SSU rRNA reveals major trends in oomycete evolution

Oomycetes are a group of heterokonts that have a huge impact on the environment as well as on human welfare, due the parasitic nature of many species. However, their evolutionary patterns are still not well understood, due in part to the lack of molecular markers suited to resolve the deep phylogeny of this group. Here, we propose a phylogeny of the whole clade based on the nuclear ribosomal small subunit gene, that comprises both culture and environmental studies derived sequences. Our analysis shows notably that i) plant pathogenesis occurred only rarely in oomycete evolution in comparison to animal parasitism ii) obligate symbiosis happened only in a few derived groups and iii) transitions from soil/freshwater to marine environment (and viceversa) are common unlike for most eukaryotic groups. This study illustrates the complexity of evolutionary patterns and will help to better understand the emergence of pathogenicity in the different oomycete group

Multi-Loci Sequence Typing (MLST) for Two Lacto-Acid Bacteria (LAB) Species: Pediococcusparvulus and P.damnosus

The control of wine microbial population during and beyond fermentation is of huge importance for wine quality. Lactic acid bacteria (LAB) in wine are responsible for malolactic fermentation (MLF) which can be desired in some cases and undesirable in others. Some LAB do not perform MLF and their uncontrolled growth could contribute to severe wine spoilage such as undesired flavours. Their identification and detection is considered crucial for numerous biotechnological applications in food fermentations, where, through acidification and secretion of bacteriocins, they contribute to reduce food spoilage and growth of pathogenic microorganisms. LAB have traditionally been classified using morphological or biochemical features. Primary isolation, biochemical identification and phenotypic analysis are laborious, time consuming and inaccurate and often lead to misidentification within some genera such as Pediococcus. Molecular identification based on suitable marker genes could be an attractive alternative to conventional morphological and biochemical methods. We assessed here the applicability of four housekeeping genes recA, rplB, pyrG and leuS in combination with the mle gene in multi-loci sequence typing (MLST) of Pediococcus parvulus and Pediococcus damnosus. Sequencing and comparative analysis of sequence data were performed on 19 strains collected during wine fermentation. A combination of these five marker genes allowed for a clear differentiation of the strains analysed, indicating their applicability in molecular typing. Analysis of the observed nucleotide polymorphisms allowed designing highly discriminative primers for a multi-loci sequence typing (MLST) method that proved successful in detecting a particular isolate or sequence type of P.parvulus when using either conventional PCR or Real Time PC

Complete Genome Sequence of Aneurinibacillus migulanus E1, a Gramicidin S- and d-Phenylalanyl-l-Propyl Diketopiperazine-Deficient Mutant

ACKNOWLEDGMENTS This work was supported by the European Union’s Seventh Framework Programme grant 245268 (ISEFOR; to L.B.). Further support came from the SwissBOL project (the Swiss Federal Office for the Environment, to L.B.) and the Sciex-Scientific Exchange Programme NMS.CH (to L.L. and L.B.).Peer reviewedPublisher PD

Pythium sterilum sp. nov. isolated from Poland, Spain and France: its morphology and molecular phylogenetic position

In a survey of Phytophthora species associated with forest decline in Spain, Poland and France, we found three Pythium isolates, which have been characterized with internal transcribed spacer rRNA gene sequences and with classical morphological descriptors for Pythium spp. These isolates showed unique internal transcribed spacer sequences, different enough from those of any described species to justify new species status. These three distinct isolates failed to produce any sex organs with an entirely asexual reproduction and were found to represent a new species for which the name Pythium sterilum is proposed. This paper describes and illustrates the morphology of P. sterilum and presents its taxonomic position and relationships with other, related Pythium species belonging to clade

Multiple barcode assessment within the Saprolegnia-Achlya clade (Saprolegniales, Oomycota, Straminipila) brings order in a neglected group of pathogens

The Saprolegnia-Achlya clade comprises species of major environmental and economic importance due to their negative impact on aquaculture and aquatic ecosystems by threatening fishes, amphibians, and crustaceans. However, their taxonomy and phylogenetic relationships remain unresolved and suffer from many inconsistencies, which is a major obstacle to the widespread application of molecular barcoding to identify pathogenic strains with quarantine implications. We assessed phylogenetic relationships of major genera using three commonly used markers (ITS, SSU rRNA, and LSU rRNA). A consensus tree of the three genes provided support for nine clades encompassing eleven documented genera and a new clade (SAP1) that has not been described morphologically. In the course of this study, we isolated a new species, Newbya dichotoma sp. nov., which provided the only culture available for this genus. In parallel, we attempted to summarize the evolution of traits in the different genera, but their successive reversals rendered the inference of ancestral states impossible. This highlights even more the importance of a bar-coding strategy for saprolegniacean parasite detection and monitoring.Facultad de Ciencias Naturales y MuseoInstituto de Botánica "Dr. Carlos Spegazzini

