Molecular studies on some soil-Streptomyces strains of western region, Kingdom of Saudi Arabia (KSA)

Random amplified polymorphic of DNA-polymerase chain reaction (RAPD-PCR) analysis of the DNA extracted from seven Streptomyces strains of western region, KSA was the aim of this study. Partial sequence of 16S rRNA gene of Streptomyces polychromogenes was also attempted. Results show that a total number of 240 amplified fragments were amplified using 10 RAPD-PCR primers (OPA11, OPB10, OPB15, OPC03, OPC07, OPC18, OPD05, OPE05, OPO14 and OPO17). A total number of 97, 73, 88, 79, 100, 108 and 82 fragments were amplified from the DNA extracts of S. polychromogenes, Streptomyces chattanoogensis, Streptomyces lucensis, Streptomyces antibioticus, Streptomyces violans, Streptomyces griseorubiginosus and Streptomyces violaceus, respectively. An obvious variation in the amplified fragments was recorded using the 10 RAPD-PCR primers (31, 27, 17, 19, 23, 29, 24, 26, 23 and 21 fragments for the primers, respectively). The highest similarity (66.7%) was found between S. lucensis and S. chattanoogensis; lowest similarity (35%) was recorded between the gray S. chattanoogensis and the red S. violaceus. The 16S rRNA gene was isolated via PCR from the DNA of S. polychromogenes (1) and sequenced. Fragments of 1003 and 837 nts were amplified using the forward and reverse primers, respectively. On matching, a final sequence of about 1452 nts (GenBank: JQ962978.1) was obtained and compared with five universal Streptomyces strains and four bacterial clones. The percent identities between the isolate of this study and the compared bacterial strains was lowest (79.1%) compared to HQ844464.1 and highest (98.3%) compared to EU520331.1. Based on the phenotypic and genotypic (16S rRNA gene) features, the strain could be classified as a new strain of S. polychromogenes.Keywords: Identification, Streptomyces, RAPD-PCR, 16S rRNA gene, KSAAfrican Journal of Biotechnology Vol. 12(19), pp. 2558-256

Halotolerant streptomycetes isolated from soil at Taif region, Kingdom of Saudi Arabia II: RAPD-PCR analysis and salt tolerance-gene isolation

The genus Streptomyces is represented in nature by the largest number of species and varieties among the family Streptomycetaceae. This study aimed at extracting the DNA of four halotolerant Streptomyces strains followed by determination of DNA fingerprinting of them using a molecular tool. A trail to isolate salt tolerance gene(s) from their DNA was also aimed. RAPD-PCR technique was applied using seven RAPD-PCR primers. Results show that a total 71 fragments (65 polymorphic and six monomorphic) were amplified from the DNA of the four identified Streptomyces strains. The fragments were divided into polymorphic and monomorphic fragments. Three primers named OPA11, OPB15 and OPC07 did not show any monomorphic fragments. A number of 43 (7, 7, 8, 2, 9, 6 and 4) representing 60.56% were considered as unique DNA markers, and were amplified using OPA11, OPB15, OPC07, OPC18, OPD04, OPE05 and OPO14, respectively. Data shows similarity matrix between the four identified Streptomycs strains based on RAPD-PCR analysis ranged from 21.8 to 40.0. Results show that the P5CR gene was detected in the DNA extracts of three species, namely, Streptomyces cirratus-02; Streptomyces rishiriensis-04; Streptomyces luteogriseus-08, while, mtlD gene was only found in the DNA extracts of S. cirratus-02.Keywords: Streptomyces, halotolerant, salt tolerance genes, RAPD-PCR, Taif, KSAAfrican Journal of Biotechnology Vol. 12(13), pp. 1452-145

Umbilical hernia in children in a developing country: Does the season have an effect on the occurrence of strangulation?

No Abstract

Streptomyces noboritoensis isolated from rhizosphere soil and its use in controlling banana-tissue culture contaminants

In this study, the role of Streptomyces noboritoensis (14) isolated from the rhizosphere of banana plant and having antagonistic activity against the bacterial- and fungal-tissue culture contaminants was determined in vitro. Results show that the filtrate was more effective against the fungal-tissue culture contaminants than the bacterial-tissue culture contaminants. This was indicated when jars were fungifree and bacteria-free after one month and 21 days from incubation, respectively. Results of in vitro application show that the filtrate of S. noboritoensis (14) as a bio-control agent could be used for controlling the contaminants in banana. Data showed that treatment F (sterilized shoots treated with Streptomyces filtrate and cultivated on Streptomyces-inoculated medium) was the most effective followed by treatment E (sterilized shoots untreated with Streptomyces filtrate and cultivated on Streptomyces-inoculated medium). Therefore, the study suggests conducting further studies towards the use of streptomycetes in the biological control in a large scale production.Keywords: Streptomyces, tissue culture contaminants, antagonistic activities, bio-controlAfrican Journal of Biotechnology Vol. 12(20), pp. 2908-291

Anatomy, morphology and evolution of the patella in squamate lizards and tuatara (Sphenodon punctatus)

The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary ossification centres and/or changes in knee joint conformation, where enhancement of extensor muscle leverage would be more beneficial.Sophie Regnault, Marc E. H. Jones, Andrew A. Pitsillides, John R. Hutchinso

Taxonomy of Streptomyces strains isolated from rhizospheres of various plant species grown in Taif region, KSA, having antagonistic activities against some microbial tissue culture contaminants

