Allergenicity to worldwide invasive grass Cortaderia selloana as environmental risk to public health

Allergies to grass pollen affects about 20% of the population worldwide. In the last few decades, the South American grass Cortaderia selloana (CS, Pampas grass) has expanded worldwide in a variety of countries including the USA, Australia and Western Europe. In many of these locations, CS has strikingly spread and has now been classified an invasive species. Many pernicious consequences of CS have been reported for local biodiversity, landscape and structures. However, the effect on human health has not been studied. To investigate this issue, we have chosen a European region on the northern cost of Spain where CS spread is overwhelming, Cantabria. We obtained CS pollen extract and analysed the allergenic reaction of 98 patients that were allergic to pollen of local grasses. We determined the skin reaction and the presence of specific IgE antibodies (sIgE) to CS or to a typical autochthonous grass, Phleum pratense. We also compared the seasonal symptoms with reported grass pollen counts in the area. The results strongly suggest that CS can cause respiratory allergies at a similar extent to the local grasses. Given that CS pollinises later than the local grasses, this would extend the period of grass allergies in the region for about three months every year, as stated by most of the patients. This is the first study reported on the effects of the striking expansion of CS on human health. Considering the strong impact that respiratory allergies have on the population, our results suggest that CS can currently constitute a relevant environmental health issue.

Essential Oil Content and Chemical Composition in 14 Selected Species From a Stretch of Restinga in Southern Brazil

The restinga is an Atlantic Forest ecosystem characterized by tree, shrub, and herb species that are rich sources of essential oils. In this study, we aim to quantify the essential oil content and determine the chemical constituents of fresh leaves of 14 plant species in a restinga stretch in southern Brazil. Essential oils were obtained by hydrodistillation in a Clevenger-type apparatus and analyzed by gas chromatography coupled to mass spectrometry. Campomanesia reitziana, Cortaderia selloana, and Sophora tomentosa had no essential oils. Total essential oil content ranged from 0.01% (Mikania involucrata) to 1.56% (Varronia curassavica). In total, 60 chemical constituents were identified, representing between 46.2% and 96.5% of the chemical composition of the essential oils. Limonene was the common constituent in all species in which the essential oils were present. The major constituents were ar-curcumene (15.1%) and cis-chrysanthenol (14.2%) in Ambrosia elatior; benzyl benzoate (43.5%) and benzyl salicylate (23.7%) in Aniba firmula; caryophyllene oxide (35.7%) and spathulenol (10.6%) in Austroeupatorium inulaefolium; spathulenol (19.8%) and caryophyllene oxide (14.0%) in Baccharis spicata; caryophyllene oxide (16.3%) in Eugenia astringens; curzerene (30.0%), limonene (13.0%), and germacrone (11.9%) in Eugenia uniflora; caryophyllene oxide (17.1%) and ledol (11.3%) in Lantana camara; caryophyllene oxide (27.7%) and limonene (12.7%) in M. involucrata; 1,8-cineole (19.8%) in Psidium cattleianum; limonene (10.2%) in Schinus terebinthifolius, and allo-aromadendrene (15.2%) in V. curassavica. We expect that our results can assist in selecting species of potential interest for herbal, phytotherapeutic, and cosmetic products.

Biorefining Potential of Wild-Grown Arundo donax, Cortaderia selloana and Phragmites australis and the Feasibility of White-Rot Fungi-Mediated Pretreatments

Arundo donax, Cortaderia selloana and Phragmites australis are high-biomass-producing perennial Poalean species that grow abundantly and spontaneously in warm temperate regions, such as in Mediterranean-type climates, like those of Southern Europe, Western United States coastal areas, or in regions of South America, South Africa and Australia. Given their vigorous and spontaneous growth, biomass from the studied grasses often accumulates excessively in unmanaged agro-forestry areas. Nonetheless, this also creates the demand and opportunity for the valorisation of these biomass sources, particularly their cell wall polymers, for biorefining applications. By contrast, a related crop, Miscanthus × giganteus, is a perennial grass that has been extensively studied for lignocellulosic biomass production, as it can grow on low-input agricultural systems in colder climates. In this study Fourier transform mid-infrared spectroscopy (FTIR), high-performance anion-exchange chromatography (HPAEC) and lignin content determinations were used for a comparative compositional characterisation of A. donax, C. selloana and P. australis harvested from the wild, in relation to a trial field-grown M. × giganteus high-yielding genotype. A high-throughput saccharification assay showed relatively high sugar release values from the wild-grown grasses, even with a 0.1M NaOH mild alkali pretreatment. In addition to this alkaline pretreatment, biomass was treated with white-rot fungi (WRF), which preferentially degrade lignin more readily than holocellulose. Three fungal species were used: Ganoderma lucidum, Pleurotus ostreatus and Trametes versicolor. Our results showed that neutral sugar contents are not significantly altered, while some lignin is lost during the pretreatments. Furthermore, sugar release upon enzymatic saccharification was enhanced, and this was dependent on the plant biomass and fungal species used in the treatment. To maximise the potential for lignocellulose valorisation, the liquid fractions from the pretreatments were analysed by high performance liquid chromatography – photodiode array detection – electrospray ionisation tandem mass spectrometry (HPLC-PDA-ESI-MSn). This study is one of the first to report on the composition of WRF-treated grass biomass, while assessing the potential relevance of breakdown products released during the treatments, beyond more traditional sugar-for-energy applications. Ultimately, we expect that our data will help promote the valorisation of unused biomass resources, create economic value, while contributing to the implementation of sustainable biorefining systems.

Atlas de la flora alóctona de Madrid, II. Nymphaceae-Gramineae

En esta segunda parte del atlas de flora alóctona de Madrid, se incluyen los órdenes Nymphaeales, Magnoliales, Laurales y las Monocotiledóneas. Se han considerado los taxones introducidos fuera de terrenos urbanos, parques o jardines, naturalizados o no. Se analizan 101 taxones y se incluyen referencias a otros 39. De los taxones analizados 58 son alóctonos en Madrid (49 naturalizados, 8 sin constancia de que lo estén y uno sin localidades concretas conocidas) y 9 en localidades próximas (8 naturalizados y 1 sin constancia de estarlo). Otros 11 son alóctonos en Madrid y podrían naturalizarse, pero no hay constancia de ello; 5 aparecen en jardines y en 6 hay sospechas de su posible presencia por usarse en cultivos o siembras extensivas. En 18 taxones hay discrepancias entre autores sobre si son o no alóctonas; en este trabajo se ha considerado que no lo son. Finalmente se propone excluir 5 taxones de la flora alóctona de Madrid. Entre los taxones incluidos Arundo donax está considerada una de las más agresivas invasoras del mundo. Algunos taxones son antiguas introducciones con poblaciones estabilizadas o en regresión. Hay muy pocas referencias a cereales naturalizados, lo que puede deberse a su baja persistencia. Algunas especies son neocolonizadoras, como Limnobium laevigatum, la más recientemente detectada, o Cortaderia selloana, en expansión.