bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of Methods for Detection of
Erysipelothrix
spp. and Their Distribution in Some Australasian Seafoods
Authors: Fidalgo S. G. , Wang Q. , Riley T. V. 
Published: July 2002

ABSTRACT

For many years,
Erysipelothrix rhusiopathiae
has been known to be the causative agent of the occupationally related infection erysipeloid. A survey of the distribution of
Erysipelothrix
spp. in 19 Australasian seafoods was conducted, and methodologies for the detection of
Erysipelothrix
spp. were evaluated. Twenty-one
Erysipelothrix
spp. were isolated from 52 seafood parts. Primary isolation of
Erysipelothrix
spp. was most efficiently achieved with brain heart infusion broth enrichment followed by subculture onto a selective brain heart infusion agar containing kanamycin, neomycin, and vancomycin after 48 h of incubation. Selective tryptic soy broth, with 48 h of incubation, was the best culture method for the detection of
Erysipelothrix
spp. with PCR. PCR detection was 50% more sensitive than culture.
E. rhusiopathiae
was isolated from a variety of different fish, cephalopods, and crustaceans, including a Western rock lobster (
Panulirus cygnus
). There was no significant correlation between the origin of the seafoods tested and the distribution of
E. rhusiopathiae
. An organism indistinguishable from
Erysipelothrix tonsillarum
was isolated for the first time from an Australian oyster and a silver bream. Overall,
Erysipelothrix
spp. were widely distributed in Australasian seafoods, illustrating the potential for erysipeloid-like infections in fishermen.
Identification of 16S Ribosomal DNA-Defined Bacterial Populations at a Shallow Submarine Hydrothermal Vent near Milos Island (Greece)
Authors: Sievert Stefan M. , Kuever Jan , Muyzer Gerard 
Published: July 2002

ABSTRACT

In a recent publication (S. M. Sievert, T. Brinkhoff, G. Muyzer, W. Ziebis, and J. Kuever, Appl. Environ. Microbiol. 65:3834–3842, 1999) we described spatiotemporal changes in the bacterial community structure at a shallow-water hydrothermal vent in the Aegean Sea near the isle of Milos (Greece). Here we describe identification and phylogenetic analysis of the predominant bacterial populations at the vent site and their distribution at the vent site as determined by sequencing of DNA molecules (bands) excised from denaturing gradient gels. A total of 36 bands could be sequenced, and there were representatives of eight major lineages of the domain
Bacteria. Cytophaga-Flavobacterium
and
Acidobacterium
were the most frequently retrieved bacterial groups. Less than 33% of the sequences exhibited 90% or more identity with cultivated organisms. The predominance of putative heterotrophic populations in the sequences retrieved is explained by the input of allochthonous organic matter at the vent site.
Plasmid Transfer between
Bacillus thuringiensis
subsp.
israelensis
Strains in Laboratory Culture, River Water, and Dipteran Larvae
Authors: Thomas D. John I. , Morgan J. Alun W. , Whipps John M. , Saunders Jon R. 
Published: July 2002

ABSTRACT

Plasmid transfer between strains of
Bacillus thuringiensis
subsp.
israelensis
was studied under a range of environmentally relevant laboratory conditions in vitro, in river water, and in mosquito larvae. Mobilization of pBC16 was detected in vitro at a range of temperatures, pH values, and available water conditions, and the maximum transfer ratio was 10
−3
transconjugant per recipient under optimal conditions. Transfer of conjugative plasmid pXO16∷Tn
5401
was also detected under this range of conditions. However, a maximum transfer ratio of 1.0 transconjugant per recipient was attained, and every recipient became a transconjugant. In river water, transfer of pBC16 was not detected, probably as a result of the low transfer frequency for this plasmid and the formation of spores by the introduced donor and recipient strains. In contrast, transfer of plasmid pXO16∷Tn
5401
was detected in water, but at a lower transfer ratio (ca. 10
−2
transconjugant per donor). The number of transconjugants increased over the first 7 days, probably as a result of new transfer events between cells, since growth of both donor and recipient cells in water was not detected. Mobilization of pBC16 was not detected in killed mosquito larvae, but transfer of plasmid pXO16::Tn
5401
was evident, with a maximum rate of 10
−3
transconjugant per donor. The reduced transfer rate in insects compared to broth cultures may be accounted for by competition from the background bacterial population present in the mosquito gut and diet or by the maintenance of a large population of
B. thuringiensis
spores in the insects.
Simple Sequence Repeat Markers Distinguish among Morphotypes of
Sphaeropsis sapinea
Authors: Burgess Treena , Wingfield Michael J. , Wingfield Brenda W. 
Published: July 2002

