Effect of paracrystalline protein surface layers on predation by Bdellovibrio bacteriovorus.

We determined that paracrystalline protein surface arrays (S layers) protected gram-negative eubacteria from predation by Bdellovibrio bacteriovorus. Aquaspirillum serpens VHA and MW5 and Aquaspirillum sinuosum were resistant to predation by B. bacteriovorus 6-5-S when fully covered by their S layers. The S layer of Aeromonas salmonicida A449 protected the cells from predication by B. bacteriovorus 109J. A predacious, plaque-forming vibrio that lysed an S-layer- variant of Caulobacter crescentus but was not predacious on the parental strain which possessed an S layer was isolated from raw sewage. Since S layers are stable components of many bacterial surfaces in nature, they can provide this protective function in both aquatic and terrestrial habitats where Bdellovibrio spp. are found.     

Buffering capacity and H+ membrane conductance of Gram-negative bacteria

Abstract Buffering capacity and membrane H⁺ conductance were examined in seven Gram-negative species: Aquaspirillum serpens, Pseudomonas aeruginosa, Alcaligenes faecalis, Escherichia coli, Salmonella typhimurium, Proteus mirabilis and Aeromonas hydrophila . All strains of Enterobacteriaceae studied here showed a decrease in both parameters as the external pH increased, over the pH range studied. The other four species presented an increase in buffering capacity and membrane conductance to protons as the external pH increased from 5.5 to 7.0.     

852. KEWA ACIDA

Recent studies showed that a group of Hypertelis species was neither related to the type of that genus or to other members of Molluginaceae. As a result, these species were segregated as a new genus in its own family, Kewaceae. The St Helenan endemic Kewa acida (Hook.) Christenh. is illustrated here and its relationships, status, cultivation and conservation are discussed.     

Four new species of southern African octocorals (Cnidaria: Alcyonacea), with a further diagnostic revision of the genus Alcyonium Linnaeus, 1758

Four new species of soft corals are described from the shallow sublittoral of southern Africa. Three of the species are referable to the genus Alcyonium Linnaeus, 1758 (family Alcyoniidae), although two of these possess growth forms that are atypical for most members of the genus. A revised diagnosis of the genus is therefore included. A new species in the family Nephtheidae is also described, this being referable to the genus Capnella Gray, 1869. All four species are from the region between the Cape of Good Hope Peninsula and the eastern Cape Province of South Africa. This is the region of the Agulhas Bank, an austroafrican biogeographic region that shows a high incidence of endemism with respect to the marine invertebrate fauna.     

Phylogenetic analysis of the genera Pseudonocardia and Actinobispora based on 16S ribosomal DNA sequences

The 16S rDNA sequences of 11 strains, nine type strains of validated Pseudonocardia species and Actinobispora yunnanensis, and two strains of unnamed Pseudonocardia species, were determined and compared with those of representatives of the family Pseudonocardiaceae. The phylogenetic analysis indicated that all of the validated species of the genera Pseudonocardia and Actinobispora consistently formed a monophyletic unit and separated well from the other genera of the family Pseudonocardiaceae. One unnamed Pseudonocardia strain was related to members of the genus Pseudonocardia, whereas the other unnamed Pseudonocardia strain formed a distinct clade within the radiation of the genus Amycolatopsis.     

Enterobacter kobei sp. nov., a new species of the family Enterobacteriaceae resembling Enterobacter cloacae

The name Enterobacter kobei sp. nov. is proposed for a group of organisms referred to as NIH Group 21 at the National Institute of Health, Tokyo. The members of this species are Gram-negative, motile rods conforming to the definition of the family Enterobacteriaceae. The DNA relatedness of 23 strains of NIH Group 21 to the representative proposed as the type strain of this species averaged 82% at 70°C, whereas the relatedness to other species within the family Enterobacteriaceae was less than 42%. Because the phenotypic resemblance to Enterobacter cloacae is very close and the DNA relatedness (12–42%) is closer to species of the genus Enterobacter than to other species of the family, the members of NIH Group 21 were placed in the genus Enterobacter. Close phenotypic and genetic relationships were also found between NIH Group 21 and a member of a group of organisms referred to as Enteric Group 69 at the Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA. It is suggested that the latter could be regarded as a subspecific rank of E. kobei, though this is subject to study of further strains. The majority of strains of E. kobei were isolated from clinical specimens. A culture of the type strain (NIH 1485-79) has been deposited in the Japan Collection of Microorganisms as JCM 8580. Received: 22 March 1996 / Accepted: 19 April 1996     

Desulfovibrio longus sp. nov., a sulfate-reducing bacterium isolated from an oil-producing well.

