Isolation and characterization of a novel n-alkane-degrading strain, Acinetobacter haemolyticus AR-46.
Strain AR-46, isolated and identified as Acinetobacter haemolyticus, evolutionally distant from the known hydrocarbon-degrading Acinetobacter spp., proved to have excellent long-chain n-alkane-degrading ability. This is the first detailed report on an n-alkane-utilizing strain belonging to this species. The preferred substrate is n-hexadecane, with an optimal temperature of 37 degrees C under aerobic conditions. Five complete and two partial open reading frames were sequenced and correlated with the early steps of monoterminal oxidation-initiated n-alkane mineralization. The encoded protein sequences and the arrangement of these genes displayed high similarity to those found in Acinetobacter sp. M-1, but AR-46 seemed to have only one alkane hydroxylase gene, with a completely different induction profile. Unique behaviour was also observed in n-alkane bioavailability. Substrate uptake occurred through the hydrophobic surface of n-alkane droplet-adhered cells possessing long, thick fimbriae, which were presumed to play a major role in n-alkane solubilization. A majority of the cells was in detached form, with thick, but short fimbriae. These free cells were permanently hydrophilic, unlike the cells of other Acinetobacter strains.
Bihari
Zoltán
Z
Institute for Biotechnology, Bay Zoltán Foundation for Applied Research, Derkovits fasor 2., H-6726 Szeged, Hungary. bihari@bay.u-szeged.hu
Pettkó-Szandtner
Aladár
A
Csanádi
Gyula
G
Balázs
Margit
M
Bartos
Péter
P
Kesseru
Péter
P
Kiss
István
I
Mécs
Imre
I
D000150:Acinetobacter / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D000473:Alkanes / Q000378:metabolism*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013379:Substrate Specificity
D000473:Alkanes; D017931:DNA Primers; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S