Physical and chemical characterization of the polysaccharide capsule of the marine bacterium,Hyphomonas strain MHS-3

Hyphomonas MHS-3 is a biphasic, marine bacterium that synthesizes an exopolysaccharide (EPS) capsule, which has a role in attaching the adherent, prosthecate developmental stages to solid substrata. To correlate structure with function, we characterized this integral EPS. It has a relatively homogeneous molecular weight of approximately 60000 daltons, is acidic, and putatively contains large concentrations ofN-acetylgalactosamine (GalNAc). The theoretical identity of the anionic component of the polymer, and the similarities betweenHyphomonas MHS-3 EPS and other adhesive marine/aquatic bacterial EPS are discussed.     

Evidence for the Adhesive Function of the Exopolysaccharide of Hyphomonas Strain MHS-3 in Its Attachment to Surfaces

Hyphomonas strain MHS-3 (MHS-3) is a marine procaryote with a biphasic life cycle and which has prosthecate stages that adhere to submerged substrata. We found that adherent forms produced an exopolysaccharide (EPS) capsule that bound Glycine max lectin, Arachis hypogaea lectin, and Bauhinia purpurea lectin (BPA), each having affinity for N-acetyl-d-galactosamine. It also bound the dye Calcofluor. BPA and Calcofluor were tested for the ability to hinder MHS-3 adhesion to glass surfaces; they reduced attachment by >50 and >85%, respectively. Periodate treatment also reduced attachment (by >80%), but pronase treatment did not. Furthermore, an EPS(sup-) variant, Hyphomonas strain MHS-3 rad, did not attach well to surfaces. These results suggest that the MHS-3 EPS capsule is an adhesin.     

Spatial and Temporal Deposition of Adhesive Extracellular Polysaccharide Capsule and Fimbriae by Hyphomonas Strain MHS-3

Hyphomonas strain MHS-3, a member of a genus of primary colonizers of surfaces immersed in marine water, synthesizes two structures that mediate adhesion to solid substrata, namely, capsular exopolysaccharide and fimbriae. Specific stains, gold-labelled lectins, and monoclonal antibodies, along with transmission electron microscopy of synchronized populations, revealed that both structures are polarly and temporally expressed. The timed synthesis and placement of the fimbriae and capsule correlated with the timing and locus of MHS-3 adhesion.     

A reassessment of some Asian species of Heterophyllium (Schimp.) Kindb. (Pylaisiadelphaceae,Bryophyta)

Introduction. Heterophyllium albicans Thér., H. henryi Tixier, H. micro-alare (Broth. & Paris) Broth. and H. tonkinense (Broth. & Paris) Broth. were all either poorly known species or known only from the type collections since their inception.

Methods. Examination of the type material confirmed that the alar cell structure in these species do not conform to the generic concept of Heterophyllium (Schimp.) Kindb. The study also revealed some new features previously unreported in these species, i.e., the filamentous pseudoparaphyllia, one of the characteristic features of the genus Isopterygium Mitt.

Key Results & Conclusions. Three new combinations, Isopterygium albicans (Thér.) Y.Jia & S.He, I. micro-alare (Broth. & Paris) Y.Jia & S.He, and I. tonkinense (Broth. & Paris) Y.Jia & S.He are proposed. Heterophyllium henryi Tixier is treated as a new synonym of Brotherella henonii (Duby) M.Fleisch.     

Habitat use and tree selection of a declining Afro-Palaearctic migrant at sub-Saharan staging and wintering sites

Capsule: Wood Warblers Phylloscopus sibilatrix showed significant selection for tree species and woodland characteristics at staging and wintering sites in sub-Saharan Africa.

Aims: To investigate home range size, habitat and tree species selection of Wood Warblers at a staging site in Burkina Faso (Koubri) and a wintering site in Ghana (Pepease).

Methods: Comparing habitat recorded at locations of radio-tagged birds and at control points, we investigated whether there was habitat and tree species selection. We also compared home range size of individual birds between the two sites.

