scholarly journals Isolation of Adherent Polycyclic Aromatic Hydrocarbon (PAH)-Degrading Bacteria Using PAH-Sorbing Carriers

2000 ◽  
Vol 66 (5) ◽  
pp. 1834-1843 ◽  
Author(s):  
Leen Bastiaens ◽  
Dirk Springael ◽  
Pierre Wattiau ◽  
Hauke Harms ◽  
Rupert deWachter ◽  
...  

ABSTRACT Two different procedures were compared to isolate polycyclic aromatic hydrocarbon (PAH)-utilizing bacteria from PAH-contaminated soil and sludge samples, i.e., (i) shaken enrichment cultures in liquid mineral medium in which PAHs were supplied as crystals and (ii) a new method in which PAH degraders were enriched on and recovered from hydrophobic membranes containing sorbed PAHs. Both techniques were successful, but selected from the same source different bacterial strains able to grow on PAHs as the sole source of carbon and energy. The liquid enrichment mainly selected for Sphingomonasspp., whereas the membrane method exclusively led to the selection ofMycobacterium spp. Furthermore, in separate membrane enrichment set-ups with different membrane types, three repetitive extragenic palindromic PCR-related Mycobacterium strains were recovered. The new Mycobacterium isolates were strongly hydrophobic and displayed the capacity to adhere strongly to different surfaces. One strain, Mycobacterium sp. LB501T, displayed an unusual combination of high adhesion efficiency and an extremely high negative charge. This strain may represent a new bacterial species as suggested by 16S rRNA gene sequence analysis. These results indicate that the provision of hydrophobic sorbents containing sorbed PAHs in the enrichment procedure discriminated in favor of certain bacterial characteristics. The new isolation method is appropriate to select for adherent PAH-degrading bacteria, which might be useful to biodegrade sorbed PAHs in soils and sludge.

2004 ◽  
Vol 54 (6) ◽  
pp. 2313-2317 ◽  
Author(s):  
Kerstin Derz ◽  
Ulrich Klinner ◽  
Ingolf Schuphan ◽  
Erko Stackebrandt ◽  
Reiner M. Kroppenstedt

The taxonomic position of a polycyclic-aromatic-hydrocarbon-degrading bacterium, strain 17A3T, isolated from contaminated soil was determined using a combination of phenotypic and genotypic properties. The isolate showed phenotypic properties that were diagnostic for species of the genus Mycobacterium. Comparative 16S rRNA gene sequence analysis assigned 17A3T to the 16S rRNA gene subgroup that contains Mycobacterium aurum, Mycobacterium austroafricanum, Mycobacterium vaccae and Mycobacterium vanbaalenii, but it could clearly be distinguished from these species using a combination of physiological, chemotaxonomic markers and internal rRNA gene spacer analyses. The data showed that strain 17A3T (=DSM 44605T=NRRL B-24244T) merits recognition as the type strain of a novel species of the genus Mycobacterium. The name Mycobacterium pyrenivorans sp. nov. is proposed for the species because of its ability to use pyrene as a sole source of carbon and energy.


2001 ◽  
Vol 67 (6) ◽  
pp. 2683-2691 ◽  
Author(s):  
L. L. Daane ◽  
I. Harjono ◽  
G. J. Zylstra ◽  
M. M. Häggblom

ABSTRACT Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were isolated from contaminated estuarine sediment and salt marsh rhizosphere by enrichment using either naphthalene, phenanthrene, or biphenyl as the sole source of carbon and energy. Pasteurization of samples prior to enrichment resulted in isolation of gram-positive, spore-forming bacteria. The isolates were characterized using a variety of phenotypic, morphologic, and molecular properties. Identification of the isolates based on their fatty acid profiles and partial 16S rRNA gene sequences assigned them to three main bacterial groups: gram-negative pseudomonads; gram-positive, non-spore-forming nocardioforms; and the gram-positive, spore-forming group,Paenibacillus. Genomic digest patterns of all isolates were used to determine unique isolates, and representatives from each bacterial group were chosen for further investigation. Southern hybridization was performed using genes for PAH degradation fromPseudomonas putida NCIB 9816-4, Comamonas testosteroni GZ42, Sphingomonas yanoikuyae B1, andMycobacterium sp. strain PY01. None of the isolates from the three groups showed homology to the B1 genes, only two nocardioform isolates showed homology to the PY01 genes, and only members of the pseudomonad group showed homology to the NCIB 9816-4 or GZ42 probes. The Paenibacillus isolates showed no homology to any of the tested gene probes, indicating the possibility of novel genes for PAH degradation. Pure culture substrate utilization experiments using several selected isolates from each of the three groups showed that the phenanthrene-enriched isolates are able to utilize a greater number of PAHs than are the naphthalene-enriched isolates. Inoculating two of the gram-positive isolates to a marine sediment slurry spiked with a mixture of PAHs (naphthalene, fluorene, phenanthrene, and pyrene) and biphenyl resulted in rapid transformation of pyrene, in addition to the two- and three-ringed PAHs and biphenyl. This study indicates that the rhizosphere of salt marsh plants contains a diverse population of PAH-degrading bacteria, and the use of plant-associated microorganisms has the potential for bioremediation of contaminated sediments.


