bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Cellulase-Catalyzed Lignocellulosic Hydrolysis by Iron and Oxidative Metal Ions and Complexes
Authors: Tejirian Ani , Xu Feng
Published: October 2010

Enzymatic lignocellulose hydrolysis plays a key role in microbially driven carbon cycling and energy conversion and holds promise for bio-based energy and chemical industries. Cellulases (key lignocellulose-active enzymes) are prone to interference from various noncellulosic substances (e.g., metal ions). During natural cellulolysis, these substances may arise from other microbial activities or abiotic events, and during industrial cellulolysis, they may be derived from biomass feedstocks or upstream treatments. Knowledge about cellulolysis-inhibiting reactions is of importance for the microbiology of natural biomass degradation and the development of biomass conversion technology. Different metal ions, including those native to microbial activity or employed for biomass pretreatments, are often tested for enzymatic cellulolysis. Only a few metal ions act as inhibitors of cellulases, which include ferrous and ferric ions as well as cupric ion. In this study, we showed inhibition by ferrous/ferric ions as part of a more general effect from oxidative (or redox-active) metal ions and their complexes. The correlation between inhibition and oxidation potential indicated the oxidative nature of the inhibition, and the dependence on air established the catalytic role that iron ions played in mediating the dioxygen inhibition of cellulolysis. Individual cellulases showed different susceptibilities to inhibition. It is likely that the inhibition exerted its effect more on cellulose than on cellulase. Strong iron ion chelators and polyethylene glycols could mitigate the inhibition. Potential microbiological and industrial implications of the observed effect of redox-active metal ions on enzymatic cellulolysis, as well as the prevention and mitigation of this effect in industrial biomass conversion, are discussed.
Participation of Valine 171 in α-Helix 5 of
Bacillus thuringiensis
Cry1Ab δ-Endotoxin in Translocation of Toxin into
Lymantria dispar
Midgut Membranes
Authors: Alzate Oscar , Osorio Cristina , Florez Alvaro M. , Dean Donald H.
Published: October 2010

The Cry1Ab δ-endotoxin V171C mutant protein exhibits a 25-fold increase in toxicity against
Lymantria dispar
, which correlates with a faster rate of partitioning into the midgut membrane and slightly decreased protein stability. This is an insect-specific mechanism; similar results were not observed in
Manduca sexta
, another Cry1Ab δ-endotoxin-susceptible insect.
Comparison of the Pathogenic Potentials of Environmental and Clinical
Vibrio parahaemolyticus
Strains Indicates a Role for Temperature Regulation in Virulence
Authors: Mahoney Jennifer C. , Gerding Matthew J. , Jones Stephen H. , Whistler Cheryl A.
Published: October 2010

Although the presence of pathogenic
Vibrio
spp. in estuarine environments of northern New England has been known for some time (C. H. Bartley and L. W. Slanetz, Appl. Microbiol. 21: 965-966, 1971, and K. R. O'Neil, S. H. Jones, and D. J. Grimes, FEMS Microbiol. Lett. 60:163-167, 1990), their virulence and the relative threat they may pose to human health has yet to be evaluated. In this study, the virulence potential of 33
Vibrio parahaemolyticus
isolates collected from the Great Bay Estuary of New Hampshire was assessed in comparison to that of clinical strains. The environmental isolates lack thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH), which are encoded by
tdh
and
trh
, respectively. Though not hemolytic, they do possess putative virulence factors, such type III secretion system 1, and are highly cytotoxic to human gastrointestinal cells. The expression of known and putative virulence-associated traits, including hemolysin, protease, motility, biofilm formation, and cytotoxicity, by clinical reference isolates correlated with increased temperature from 28°C to 37°C. In contrast, the environmental isolates did not induce their putative virulence-associated traits in response to a temperature of 37°C. We further identified a significant correlation between hemolytic activity and growth phase among clinical strains, whereby hemolysin production decreases with increasing cell density. The introduction of a
tdh
::
gfp
promoter fusion into the environmental strains revealed that they regulate this virulence-associated gene appropriately in response to temperature, indicating that their existing regulatory mechanisms are primed to manage newly acquired virulence genes.
Increased Ethanol Productivity in Xylose-Utilizing
Saccharomyces cerevisiae
via a Randomly Mutagenized Xylose Reductase
Authors: Runquist David , Hahn-Hägerdal Bärbel , Bettiga Maurizio
Published: October 2010

Baker's yeast (
Saccharomyces cerevisiae
) has been genetically engineered to ferment the pentose sugar xylose present in lignocellulose biomass. One of the reactions controlling the rate of xylose utilization is catalyzed by xylose reductase (XR). In particular, the cofactor specificity of XR is not optimized with respect to the downstream pathway, and the reaction rate is insufficient for high xylose utilization in
S. cerevisiae.
The current study describes a novel approach to improve XR for ethanol production in
S. cerevisiae
. The cofactor binding region of XR was mutated by error-prone PCR, and the resulting library was expressed in
S. cerevisiae
. The
S. cerevisiae
library expressing the mutant XR was selected in sequential anaerobic batch cultivation. At the end of the selection process, a strain (TMB 3420) harboring the XR mutations N272D and P275Q was enriched from the library. The
V
max
of the mutated enzyme was increased by an order of magnitude compared to that of the native enzyme, and the NADH/NADPH utilization ratio was increased significantly. The ethanol productivity from xylose in TMB 3420 was increased ∼40 times compared to that of the parent strain (0.32 g/g [dry weight {DW}] × h versus 0.007 g/g [DW] × h), and the anaerobic growth rate was increased from ∼0 h
−1
to 0.08 h
−1
. The improved traits of TMB 3420 were readily transferred to the parent strain by reverse engineering of the mutated XR gene. Since integrative vectors were employed in the construction of the library, transfer of the improved phenotype does not require multicopy expression from episomal plasmids.
Importance of SigB for
Listeria monocytogenes
Static and Continuous-Flow Biofilm Formation and Disinfectant Resistance
Authors: van der Veen Stijn , Abee Tjakko
Published: October 2010

