Development of corn silk as a biocarrier for Zymomonas mobilis biofilms in ethanol production from rice straw
Files (Excerpt)
Issued Date
2016
Genre
Language
eng
File Type
application/pdf
No. of Pages/File Size
7 pages
Citation
The Journal of General and Applied Microbiology 62.2 (April 2016), 68-74
Title
Development of corn silk as a biocarrier for Zymomonas mobilis biofilms in ethanol production from rice straw
Abstract
Z. mobilis cell immobilization has been proposed
as an effective means of improving ethanol production.
In this work, polystyrene and corn silk were
used as biofilm developmental matrices for Z.
mobilis ethanol production with rice straw hydrolysate
as a substrate. Rice straw was hydrolyzed
by dilute sulfuric acid (H2SO4) and enzymatic hydrolysis.
The final hydrolysate contained furfural
(271.95 ± 76.30 ppm), 5-hydroxymethyl furfural
(0.07 ± 0.00 ppm), vanillin (1.81 ± 0.00 ppm),
syringaldehyde (5.07 ± 0.83 ppm), 4-
hydroxybenzaldehyde (4-HB) (2.39 ± 1.20 ppm) and
acetic acid (0.26 ± 0.08%). Bacterial attachment or
biofilm formation of Z. mobilis strain TISTR 551
on polystyrene and delignified corn silk carrier
provided significant ethanol yields. Results showed
up to 0.40 ± 0.15 g ethanol produced/g glucose consumed
when Z. mobilis was immobilized on a polystyrene
carrier and 0.51 ± 0.13 g ethanol produced/
g glucose consumed when immobilized on
delignified corn silk carrier under batch fermentation
by Z. mobilis TISTR 551 biofilm. The higher
ethanol yield from immobilized, rather than free
living, Z. mobilis could possibly be explained by a
higher cell density, better control of anaerobic conditions
and higher toxic tolerance of Z. mobilis
biofilms over free cells.