Results: Home range size did not differ between the two sites. There was significant selection for tree species at both Koubri and Pepease: Anogeissus leiocarpus and Albizia zygia, respectively. At Koubri, there was significant avoidance of the most common tree species (Azadirachta indica, Mangifera indica (both non-native), Vitellaria paradoxa and Acacia spp.). In addition, there was a preference for taller trees and greater tree density at both sites. However, the probability of a point being used declined with increasing number of taller (>14?m) trees.

Conclusion: Fine-scale selection of woodland habitats suggests that Wood Warblers are likely to suffer the consequences of ongoing land-use change in their West African wintering grounds.     

Taxonomic notes on Weissia subgenus Astomum,including Weissia wilsonii D.A.Callaghan,a new species from Europe

Introduction. The present study investigates the taxonomy of European members of Weissia Hedw. subgenus Astomum Hampe., a group considered taxonomically difficult and including species of high conservation concern.

Methods. A broad set of samples were subject to DNA sequencing and morphological analysis, plus a review of type material was undertaken.

Key Results and Conclusions. Three taxonomic additions and changes are supported. (1) Weissia longifolia var. angustifolia (Baumgartner) Crundw. & Nyholm is raised to species rank, W. angustifolia (Baumgartner) D.A.Callaghan, comb. et. stat. nov. (2) The type of W. multicapsularis (Sm.) Mitt. comprises an intermix of Phascum cuspidatum Hedw. and W. longifolia Mitt., and the protologue refers to unique features of P. cuspidatum but no such features of W. longifolia. Weissia multicapsularis is therefore described as a new synonym of P. cuspidatum. (3) Plants that have been named as W. multicapsularis by modern authors comprise an undescribed species, here named W. wilsonii D.A.Callaghan, sp. nov. An illustrated key to European species of Weissia subgenus Astomum is provided.     

Cheilolejeunea morganii Bever. & Glenny (Lejeuneaceae,Marchantiopsida), a newly described species from lowland indigenous forest sites in New Zealand

Introduction. Cheilolejeunea morganii Bever. & Glenny, a new species of Cheilolejeunea from a lowland forest habitat in eastern Taranaki in the North Island of New Zealand, is described and illustrated.

Methods. DNA sequences were extracted from recently collected material at two locations and compared with those for species in a published phylogeny of the genus to establish the position of C. morganii. Photographic images were obtained of key features of the species for the preparation of illustrations for publication.

Key results. Cheilolejeunea morganii does not match any species described for New Zealand or Australia. The sequencing results indicate its position in the phylogeny is close to Section Paroicae. A key to the New Zealand species of Cheilolejeunea is provided.

Conclusions. In the Australasian flora, C. morganii is distinguished from other species by its combination of monoicy, pycnolejeuneoid gynoecial innovations, lobule length less than 50% lobe length and a multicellular second lobule tooth with 3–4 cells uniseriate. A case is presented for the recognition of the species as a New Zealand endemic.     

Inter- and intra-specific diversity of Cuban Pinguicula (Lentibulariaceae) based on morphometric analyses and its relation with geographical distribution

Background: Phenotypic variations have been observed in populations of west Cuban Pinguicula species. Such populations occur in patches under different ecological conditions associated with specialised habitats and separated by geographical and ecological barriers, which can lead to morphological differentiation.

Aims: To analyse morphological diversity among species and populations of Cuban Pinguicula; and to test if morphological variability is associated with geographical distribution and distance between populations.

Methods: We sampled a total of eight populations of P. albida, P. cubensis and P. filifolia and tested for morphometric differences among them by Principal Component Analysis (PCA) and analysis of variance (ANOVA) based on 31 quantitative traits. We also assessed the geographical isolation with respect to morphological distance.

Results: The studied species showed high morphological variability at both species and population level. Reproductive characteristics appeared to be more promissory than vegetative ones in distinguishing geographical groups since they clearly defined populations; nevertheless a strong component of individual variation was observed. According to the distance analysis, such morphological variations were correlated with fragmented populations and isolation and allowed the differentiation of two morphotypes of P. albida and two of P. filifolia.

Conclusions: We conclude that high phenotypic variation of the analysed species is related to geographical and ecological isolation which have led to the differentiation of morphotypes within species.     

