Isolation and characterization of a thermophilic Bacillus sp. JF8 capable of degrading polychlorinated biphenyls and naphthalene

Shimura, Minoru

doi:10.1016/s0378-1097(99)00337-7

Cited by 13 publications

(22 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…strain JF8 was grown on Castenholz D medium at 60 uC. Biphenyl was provided as vapour (Shimura et al, 1999), and 1?5 % agar was added for solid medium. Escherichia coli MV1184, DH5a and JM 109 (Takara Biomedicals) were used as hosts for plasmid construction and for gene expression at 37 uC.…”

Section: Methodsmentioning

confidence: 99%

“…We have isolated and characterized a naphthalene-and biphenyl-utilizing Grampositive thermophilic bacterium, Bacillus sp. JF8, which can degrade PCBs (Shimura et al, 1999). To study the structure, molecular organization, regulation and phylogeny of the genes/enzymes involved in degradation of biphenyl, we initially cloned and characterized the extradiol dioxygenase of the biphenyl pathway, BphC_JF8 (Hatta et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

“…Some of the sample (1 ml) was injected by an auto-injector (Hewlett Packard; model 7673) in the spitless mode. Identification of PCB congeners has been described previously (Shimura et al, 1999). For the identification of the hydroxylated derivatives of benzene, biphenyl, naphthalene and phenanthrene, the initial oven temperature of 60 uC was programmed to increase by 20 uC min 21 to 300 uC, where it was held for 5 min.…”

mentioning

confidence: 99%

See 2 more Smart Citations

bph genes of the thermophilic PCB degrader, Bacillus sp. JF8: characterization of the divergent ring-hydroxylating dioxygenase and hydrolase genes upstream of the Mn-dependent BphC

et al. 2005

View full text Add to dashboard Cite

Bacillus sp. JF8 is a thermophilic polychlorinated biphenyl (PCB) degrader, which utilizes biphenyl and naphthalene. A thermostable, Mn-dependent 2,3-dihydroxybiphenyl 1,2-dioxygenase, BphC_JF8, has been characterized previously. Upstream of bphC are five ORFs exhibiting low homology with, and a different gene order from, previously characterized bph genes. From the 59 to 39 direction the genes are: a putative regulatory gene (bphR), a hydrolase (bphD), the large and small subunits of a ring-hydroxylating dioxygenase (bphA1A2), and a cis-diol dehydrogenase (bphB). Hybridization studies indicate that the genes are located on a plasmid. Ring-hydroxylating activity of recombinant BphA1A2_JF8 towards biphenyl, PCB, naphthalene and benzene was observed in Escherichia coli cells, with complementation of non-specific ferredoxin and ferredoxin reductase by host cell proteins. PCB degradation by recombinant BphA1A2_JF8 showed that the congener specificity of the recombinant enzyme was similar to Bacillus sp. JF8. BphD_JF8, with an optimum temperature of 85 6C, exhibited a narrow substrate preference for 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid. The Arrhenius plot of BphD_JF8 was biphasic, with two characteristic energies of activation and a break point at 47 6C.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

bph genes of the thermophilic PCB degrader, Bacillus sp. JF8: characterization of the divergent ring-hydroxylating dioxygenase and hydrolase genes upstream of the Mn-dependent BphC

et al. 2005

View full text Add to dashboard Cite

show abstract

“…After 24 h of incubation, the 5-ml aliquot was extracted by ethyl acetate. PCBs recovered in the ethyl acetate layer were analyzed by GC-MS, as described previously (27). The percent degradation was calculated in comparison to heat-inactivated cells.…”

Section: Methodsmentioning

confidence: 99%

Novel Approach to the Improvement of Biphenyl and Polychlorinated Biphenyl Degradation Activity: Promoter Implantation by Homologous Recombination