2009 ◽  
Vol 75 (19) ◽  
pp. 6322-6330 ◽  
Author(s):  
Aurélie Cébron ◽  
Thierry Beguiristain ◽  
Pierre Faure ◽  
Marie-Paule Norini ◽  
Jean-François Masfaraud ◽  
...  

ABSTRACT The polycyclic aromatic hydrocarbon (PAH) contamination, bacterial community, and PAH-degrading bacteria were monitored in aged PAH-contaminated soil (Neuves-Maisons [NM] soil; with a mean of 1,915 mg of 16 PAHs·kg−1 of soil dry weight) and in the same soil previously treated by thermal desorption (TD soil; with a mean of 106 mg of 16 PAHs·kg−1 of soil dry weight). This study was conducted in situ for 2 years using experimental plots of the two soils. NM soil was colonized by spontaneous vegetation (NM-SV), planted with Medicago sativa (NM-Ms), or left as bare soil (NM-BS), and the TD soil was planted with Medicago sativa (TD-Ms). The bacterial community density, structure, and diversity were estimated by real-time PCR quantification of the 16S rRNA gene copy number, temporal thermal gradient gel electrophoresis fingerprinting, and band sequencing, respectively. The density of the bacterial community increased the first year during stabilization of the system and stayed constant in the NM soil, while it continued to increase in the TD soil during the second year. The bacterial community structure diverged among all the plot types after 2 years on site. In the NM-BS plots, the bacterial community was represented mainly by Betaproteobacteria and G ammaproteobacteria. The presence of vegetation (NM-SV and NM-Ms) in the NM soil favored the development of a wider range of bacterial phyla (Alphaproteobacteria, Betaproteobacteria, G ammaproteobacteria, Verrucomicrobia, Actinobacteria, Firmicutes, and Chlorof l exi) that, for the most part, were not closely related to known bacterial representatives. Moreover, under the influence of the same plant, the bacterial community that developed in the TD-Ms was represented by different bacterial species (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Actinobacteria) than that in the NM-Ms. During the 2 years of monitoring, the PAH concentration did not evolve significantly. The abundance of gram-negative (GN) and gram-positive (GP) PAH-degrading bacteria was estimated by real-time PCR quantification of specific functional genes encoding the α subunit of PAH-ring hydroxylating dioxygenase (PAH-RHDα). The percentage of the PAH-RHDα GN bacterial genes relative to 16S rRNA gene density decreased with time in all the plots. The GP PAH-RHDα bacterial gene proportion decreased in the NM-BS plots but stayed constant or increased under vegetation influence (NM-SV, NM-Ms, and TD-Ms).


2011 ◽  
Vol 77 (21) ◽  
pp. 7856-7860 ◽  
Author(s):  
Tony Gutierrez ◽  
David R. Singleton ◽  
Michael D. Aitken ◽  
Kirk T. Semple

ABSTRACTPolycyclic aromatic hydrocarbon (PAH)-degrading bacteria associated with an algal bloom in Tampa Bay, FL, were investigated by stable isotope probing (SIP) with uniformly labeled [13C]naphthalene. The dominant sequences in clone libraries constructed from13C-enriched bacterial DNA (from naphthalene enrichments) were identified as uncharacterized members of the familyRhodobacteraceae. Quantitative PCR primers targeting the 16S rRNA gene of these uncultivated organisms were used to determine their abundance in incubations amended with unlabeled naphthalene and phenanthrene, both of which showed substantial increases in gene copy numbers during the experiments. As demonstrated by this work, the application of uniformly13C-labeled PAHs in SIP experiments can successfully be used to identify novel PAH-degrading bacteria in marine waters.