ABSTRACT

Sphaeropsis sapinea
is a fungal endophyte of
Pinus
spp. that can cause disease following predisposition of trees by biotic or abiotic stresses. Four morphotypes of
S. sapinea
have been described from within the natural range of the fungus, while only one morphotype has been identified on exotic pines in the Southern Hemisphere. The aim of this study was to develop robust polymorphic markers that could be used in both taxonomic and population studies. Inter-short-sequence-repeat primers containing microsatellite sequences and degenerate anchors at the 5′ end were used to target microsatellite-rich areas in an
S. sapinea
isolate. PCR amplification using an annealing temperature of 49°C resulted in profiles containing 5 to 10 bands. These bands were cloned and sequenced, and new short-sequence-repeat (SSR) primer pairs were designed that flanked microsatellite-rich regions. Eleven polymorphic SSR markers were tested on 40 isolates of
S. sapinea
representing different morphotypes as well as on 2 isolates of the closely related species
Botryosphaeria obtusa
. The putative I morphotype was found to be identical to
B. obtusa
. Otherwise, the markers clearly distinguished the remaining three morphotypes and, furthermore, showed that the C morphotype was more closely related to the A than the B morphotype. The B morphotype was the most genetically diverse, and the isolates could be further divided based on their geographic origins. Sequencing of different alleles from each locus showed that the most polymorphic markers had mutations within a microsatellite sequence.
Effect of Introns and AT-Rich Sequences on Expression of the Bacterial Hygromycin B Resistance Gene in the Basidiomycete
Schizophyllum commune
Authors: Scholtmeijer Karin , Wösten Han A. B. , Springer Jan , Wessels Joseph G. H. 
Published: July 2002

ABSTRACT

Previously, it was shown that introns are required for efficient mRNA accumulation in
Schizophyllum commune
and that the presence of AT-rich sequences in the coding region of genes can result in truncation of transcripts in this homobasidiomycete. Here we show that intron-dependent mRNA accumulation and truncation of transcripts are two independent events that both affect expression of the bacterial hygromycin B resistance gene in
S. commune
.
Effect of Selenite on Growth and Protein Synthesis in the Phototrophic Bacterium
Rhodobacter sphaeroides
Authors: Bebien Magali , Chauvin Jean-Paul , Adriano Jean-Marc , Grosse Sandrine , Verméglio André 
Published: July 2002

ABSTRACT

The effect of selenite on the growth rate and protein synthesis has been investigated in
Rhodobacter sphaeroides
. This photosynthetic bacterium efficiently reduces selenite with intracellular accumulation under both dark aerobic and anaerobic photosynthetic conditions. Addition of 1 mM selenite under these two growth conditions does not affect the final cell density, although a marked slowdown in growth rate is observed under aerobic growth. The proteome analysis of selenite response by two-dimensional gel electrophoresis shows an enhanced synthesis of some chaperones, an elongation factor, and enzymes associated to oxidative stress. The induction of these antioxidant proteins confirms that the major toxic effect of selenite is the formation of reactive oxygen species during its metabolism. In addition, we show that one mutant unable to precipitate selenite, selected from a transposon library, is affected in the
smoK
gene. This encodes a constituent of a putative ABC transporter implicated in the uptake of polyols. This mutant is less sensitive to selenite and does not express stress proteins identified in the wild type in response to selenite. This suggests that the entry of selenite into the cytoplasm is mediated by a polyol transporter in
R. sphaeroides
.
Evidence for the Biosynthesis of Bryostatins by the Bacterial Symbiont “
Candidatus
Endobugula sertula” of the Bryozoan
Bugula neritina
Authors: Davidson S. K. , Allen S. W. , Lim G. E. , Anderson C. M. , Haygood M. G. 
Published: July 2002

