초록
<P><B>Abstract</B></P> <P>The extent of inhibition of two strains of <I>Clostridium thermocellum</I> by a <I>Populus</I> hydrolysate was investigated. A Monod-based model of wild type (WT) and <I>Populus</I> hydrolysate tolerant mutant (PM) strains of the cellulolytic bacterium <I>C. thermocellum</I> was developed to quantify growth kinetics in standard media and the extent of inhibition to a <I>Populus</I> hydrolysate. The PM was characterized by a higher growth rate (<I>μ</I> <SUB>max</SUB> =1.223 vs. 0.571h<SUP>−1</SUP>) and less inhibition (<I>K<SUB>I,gen</SUB> </I> =0.991 vs. 0.757) in 10% v/v <I>Populus</I> hydrolysate compared to the WT. In 17.5% v/v <I>Populus</I> hydrolysate inhibition of PM increased slightly (<I>K<SUB>I,gen</SUB> </I> =0.888), whereas the WT was strongly inhibited and did not grow in a reproducible manner. Of the individual inhibitors tested, 4-hydroxybenzoic acid was the most inhibitory, followed by galacturonic acid. The PM did not have a greater ability to detoxify the hydrolysate than the WT.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Analyzed a <I>Populus</I> hydrolysate mutant and wild type strain of <I>Clostridium thermocellum.</I> </LI> <LI> Used a Monod based kinetic model for growth with and without <I>Populus</I> hydrolysate. </LI> <LI> <I>Populus</I> mutant had a faster growth rate and was less inhibited than wild type. </LI> <LI> <I>Populus</I> mutant is more tolerant to individual inhibitors than the wild type. </LI> <LI> <I>Populus</I> mutant has a lower ability to detoxify the hydrolysate than wild type. </LI> </UL> </P>