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Engineering of E. coli
for increased production of L-lactic acid
Tengku Elida Tengku Zainal Mulok1,2, Mei-Ling
Chong1, Yoshihito Shirai3, Raha Abdul
Rahim1 and Mohd Ali Hassan1*
1Deparment
of Bioprocess Technology, Faculty of Biotechnology and
Biomolecular Sciences, University Putra Malaysia, 43400
Serdang, Selangor, Malaysia.
2Department
of Microbiology, Faculty of Applied Science, Universiti
Teknologi MARA, 40450 Shah Alam, Selangor, Malaysia.
3Graduate
School of Life Sciences and System Engineering, Kyushu
Institute of Technology, 808-0196 Hibikino 2-4, Wakamatsu-ku,
Kitakyushu-shi, Fukuoka, Japan.
*Corresponding author. E-mail:
alihas@biotech.upm.edu.my. Tel.: +603-89467590. Fax:
+603-89467593
Accepted 11
June, 2009 |
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An over-expressed L-ldh gene derivative of Escherichia
coli BAD-ldh was developed. L-ldh gene from
Enterococcus facelis KK1 consisted of an open reading
frame of 954 bp encoding 316 amino acids. L-ldh gene was
cloned into pBAD vector and transformed into E. coli
SZ85 by electroporation. SDS-page and western blotting
method confirmed the presence of recombinant L-LDH enzyme
with the approximate size of 40 kD. The activity of
L-lactate dehydrogenase was achieved at 170 U ml-1.
E. coli BAD85 was found to produce 0.62 g l-1
of lactic acid from 1 g l-1 of fructose in 24 h.
L-ldh gene from was successfully transformed into E. coli
SZ85 with the maximum production of L-lactic acid at 0.62 g
l-1.
Key
words:
Enterobacter, fermentation processes, genes, lactic
acid bacteria, molecular genetics, L-ldh gene. |