Ohtsubo

Shimura

Delawary

et al. 2003

Appl Environ Microbiol

View full text Add to dashboard Cite

To improve the capabilities of microorganisms relevant for biodegradation, we developed a new genetic approach and applied it to the bph operon (bphEGF[orf4]A1A2A3CD[orf1]A4R) of Pseudomonas sp. strain KKS102 to enhance its biphenyl-and polychlorinated biphenyl (PCB)-degrading activity. A native promoter of the bph operon, which was under control, was replaced through homologous recombination by a series of promoters that had constitutive activity. By testing a series of promoters with various strengths, we were able to obtain strains that have enhanced degradation activity for biphenyl and PCBs. This strategy removes the rate-limiting factor associated with transcription and has the potential to improve the degradation activity of a wide variety of microorganisms involved in biodegradation.The use of microbial metabolic potential for elimination of environmental pollutants is a promising technology. Although various factors such as pathway enzyme specificity, substrate availability, incomplete degradation pathways, and the transcription and translation of genes for bioconversion can limit efficient biodegradation, genetic engineering can be used to overcome such factors and improve degradation (3,9,20,22,30).Among pollutants, polychlorinated biphenyls (PCBs) are the most serious pollutants, and their degradation by microorganisms has been studied extensively (9, 10). Pseudomonas sp. strain KKS102 is one of the well-characterized PCB and biphenyl degraders, and its bph gene organization, catabolic route, and regulatory mechanisms have been characterized. The bph genes are organized into an operon in the following order: bphEGF(orf4)A1A2A3CD(orf1) A4R (8, 13-15). The transcription of the bph operon is dependent on the pE promoter, which is located upstream of the bphE gene and is controlled by a negative regulator, BphS. The bphS gene is divergently orientated upstream of bphE and is separated from bphE by an insertion sequence (17). The repression mediated by BphS protein is counteracted by a meta-cleaved intermediate of biphenyl degradation (17,18).It is generally recognized that microorganisms can be genetically engineered to increase the rate of pollutant removal. The design of improved microorganisms includes various optimization strategies among which altering the level of transcription is a good target. In general, genes encoding catalytic activities are organized into an operon and transcription of the operon is under the control of activator(s) (6). Various efforts have been made to increase the level of transcription, e.g., creation of mutant regulators that mediate a higher level of transcription or recognize new substrates (2, 19, 21) and construction of plasmids or transposons that carry degradative genes under the control of constitutive promoters (11,16). The transcription level should be optimized through trials with a series of promoters of different strengths if we are to exclude the ratelimiting steps associated with transcription. It can be expected that application of too strong a promoter re...

show abstract

“…The whole genome sequence has been determined [17], showing that G. kaustophilus HTA426 harbors the circular plasmid pHTA426 (Figure 1). Because the members of the genus Geobacillus include strains that are useful for high-temperature processes, as demonstrated by strains that are capable of degrading hydrocarbons [18], long-chain alkanes [19][20][21], biphenyls [22], parain-wax [23], or nylons [24], we have studied biotechnological applications of the genus using G. kaustophilus HTA426 as a model and pilot strain.…”

Section: Archaea -New Biocatalysts Novel Pharmaceuticals and Variousmentioning

confidence: 99%

Plasmid Curing is a Promising Approach to Improve Thermophiles for Biotechnological Applications: Perspectives in Archaea

Mizuno¹,

Ohshiro²,

Suzuki³

2017

Archaea - New Biocatalysts, Novel Pharmaceuticals and Various Biotechnological Applications

View full text Add to dashboard Cite

Thermophiles are atractive as host cells for microbial processes to produce or degrade various compounds. In these applications, it is often desirable to improve the properties of thermophiles, such as their growth rate, cell density, and protein productivity, although this is rarely achieved because of the lack of general approaches. In this chapter, we describe the elimination of the pHTA426 plasmid from a moderate thermophile, Geobacillus kaustophilus HTA426, and its efects on the microbial properties. This process, called plasmid curing, was simply achieved using a DNA intercalator and conirmed by phenotypic and genotypic analyses. Of note, pHTA426 curing had beneicial efects on diverse properties, probably because of the reduced energy burden in terms of plasmid replication at high temperatures. The result suggests that plasmid curing is a simple and versatile approach for improving thermophiles. In particular, this approach may be efective for archaeal thermophiles because they grow at much higher temperatures and could have the greater energy burden on plasmid replication. Data mining has also shown that plasmids are distributed in archaeal thermophiles. This chapter provides a new tip for improving archaeal thermophiles, thereby increasing the opportunities for their use in various biotechnological applications.

show abstract

Isolation and characterization of a thermophilic Bacillus sp. JF8 capable of degrading polychlorinated biphenyls and naphthalene

Cited by 13 publications

References 17 publications

bph genes of the thermophilic PCB degrader, Bacillus sp. JF8: characterization of the divergent ring-hydroxylating dioxygenase and hydrolase genes upstream of the Mn-dependent BphC

bph genes of the thermophilic PCB degrader, Bacillus sp. JF8: characterization of the divergent ring-hydroxylating dioxygenase and hydrolase genes upstream of the Mn-dependent BphC

Novel Approach to the Improvement of Biphenyl and Polychlorinated Biphenyl Degradation Activity: Promoter Implantation by Homologous Recombination

Plasmid Curing is a Promising Approach to Improve Thermophiles for Biotechnological Applications: Perspectives in Archaea

Contact Info

Product

Resources

About