A novel type of sulfate-reducing bacteria with unusual morphology was isolated from an oil-producing well in the Paris Basin. The cells of this bacterium, strain SEBR 2582T (T = type strain), are long, thin, flexible rods, contain desulfoviridin, and are physiologically similar to members of the genus Desulfovibrio. On the basis of 16S rRNA sequence data, this strain should be included in the genus Desulfovibrio. However, strain SEBR 2582T differs from other members of this genus morphologically, physiologically, and phylogenetically. Thus, a new species, Desulfovibrio longus sp. nov., is proposed for this organism.     

Phylogenetic relationship among cockroach families inferred from mitochondrial12S rRNA gene sequence

A number of phylogenies exist for cockroaches that differ in the postulated relationships among families and genera. The relationship of the wood-feeding genus, Cryptocercus, to other cockroach families and to termites, has generated considerable debate. Grandcolas (1994), based on morphological analysis, synonymized the family Cryptocercidae with Polyphagidae and placed the genus Cryptocercus in the subfamily Polyphaginae. To determine if an independent set of characters supports the placement of Cryptocercus in Polyphaginae, a phylogenetic analysis of relationships among representative genera of the five cockroach families was undertaken. DNA sequence of a -430 base pair portion of the mitochondrial small ribosomal subunit gene from representatives of Blattidae, Blattellidae, Blaberidae and Cryptocercus, previously published by Kambhampati (1995) and Kambhampati et al. (1996), and the homologous sequence from representatives of Polyphagidae were used in the analysis. A total of twenty cockroach taxa and three termite genera were included in the study. Because a recent study showed that Cryptocercus punctulatus consists of a species complex, DNA sequence from four individuals collected in different parts of the U.S.A. was included in the study. The trees estimated from parsimony and neighbour-joining analyses indicated that Cryptocercus is a monophyletic clade which is most closely related to members of Blattidae. Polyphagidae is indicated as a sister group to the Blattidae + Cryptocercus complex, suggesting that Polyphagidae may belong to the superfamily Blattoidea rather than to Blaberoidea as proposed by McKittrick (1964). Blaberidae and Blattellidae were sister groups as previously proposed. Based on the present analysis, I propose that the genus Cryptocercus be retained in the family Cryptocercidae. Cockroaches     

Further studies on Nephroselmis and its allies (Prasinophyceae). II. Mamiella gen. nov., Mamiellaceae fam. nov., Mamiellales ord. nov.

The marine prasinophycean flagellate presently known as Nephroselmis gilva has been examined, using both the type culture and material from temperate (Denmark, New Zealand) and tropical waters (Thailand). All cell surfaces are covered with unmineralized scales, two types on the body, two on the flagella including flagellar hairs. The detailed structure of the scales is described, using high power electron microscopy of detached positive–stained scales. Previously overlooked organelles within the cell include large numbers of extrusive bodies, a rare type of organelle in chlorophyll–a– and –b–containing organisms, and an eyespot. N. gilva differs profoundly from the type species of Nephroselmis , and is transferred to the new genus Mamiella. Mamiella gilva is closely related to Mantoniella squamata. Together with the genus Dolichomastix they form the new family, Mamiellaceae, a small group of marine flagellates of worldwide distribution.
The members of the new family probably represent the most primitive extant prasinophytes. When compared with other members of the class, its species stand out, particularly by the lack of small square or diamond–shaped scales on the flagella and cell body. It is suggested that the Mamiellaceae should be referred to a separate order, Mamiellales.     

Enterobacter cowaniisp. nov., a New Species of the Family Enterobacteriaceae

The name Enterobacter cowanii sp. nov. is proposed for a group of organisms referred to as NIH Group 42. Members of this species are Gram-negative, motile rods conforming to the definition of the family Enterobacteriaceae. The DNA relatedness of nine strains of NIH Group 42 to the proposed type strain of this species averaged 85% at 70°C, whereas the relatedness to other species within the family Enterobacteriaceae was less than 38%. Because the DNA relatedness (5–38%) is closer to species of the genus Enterobacter than to other species of the family, the members of NIH Group 42 were placed in the genus Enterobacter. The majority of strains of E. cowanii were isolated from clinical specimens. A culture of the type strain (888-76) has been deposited in the Japan Collection of Microorganisms as JCM 10956. Received: 22 June 2000 / Accepted: 26 June 2000     