ABSTRACT

The marine bryozoan,
Bugula neritina
, is the source of the bryostatins, a family of macrocyclic lactones with anticancer activity. Bryostatins have long been suspected to be bacterial products.
B. neritina
harbors the uncultivated gamma proteobacterial symbiont “
Candidatus
Endobugula sertula.” In this work several lines of evidence are presented that show that the symbiont is the most likely source of bryostatins. Bryostatins are complex polyketides similar to bacterial secondary metabolites synthesized by modular type I polyketide synthases (PKS-I). PKS-I gene fragments were cloned from DNA extracted from the
B. neritina-“E. sertula”
association, and then primers specific to one of these clones, KSa, were shown to amplify the KSa gene specifically and universally from total
B. neritina
DNA. In addition, a KSa RNA probe was shown to bind specifically to the symbiotic bacteria located in the pallial sinus of the larvae of
B. neritina
and not to
B. neritina
cells or to other bacteria. Finally,
B. neritina
colonies grown in the laboratory were treated with antibiotics to reduce the numbers of bacterial symbionts. Decreased symbiont levels resulted in the reduction of the KSa signal as well as the bryostatin content. These data provide evidence that the symbiont
E. sertula
has the genetic potential to make bryostatins and is necessary in full complement for the host bryozoan to produce normal levels of bryostatins. This study demonstrates that it may be possible to clone bryostatin genes from
B. neritina
directly and use these to produce bryostatins in heterologous host bacteria.
Diversity of Toxic and Nontoxic
Nodularia
Isolates (Cyanobacteria) and Filaments from the Baltic Sea
Authors: Laamanen Maria J. , Gugger Muriel F. , Lehtimäki Jaana M. , Haukka Kaisa , Sivonen Kaarina 
Published: July 2002

ABSTRACT

Cyanobacteria of the genus
Nodularia
form toxic blooms in brackish waters worldwide. In addition,
Nodularia
spp. are found in benthic, periphytic, and soil habitats. The majority of the planktic isolates produce a pentapeptide hepatotoxin nodularin. We examined the morphologic, toxicologic, and molecular characters of 18 nodularin-producing and nontoxic
Nodularia
strains to find appropriate markers for distinguishing the toxic strains from the nontoxic ones in field samples. After classical taxonomy, the examined strains were identified as
Nodularia
sp.,
Nodularia spumigena
,
N. baltica
,
N. harveyana
, and
N. sphaerocarpa
. Morphologic characters were ambiguous in terms of distinguishing between the toxic and the nontoxic strains. DNA sequences from the short 16S-23S rRNA internally transcribed spacer (ITS1-S) and from the phycocyanin operon intergenic spacer and its flanking regions (PC-IGS) were different for the toxic and the nontoxic strains. Phylogenetic analysis of the ITS1-S and PC-IGS sequences from strains identified as
N. spumigena,
and
N. baltica
, and
N. litorea
indicated that the division of the planktic
Nodularia
into the three species is not supported by the ITS1-S and PC-IGS sequences. However, the ITS1-S and PC-IGS sequences supported the separation of strains designated
N. harveyana
and
N. sphaerocarpa
from one another and the planktic strains.
Hae
III digestion of PCR amplified PC-IGS regions of all examined 186
Nodularia
filaments collected from the Baltic Sea produced a digestion pattern similar to that found in toxic isolates. Our results suggest that only one planktic
Nodularia
species is present in the Baltic Sea plankton and that it is nodularin producing.
Genetic and Functional Analysis of the
tbc
Operons for Catabolism of Alkyl- and Chloroaromatic Compounds in
Burkholderia
sp. Strain JS150
Authors: Kahng Hyung-Yeel , Malinverni Juliana C. , Majko Michelle M. , Kukor Jerome J. 
Published: July 2002

ABSTRACT

Burkholderia
sp. strain JS150 is able to metabolize a wide range of alkyl-and chloroaromatic hydrocarbons through multiple, apparently redundant catabolic pathways. Previous research has shown that strain JS150 is able to synthesize enzymes for multiple upper pathways as well as multiple lower pathways to accommodate variously substituted catechols that result from degradation of complex mixtures of monoaromatic compounds. We report here the genetic organization and functional characterization of a gene cluster, designated
tbc
(for toluene, benzene, and chlorobenzene utilization), which has been cloned as a 14.3-kb DNA fragment from strain JS150 into vector pRO1727. The cloned DNA fragment expressed in
Pseudomonas aeruginosa
PAO1c allowed the recombinant to grow on toluene or benzene and to transform chlorobenzene, trichloroethylene, phenol, and cresols. The
tbc
genes are organized into two divergently transcribed operons,
tbc1
and
tbc2
, each comprised of six open reading frames. Similarity searches of databases revealed that the
tbc1
and
tbc2
genes showed significant homology to multicomponent cresol and phenol hydroxylases and to toluene and benzene monooxygenases, respectively. Deletion mutagenesis and product analysis were used to demonstrate that
tbc2
plays a role in the initial catabolism of the unactivated alkyl- or chloroaromatic substrate and that the
tbc1
gene products play a role in the catabolism of the first metabolite that results from transformation of the initial substrate. Phylogenetic analysis was used to compare individual components of these
tbc
monooxygenases with similar sequences in the databases. These results provide further evidence for the existence of multiple, functionally redundant alkyl- and chloroaromatic monooxygenases in strain JS150.
Expression of a
Pseudomonas putida
Aminotransferase Involved in Lysine Catabolism Is Induced in the Rhizosphere
Authors: Espinosa-Urgel Manuel , Ramos Juan-Luis 
Published: July 2002

