Screening of lysine production by Escherichia coli and Klebsiella isolates at different carbon sources

Abstract

Lysine is an essential amino acid that is not biologically manufactured in the body. Different chemical methods for lysine production are expensive and give low yields. The present study was conducted with the purpose to evaluate the biochemical production of lysine by different carbon sources using bacterial isolates. Three carbon sources namely glucose, sucrose, and fructose were used to evaluate the biochemical production of lysine by Escherichia coli and Klebsiella spp. isolates. Optimum incubation periods were between 48-96 hours. An extensive amount of lysine was produced by all of these isolates in L6 fermentation medium. Maximum lysine was produced by Klebsiella isolate K1 6.48 g/L after 96 hours of incubation by using glucose as carbon source followed by 6.0 g/L by Klebsiella isolates K3 after 72 hours of incubation when sucrose was used as a carbon source at 37 °C. Highest amount of lysine was produced at 96 hours by Klebsiella isolates in addition to E. coli. From all three carbon sources using Klebsiella isolates and E. coli, glucose showed better lysine production.

Keywords

• bacterial isolates
• fermentation media
• fermentative production of lysine.