Geobacillus toebii subsp. decanicus subsp. nov., a hydrocarbon-degrading, heavy metal resistant bacterium from hot compost.
A thermophilic, spore-forming bacterial strain L1(T) was isolated from hot compost "Pomigliano Environment" s.p.a., Pomigliano, Naples, Italy. The strain was identified by using a polyphasic taxonomic approach. L1(T) resulted in an aerobic, gram-positive, rod-shaped, thermophilic with an optimum growth temperature of 68 degrees C chemorganotrophic bacterium which grew on hydrocarbons as unique carbon and energy sources and was resistant to heavy metals. The G+C DNA content was 43.5 mol%. Phylogenetic analysis of 16S rRNA gene sequence and Random Amplified Polymorphic DNA-PCR (RAPD-PCR) analysis of L1(T) and related strains showed that it forms within Geobacillus toebii, a separate cluster in the Geobacillus genus. The composition of cellular fatty acids analyses by Gas-Mass Spectroscopy differed from that typical for the genus Geobacillus in that it is lacking in iso-C15 fatty acid, while iso-C16 and iso-C17 were predominant. Isolates grew on a rich complex medium at temperatures between 55-75 degrees C and presented a doubling time (t(d)) of 2 h and 6 h using complex media and hydrocarbon media, respectively. Among hydrocarbons tested, n-decane (2%) was the more effective to support the growth (1 g/L of wet cells). The microorganism showed resistance to heavy metal tested during the growth. Furthermore, intracellular alpha-galactosidase and alpha-glucosidase enzymatic activities were detectable in the L1(T) strain. Based on phenotypic, phylogenetic, fatty acid analysis and results from DNA-DNA hybridization, we propose assigning a novel subspecies of Geobacillus toebii, to be named Geobacillus toebii subsp. decanicus subsp. nov., with the type strain L1(T) (=DSM 17041=ATCC BAA 1004).
Poli
Annarita
A
Istituto di Chimica Biomolecolare (ICB), CNR, Napoli, Italy.
Romano
Ida
I
Caliendo
Gaetano
G
Nicolaus
Giancarlo
G
Orlando
Pierangelo
P
Falco
Antonio de
Ad
Lama
Licia
L
Gambacorta
Agata
A
Nicolaus
Barbara
B
D001406:Bacillaceae / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D006838:Hydrocarbons / Q000378:metabolism*; D019216:Metals, Heavy / Q000494:pharmacology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D019105:Random Amplified Polymorphic DNA Technique / Q000379:methods; D012987:Soil; D012988:Soil Microbiology
D005227:Fatty Acids; D006838:Hydrocarbons; D019216:Metals, Heavy; D012336:RNA, Ribosomal, 16S; D012987:Soil