ABSTRACT

Using a transposon carrying a promoterless
lux
operon to generate transcriptional fusions by insertional mutagenesis, we have identified a
Pseudomonas putida
gene with increased expression in the presence of corn root exudates. Expression of the transcriptional fusion, induced by the amino acid lysine, was detected in
P
.
putida
in the rhizosphere of plants as well as in response to seed exudates. The mutant was unable to grow on lysine or δ-aminovalerate as carbon sources, which indicates that the affected function is involved in the pathway for lysine catabolism. However, the mutant strain grew with glutaric acid, the product of δ-aminovalerate metabolism via glutaric acid semialdehyde, as a C source. The translated sequence of the interrupted gene showed high levels of similarity with aminotransferases. These sets of data suggest that the product of this gene has δ-aminovalerate aminotransferase activity. This is the first direct genetic evidence correlating a DNA sequence with such activity in
Pseudomonadaceae
.
Cyt1Aa from
Bacillus thuringiensis
subsp.
israelensis
Is Toxic to the Diamondback Moth,
Plutella xylostella
, and Synergizes the Activity of Cry1Ac towards a Resistant Strain
Authors: Sayyed Ali H. , Crickmore Neil , Wright Denis J. 
Published: July 2002

ABSTRACT

The
Bacillus thuringiensis
subsp.
israelensis
cytolytic protein Cyt1Aa was found to be toxic to an insecticide-susceptible laboratory population of
Plutella xylostella
. Cry1Ac-resistant populations of
P. xylostella
showed various degrees of resistance to Cyt1Aa. Cyt1Aa/Cry1Ac mixtures showed a marked level of synergism in the Cry1Ac-resistant populations.
Characterization of Rhizobial Isolates of
Phaseolus vulgaris
by Staircase Electrophoresis of Low-Molecular-Weight RNA
Authors: Velázquez Encarna , Martı́nez-Romero Esperanza , Rodrı́guez-Navarro Dulce Nombre , Trujillo Martha E. , Daza Antonio , Mateos Pedro F. , Martı́nez-Molina Eustoquio , van Berkum Peter 
Published: July 2002

ABSTRACT

Low-molecular-weight (LMW) RNA molecules were analyzed to characterize rhizobial isolates that nodulate the common bean growing in Spain. Since LMW RNA profiles, determined by staircase electrophoresis, varied across the rhizobial species nodulating beans, we demonstrated that bean isolates recovered from Spanish soils presumptively could be characterized as
Rhizobium etli
,
Rhizobium gallicum
,
Rhizobium giardinii
,
Rhizobium leguminosarum
bv. viciae and bv. trifolii, and
Sinorhizobium fredii
.
Genetic Diversity of Pierce's Disease Strains and Other Pathotypes of
Xylella fastidiosa
Authors: Hendson Mavis , Purcell Alexander H. , Chen Deqiao , Smart Chris , Guilhabert Magalie , Kirkpatrick Bruce 
Published: July 2002

ABSTRACT

Strains of
Xylella fastidiosa
isolated from grape, almond, maple, and oleander were characterized by enterobacterial repetitive intergenic consensus sequence-, repetitive extragenic palindromic element (REP)-, and random amplified polymorphic DNA (RAPD)-PCR; contour-clamped homogeneous electric field (CHEF) gel electrophoresis; plasmid content; and sequencing of the 16S-23S rRNA spacer region. Combining methods gave greater resolution of strain groupings than any single method. Strains isolated from grape with Pierce's disease (PD) from California, Florida, and Georgia showed greater than previously reported genetic variability, including plasmid contents, but formed a cluster based on analysis of RAPD-PCR products,
Not
I and
Spe
I genomic DNA fingerprints, and 16S-23S rRNA spacer region sequence. Two groupings of almond leaf scorch (ALS) strains were distinguished by RAPD-PCR and CHEF gel electrophoresis, but some ALS isolates were clustered within the PD group. RAPD-PCR, CHEF gel electrophoresis, and 16S-23S rRNA sequence analysis produced the same groupings of strains, with RAPD-PCR resolving the greatest genetic differences. Oleander strains, phony peach disease (PP), and oak leaf scorch (OLS) strains were distinct from other strains. DNA profiles constructed by REP-PCR analysis were the same or very similar among all grape strains and most almond strains but different among some almond strains and all other strains tested. Eight of 12 ALS strains and 4 of 14 PD strains of
X. fastidiosa
isolated in California contained plasmids. All oleander strains carried the same-sized plasmid; all OLS strains carried the same-sized plasmid. A plum leaf scald strain contained three plasmids, two of which were the same sizes as those found in PP strains. These findings support a division of
X. fastidiosa
at the subspecies or pathovar level.
Community Structure of Denitrifiers,
Bacteria
, and
Archaea
along Redox Gradients in Pacific Northwest Marine Sediments by Terminal Restriction Fragment Length Polymorphism Analysis of Amplified Nitrite Reductase (
nirS
) and 16S rRNA Genes
Authors: Braker Gesche , Ayala-del-Rı́o Héctor L. , Devol Allan H. , Fesefeldt Andreas , Tiedje James M. 
Published: July 2002