Listeria monocytogenes
is a food-borne pathogen that is able to form biofilms in food processing facilities. Biofilms are generally more resistant to antimicrobial agents, making it difficult to eradicate them during cleanup procedures. So far, little is known about the function of stress resistance mechanisms in biofilm formation and their resistance to disinfectants. In this study, we investigated the role of
sigB
, which encodes a major transcriptional regulator of stress response genes, in
L. monocytogenes
static and continuous-flow biofilm formation and its function in the resistance of biofilm cells to the disinfectants benzalkonium chloride and peracetic acid. Quantitative real-time PCR and promoter reporter studies showed that
sigB
is activated in static and continuous-flow biofilms. Biofilm formation studies using an in-frame
sigB
deletion mutant and complementation mutant showed that the presence of SigB is required to obtain wild-type levels of both static and continuous-flow biofilms. Finally, disinfection treatments of planktonically grown cells and cells dispersed from static and continuous-flow biofilms showed that SigB is involved in the resistance of both planktonic cells and biofilms to the disinfectants benzalkonium chloride and peracetic acid.
Quantification of the Emetic Toxin Cereulide in Food Products by Liquid Chromatography-Mass Spectrometry Using Synthetic Cereulide as a Standard
Authors: Biesta-Peters Elisabeth G. , Reij Martine W. , Blaauw Richard H. , in ′t Veld Paul H. , Rajkovic Andreja , Ehling-Schulz Monika , Abee Tjakko
Published: October 2010

Bacillus cereus
produces the emetic toxin cereulide, a cyclic dodecadepsipeptide that can act as a K
+
ionophore, dissipating the transmembrane potential in mitochondria of eukaryotic cells. Because pure cereulide has not been commercially available, cereulide content in food samples has been expressed in valinomycin equivalents, a highly similar cyclic potassium ionophore that is commercially available. This research tested the biological activity of synthetic cereulide and validated its use as a standard in the quantification of cereulide contents in food samples. The synthesis route consists of 10 steps that result in a high yield of synthetic cereulide that showed biological activity in the HEp-2 cell assay and the boar sperm motility assay. The activity is different in both methods, which may be attributed to differences in K
+
content of the test media used. Using cereulide or valinomycin as a standard to quantify cereulide based on liquid chromatography-mass spectrometry (LC-MS), the concentration determined with cereulide as a standard was on average 89.9% of the concentration determined using valinomycin as a standard. The recovery experiments using cereulide-spiked food products and acetonitrile as extraction solute showed that the LC-MS method with cereulide as a standard is a reliable and accurate method to quantify cereulide in food, because the recovery rate was close to 100% over a wide concentration range.
Surface Display of a Functional Minicellulosome by Intracellular Complementation Using a Synthetic Yeast Consortium and Its Application to Cellulose Hydrolysis and Ethanol Production
Authors: Tsai Shen-Long , Goyal Garima , Chen Wilfred
Published: October 2010

In this paper, we report the surface assembly of a functional minicellulosome by using a synthetic yeast consortium. The basic design of the consortium consisted of four different engineered yeast strains capable of either displaying a trifunctional scaffoldin, Scaf-ctf (SC), carrying three divergent cohesin domains from
Clostridium thermocellum
(t),
Clostridium cellulolyticum
(c), and
Ruminococcus flavefaciens
(f), or secreting one of the three corresponding dockerin-tagged cellulases (endoglucanase [AT], exoglucanase [EC/CB], or β-glucosidase [BF]). The secreted cellulases were docked onto the displayed Scaf-ctf in a highly organized manner based on the specific interaction of the three cohesin-dockerin pairs employed, resulting in the assembly of a functional minicellulosome on the yeast surface. By exploiting the modular nature of each population to provide a unique building block for the minicellulosome structure, the overall cellulosome assembly, cellulose hydrolysis, and ethanol production were easily fine-tuned by adjusting the ratio of different populations in the consortium. The optimized consortium consisted of a SC:AT:CB:BF ratio of 7:2:4:2 and produced almost twice the level of ethanol (1.87 g/liter) as a consortium with an equal ratio of the different populations. The final ethanol yield of 0.475 g of ethanol/g of cellulose consumed also corresponded to 93% of the theoretical value. This result confirms the use of a synthetic biology approach for the synergistic saccharification and fermentation of cellulose to ethanol by using a yeast consortium displaying a functional minicellulosome.
Selectivity of Fungal Sesquiterpene Synthases: Role of the Active Site's H-1α Loop in Catalysis
Authors: López-Gallego Fernando , Wawrzyn GraysonT. , Schmidt-Dannert Claudia
Published: October 2010