The systematic position of Phaeocryptopus gaeumannii

Phaeocryptopus gaeumannii, causal agent of the Douglas-fir foliar disease Swiss needle cast, is the only known pathogenic species of the genus. Current classifications place Phaeocryptopus in the Venturiaceae (Pleosporales), typified by the apple-scab pathogen Venturia inaequalis. All core members of this family have hyphomycetous anamorphs. We sought to confirm these relationships by means of phylogenetic analyses of the small (SSU) and large (LSU) subunits and internal transcribed spacer (ITS) region of nuclear ribosomal gene sequences (nrDNA). Analyses indicated that both the genus Phaeocryptopus and the family Venturiaceae, as currently defined, are unnatural groups. Phaeocryptopus nudus, type of the genus, is aligned in the Dothioraceae (Dothideales) and P. gaeumannii in the Mycosphaerellaceae (Capnodiales) near species of Mycosphaerella and Rasutoria. Core representatives of Venturiaceae formed an unambiguous clade but ordinal placement was unresolved. The family apparently is not included in the Pleosporales, Dothideales, Myriangiales or Capnodiales. Coelomycetous Rhizosphaera form-species are accepted generally as anamorphic states of Phaeocryptopus, however the relationship never has been established conclusively. Species of Rhizosphaera are closely related to P. nudus but not to P. gaeumannii, supporting an anamorph-teleomorph connection between Rhizosphaera and Phaeocryptopus and providing further evidence that P. gaeumanii is not congeneric with P. nudus.     

Fatty acid and sterol composition of three phytomonas species.

Fatty acid and sterol analysis were performed on Phytomonas serpens and Phytomonas sp. grown in chemically defined and complex medium, and P. fran?ai cultivated in complex medium. The three species of the genus Phytomonas had qualitatively identical fatty acid patterns. Oleic, linoleic, and linolenic were the major unsaturated fatty acids. Miristic and stearic were the major saturated fatty acids. Ergosterol was the only sterol isolated from Phytmonas sp. and P. serpens grown in a sterol-free medium, indicating that it was synthesized de novo. When P. fran?ai that does not grow in defined medium was cultivated in a complex medium, cholesterol was the only sterol detected. The fatty acids and sterol isolated from Phytomonas sp. and P. serpens grown in a chemically defined lipid-free medium indicated that they were able to biosynthesize fatty acids and ergosterol from acetate or from acetate precursors such as glucose or threonine.     

Phylogenetic relationships of the European lacertid genera Archaeolacerta and Iberolacerta and their relationships to some other 'Archaeolacertae' (sensu lato) from Near East, derived from mitochondrial DNA sequences

Parts of the mitochondrial genes coding for 12SrRNA and 16SrRNA (together about 960 bp) were sequenced for all Mediterranean species of 'Mountain lizards' of the genera Archaeolacerta ( sensu lato ) and Iberolacerta . All subspecies of the Iberian species Iberolacerta cyreni and I. monticola were included in this study. In addition, samples of Apathya cappadocica and Darevskia rudis were analysed to elucidate the relationships of the European 'Mountain lizards' to their possible relatives in the Near East. Maximum parsimony and neighbour joining analyses lead to the following major conclusions: (i) the monophyly of the genus Iberolacerta is very well supported; (ii) Archaeolacerta bedriagae (the type species of the genus) is most basal with respect to the ingroup taxa. If we accept Iberolacerta as a genus, Archaeolacerta becames paraphyletic. Therefore, we propose to restrict Archaeolacerta to the type species and to treat A. mosorensis and A. oxycephala provisionally as members of the collective genus Lacerta ; (iii) within the genus Iberolacerta three groups were found: a Pyrenean group, an Iberian group and I. horvathi . The relationships among these groups remain unresolved; and (iv) the Peña de Francia lizards, described originally as a subspecies of I. cyreni , are in fact more closely related to I. monticola .     

Basispora,a new genus of the Ralfsiaceae

Basispora is recognised as a new genus of the Ralfsiaceae (Phaeophyceae), distinguished from other members of this family by the terminal unilocular sporangia arising on long stalks from near the base of the simple, often assurgent, laterally free erect filaments. The type species Basispora africana is described; it is widely distributed along the West African coast. Two other taxa from New Zealand, formerly included in Hapalospongidium, are transferred to this new genus, necessitating the new combinations Basispora saxigena and B. durvilleae. These three species are separated on the structure of the vegetative thallus, dimensions, shape of the sporangial stalk and on the type of substrate on which they grow.     

A revision of the genus Labidochromis (Teleostei: Cichlidae) from Lake Malawi

The diagnosis of the genus Labidochromis is revised to include species with bicuspid outer teeth. Sixteen species, of which 13 are new, are described and illustrated and the validity of five others is discussed. The interrelationships between members of the genus and the relationship of the genus to other genera are discussed. No clearly defined sister group to the genus has been found either within or outside the Lake Malawi cichlid species flock. A key based on the coloration of known species is included.     