1996 ◽  
Vol 42 (3) ◽  
pp. 252-258 ◽  
Author(s):  
Brian A. Wrenn ◽  
Albert D. Venosa

A most-probable-number (MPN) procedure was developed to separately enumerate aliphatic and aromatic hydrocarbon degrading bacteria, because most of the currently available methods are unable to distinguish between these two groups. Separate 96-well microtiter plates are used to estimate the sizes of these two populations. The alkane-degrader MPN method uses hexadecane as the selective growth substrate and positive wells are detected by reduction of iodonitrotetrazolium violet, which is added after incubation for 2 weeks at 20 °C. Polycyclic aromatic hydrocarbon degraders are grown on a mixture of phenanthrene, anthracene, fluorene, and dibenzothiophene in a second plate. Positive wells turn yellow to greenish-brown from accumulation of the partial oxidation products of the aromatic substrates and they can be scored after a 3-week incubation period. These MPN procedures are accurate and selective. For pure cultures, heterotrophic plate counts on a nonselective medium and the appropriate MPN procedure provide similar estimates of the population density. Bacteria that cannot grow on the selective substrates do not produce false positive responses even when the inoculum density is very high. Thus, this method, which is simple enough for use in the field, provides reliable estimates for the density and composition of hydrocarbon-degrading microbial populations.Key words: most probable number, polycyclic aromatic hydrocarbon, alkane, hydrocarbon, bacteria.


1997 ◽  
Vol 43 (4) ◽  
pp. 368-377 ◽  
Author(s):  
Fadi Dagher ◽  
Eric Déziel ◽  
Patricia Lirette ◽  
Gilles Paquette ◽  
Jean-Guy Bisaillon ◽  
...  

Five polycyclic aromatic hydrocarbon (PAH) degrading bacterial strains, Pseudomonas putida 34, Pseudomonas fluorescens 62, Pseudomonas aeruginosa 57, Sphingomonas sp. strain 107, and the unidentified strain PL1, were isolated from two contaminated soils and characterized for specific features regarding PAH degradation. Degradation efficiency was determined by the rapidity to form clearing zones around colonies when sprayed with different PAH solutions and the growth in liquid medium with different PAHs as sole source of carbon and energy. The presence of plasmids, the production of biosurfactants, the effect of salicylate on PAH degradation, the transformation of indole to indigo indicating the presence of an aromatic ring dioxygenase activity, and the hybridization with the SphAb probe representing a sequence highly homologous to the naphthalene dioxygenase ferredoxin gene nahAb were examined. The most efficient strain in terms of substrate specificity and rapidity to degrade different PAHs was Sphingomonas sp. strain 107, followed by strain PL1 and P. aeruginosa 57. The less efficient strains were P. putida 34 and P. fluorescens 62. Each strain transformed indole to indigo, except strain PL1. Biosurfactants were produced by P. aeruginosa 57 and P. putida 34, and a bioemulsifier was produced by Sphingomonas sp. strain 107. The presence of salicylate in solid medium has accelerated the formation of clearing zones and the transformation of indole by Sphingomonas sp. strain 107 and P. aeruginosa 57 colonies. Plasmids were found in Sphingomonas sp. strain 107 and strain PL1. The SphAb probe hybridized with DNA extracted from each strain. However, hybridization signals were detected only in the plasmidic fraction of Sphingomonas sp. strain 107 and strain PL1. Using a polymerase chain reaction (PCR) approach, we determined that several genes encoding enzymes involved in the upper catabolic pathway of naphthalene were present in each strain. Sequencing of PCR DNA fragments revealed that, for all the five strains, these genes are highly homologous with respective genes found in the pah, dox, and nah opérons, and are arranged in a polycistronic operon. Results suggest that these genes are ordered in the five selected strains like the pah, nah, and dox opérons.Key words: polycyclic aromatic hydrocarbons, biodegradation, polymerase chain reaction, naphthalene catabolic genes.


Sign in / Sign up

Export Citation Format

Share Document