ABSTRACT

Steep vertical gradients of oxidants (O
2
and NO
3
−
) in Puget Sound and Washington continental margin sediments indicate that aerobic respiration and denitrification occur within the top few millimeters to centimeters. To systematically explore the underlying communities of denitrifiers,
Bacteria
, and
Archaea
along redox gradients at distant geographic locations, nitrite reductase (
nirS
) genes and bacterial and archaeal 16S rRNA genes (rDNAs) were PCR amplified and analyzed by terminal restriction fragment length polymorphism (T-RFLP) analysis. The suitablility of T-RFLP analysis for investigating communities of
nirS
-containing denitrifiers was established by the correspondence of dominant terminal restriction fragments (T-RFs) of
nirS
to computer-simulated T-RFs of
nirS
clones. These clones belonged to clusters II, III, and IV from the same cores and were analyzed in a previous study (G. Braker, J. Zhou, L. Wu, A. H. Devol, and J. M. Tiedje, Appl. Environ. Microbiol. 66:2096–2104, 2000). T-RFLP analysis of
nirS
and bacterial rDNA revealed a high level of functional and phylogenetic diversity, whereas the level of diversity of
Archaea
was lower. A comparison of T-RFLPs based on the presence or absence of T-RFs and correspondence analysis based on the frequencies and heights of T-RFs allowed us to group sediment samples according to the sampling location and thus clearly distinguish Puget Sound and the Washington margin populations. However, changes in community structure within sediment core sections during the transition from aerobic to anaerobic conditions were minor. Thus, within the top layers of marine sediments, redox gradients seem to result from the differential metabolic activities of populations of similar communities, probably through mixing by marine invertebrates rather than from the development of distinct communities.
Cloning and Expression of a
Ralstonia eutropha
HF39 Gene Mediating Indigo Formation in
Escherichia coli
Authors: Drewlo Sascha , Brämer Christian O. , Madkour Mohamed , Mayer Frank , Steinbüchel Alexander 
Published: July 2002

ABSTRACT

On complex medium
Escherichia coli
strains carrying hybrid plasmid pBEC/EE:11.0, pSKBEC/BE:9.0, pSKBEC/PP:3.3, or pSKBEC/PP:2.4 harboring genomic DNA of
Ralstonia eutropha
HF39 produced a blue pigment characterized as indigo by several chemical and spectroscopic methods. A 1,251-bp open reading frame (
bec
) was cloned and sequenced. The deduced amino acid sequence of
bec
showed only weak similarities to short-chain acyl-coenzyme A dehydrogenases, and the gene product catalyzed formation of indoxyl, a reactive preliminary stage for production of indigo.
New Pulp Biobleaching System Involving Manganese Peroxidase Immobilized in a Silica Support with Controlled Pore Sizes
Authors: Sasaki Toshiya , Kajino Tsutomu , Li Bo , Sugiyama Hidehiko , Takahashi Haruo 
Published: July 2002

ABSTRACT

Attempts have been made to use manganese peroxidase (MnP) for chlorine-free pulp biobleaching, but they have not been commercially viable because of the enzyme's low stability. We developed a new pulp biobleaching method involving mesoporous material-immobilized manganese peroxidase from
Phanerochaete chrysosporium
. MnP immobilized in FSM-16, a folded-sheet mesoporous material whose pore size is nearly the same as the diameter of the enzyme, had the highest thermal stability and tolerance to H
2
O
2
. MnP immobilized in FSM-16 retained more than 80% of its initial activity even after 10 days of continuous reaction. We constructed a thermally discontinuous two-stage reactor system, in which the enzyme (39°C) and pulp-bleaching (70°C) reactions were performed separately. When the treatment of pulp with MnP by means of the two-stage reactor system and alkaline extraction was repeated seven times, the brightness of the pulp increased to about 88% within 7 h after completion of the last treatment.