Trolox-equivalent antioxidant capacity and composition of five alpine plant species growing at different elevations on the Qinghai–Tibetan Plateau

Background: Alpine plants on the Qinghai–Tibetan Plateau are exposed to an extremely harsh environment, namely severe cold, strong ultraviolet radiation, hypoxia and low CO₂ partial pressure. These conditions are sources of oxidative stress, which increase in severity with increasing elevation.

Aims: To examine whether antioxidant capacity and chemical composition of alpine plants change with increasing elevation.

Methods: We measured the Trolox-equivalent antioxidant capacity (TEAC) and chemical composition of five alpine plant species at 3016, 3814 and 4621 m a.s.l.

Results: With increasing elevation: (1) the TEAC increased and total phenols and tannins tended to increase in two forb and two shrub species but not in a sedge species; (2) concentrations of protein and fat increased in all five plant species; (3) polyunsaturated fatty acids (PUFA) increased and (4) mineral concentrations tended to decrease, but trends were inconsistent.

Conclusions: We conclude that with increasing elevation, TEAC and total phenols and tannins increased which we interpreted as an adaptation to higher oxidative stress; and protein and fat contents increased to support high metabolic activity. The increase in PUFA and the trend for minerals to decrease with increasing elevation require further investigation.     

Brood sex ratio in expansive and non-expansive tern species in east-central Poland

Capsule Evidence from two tern species does not support the theory that species in expansion should bias their brood sex ratios towards the more dispersing sex.

Aims Sex ratio theory predicts that when a species is in expansion, the sex ratio should be biased towards the more dispersing sex. We compared the sex ratio of nestlings in two closely related species of terns, characterized by different expansion rates: the White-winged Tern Chlidonias leucopterus (an expansive species) and the Black Tern Chlidonias niger (a non-expansive species).

Methods The fieldwork was carried out in the valleys of the Rivers Bug and Narew in east-central Poland, from 2008 to 2014, during which time eight White-winged Tern colonies and ten Black Tern colonies were monitored. Nest inspections began around 15–20 May, when the first eggs were laid, and continued until mid-July, when the last nestlings were 7–20 days old.

Results The nestling sex ratios were similar in both species, and the differences between number of females and males were not significant (White-winged Tern: 56.6% females vs. 43.4% males; Black Tern: 57.4% females vs. 42.6% males).

Conclusions The lack of differences in nestling sex ratio in these species may be due to the cessation of the White-winged Tern's expansion in this area or because the sex ratio is characteristic of Sternidae species, as similar results have been reported for other tern species.     

Functional group dominance and not productivity drives species richness

Background: There is a lack of consensus about the productivity–richness relationship, with several recent studies suggesting that it is not productivity but other factors that are the important drivers that determine species richness.

Aims: Here, we examine the relationship between productivity, functional group dominance and plant species richness at the plot scale in Tibetan Plateau meadows. These alpine meadows are ideal to examine the species productivity-richness relationship because they have a very high species richness, a large gradient in productivity, and can be dominated by either graminoids (grasses and sedges) or forbs.

Methods: We measured plant species richness and above-ground biomass along a natural gradient of functional group abundance in 44 plots distributed across five natural, winter-grazed but otherwise undisturbed sites in the eastern part of the Qing-Hai Tibetan Plateau, in Gansu province, China in 2008.

Results: Graminoid abundance (i.e. graminoid biomass as percent of the total above-ground biomass) explained 39% of plot differences in species richness while neither productivity nor the biomass of the three most abundant plant species, either individually or combined, were a significant predictor of species richness.

Conclusions: Our results show that within these alpine meadows, a shift from graminoid to forb dominance, rather than the individual dominant species or productivity itself, is strongly correlated with species richness. Thus, differences in functional group abundance can be a strong driver of observed plant species richness patterns.     

