Transgenic Arabidopsis thaliana plants expressing bacterial γ-hexachlorocyclohexane dehydrochlorinase LinA.

Background: γ-Hexachlorocyclohexane (γ-HCH), an organochlorine insecticide of anthropogenic origin, is a persistent organic pollutant (POP) that causes environmental pollution concerns worldwide. Although many γ-HCH-degrading bacterial strains are available, inoculating them directly into γ-HCH-contaminated soil is ineffective because of the low survival rate of the exogenous bacteria. Another strategy for the bioremediation of γ-HCH involves the use of transgenic plants expressing bacterial enzyme for γ-HCH degradation through phytoremediation.

Increase of secondary metabolites in sweet basil (Ocimum basilicum L.) leaves by exposure to NO with plasma technology.

Exposure to NO generated by plasma technology activates immunity in Arabidopsis through tryptophan metabolites. However, little is known about the effects of NO exposure on other plant species. Sweet basil synthesizes many valuable secondary metabolites in its leaves.

Possible involvement of zinc transporter ZIP13 in myogenic differentiation.

Ehlers-Danlos syndrome spondylodysplastic type 3 (EDSSPD3, OMIM 612350) is an inherited recessive connective tissue disorder that is caused by loss of function of SLC39A13/ZIP13, a zinc transporter belonging to the Slc39a/ZIP family. We previously reported that patients with EDSSPD3 harboring a homozygous loss of function mutation (c.221G > A, p.

Clamping-mediated incorporation of single-stranded DNA with concomitant DNA synthesis by Taq polymerase involves nick-translation.

The development and characterization of a new enzyme reaction contribute to advancements in modern biotechnology. Here, we report a novel CIS (clamping-mediated incorporation of single-stranded DNA with concomitant DNA synthesis) reaction catalyzed by Taq polymerase. In the reaction, a single-stranded DNA (ssDNA) with 3' Cs is attached with a preformed 3' G-tail of double-stranded DNA (dsDNA); DNA syntheses starting from both 3' ends result in the incorporation of ssDNA.

Draft genome sequence of sp. strain TKC, isolated from a γ-hexachlorocyclohexane-degrading community.

sp. strain TKC was isolated from a microbial community enriched with γ-hexachlorocyclohexane (γ-HCH). This strain did not show γ-HCH-degrading activity but was one of the major members of the community.

Degradation of DDT by γ-hexachlorocyclohexane dehydrochlorinase LinA.

1,1,1-Trichloro-2,2-bis(4-chlorophenyl)-ethane (DDT) is the first synthetic insecticide and one of the most widely used pesticides. The use of DDT has been banned, but it remains one of the most notorious environmental pollutants around the world. In this study, we found that γ-hexachlorocyclohexane (γ-HCH) dehydrochlorinase LinA from a γ-HCH-degrading bacterium, Sphingobium japonicum UT26, converts DDT to 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethylene (DDE).

Host range of strand-biased circularizing integrative elements: a new class of mobile DNA elements nesting in Gammaproteobacteria.

Background: The strand-biased circularizing integrative elements (SEs) are putatively non-mobilizable integrative elements for transmitting antimicrobial resistance genes. The transposition mode and the prevalence of SEs in prokaryotes remain vague.

Results: To corroborate the transposition mode and the prevalence of SEs, hypothetical transposition intermediates of an SE were searched for in genomic DNA fractions of an SE host.

Reconstruction of a Soil Microbial Network Induced by Stress Temperature.

The microbial community is viewed as a network of diverse microorganisms connected by various interspecific interactions. While the stress gradient hypothesis (SGH) predicts that positive interactions are favored in more stressful environments, the prediction has been less explored in complex microbial communities due to the challenges of identifying interactions. Here, by applying a nonlinear time series analysis to the amplicon-based diversity time series data of the soil microbiota cultured under less stressful (30°C) or more stressful (37°C) temperature conditions, we show how the microbial network responds to temperature stress.

Algorisms used for in silico finishing of bacterial genomes based on short-read assemblage implemented in GenoFinisher, AceFileViewer, and ShortReadManager.