Sesquiterpene synthases are responsible for the cyclization of farnesyl pyrophosphate into a myriad of structurally diverse compounds with various biological activities. We examine here the role of the conserved active site H-α1 loop in catalysis in three previously characterized fungal sesquiterpene synthases. The H-α1 loops of Cop3, Cop4, and Cop6 from
Coprinus cinereus
were altered by site-directed mutagenesis and the resultant product profiles were analyzed by gas chromatography-mass spectrometry and compared to the wild-type enzymes. In addition, we examine the effect of swapping the H-α1 loop from the promiscuous enzyme Cop4 with the more selective Cop6 and the effect of acidic or basic conditions on loop mutations in Cop4. Directed mutations of the H-α1 loop had a marked effect on the product profile of Cop3 and Cop4, while little to no change was shown in Cop6. Swapping of the Cop4 and Cop6 loops with one another was again shown to influence the product profile of Cop4, while the product profile of Cop6 remained identical to the wild-type enzyme. The loop mutations in Cop4 also implicate specific residues responsible for the pH sensitivity of the enzyme. These results affirm the role of the H-α1 loop in catalysis and provide a potential target to increase the product diversity of terpene synthases.
Nod1 and Nod2 Regulation of Inflammation in the
Salmonella
Colitis Model
Authors: Geddes Kaoru , Rubino Stephen , Streutker Catherine , Cho Joon Ho , Magalhaes Joao G. , Le Bourhis Lionel , Selvanantham Thirumahal , Girardin Stephen E. , Philpott Dana J.
Published: October 2010

The pattern recognition molecules Nod1 and Nod2 play important roles in intestinal homeostasis; however, how these proteins impact on the development of inflammation during bacterial colitis has not been examined. In the streptomycin-treated mouse model of
Salmonella
colitis, we found that mice deficient for both Nod1 and Nod2 had attenuated inflammatory pathology, reduced levels of inflammatory cytokines, and increased colonization of the mucosal tissue. Nod1 and Nod2 from both hematopoietic and nonhematopoietic sources contributed to the pathology, and all phenotypes were recapitulated in mice deficient for the signaling adaptor protein Rip2. However, the influence of Rip2 was strictly dependent on infection conditions that favored expression of the
Salmonella
pathogenicity island 2 (SPI-2) type III secretion system (TTSS), as Rip2 was dispensable for inflammation when mice were infected with bacteria grown under conditions that promoted expression of the SPI-1 TTSS. Thus, Nod1 and Nod2 can modulate inflammation and mediate efficient clearance of bacteria from the mucosal tissue during
Salmonella
colitis, but their role is dependent on the expression of the SPI-2 TTSS.
Counterclockwise Circular Motion of Bacteria Swimming at the Air-Liquid Interface
Authors: Lemelle Laurence , Palierne Jean-François , Chatre Elodie , Place Christophe
Published: October 2010

Flagellar propulsion of swimming
Escherichia coli
produces circling clockwise motions near planar solid surfaces. Counterclockwise motion was first reported near air-TN medium interfaces, showing that slip at the interface is a key parameter of bacterial swimming.
Repression of
sigK
Intervening (
skin
) Element Gene Expression by the CI-Like Protein SknR and Effect of SknR Depletion on Growth of
Bacillus subtilis
Cells
Authors: Kimura Tatsu , Amaya Yukie , Kobayashi Kazuo , Ogasawara Naotake , Sato Tsutomu
Published: October 2010

The
Bacillus subtilis
phage DNA-like
sigK
intervening (
skin
) element (48 kb) is excised from the chromosome by DNA rearrangement, and a composite gene,
sigK
(
spoIIIC
and
spoIVCB
), is created on the chromosome during sporulation. In this study, we first focused on the role of
sknR
(
skin
repressor), which has homology with the gene encoding the Xre repressor of defective phage PBSX. The depletion of SknR caused overexpression of the region between
yqaF
and
yqaN
(the
yqaF-yqaN
operon) and a growth defect in
B. subtilis
. Point mutation analysis and an electrophoretic mobility shift assay (EMSA) suggested that SknR functions as a negative regulator of gene expression in the
yqaF-yqaN
operon of the
skin
element through direct interaction with operators of 2-fold symmetry located in the intergenic region between
sknR
and
yqaF
. Deletion analysis revealed that the lethal effect of depletion of SknR was related to overexpression of
yqaH
and
yqaM
, whose products were previously reported to associate with DnaA and DnaC, respectively. Furthermore, overexpression of either
yqaH
or
yqaM
caused cell filamentation and abnormal chromosome segregation, which suggested that overproduction of these proteins inhibits DNA replication. Moreover, overexpression of
yqaM
inhibited the initiation of replication. Taken together, these data demonstrate that the
B. subtilis skin
element carries lethal genes, which are induced by the depletion of
sknR
.
FliZ Regulates Expression of theSalmonellaPathogenicity Island 1 Invasion Locus by Controlling HilD Protein Activity inSalmonella entericaSerovar Typhimurium
Authors: Chubiz Jessica E. Cott , Golubeva Yekaterina A. , Lin Dongxia , Miller Lucas D. , Slauch James M.
Published: October 2010