Bacterial amelioration of bauxite residue waste of industrial alumina plants

The high alkali content of bauxite residue deposits from alumina production plants in industrial nations poses a challenge to reestablish flora and fauna at the deposit sites. The present study demonstrated that low levels of injured bacterial cells in the bauxite residue actively grew using various added nutrients and/or hay. The organisms grew from less than 10 to more than 10⁹ cells g⁻¹ bauxite residue and formed organic acids that lowered the pH from 13 to about 7.0. A total of 150 cultures was isolated from treated bauxite residue and included species of Bacillus, Lactobacillus, Leuconostoc, Micrococcus, Staphylococcus, Pseudomonas, Flavobacterium and Enterobacter. Scanning electron micrographs demonstrated that untreated particles (control) of the bauxite residue were clumped together, and in treated bauxite residue these particles were highly dispersed with microcolonial structures. Furthermore, the treated bauxite residue supported growth of several plants and earthworms that survived for over 300 days. In a test plot bioremediation on a residue deposit at Alcoa Point Comfort, TX, the Bermuda grass hay used was effective mulch material and encouraged water filtration, leading to establishment and growth of salt-tolerant vegetative species. Journal of Industrial Microbiology & Biotechnology (2001) 27, 228–233. Received 20 January 2001/ Accepted in revised form 11 July 2001     

The capsule polysaccharide structure and biogenesis for non-O1 Vibrio cholerae NRT36S: genes are embedded in the LPS region

Background  

In V. cholerae, the biogenesis of capsule polysaccharide is poorly understood. The elucidation of capsule structure and biogenesis is critical to understanding the evolution of surface polysaccharide and the internal relationship between the capsule and LPS in this species. V. cholerae serogroup O31 NRT36S, a human pathogen that produces a heat-stable enterotoxin (NAG-ST), is encapsulated. Here, we report the covalent structure and studies of the biogenesis of the capsule in V. cholerae NRT36S.     

The diversity and community dynamics of hazelwood lichens and bryophytes along a major gradient of human impact

Background: Oceanic hazelwoods in western Scotland are hypothesised to be unmanaged post-glacial relicts, representing an unusual type of old-growth forest habitat in Europe. They are characterised by an exceptionally high epiphytic diversity, including their status as ‘hotspots’ for indicators of woodland ecological continuity.

Aims: The aim of this study was to evaluate the effects of climate, pollution and management on the occurrence of epiphytic lichens and bryophytes on Corylus avellana.

Methods: Thirteen hazelwood study sites were systematically sampled along a climate, pollution and management gradient in Britain. Epiphyte composition and richness were examined in a strict hierarchical framework, and compared against site-, stool- and stem-scale environmental predictors.

Results: The study showed that along the gradient from ‘clean-air’ relict sites to ‘polluted’ coppiced sites: (i) epiphytic local stem-scale diversity declined, (ii) there was a loss of late-successional species including foliose cyano- and tripartite lichens and bryophytes and (iii) stem sizes were reduced, providing a further limit to the accumulation of species richness within a site.

Conclusions: Relict hazelwoods in western Scotland are confirmed as an example of the most intact epiphyte communities. In particular, we show that the transition to coppicing can be clearly linked to ecological processes causing species loss.     

New solvent-producing Clostridium sp. strains, hydrolyzing a wide range of polysaccharides, are closely related to Clostridium butyricum

Thirteen new Clostridium strains, previously isolated from soil and found to produce high amounts of solvents from glucose, hydrolyzed a great variety of α- and β-glycans, including raw starch, xylan, pectin, inulin and cellulose. The sequences of the PCR-amplified DNA fragments containing the variable 3′ part of one of the 16S rRNA genes were 99.5% identical. The macrorestriction pattern of two endonucleolytic digests of chromosomal DNA in the pulsed-field gel electrophoresis (PFGE) confirmed their high homogeneity on the DNA level. The complete 16S rRNA gene sequence of three selected strains was 99.8% identical to the 16S rRNA gene sequence from Clostridium butyricum and separates them from C. acetobutylicum. To the closely related four species of solventogenic clostridia a new group of strains has to be added, which has a great potential for the direct fermentation of biomass. Journal of Industrial Microbiology & Biotechnology (2001) 27, 329–335. Received 12 September 2000/ Accepted in revised form 25 July 2001     

Rhabdias rhampholeonis n. sp. and Rhabdias mariauxi n. sp. (Nematoda, Rhabdiasoidea), first lung worms from leaf chameleons: Description, molecular evidence and notes on biology

