초록
<P>Methanol is regarded as an attractive substrate for biotechnological production of value-added bulk products, such as amino acids and polyamines. In the present study, the methylotrophic and thermophilic bacterium <I>B</I><I>acillus methanolicus</I> was engineered into a microbial cell factory for the production of the platform chemical 1,5-diaminopentane (cadaverine) from methanol. This was achieved by the heterologous expression of the <I>E</I><I>scherichia coli</I> genes <I>cad</I><I>A</I> and <I>ldc</I><I>C</I> encoding two different lysine decarboxylase enzymes, and by increasing the overall L-lysine production levels in this host. Both CadA and LdcC were functional in <I>B</I><I>. methanolicus</I> cultivated at 50°C and expression of <I>cad</I><I>A</I> resulted in cadaverine production levels up to 500 mg l<SUP>−1</SUP> during shake flask conditions. A volume-corrected concentration of 11.3 g l<SUP>−1</SUP> of cadaverine was obtained by high-cell density fed-batch methanol fermentation. Our results demonstrated that efficient conversion of L-lysine into cadaverine presumably has severe effects on feedback regulation of the L-lysine biosynthetic pathway in <I>B</I><I>. methanolicus</I>. By also investigating the cadaverine tolerance level, <I>B</I><I>. methanolicus</I> proved to be an exciting alternative host and comparable to the well-known bacterial hosts <I>E</I><I>. coli</I> and <I>C</I><I>orynebacterium glutamicum</I>. This study represents the first demonstration of microbial production of cadaverine from methanol.</P>