A prerequisite forSalmonella entericato cause both intestinal and systemic disease is the direct injection of effector proteins into host intestinal epithelial cells via a type three secretion system (T3SS); the T3SS genes are carried onSalmonellapathogenicity island 1 (SPI1). These effector proteins induce inflammatory diarrhea and bacterial invasion. Expression of the SPI1 T3SS is tightly regulated in response to environmental signals through a variety of global regulatory systems. We have previously shown that three AraC-like regulators, HilD, HilC, and RtsA, act in a complex feed-forward regulatory loop to control the expression of thehilAgene, which encodes the direct regulator of the SPI1 structural genes. In this work, we characterize a major positive regulator of this system, the flagellar protein FliZ. Through genetic and biochemical analyses, we show that FliZ posttranslationally controls HilD to positively regulatehilAexpression. This mechanism is independent of other flagellar components and is not mediated through the negative regulator HilE or through FliZ-mediated RpoS regulation. We demonstrate that FliZ controls HilD protein activity and not stability. FliZ regulates HilD in the absence of Lon protease, previously shown to degrade HilD. Indeed, it appears that FliZ, rather than HilD, is the most relevant target of Lon as it relates to SPI1 expression. Mutants lacking FliZ are significantly attenuated in their ability to colonize the intestine but are unaffected during systemic infection. The intestinal attenuation is partially dependent on SPI1, but FliZ has additional pleiotropic effects.
MzrA-EnvZ Interactions in the Periplasm Influence the EnvZ/OmpR Two-Component Regulon
Authors: Gerken Henri , Misra Rajeev
Published: October 2010

MzrA was identified as a modulator of the EnvZ/OmpR two-component signal transduction system. Previous evidence indicated that MzrA interacts with EnvZ and modulates its enzymatic activities to influence OmpR phosphate (OmpR∼P) levels. Moreover, MzrA was shown to connect the bacterial envelope stress response systems CpxA/CpxR and σ
E
to EnvZ/OmpR to widen the defensive response regulatory network. In this study, experiments were carried out to establish whether the membrane or periplasmic domain of MzrA is critical for MzrA-EnvZ interactions and to reveal MzrA residues that play an important role in these interactions. Data obtained from chimeric constructs, in which the transmembrane domain of MzrA was replaced with the unrelated transmembrane domain of NarX or signal sequence of PhoA, showed that the transmembrane domain residues of MzrA do not play a critical role in MzrA-EnvZ interactions. The importance of the periplasmic domain of MzrA in MzrA-EnvZ interactions was revealed by characterizing bifunctional, fully soluble, and periplasmically localized MalE::MzrA chimeras. This was further corroborated through the isolation of loss-of-function, single-amino-acid substitutions in the conserved periplasmic domain of MzrA that interfered with MzrA-EnvZ binding in a bacterial two-hybrid system. Together, the data suggest that the binding of MzrA to EnvZ influences the ability of EnvZ to receive and/or respond to environmental signals in the periplasm and modulate its biochemical output to OmpR.
Draft Genome Sequence of
Streptomyces clavuligerus
NRRL 3585, a Producer of Diverse Secondary Metabolites
Authors: Song Ju Yeon , Jeong Haeyoung , Yu Dong Su , Fischbach Michael A. , Park Hong-Seog , Kim Jae Jong , Seo Jeong-Sun , Jensen Susan E. , Oh Tae Kwang , Lee Kye Joon , Kim Jihyun F.
Published: October 2010

Streptomyces clavuligerus
is an important industrial strain that produces a number of antibiotics, including clavulanic acid and cephamycin C. A high-quality draft genome sequence of the
S. clavuligerus
NRRL 3585 strain was produced by employing a hybrid approach that involved Sanger sequencing, Roche/454 pyrosequencing, optical mapping, and partial finishing. Its genome, comprising four linear replicons, one chromosome, and four plasmids, carries numerous sets of genes involved in the biosynthesis of secondary metabolites, including a variety of antibiotics.
Biologically Active Isoforms of CobB Sirtuin Deacetylase in
Salmonella enterica
and
Erwinia amylovora
Authors: Tucker Alex C. , Escalante-Semerena Jorge C.
Published: October 2010

Sirtuins are NAD
+
-dependent protein deacylases that are conserved in all domains of life and are involved in diverse cellular processes, including control of gene expression and central metabolism. Eukaryotic sirtuins have N-terminal extensions that have been linked to protein multimerization and cellular localization. Here the first evidence of sirtuin isoforms in bacteria is reported. The enterobacterium
Salmonella enterica
synthesizes two isoforms of CobB sirtuin, a shorter 236-amino-acid isoform (here CobB
S
) and a longer 273-amino-acid isoform (here CobB
L
). The N-terminal 37-amino-acid extension of CobB
L
is amphipathic, containing 18 basic amino acids (12 of which are Arg) and 13 hydrophobic ones; both isoforms were active
in vivo
and
in vitro
. Northern blot and transcription start site analyses revealed that
cobB
is primarily expressed as two monocistronic
cobB
mRNAs from two transcription start sites, one of which was mapped within the neighboring
ycfX
gene and the other of which was located within
cobB
. Additionally, a low-abundance
ycfX
-
cobB
bicistronic mRNA was observed which could encode up to three proteins (YcfX, CobB
L
, and CobB
S
). CobB
L
isoforms are common within the family
Enterobacteriaceae
, but species of the genus
Erwinia
(including the plant pathogen
Erwinia amylovora
) encode only the CobB
L
isoform. The CobB
L
isoform from
E. amylovora
restored growth of as
S. enterica cobB
mutant strain on low acetate.
The Opportunistic Human PathogenAcinetobacter baumanniiSenses and Responds to Light
Authors: Mussi María A. , Gaddy Jennifer A. , Cabruja Matías , Arivett Brock A. , Viale Alejandro M. , Rasia Rodolfo , Actis Luis A.
Published: October 2010

