15 research outputs found
Phytostabilization of polluted military soil supported by bioaugmentation with PGP-trace element tolerant bacteria isolated from helianthus petiolaris
Lead (Pb) and cadmium (Cd) are major environmental pollutants, and the accumulation of these elements in soils and plants is of great concern in agricultural production due to their toxic effects on crop growth. Also, these elements can enter into the food chain and severely affect human and animal health. Bioaugmentation with plant growth-promoting bacteria (PGPB) can contribute to an environmentally friendly and effective remediation approach by improving plant survival and promoting element phytostabilization or extraction under such harsh conditions. We isolated and characterised Pb and Cd-tolerant root-associated bacteria from Helianthus petiolaris growing on a Pb/Cd polluted soil in order to compose inoculants that can promote plant growth and also ameliorate the phytostabilization or phytoextraction efficiency. One hundred and five trace element-tolerant rhizospheric and endophytic bacterial strains belonging to eight different genera were isolated from the aromatic plant species Helianthus petiolaris. Most of the strains showed multiple PGP-capabilities, ability to immobilise trace elements on their cell wall, and promotion of seed germination. Bacillus paramycoides ST9, Bacillus wiedmannii ST29, Bacillus proteolyticus ST89, Brevibacterium frigoritolerans ST30, Cellulosimicrobium cellulans ST54 and Methylobacterium sp. ST85 were selected to perform bioaugmentation assays in greenhouse microcosms. After 2 months, seedlings of sunflower (H. annuus) grown on polluted soil and inoculated with B. proteolyticus ST89 produced 40% more biomass compared to the non-inoculated control plants and accumulated 20 % less Pb and 40% less Cd in the aboveground plant parts. In contrast, B. paramycoides ST9 increased the bioaccumulation factor (BAF) of Pb three times and of Cd six times without inhibiting plant growth. Our results indicate that, depending on the strain, bioaugmentation with specific beneficial bacteria can improve plant growth and either reduce trace element mobility or enhance plant trace element uptake.Fil: Saran, Anabel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - San Luis; Argentina. Instituto Nacional de TecnologÃa Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; Argentina. Hasselt University; BélgicaFil: Imperato, Valeria. Hasselt University; BélgicaFil: Fernandez, Lucia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - San Luis; Argentina. Instituto Nacional de TecnologÃa Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; ArgentinaFil: Gkorezis, Panos. Hasselt University; BélgicaFil: d´Haen, Jan. Hasselt University; BélgicaFil: Merini, Luciano Jose. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - San Luis; Argentina. Instituto Nacional de TecnologÃa Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; ArgentinaFil: Vangronsveld, Jaco. Hasselt University; Bélgica. Maria Curie Sklodowska University; PoloniaFil: Thijs, Sofie. Hasselt University; Bélgic
Exploring the Diversity and Aromatic Hydrocarbon Degrading Potential of Epiphytic Fungi on Hornbeams from Chronically Polluted Areas
Plants can ‘catch’ and mitigate airborne pollutants and are assisted by fungi inhabiting their leaves. The structure and function of the fungal communities inhabiting the phyllosphere of hornbeam trees growing in two chronically polluted areas, the oilfield of Bóbrka and the city center of Warsaw, were compared to the ones growing in one nature reserve, the BiaÅ‚owieża National Park. Fungi were isolated and characterized both phylogenetically and functionally for their potential role in air pollution mitigation. Both culture-dependent (e.g., enzyme assays and tolerance tests) and culture-independent methods (e.g., ITS and shotgun sequencings) were used. Furthermore, the degradation potential of the fungi was assessed by gas chromatography mass spectrometry (GC-MS). Shotgun sequencing showed that the phyllosphere fungal communities were dominated by fungi belonging to the phylum Ascomycota. Aureobasidium was the only genus detected at the three locations with a relative abundance ≥1.0%. Among the cultivated epiphytic fungi from Bóbrka, Fusarium sporotrichioides AT11, Phoma herbarum AT15, and Lophiostoma sp. AT37 showed in vitro aromatic hydrocarbon degradation potential with laccase activities of 1.24, 3.62, and 7.2 µU L−1, respectively, and peroxidase enzymes with activities of 3.46, 2.28, and 7.49 µU L−1, respectively. Furthermore, Fusarium sporotrichioides AT11 and Phoma herbarum AT15 tolerated exposure to airborne naphthalene and benzene. Lophiostoma sp. AT37 was the most tolerant to exposure to these pollutants, in line with being the best potential aromatic hydrocarbon degrader isolated in this study.Fil: Imperato, Valeria. Hasselt University; BélgicaFil: Portillo Estrada, Miguel. Universiteit Antwerp; BélgicaFil: Saran, Anabel. Gobierno de la Provincia de La Pampa. Ministerio Público. Agencia de Investigación CientÃfica; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Patagonia Confluencia; ArgentinaFil: Thoonen, Anneleen. Hasselt University; BélgicaFil: Kowalkowski, Lukasz. Hasselt University; Bélgica. Warsaw University of Life Sciences; PoloniaFil: Gawronski, Stanislaw W.. Warsaw University of Life Sciences; PoloniaFil: Rineau, Francois. Hasselt University; BélgicaFil: Vangronsveld, Jaco. Hasselt University; Bélgica. Maria Curie-SkÅ‚odowska University; PoloniaFil: Thijs, Sofie. Hasselt University; Bélgic