In these days, for bacterial genome sequence determination, ultralong reads with homopolymeric troubles are used in combinations with short reads, resulting in genomic sequences with possible incorrect uniformity of repeat sequences. We have been determining complete bacterial genomic sequences based on NGS short reads and Newbler assemblage by utilizing functions implemented in 3 software GenoFinisher, AceFileViewer, and ShortReadManager without conducting additional experiments for gap closing, proving the concept that NGS short reads enclose enough information to determine complete genome sequences. Although some manual in silico tasks are to be conducted, they will ultimately be solved in a single pipeline.

Genome evolution related to γ-hexachlorocyclohexane metabolic function in the soil microbial population.

γ-Hexachlorocyclohexane (γ-HCH)-degrading strain, Sphingobium sp. TA15, was newly isolated from an experimental field soil from which the archetypal γ-HCH-degrading strain, S. japonicum UT26, was isolated previously.

Microbial communities developing within bulk sediments under fish carcasses on a tidal flat.

Animal carcasses are often brought into tidal flats where they are at the boundary between terrestrial and marine ecosystems. Since these carcasses act as microhabitats with large amounts of energy and nutrients, they likely develop unique bacterial assemblages in the ambient sediment, which in turn may stimulate colonization of other organisms such as protozoans. However, little is known about the microbial assemblages colonized in sediment around animal carcasses in the tidal zone.

A transcriptional regulator, IscR, of Burkholderia multivorans acts as both repressor and activator for transcription of iron-sulfur cluster-biosynthetic isc operon.

Bacterial iron-sulfur (Fe-S) clusters are essential cofactors for many metabolic pathways, and Fe-S cluster-containing proteins (Fe-S proteins) regulate the expression of various important genes. However, biosynthesis of such clusters has remained unknown in genus Burkholderia. Here, we clarified that Burkholderia multivorans ATCC 17616 relies on the ISC system for the biosynthesis of Fe-S clusters, and that the biosynthetic genes are organized as an isc operon, whose first gene encodes IscR, a transcriptional regulatory Fe-S protein.

Transcriptome Analysis of Zygotic Induction During Conjugative Transfer of Plasmid RP4.

Conjugative transfer of bacterial plasmid is one of the major mechanisms of horizontal gene transfer, which is mediated by direct contact between donor and recipient cells. Gene expression of a conjugative plasmid is tightly regulated mostly by plasmid-encoded transcriptional regulators, but it remains obscure how differently plasmid genes are expressed in each cell during the conjugation event. Here, we report a comprehensive analysis of gene expression during conjugative transfer of plasmid RP4, which is transferred between isogenic strains of KT2440 at very high frequency.

Structural and catalytic effects of surface loop-helix transplantation within haloalkane dehalogenase family.

Engineering enzyme catalytic properties is important for basic research as well as for biotechnological applications. We have previously shown that the reshaping of enzyme access tunnels via the deletion of a short surface loop element may yield a haloalkane dehalogenase variant with markedly modified substrate specificity and enantioselectivity. Here, we conversely probed the effects of surface loop-helix transplantation from one enzyme to another within the enzyme family of haloalkane dehalogenases.

Long-term changes and effect of pterygium size on corneal topographic irregularity after recurrent pterygium surgery.

This retrospective observational study compared long-term topographic changes after recurrent- and primary-pterygium surgery depending on pterygium size. Patients who underwent recurrent-pterygium excision between 2002-2013 and age, sex, and pterygium size-matched controls who underwent primary-pterygium surgery were included (33 eyes of 33 patients in each group). Pterygium size was graded per advancing edge position: <1/3 of corneal diameter (grade 1), outside the pupil (grade 2), and within the pupillary area (grade 3).

Expression of an alcohol dehydrogenase gene in a heterotrophic bacterium induces carbon dioxide-dependent high-yield growth under oligotrophic conditions.

strain UT26, whose γ-hexachlorocyclohexane-degrading ability has been studied in detail, is a typical aerobic and heterotrophic bacterium that needs organic carbon sources for its growth, and cannot grow on a minimal salt agar medium prepared without adding any organic carbon sources. Here, we isolated a mutant of UT26 with the ability to grow to visible state on such an oligotrophic medium from a transposon-induced mutant library. This high-yield growth under oligotrophic conditions (HYGO) phenotype was CO-dependent and accompanied with CO incorporation.