Phytophthora cinnamomi and other fine root pathogens in north temperate pine forests

A number of fine root pathogens, including Phytophthora cinnamomi, Pythium ultimum var. ultimum, Pythium undulatum, Pythium violae, Fusarium sp., and two incompletely identified Verticillium species, were isolated from soils taken from under Scots pine trees at five sites in north Scotland, including semi-natural forests and plantations. At least two root pathogens were recovered from each forest. Morphological and molecular data supported the identification of Phytophthora cinnamomi from three of the sites investigated. Isolates of Phytophthora cinnamomi, Pythium ultimum var. ultimum and an incompletely identified Fusarium sp. caused growth reductions of Scots pine seedlings, as determined by dry weight; the most virulent species were Phytophthora cinnamomi and Fusarium sp. The most severe disease symptoms were caused by a mixed inoculum containing Phytophthora cinnamomi, Pythium ultimum var. ultimum and Fusarium sp., or by the Fusarium isolate alone. These nonspecific pathogens may persist on the roots of understorey and herbaceous plants in the pine forest

A new species of Pythium with ornamented oogonia: morphology, taxonomy, internal transcribed spacer region of its ribosomal RNA, and its comparison with related species

Pythium spiculum sp. nov. was isolated from soil samples taken in a vineyard in the Burgundian region of France and from different locations in Spain and Portugal. The oomycete has spiny oogonia and does not sporulate readily. It resembles Pythium mamillatum Meurs, but has its own distinguishing characteristics. It also exhibits sickle-shaped as well as spherical appressoria which at times are associated with sex organs like those found in Pythium abappressorium Paulitz and Pythium contiguanum Paul. Sequencing of the internal transcribed spacer region of its nuclear ribosomal DNA and a close look at its morphological characters have now enabled us to describe it as a new species. The internal transcribed spacer region of its rRNA gene sequence is comprised of 945 bases. This oomycete is closely related to the members that form ornamented or spiny oogonia like Pythiummamillatum, Pythium spinosum and Pythium irregulare but also with those producing smooth-walled oogonia like Pythium paroecandrum, Pythium sylvaticum and Pythium cylindrosporum. Taxonomic description of this new species, its comparison with related oomycetes, the sequence of the internal transcribed spacer region of its rRNA gene and the phylogenetic tree, are given her

Modelling of Reactive Black 5 decolourization in the presence of heavy metals by the newly isolated Pseudomonas aeruginosa strain Gb30

Acknowledgements This work was supported by the Ministry of Higher Education and Scientific Research of Tunisia.Peer reviewedPostprin

Increased Biological Activity of Aneurinibacillus migulanus Strains Correlates with the Production of New Gramicidin Secondary Metabolites

Acknowledgments This project was funded by the Government of Kuwait (to FA) and the European Union Seventh Framework Programme under grant agreement 245268 (ISEFOR; to LB and SW). Further support came from the SwissBOL project, financed by the Swiss Federal Office for the Environment (grant holder LB) and the Sciex–Scientific Exchange Programme (http://nms.ch/) (NMS.CH; to LL and LB). LL is indebted to the Ministry of Education, Science, Research and Sport of the Slovak Republic for financial support in the frame of the project “VEGA 1/0061/16” and “VEGA 1/0046/16”. Funding This project was funded by the Government of Kuwait (to FA) and the European Union Seventh Framework Programme under grant agreement 245268 (ISEFOR; to LB and SW). Further support came from the SwissBOL project, financed by the Swiss Federal Office for the Environment (grant holder LB) and the Sciex–Scientific Exchange Programme NMS.CH (to LL and LB). LL is indebted to the Ministry of Education, Science, Research and Sport of the Slovak Republic for financial support in the frame of the project “VEGA 1/0061/16.”Peer reviewedPublisher PD

Phoenix dactylifera L. sap enhances wound healing in Wistar rats : Phytochemical and histological assessment

Acknowledgment Financial support of the Tunisian Ministry of Higher Education and Scientific Research is gratefully acknowledged.Peer reviewedPostprin