This work was designed to identify and taxonomically classify Streptomyces strains isolated from the rhizospheres of various plant species; banana, rose, pomegranate and grape plants, having antagonistic activity against some microbial (bacteria and fungi) tissue culture contaminants. Streptomyces strains with the most potent antagonistic traits were identified using sequencing of 16S rRNA gene amplicons generated by PCR of DNA and blasting the sequences into GenBank. The Streptomyces isolates had antagonism against five identified fungi (Aspergillus fumigates, Aspergillus flavus, Aspergillus nidulans (1), Aspergillus nidulans (2), Cladosporium herbarum) and against five out of the 11 Gram positive bacilli bacterial contaminants. The three selected Streptomyces isolates (14, 15 and 17) were identified as strains of Streptomyces noboritoensis, Streptomyces albolongus and Streptomyces griseorubiginosus, respectively. Isolate 14 for which 1443 nucleotides were obtained was compared with eight universal Streptomyces strains and was classified as a new species of gray Streptomyces, to be named Streptomyces noboritoensis SSMA2-KSA strain. This study recommends conducting further studies on the use of streptomycetes in the biological control in a large scale production.Keywords: Taxonomy, Streptomyces, microbial tissue culture contaminants, antagonistic activities, 16S rRNAAfrican Journal of Biotechnology Vol. 12(14), pp. 1657-166

False Data Injection Attacks Against Synchronization Systems in Microgrids

Synchronization systems play a vital role in the day-to-day operation of power systems and their restoration after cascading failures. Hence, their resilience to cyberattacks is imperative. In this paper, we demonstrate that a well-planned false data injection attack against the synchronization system of a generator is capable of causing tripping subsequently leading to instability and blackout. We present an analytical framework behind the design and implementation of the proposed cyberattack. Moreover, we derive and discuss the conditions for which a cyberattack interfering with a synchronizing signal can be successful. Effective physical mitigation strategies are then proposed to improve the cyber-resilience of synchronization systems. The proposed cyberattack model and mitigation strategies are verified for a microgrid test system using an OPAL-RT real-time simulator

Proceedings of the Salford Postgraduate Annual Research Conference (SPARC) 2011

These proceedings bring together a selection of papers from the 2011 Salford Postgraduate Annual Research Conference(SPARC). It includes papers from PhD students in the arts and social sciences, business, computing, science and engineering, education, environment, built environment and health sciences. Contributions from Salford researchers are published here alongside papers from students at the Universities of Anglia Ruskin, Birmingham City, Chester,De Montfort, Exeter, Leeds, Liverpool, Liverpool John Moores and Manchester

Surface Percolation for Soil Improvement by Biocementation Utilizing In Situ Enriched Indigenous Aerobic and Anaerobic Ureolytic Soil Microorganisms

The use of biocementation via microbially induced carbonate precipitation (MICP) for improving the mechanical properties of weak soils in the laboratory has gained increased attention in recent years. This study proposes an approach for applying biocementation in situ, by combining the surface percolation of nutrients and cementation solution (urea/CaCl2) with in situ cultivation of indigenous soil urease positive microorganisms under non-sterile conditions. The enrichment of indigenous ureolytic soil bacteria was firstly tested in batch reactors. Using selective conditions (i.e., pH of 10 and urea concentrations of 0.17 M), highly active ureolytic microorganisms were enriched from four diverse soil samples under both oxygen-limited (anoxic) and oxygen-free (strictly anaerobic) conditions, providing final urease activities of more than 10 and 5 U/mL, respectively. The enrichment of indigenous ureolytic soil microorganisms was secondly tested in pure silica sand columns (300 and 1000 mm) for biocementation applications using the surface percolation approach. By applying the same selective conditions, the indigenous ureolytic soil microorganisms with high urease activity were also successfully enriched for both the fine and coarse sand columns. However, the in situ enriched urease activity was highly related to the dissolved oxygen of the percolated growth medium. The results showed that the in situ cultivated urease activity may produce non-clogging cementation over the entire 1000-mm columns, with unconfined compressive strength varying between 850–1560 kPa (for coarse sand) and 150–700 kPa (for fine sand), after 10 subsequent applications of cementation solution. The typically observed loss of ureolytic activity during the repeated application of the cementation solution was recovered by providing more growth medium under selective enrichment conditions, enabling the in situ enriched ureolytic microorganisms to increase in numbers and urease activity in such a way that continued cementation was possible

Predicting Distribution of Aedes Aegypti and Culex Pipiens Complex, Potential Vectors of Rift Valley Fever Virus in Relation to Disease Epidemics in East Africa.

The East African region has experienced several Rift Valley fever (RVF) outbreaks since the 1930s. The objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. Understanding disease vector potential distributions is a major concern for disease transmission dynamics. DIVERSE ECOLOGICAL NICHE MODELLING TECHNIQUES HAVE BEEN DEVELOPED FOR THIS PURPOSE: we present a maximum entropy (Maxent) approach for estimating distributions of potential RVF vectors in un-sampled areas in East Africa. We modelled the distribution of two species of mosquitoes (Aedes aegypti and Culex pipiens complex) responsible for potential maintenance and amplification of the virus, respectively. Predicted distributions of environmentally suitable areas in East Africa were based on the presence-only occurrence data derived from our entomological study in Ngorongoro District in northern Tanzania. Our model predicted potential suitable areas with high success rates of 90.9% for A. aegypti and 91.6% for C. pipiens complex. Model performance was statistically significantly better than random for both species. Most suitable sites for the two vectors were predicted in central and northwestern Tanzania with previous disease epidemics. Other important risk areas include western Lake Victoria, northern parts of Lake Malawi, and the Rift Valley region of Kenya. Findings from this study show distributions of vectors had biological and epidemiological significance in relation to disease outbreak hotspots, and hence provide guidance for the selection of sampling areas for RVF vectors during inter-epidemic periods