Light is a ubiquitous environmental signal that many organisms sense and respond to by modulating their physiological responses accordingly. While this is an expected response among phototrophic microorganisms, the ability of chemotrophic prokaryotes to sense and react to light has become a puzzling and novel issue in bacterial physiology, particularly among bacterial pathogens. In this work, we show that the opportunistic pathogenAcinetobacter baumanniisenses and responds to blue light. Motility and formation of biofilms and pellicles were observed only when bacterial cells were incubated in darkness. In contrast, the killing ofCandida albicansfilaments was enhanced when they were cocultured with bacteria under light. These bacterial responses depend on the expression of theA. baumanniiATCC 17978 A1S_2225 gene, which codes for an 18.6-kDa protein that contains an N-terminalblue-light-sensing-usingflavin (BLUF) domain and lacks a detectable output domain(s). Spectral analyses of the purified recombinant protein showed its ability to sense light by a red shift upon illumination. Therefore, the A1S_2225 gene, which is present in several members of theAcinetobactergenus, was namedblue-light-sensingA(blsA). Interestingly, temperature plays a role in the ability ofA. baumanniito sense and respond to light via the BlsA photoreceptor protein.
Characterization of a Novel Riboswitch-Regulated Lysine Transporter inAggregatibacter actinomycetemcomitans
Authors: Jorth Peter , Whiteley Marvin
Published: October 2010

Aggregatibacter actinomycetemcomitansis an opportunistic pathogen that resides primarily in the mammalian oral cavity. In this environment,A. actinomycetemcomitansfaces numerous host- and microbe-derived stresses, including intense competition for nutrients and exposure to the host immune system. While it is clear thatA. actinomycetemcomitansresponds to precise cues that allow it to adapt and proliferate in the presence of these stresses, little is currently known about the regulatory mechanisms that underlie these responses. Many bacteria use noncoding regulatory RNAs (ncRNAs) to rapidly alter gene expression in response to environmental stresses. Although no ncRNAs have been reported inA. actinomycetemcomitans, we propose that they are likely important for colonization and persistence in the oral cavity. Using a bioinformatic and experimental approach, we identified three putative metabolite-sensing riboswitches and nine small regulatory RNAs (sRNAs) inA. actinomycetemcomitansduring planktonic and biofilm growth. Molecular characterization of one of the riboswitches revealed that it is a lysine riboswitch and that its target gene,lysT, encodes a novel lysine-specific transporter. Finally, we demonstrated thatlysTand thelysTlysine riboswitch are conserved in over 40 bacterial species, including the phylogenetically related pathogenHaemophilus influenzae.
Sequencing of Multiple Clostridial Genomes Related to Biomass Conversion and Biofuel Production
Authors: Hemme Christopher L. , Mouttaki Housna , Lee Yong-Jin , Zhang Gengxin , Goodwin Lynne , Lucas Susan , Copeland Alex , Lapidus Alla , Glavina del Rio Tijana , Tice Hope , Saunders Elizabeth , Brettin Thomas , Detter John C. , Han Cliff S. , Pitluck Sam , Land Miriam L. , Hauser Loren J. , Kyrpides Nikos , Mikhailova Natalia , He Zhili , Wu Liyou , Van Nostrand Joy D. , Henrissat Bernard , He Qiang , Lawson Paul A. , Tanner Ralph S. , Lynd Lee R. , Wiegel Juergen , Fields Matthew W. , Arkin Adam P. , Schadt Christopher W. , Stevenson Bradley S. , McInerney Michael J. , Yang Yunfeng , Dong Hailiang , Xing Defeng , Ren Nanqi , Wang Aijie , Huhnke Raymond L. , Mielenz Jonathan R. , Ding Shi-You , Himmel Michael E. , Taghavi Safiyh , van der Lelie Daniël , Rubin Edward M. , Zhou Jizhong
Published: October 2010

Modern methods to develop microbe-based biomass conversion processes require a system-level understanding of the microbes involved. Clostridium species have long been recognized as ideal candidates for processes involving biomass conversion and production of various biofuels and other industrial products. To expand the knowledge base for clostridial species relevant to current biofuel production efforts, we have sequenced the genomes of 20 species spanning multiple genera. The majority of species sequenced fall within the class III cellulosome-encoding
Clostridium
and the class V saccharolytic
Thermoanaerobacteraceae
. Species were chosen based on representation in the experimental literature as model organisms, ability to degrade cellulosic biomass either by free enzymes or by cellulosomes, ability to rapidly ferment hexose and pentose sugars to ethanol, and ability to ferment synthesis gas to ethanol. The sequenced strains significantly increase the number of noncommensal/nonpathogenic clostridial species and provide a key foundation for future studies of biomass conversion, cellulosome composition, and clostridial systems biology.
Radiological oracle
Authors: Barnett Timothy P.
Published: October 2010

CLINICAL RADIOLOGY OF THE HORSE, 3rd edn Janet Butler, Christopher Colles, Sue Dyson, Svend Kold and Paul Poulos
Computer‐aided veterinary learning at the University of Cambridge
Authors: Holmes M. A. , Nicholls P. K.
Published: October 2010

An approach to computer‐assisted learning in veterinary education at the University of Cambridge, involving the development of four types of learning module, is outlined. A tutorial on regional perineural anaesthesia in the horse, based on the familiar tape‐slide format but with significant improvements, is described. A question and answer self‐assessment package and a computer‐based ‘digital lecture’ are also discussed, together with a case simulation involving the investigation of a polydipsic dog. All the tutorials were developed using standard software packages and image digitising processes. The philosophy behind the development of these computer‐assisted learning packages is discussed.
Comparison and assessment of casting materials for use in small animals
Authors: Langley‐Hobbs S. J. , Abercromby R. H. , Pead M. J.
Published: October 2010

