Kinetics study and substrate optimization for the growth of Pediococcus acidilactici 4E5 by batch fermentation.

Date

2011

Degree

Bachelor of Science in Chemical Engineering

Major Course

Major in Microbiology

College

College of Engineering and Agro-Industrial Technology (CEAT)

Abstract

Pediococcus acidilactici 4E5 is a strain lactic acid bacteria that is widely used for vegetable and meat fermentation. It produces antibacterial compounds like bacteriocin which inhibits the growth of pathogenic organisms that causes food spoilage thus, they are utilized in biopreservation processes. Response surface methodology was applied in this study to evaluate the effect of varying substrate composition (% carbon, % nitrogen and % yeast extract) on the growth of P. acidilactici 4E5 isolated from "burong tilapia" Cheese whey, soybean meal extract and baker's yeast extract were used as an alternative low-cost nutrient source for possible use on large scale production. The highest growth was obtained on the medium with 1.3% carbon, 2% nitrogen and 5% yeast extract with 9.0x10⁹ cfu/mL and 8.75x10⁹ cfu/mL for Trials 1 and 2. This result was consistent with the predicted optimized composition generated by the Design Expert analysis program that has the highest value of desirability. This result was used for the kinetic analysis on the growth of Pediococcus acidilactici 4E5 in varying concentrations of carbon (1.3%, 3.15% yeast extract(5%) was held constant. The pH was also measured for the medium with different concentrations of sugar and that for MRS. The result showed to be decreasing with the timer of fermentation which signifies the production of lactic acid during the fermentation period. The specific growth rate was then determined through graphical method in order to specify tyhe most suitable growth kinetic model. The Monod, Tessier and Andrews inhibition model were found not applicable to define the kinetics of fermentation. The growth of Pediococcus acidilactici 4E5 was best described by the Moser Model yielding a Mmax value of 0.173319hr⁻¹ and Ks value equal to 4744.6141 ug/mL.

Language

English

Location

UPLB College of Engineering and Agro-Industrial Technology (CEAT)

Call Number

LG 993 2011 E62 F86

Document Type

Thesis

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