Microbial Production of L-Isoleucine from Different Substrates using Locally Isolated Bacteria

The present study was designed especially to see the microbial production of L-isoleucine from different substrates using locally isolated bacteria. Twenty one bacterial isolates from irrigation water channels and soil were screened for amino acids production using different fermentation media. In FM-1 medium bacterial isolates were grown in which UAF AF12 gave 6.1 g/L of isoleucine, which was followed by strain UAF AF10, which gave 4.9 g/L of alanine. Histidine was another prominent amino acid (4.7 g/L) by UAF AF6. Six isolates were non-producers for isoleucine. Isoleucine was found to be the best produced amino acid, which was produced by an isolate UAF AF12 in a quantity of 6.1 g/L after 24 h of fermentation in FM-1 medium. It was followed by alanine produced by UAF AL10 in an amount of 5.8 g/L after 72 h. Among others, the main amino acids were, valine (5.4 g/L by UAF AL17), glutamic acid (3.9 g/L by UAF AF21), lysine (3.8 g/L by UAF AM1-18), histidine (4.7 g/L by UAF AF6) and aspartic acid (3.9 g/L by UAF AF14). The best fermentation time was between 48-72 h of fermentation but sometimes appreciable amounts of amino acids were also produced after 24 h of fermentation. © 2010 Friends Science Publishers