This paper describes an investigation to evaluate the properties and uses of the different casting materials available for small animals. After a consideration of the properties that make an ‘ideal cast’, clinically relevant tests were performed on tubular casts of the various products. No single product demonstrated consistent superiority by all the criteria. All the products tested can be useful in a variety of situations, and suggestions for their uses are set out.
Ten‐year survey of British bats for the existence of rabies
Authors: Whitby J. E. , Johnstone P. , Parsons G. , King A. A. , Hutson A. M.
Published: October 2010

In 1985, a notable increase in the number of recorded cases of rabies in European bats was observed, indicating a possible spread of the rabies virus in these bats. Because of concern that the disease could be introduced into the United Kingdom by bats crossing from mainland Europe, a programme of screening dead bats for the presence of rabies and rabiesrelated viruses was initiated at the Rabies Research and Diagnostic Unit at the Central Veterinary Laboratory. Over a period of 10 years (January 1986 to December 1995), 1882 bats belonging to 23 species from all parts of England, Scotland and Wales have been screened for rabies antigen. All of these bats were found to be negative. Forty‐one serotine bats (Eptesicus serotinus), the species of bat most commonly infected in Europe, were included in the total. Subsequent to this survey, in June 1996, a European bat lyssavirus 2 was isolated from a Daubenton's bat (Myotis daubentonii) in Newhaven, East Sussex. It is possible that this bat originated from mainland Europe but this cannot be established with certainty.
Causes of mortality and morbidity in exhibition budgerigars in the United Kingdom
Authors: Baker J. R.
Published: October 2010

In a survey of the causes of mortality and morbidity in exhibition budgerigars from 1984 to 1995, 1525 birds were examined post mortem. Megabacteriosis was the most common disease and trichomoniasis, enteritis, pneumonia, hepatitis and a degenerative disease of the gizzard lining were also common. A wide variety of less common diseases was also found.
Estimation of the weight and body condition of ostriches (Struthio camelus) from body measurements
Authors: Deeming D. C. , Sibly R. M. , Magole I. L.
Published: October 2010

The body dimensions and weights of over 100 ostriches were analysed to investigate which body measurements provided the best estimators of bodyweight. The data were divided between growing and adult birds (below and above two years old) for regression analyses. The residual standard deviation of weight was 0.117 for growing birds, using tibiotarsal length and abdominal girth as predictors. The analogous figure for adults was 0.078 using back length and abdominal girth. An assessment of body condition was made by calculating the average weight‐for‐size of a bird from skeletal measurements which are unaffected by gross changes in weight, and then comparing it with its estimated or actual weight. These estimates of the weight of a typical ostrich should be useful in veterinary practice, particularly when the weight of a bird is required for the administration of medication.
Antithrombin‐III activity in plasma of healthy and sick cattle
Authors: Pusterla N. , Braun U. , Forrer R. , Lutz H.
Published: October 2010

Antithrombin‐III (AT‐III) activity was determined in the plasma of 32 healthy cows. The range of activities was between 105 and 160 per cent of a human reference plasma; the median activity was 132.5 per cent, and the 5 per cent and the 95 per cent quartiles were 111.1 per cent and 153.9 per cent of the standard. The activity of AT‐III was also determined in 82 cows with a variety of internal diseases. In cows with hepatopathy, acute enteritis, generalised peritonitis, blood loss, idiopathic cardiomyopathy, glomerulonephritis and disseminated coagulopathy, the activity of AT‐III was lower than in healthy animals. The lower values were due to decreased synthesis, increased consumption, or the loss of AT‐III. An acquired deficiency of AT‐III appears to favour the development of thrombophlebitis.
Repeated oestrus synchrony and fixed‐time artificial insemination in beef cows
Authors: Penny C. D. , Lowman B. G. , Scott N. A. , Scott P. R.
Published: October 2010

The feasibility of breeding spring‐calving, single‐suckled beef cows without the use of natural service was investigated over two breeding seasons by using repeated oestrus synchrony and fixed‐time artificial insemination (AI). Initially, cows were oestrus‐synchronised with subcutaneous norgestomet implants inserted for 10 days, with an injection of prostaglandin before the implants were removed. The cows were inseminated once 56 hours after the implants were removed, and 12 days later they were re‐treated with norgestomet implants to allow a second synchronised service. Twenty‐one days after the first synchronised AI, milk samples were taken for progesterone assay and the norgestomet implants were removed. The cows received a second service 56 hours later if the 21‐day milk progesterone assay suggested that they were not pregnant. All the cows receiving a second service were retreated with norgestomet implants to allow a third synchronised service as necessary. Pregnancy was later confirmed by rectal palpation. In the first year, 48 cows entered the programme and the pregnancy rates to the first, second and third synchronised services were 56, 69 and 40 per cent, respectively, with 17 per cent of cows barren at the end of the breeding period. In the second year, 69 cows entered the programme and the pregnancy rates were 58, 48 and 33 per cent to the successive services with 20 per cent of cows barren at the end of the breeding period. The accuracy of milk progesterone assay for pregnancy diagnosis was 84 per cent and 87 per cent in the first and second years, respectively.
Infectivity assays of foot‐and‐mouth disease virus: contact transmission between cattle and buffalo (Bubalus bubalis) in the early stages of infection
Authors: Gomes I. , Ramalho A. K. , Augé de Mello P.
Published: October 2010

