Improvement of Folate Biosynthesis by Lactic Acid Bacteria Using Response Surface Methodology
Norfarina Muhamad Nor1, Rosfarizan Mohamad1,2*, Hooi Ling Foo1,2 and Raha Abdul Rahim2,3
1Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, University of Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
2Laboratory of Industrial Biotechnology, Institute of Bioscience, University of Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
3Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University of Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia
Article history:
Received July 8, 2009
Accepted October 6, 2009
Key words:
folate, lactic acid bacteria, Lactobacillus plantarum I-UL4, response surface methodology
Summary:
Lactic acid bacteria (Lactococcus lactis NZ9000, Lactococcus lactis MG1363, Lactobacillus plantarum I-UL4 and Lactobacillus johnsonii DSM 20553) have been screened for their ability to produce folate intracellularly and/or extracellularly. L. plantarum I-UL4 was shown to be superior producer of folate compared to other strains. Statistically based experimental designs were used to optimize the medium formulation for the growth of L. plantarum I-UL4 and folate biosynthesis. The optimal values of important factors were determined by response surface methodology (RSM). The effects of carbon sources, nitrogen sources and para-aminobenzoic acid (PABA) concentrations on folate biosynthesis were determined prior to RSM study. The biosynthesis of folate by L. plantarum I-UL4 increased from 36.36 to 60.39 μg/L using the optimized medium formulation compared to the selective Man de Rogosa Sharpe (MRS) medium. Conditions for the optimal growth of L. plantarum I-UL4 and folate biosynthesis as suggested by RSM were as follows: lactose 20 g/L, meat extract 16.57 g/L and PABA 10 μM.
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