those three isolates were identified as yeast Pichia kudriavzevii. Prior its utilization as fermentation substrate, lignocellulose is subjected to complex hidrolysis reactions, which results certain toxic compounds (furfural and organic acid). Our results indicate that P. kudriavzevii isolates were sensitive toward 0.15% furfural and 0.375% acetic acid. Interestingly, supplementation of 1.5% L-proline in the medium significantly enhanced the survival rate of all P. kudriavzevii isolates against the particular toxic compounds. Moreover, supplementation of L-proline also enhanced the production of ethanol in glucose as substrate, in a dose dependent manner. Indeed, addition of 1.5% L-proline could increase the ethanol yield of isolate E, R and T for approximately 57%, 53%, and 62%, respectively, as compared to that 0.5% L-proline. The highest ethanol production was exhibited by isolate T (14g/100mL) in 1.5% L-proline treatment. Our data indicate, that L-proline supplementation may potentially be applied to enhance ethanol production by P. kudriavzevii isolates, particularly for its future application in lignocellulose-based ethanol productions.