EXPRESSION OF ALKANE HYDROXYLASE FROM ACINETOBACTER SP. STRAIN ADP1 IS INDUCED BY A BROAD RANGE OF N-ALKANES AND REQUIRES THE TRANSCRIPTIONAL ACTIVATOR ALKR

In Acinetobacter sp, strain ADP1, alkane degradation depends on at lea st five essential genes. rubAB and xcpR are constitutively transcribed . Here we describe inducible transcription of alkM, which strictly dep ends on the presence of the transcriptional activator AlkR, alkR itsel f is expressed at a low level, while a chromosomally located alkM::lac Z fusion is inducible by middle-chain-length alkanes from heptane to u ndecane, which do not support growth of ADP1, and by long-chain-length alkanes from dodecane to octadecane, which are used as sources of car bon and energy, The putative AlkM substrate 1-dodecene is also an effe ctive inducer. Products of alkane hydroxylase activity like 1-dodecano l prevent induction of alkM expression. alkM is expressed only in stat ionary phase, suggesting its dependence on at least one other regulato ry mechanism.