Rhabdias rhampholeonis n. sp. from Rhampholeon (Rh.) spectrum, Cameroon, and Rhabdias mariauxi n. sp. from Rieppeleon brevicaudatus, Tanzania, are the first lung worms from leaf chameleons. The new species are similar to the majority of species parasitic in chamaeleonids by having a long (≥10 mm) and thick body (≥500 µm), long oesophagus (≥800 µm), wide buccal capsule (≥40 µm) and low buccal ratio (<0.5). They most closely resemble Rhabdias chamaeleonis and Rhabdias cristati parasitic in Trioceros spp. from East Africa and Cameroon, respectively. Main distinctive characters are a buccal capsule composed of two segments and the head shape. The dorso-ventrally flattened buccal capsule of R. mariauxi n. sp. is unique in Rhabdias parasitising Chamaeleonidae. Sequences of the 12S rDNA and mitochondrial cytochrome c oxidase subunit 1 (coxI) genes were obtained and compared to those of Rhabdias okuensis, the only sequences published for chamaeleonid lung worms. The smallest nucleotide interspecific distances were found between R. mariauxi n. sp. and the former species of Trioceros from Cameroon. Hermaphroditism in females in the lungs, and R. mariauxi n. sp. free-living stages are like in other species from Chamaeleonidae, but the number of infective larvae produced per free-living female (one or two) was not fixed.     

Water-induced stress influences the relative investment in cleistogamous and chasmogamous flowers of an invasive grass,Microstegium vimineum (Poaceae)

Background: Global climate change has the potential to shape evolutionary trajectories of invasive species via many routes, including through changes in mating systems. Many cleistogamous (CL) plants adjust investment in CL (selfed) vs. chasmogamous (CH, potentially outcrossed) progeny across environmental gradients. However, the details of such adjustments are lacking for highly invasive plant species.

Aims: We used a highly invasive grass, Microstegium vimineum, as a model for understanding how changes in water-induced stress (including potential associated changes in soil nutrient availability) might affect mating systems and thus evolutionary change in invasive species. We predicted that plants would respond to increased water-induced stress through a relative reduction in investment in CL vs. CH reproduction (i.e., a decrease in the CL:CH ratio).

Methods: Under greenhouse conditions, we measured fecundity (number of inflorescences and florets per plant) as well as relative investment in CL vs. CH florets (CL:CH ratios for number of inflorescences, florets per inflorescence, overall florets) in response to three watering treatments approximating mesic (low) to inundated (high) conditions.

Results: Plant biomass was significantly lower in high-watering treatment relative to intermediate and low treatments, indicating that the high-water condition was stressful. Contrary to expectations, stressed plants significantly increased relative investment in CL reproduction, a pattern associated with decreased inflorescence number and increased numbers of CL florets per inflorescence.

Conclusions: We conclude that changes in water-induced stress could strongly influence realised rates of outcrossing in this invasive plant, leading to mating system evolution, and altered invasiveness.     

Adobe bricks can help identify historic weed flora – a case study from south-western Hungary

Background: The adobe bricks of old buildings can preserve diaspores of cultivated and weed species associated with arable fields. Recovery of these plant remains can provide insight into historical agriculture, and former weed flora.

Aims: This study aims to describe and evaluate the changes in the weed flora in south-western Hungary, based on archaeobotanical findings and contemporary plot surveys.

Methods: Plant remains of 51 adobe bricks dating from 1850 to 1950 were identified in south-western Hungary and compared with the flora of 104 plots from the same region.

Results: A total of 276 species were identified from the adobe bricks, while the present-day plot survey yielded 305 species. A significant difference was found between the historical (60- to 160-year-old) and current species richness of the weed flora. The proportion of rare and threatened species decreased by 38.1%. A total of 142 weed species identified from the adobe bricks have declined, and 40 of them even disappeared in comparison with the contemporary surveys. Today, in Hungary and neighbouring countries, more than 80 of these species are rare or threatened and some of them are extinct or critically endangered.

Conclusions: Our findings show that many weed species that flourished in the early twentieth century have declined. This is most likely due to the intensive management practices of cultivated fields and the spread of invasive neophyte taxa. We showed that analysing the botanical information preserved in adobe bricks is a reliable method that can provide evidence of long-term changes in weed flora.