Esterase activity in <i>A</i>. <i>tumefaciens</i> NTL4 and derivatives.

<p>The esterase activity in NTL4 and the <i>estC</i> mutant strains harboring the pBBR1MCS-5 vector control (pBBR), pEstC or pEstC_S101A was assayed in crude lysates prepared from exponential phase cultures. A unit of esterase activity is defined as the amount of enzyme capable of hydrolyzing <i>p</i>-nitrophenyl butyrate to generate 1 μmol of <i>p</i>-nitrophenol at 25°C. Asterisks indicate a significant difference (<i>P</i> < 0.05) from NTL4 or the <i>estC</i> mutant harboring vector control.