No differences were observed between cattle and Indian buffalo (Bubalus bubalis) in terms of temperature, viraemia or virus replication in the pharyngeal area, during the acute phase of foot‐and‐mouth disease. Like cattle, the Indian buffalo became infected and excreted virus before any clinical signs of foot‐and‐mouth disease developed. The disease was transmitted from cattle to buffalo and vice versa, during the acute stage of infection, as if the animals had been of the same species, presumably because of their close phylogenetic relationship. There were more tongue lesions in the cattle than in the buffalo. Foot lesions in the buffalo at first had a scaley appearance, but later became vesicular. Anti‐virus infection associated antigen and neutralising antibodies were synthesised at the same time in both species and reached similar titres in the same period. Persistent infection in the buffalo during the first 35 days after infection was similar to that in the cattle.
Ageing draft and trotter horses by their dentition
Authors: Muylle S. , Simoens P. , Lauwers H. , Van Loon G.
Published: October 2010

The accuracy of ageing horses by their dentition was assessed by comparing the dental features with the known dates of birth of 212 trotter horses and 189 Belgian draft horses. The horses ranged in age from two to 25 years. In both breeds it was observed that the shedding of the incisors and the appearance of the dental stars were the most reliable features for age determination. In young animals, the dental configuration was similar in both breeds. With increasing age the incisor teeth of draft horses were more liable to abrasion than those of trotter horses. The sequential changes in appearance of the permanent incisors occurred earlier in draft horses than in trotters.
Trace metals in keratinising epithelia in beagle dogs
Authors: Lansdown A. B. G. , Sampson B.
Published: October 2010

The concentrations of the trace elements zinc, copper and iron and the minerals calcium and magnesium were measured in keratinising epithelia from 12 beagle dogs. The richly vascular tissues of the snout and tongue that showed parakeratotic changes, contained the highest concentrations of iron, zinc and copper. Zinc, calcium and magnesium concentrations were high in the pressure keratinisation tissue of the footpad. There was a high concentration of calcium in the nose tip. The thin skin of the back contained the lowest concentration of all five elements.
Field efficacy of injectable doramectin against Chorioptes bovis in naturally infected cattle
Authors: Losson B. J. , Mignon B. , Bossaert K. , Leclipteux T. , Lonneux J.‐F.
Published: October 2010

A single subcutaneous injection of doramectin at a dose rate of 200 μg/kg bodyweight was effective in controlling an infection of Chorioptes bovis mites in naturally infected cattle. From 14 days after treatment, the geometric mean number of live mites was significantly lower (P<0.001) in the doramectin‐treated cattle than in the control group at each sampling until day 35. The percentage efficacy (treated versus controls) of doramectin against C bovis at day 35 was 99.9 per cent and the percentage reduction (day 35 versus day 0) in the treated animals was 99.3 per cent. At day 35, all seven controls were still positive for C bovis whereas five of the eight doramectin‐treated animals were free of live mites.
Evaluation of false ultrasonographic diagnoses in cows by measuring plasma levels of bovine pregnancy‐associated glycoprotein 1
Authors: Szenci O. , Taverne M.A.M. , Beckers J.F. , Sulon J. , Varga J. , Börzsönyi L. , Hanzen Ch. , Schekk Gy.
Published: October 2010

Between days 27 and 59 after artificial insemination (AI), 189 ultrasonographic pregnancy diagnoses were made in 56 dairy cows using a 7.5 MHz linear‐array rectal transducer. Blood samples were withdrawn from a jugular vein on the day of Al, on day 21, and after each ultrasonographic examination between days 27 and 31, days 34 and 38, days 41 and 45 and days 55 and 59 after AI. Plasma concentrations of bovine pregnancy‐ associated glycoprotein 1 (bPAG‐1) were measured by radioimmunoassay. The results showed that before day 31, ultrasonographic scanning was not very sensitive because six of the 30 calving cows were incorrectly diagnosed as non‐pregnant. In five of these animals, the uterus was located far cranial to the pelvic inlet. Five of the cows examined between days 27 and 31 were pregnant on the basis of plasma bPAG‐1 levels on the same day, using 0.5 ng/ml as the cut‐off point. Plasma levels of bPAG‐1 and progesterone proved that four of the cows which had early positive ultrasonographic diagnoses but did not produce a calf, were pregnant when they were examined.
Tonsillar biopsy and PrPSc detection in the preclinical diagnosis of scrapie
Authors: Schreuder B. E. C. , van Keulen L. J. M. , Vromans M. E. W. , Langeveld J. P. M. , Smits M. A.
Published: October 2010

Preliminary findings have indicated that in naturally infected sheep, fully susceptible to scrapie (vRQ‐homozygous), PrPSc can be detected in the tonsils approximately one year before the expected onset of clinical disease, whereas no immunostaining can be detected in animals with a semi‐resistant genotype. This paper describes the technique for taking tonsillar biopsies from sheep and gives the results of the completed experiment. In another experiment PrPSc was detected even earlier in comparable vRQ‐homozygous sheep born and raised in different surroundings. At three‐and‐a‐half months of age no PrPSc could be detected in three homozygous susceptible sheep (VRQ/VRQ), but PrpSc was detected at four months in one similar sheep. At eight months of age all seven sampled VRQ/VRQ sheep showed positive immunostaining in the biopsies, but none of the biopsies from three VRQ/ARQ heterozygotes showed any immunostaining; they were positive when sampled at 14 to 15 months of age. Biopsies from VRQ/ARR sheep were negative throughout this period. On the basis of the established or expected incubation period, PrPSc could thus be detected in the tonsils of live susceptible animals at between one‐third and a half of the incubation period, more than oneand‐a‐half years before clinical signs normally appear in both these genotypes.
Ageing Arab horses by their dentition
Authors: Muylle S. , Simoens P. , Lauwers H. , Van Loon G.
Published: October 2010