Special Issue: Microbial Degradation of Xenobiotics.

Xenobiotics are released into the environment by human activities, and they often cause problems such as environmental pollution, since most such compounds cannot be readily degraded, and have harmful effects on human beings and the natural ecosystem [...

Properties and efficient scrap-and-build repairing of mechanically sheared 3' DNA ends.

Repairing of DNA termini is a crucial step in a variety of DNA handling techniques. In this study, we investigated mechanically-sheared DNA 3'-ends (MSD3Es) to establish an efficient repair method. As opposed to the canonical view of DNA terminus generated by sonication, we showed that approximately 47% and 20% of MSD3Es carried a phosphate group and a hydroxyl group, respectively.

Conjugative Transfer of IncP-9 Catabolic Plasmids Requires a Previously Uncharacterized Gene, , Whose Homologs Are Conserved in Various MPF-Type Plasmids.

Conjugative transfer of bacterial plasmids to recipient cells is often mediated by type IV secretion machinery. Experimental investigations into the minimal gene sets required for efficient conjugative transfer suggest that such gene sets are variable, depending on plasmids. We have been analyzing the conjugative transfer of -derived and IncP-9 plasmids, NAH7 and pWW0, whose conjugation systems belong to the MPF type.

Lessons from the genomes of lindane-degrading sphingomonads.

Bacterial strains capable of degrading man-made xenobiotic compounds are good materials to study bacterial evolution towards new metabolic functions. Lindane (γ-hexachlorocyclohexane, γ-HCH, or γ-BHC) is an especially good target compound for the purpose, because it is relatively recalcitrant but can be degraded by a limited range of bacterial strains. A comparison of the complete genome sequences of lindane-degrading sphingomonad strains clearly demonstrated that (i) lindane-degrading strains emerged from a number of different ancestral hosts that have recruited lin genes encoding enzymes that are able to channel lindane to central metabolites, (ii) in sphingomonads lin genes have been acquired by horizontal gene transfer mediated by different plasmids and in which IS6100 plays a role in recruitment and distribution of genes, and (iii) IS6100 plays a role in dynamic genome rearrangements providing genetic diversity to different strains and ability to evolve to other states.

Suppression of substrate inhibition in phenanthrene-degrading Mycobacterium by co-cultivation with a non-degrading Burkholderia strain.

In natural environments contaminated by recalcitrant organic pollutants, efficient biodegradation of such pollutants has been suggested to occur through the cooperation of different bacterial species. A phenanthrene-degrading bacterial consortium, MixEPa4, from polluted soil was previously shown to include a phenanthrene-degrading strain, Mycobacterium sp. EPa45, and a non-polycyclic aromatic hydrocarbon (PAH)-degrading strain, Burkholderia sp.

Optimization of single strand DNA incorporation reaction by Moloney murine leukaemia virus reverse transcriptase.

In this study, we investigated CIS reaction (clamping-mediated incorporation of single-stranded DNA with concomitant DNA syntheses) of Moloney murine leukaemia virus reverse transcriptase (MMLV-RT), and established a set of conditions with which single-stranded DNA is ligated to a G-tailed model substrate DNA at efficiencies close to 100%. Prior to the CIS reaction, a target blunt-end DNA was 3' G-tailed by MMLV-RT in the presence of a tailing enhancer, deoxycytidine. In the CIS reaction, the G-tail reacted with a single-stranded DNA carrying a stretch of Cs on its 3' end (termed as GAO for guide adaptor oligonucleotide), and MMLV-RT performed DNA polymerization, starting from the 3' overhang, using the GAO as a template.

Establishment of plasmid vector and allelic exchange mutagenesis systems in a mycobacterial strain that is able to degrade polycyclic aromatic hydrocarbon.

Plasmid vector and allelic exchange mutagenesis systems were established for the genetic analysis of a phenanthrene-degrading mycobacterial strain, Mycobacterium sp. EPa45. Successful application of these systems revealed the necessity of the EPa45 phdI gene for the degradation of 1-hydroxy-2-naphthoate, which has been proposed to be an intermediate product in the degradation pathway of phenanthrene.