Use of Rice Hull Hydrolyzate in the Cultivation of Lactobacillus acidophilus
Use of Rice Hull Hydrolyzate in the Cultivation of Lactobacillus acidophilus
Files (excerpt)
Published date
2012
Resource type
Publisher
ISBN
ISSN
DOI
Call no.
Other identifier(s)
Edition
Copyrighted date
Language
eng
File type
application/pdf
Extent
9 pages
Other title(s)
Authors
Advisor
Other Contributor(s)
Citation
KKU Res. J. 2012; 17(5):778-786
http : //resjournal.kku.ac.th
http : //resjournal.kku.ac.th
Degree name
Degree level
Degree discipline
Degree department
Degree grantor
Abstract
This project aims to minimize the cost of production of live L. acidophilus by replacing the expensive
carbon source in the fermentation medium with the rice hull hydrolyzate and compare the growth efficiency of
the microbe in the rice hull formulated medium with the rich medium (de Man Rogosa Sharpe or MRS). Rice
hull was hydrolyzed with diluted H2
SO4
and HCl at various concentrations 0.25, 0.5 and 1% v/v at 120
o
C for 30
minutes. The hydrolyzate was further overliming with Ca(OH)
2
and filter through the diatomaceous earth. The
treatment with 0.5% and 1% HCl provided the reducing sugar of 23.05 and 27.45 g/L which were close to MRS
broth of 20.88 g/L. The hydrolyzate from the treatment with 1% HCl was further mixed with MRS in the ratio of
MRS: hydrolyzate of 25: 75 and 10: 90 v/v. The MRS mixed with the hydrolyzate in the ratio of 25:75 v/v gave
the maximum specific growth rate (µmax
) of 0.437 hour
-1
which was comparable to the MRS broth of 0.424 hour
-1
.
The biomass yield (Yx/s
), dry weight and viable cell number on the formulated medium at 48 hours cultivation
were 0.21 g/g, 2.61 mg/ml and 2.07 × 10
8
CFU/ml respectively in comparison to MRS at 48 hours cultivation
which were 0.19 g/g, 3.07 mg/ml and 2.19 × 10
8
CFU/ml (viable cell number in MRS represented the maximum
level at 9 hours) respectively. The total acidity produced by the culture in formulated medium and MRS were
1.461% and 1.761%. Although, the formulated medium from rice hull hydrolyzate reduced the production cost in
term of medium requirement, the time required for obtaining the same amount of viable cells in the hydrolyzate
was longer than using MRS as a sole medium.