The dentition of 170 Arab horses of known ages was examined and compared with the dental characteristics of trotter horses and Belgian draft horses of the same ages. The results indicated that inaccuracies in the determination of the age of horses by their dentition may result, at least partly, from differences between the breeds of horse involved because there were some major differences between the three breeds examined. These differences increased as the horses' true age increased. In general, the rate of dental wear was slower in the Arab horses than in trotter horses and Belgian draft horses.
Measurement of arterial oxygen‐haemoglobin saturation in newborn lambs by pulse oximetry
Authors: Norton J. R. , Jackson P. G. G. , Taylor P. M.
Published: October 2010

Percentage arterial oxygen saturation (SpO2) was measured in 69 neonatal lambs at one, five and 10 minutes after birth using a pulse oximeter applied to the tail. The lambs were given a subjective vitality score from 1 to 4, with 1 being normal and 4 being stillborn. Of the 42 lambs born after a normal parturition, 19 were measured after one minute, 29 after five minutes and 24 after 10 minutes; the mean (sd) SpO2 values of these groups were 67 (15) per cent, 84 (9) per cent and 83 (9) per cent, respectively. Of the 27 lambs born after dystocia, 16 were measured after one minute, 18 after five minutes and 12 after 10 minutes; the mean (sd) SpO2 values of these groups were 61 (15) per cent, 69 (16) per cent and 69 (19) per cent, respectively. The values measured in the lambs born after dystocia were significantly lower than those in the lambs born normally at five and 10 minutes (P<0.005 and P<0.05, respectively). Of the lambs born with a vitality score of 1, 24 were measured after one minute, 33 after five minutes and 26 after 10 minutes; they had mean SpO2 values of 72 (11), 82 (10) and 81 (12) per cent, respectively. Of the lambs born with vitality scores of 2 or 3, 11 were measured after one minute, 14 after five minutes and 10 after 10 minutes; they had mean SpO2 values of 48 (6), 68 (17) and 72 (20) per cent, respectively. The SPO2 values of the lambs with vitality scores of 2 or 3 were significantly lower than those of the lambs with a vitality score of 1 at one and five minutes after birth (P<0.0001 and P<0.05, respectively).
Efficacy of doxycycline in feed for the control of pneumonia caused by Pasteurella multocida and Mycoplasma hyopneumoniae in fattening pigs
Authors: Bousquet E. , Pommier P. , Wessel‐Robert S. , Morvan H. , Benoit‐Valiergue H. , Laval A.
Published: October 2010

A multicentre, controlled, randomised and blinded study was carried out in three French pig herds to assess the efficacy of doxycycline administered in the feed for the control of pneumonia. About 20 per cent of 363 pigs from the three fattening units were diseased at the start of the study. Pneumonic lesions were found on pigs examined postmortem and Pasteurella multocida was isolated from the lungs of pigs in all the herds. Mycoplasma hyopneumoniae infection was confirmed either by detection in pneumonic lungs or by seroconversion in pigs sampled three weeks apart. P multocida, Bordetella bronchiseptica and Actinobacillus pleuropneumoniae were isolated from 64 per cent, 50 per cent and 2 per cent, respectively, of 148 nasal swabs. The following variables were significantly different between the treated and untreated groups (P≤0.001): the incidence of diseased pigs during the three weeks from the start of treatment (8.1 per cent in treated group v 35.4 per cent in control group), mean daily weight gain over the same period (934 g/day in the treated group v 834 g/day in the control group) and the cure rate of pigs which were diseased at the start of treatment (73.5 per cent in treated group v 35.3 per cent in control group). These data demonstrate that an average dose of 11 mg doxycycline/kg bodyweight per day in feed for eight days was effective in controlling pneumonia due to P multocida and M hyopneumoniae in these fattening pigs.
Serological and immunohistochemical study of African swine fever in wild boar in Spain
Authors: Pérez J. , Fernández A. , Sierra M. A. , Herráez P. , Fernández A. I. , Martín de las Mulas J.
Published: October 2010

A serological and immunohistochemical study of African swine fever was carried out in wild boar killed in seven municipalities in the north of the province of Cordoba during two hunting seasons (1991–92 and 1992–93), when the area was affected by the disease. Fourteen of 147 wild boar analysed by ELISA and immunoblotting had antibodies to African swine fever virus. The immunohistochemical study revealed that four cases (two seropositive and two seronegative) showed immunoreactivity to the anti‐vP73 monoclonal antibody. Two of the VP73+wild boar had severe generalised haemorrhages consistent with the acute form of the disease, and another had lesions consistent with subacute African swine fever, but none of the remaining 144 animals had gross or microscopic changes suggestive of the disease. These results indicate that wild boar can suffer from African swine fever without showing clinical signs. The disease in wild boar was associated with the disease in domestic pigs. Thus, no African swine fever‐positive boar were found either in one municipality with no outbreaks in domestic pigs or in three municipalities with only one outbreak in pigs during the hunting seasons and during the previous year. These results suggest that European wild boar do not play an important role as carriers of the virus of African swine fever.