Complete genome sequence of Paludibacter propionicigenes type strain (WB4)

Paludibacter propionicigenes Ueki et al. 2006 is the type species of the genus Paludibacter, which belongs to the family Porphyromonadaceae. The species is of interest because of the position it occupies in the tree of life where it can be found in close proximity to members of the genus Dysgonomonas. This is the first completed genome sequence of a member of the genus Paludibacter and the third sequence from the family Porphyromonadaceae. The 3,685,504 bp long genome with its 3,054 protein-coding and 64 RNA genes consists of one circular chromosome and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Phylogenetic analysis of the genus Microbacterium based on 16S rRNA gene sequences

Abstract 16S rRNA gene (rDNA) studies of the six species of the genus Microbacterium, M. lacticum, M. laevaniformans, M. dextranolyticum, M. imperiale, M. arborescens and M. aurum , were performed and the primary structures were compared with those of 29 representative actinobacteria and related organisms. Phylogenetic analysis indicated that six species of the genus Microbacterium and representative four species of the genus Aureobacterium appear to be phylogenetically coherent as was suggested by Rainey et al., although the peptidoglycan types of these two genera are different (peptidoglycan type B1 or B2). Thus, the phylogenetical analyses revealed that members of actinobacteria with group B-peptidoglycan do not cluster according to their peptidoglycan types, but form compact cluster different from actinobacteria or actinomycetes with group A-peptidoglycan.     

Phylogenetics and evolution of the aphid genus Uroleucon based on mitochondrial and nuclear DNA sequences

The genus Uroleucon, and the related genus Macrosiphoniella, represent a large Tertiary radiation of aphids, with a total of about 300 species distributed throughout the world, primarily on host plant species in the family Asteraceae. A molecular phylogenetic study was conducted to identify major clades within Uroleucon and to address the cladistic validity of current subgeneric categories, the evolution of host plant associations, the age of origin, and intercontinental movements in this genus. The seventeen study species included members of the three major subgenera of Uroleucon, species from Europe and North America, one member of Macrosiphoniella, and two outgroups. Data consisted of DNA sequences for three mitochondrial regions and the nuclear gene EF1alpha, for a total of 4287 sites. Nodes supported strongly in both parsimony and maximum likelihood analyses suggest that: (1) Nearctic Uromelan are a monophyletic group branching near the base of the genus and not related to European Uromelan, (2) the New World subgenus Lambersius is possibly monophyletic but is not a tightly related group and is not closely related to other North American species, and (3) Nearctic members of subgenus Uroleucon are a closely related monophyletic group not allied with Nearctic Uromelan or Lambersius. Instead they represent a separate colonization by an Old World ancestor, as they are nested within a strongly supported clade containing European members of both subgenera Uroleucon and Uromelan. Neither of these subgenera is monophyletic. Molecular clock calculations, based on calibrations of mitochondrial divergences from other insects, suggest that Uroleucon + Macrosiphoniella is a relatively recent radiation, probably no more than 5–10 million years old. Although largely confined to Asteraceae, this clade did not radiate in parallel with its host plants. Rather, lateral movement between lineages of Asteraceae must have occurred repeatedly.     

Vaxiations in floral development in Peperomia (Piperaceae) and their taxonomic implications

The floral development of two species of Peperomia, Peperomia reflexa A. Dietr. (P. tetraphylla (G. Font.) Hook. et Am.) and P. serpens C. DC., is described. The initiation order is in an acropetal succession and resembles that in P. metallica L. Lind. et Rod., P.pellucida (L.) Kunth and P. rubella Hook., although many more bracts are produced in these two species than in P. metallica. The arrangement of bracts and floral primordia is orthostichous in P. reflexa, but parastichous in P. serpens. The floral apices in P. reflexa are transversely ellipsoidal protuberances at first, then become saddle-shaped when they begin to produce simultaneously staminal primordia. They are similar to those of P. metallica, P. pellucida and P. rubella. However, their initiation of floral primordia is much delayed compared to the size of the bracts. The triangular or transvcrsely cuneate ridges then become L-shaped in P. serpens, this shape is related to the parastichous phyllotaxy of the bracts. So, the staminal primordia are successively initiated and develop at different rates. Therefore, they are not always the same size. The staminal primordia are initiated above the level of the floral apex in P. reflexa and P. serpens but below it in P. metallica, P. pellucida and P. rubella. The abaxial position of the carpel primordium on the apex and the closure of the ovary in P. reflexa and P. serpens are also similar to those in P. metallica, P. pellucida and P. rubella. The shape of the upper part of the ovary, stigmas and indumentum vary between the species. In P. reflexa, the upper part of the ovary becomes ovoid and acclivous, or leaning acropetally, to the axis of inflorescence. In P. serpens, it becomes helmet-shaped. The flowers of P.serpens are surrounded by the outgrowth of the axis of the inflorescence. The ontogenetical features of ovaries in Peperomia indicate that the fruit characters are useful in the taxonomy of the genus.