Characterisation of the Carpinus betulus L. Phyllomicrobiome in Urban and Forest Areas
Urban green areas are highly valued by citizens for their contribution to the quality of life in cities. Plants play an important role in mitigating airborne pollutants and are assisted in this role by the metabolic capacities of the millions of microbial cells that colonize leaf surfaces (phyllosphere). Many factors influence phyllosphere microbial community composition and function, but to what extent does airborne pollution in cities impact the composition of microbial communities and their functional degradation genes? Here we describe the characterization of the phyllospheric bacterial communities of Carpinus betulus L. trees (hornbeam) across three locations: the city center of Warsaw (Poland), a forest in a UNESCO World Heritage Site (Białowieża), and a forest in one of the world’s oldest operational oil fields (Bóbrka). C. betulus contained higher particulate matter (PM) concentrations, with higher concentrations of palladium and radon in the PM, on leaves in Warsaw than in the forests. Volatile organic compound (VOC) analyses of sampled air revealed higher concentrations of butanone methyl propanal, butylbenzene, and cyclohexane in Bóbrka than Warsaw and Białowieża, while in Warsaw, xylene and toluene were higher. Shotgun microbiome sequencing uncovered a dominance of Gammaproteobacteria (71%), mainly Pseudomonas spp., Actinobacteria, Alpha- and Betaproteobacteria, and Firmicutes. Community composition and function differed significantly between the forests and Warsaw city center. Statistically more hydrocarbon degradation genes were found in Białowieża compared to Warsaw and Bóbrka, and in vitro tests of diesel degradation and plant growth promotion traits of culturable representatives revealed that Białowieża held the highest number of bacteria with plant beneficial properties and degradation genes. This study provides the first detailed insights into the microbiome of C. betulus and sets the stage for developing to a more integrated understanding of phyllosphere microbiota in cities, and their relationships with human health
The recruitment process of foreign workers
Case study was implemented for Posti in the mail delivery section, since it has a high number of foreign worker and the emphasis was on the recruitment process of foreign workers.
The purpose of my thesis is to discuss the recruitment process of foreign workers and show the value foreign workers can bring to the Finnish labour market. The research also discusses the different bureaucratic requirement and their variation within EU citizens, non-EU citizens and refugee/asylum seekers and the reasons for them. Research discusses the cultural implications and integration processes for foreign workers.
The empirical part of my thesis includes the data from Posti’s workers in mail delivery section. Interviews were conducted with the recruitment manager at Posti and with a foreign employee in the mail delivery sector at Posti. I analyze the recruitment process at Posti and indicate knowledge required for it. Recruitment questionnaires, as well as Geert Hofstede’s theory and the data about immigration to Finland, are used as secondary sources in the empirical parts. I have used the secondary sources also to discuss about the value foreign workers bring to the company.
In addition, my thesis discusses the various requirements and legal aspects of hiring a foreign worker and challenges and benefits coming with it.
Based on the research, high amount of foreign worker indicated the process is already working but some small suggestions and an integration program was suggested for the future.
In conclusion, my thesis offers a view on how recruitment process is implemented at practical level in a relative big Finnish compan
Enhancing the Rice Seedlings Growth Promotion Abilities of Azoarcus sp. CIB by Heterologous Expression of ACC Deaminase to Improve Performance of Plants Exposed to Cadmium Stress
© 2020 by the authors.Environmental pollutants can generate stress in plants causing increased ethylene production that leads to the inhibition of plant growth. Ethylene production by the stressed plant may be lowered by Plant Growth-Promoting Bacteria (PGPB) that metabolizes the immediate precursor of ethylene 1-aminocyclopropane-1-carboxylate (ACC). Thus, engineering PGPB with ACC deaminase activity can be a promising alternative to mitigate the harmful effects of pollutants and thus enhance plant production. Here we show that the aromatics-degrading and metal-resistant Azoarcus sp. CIB behaves as a PGP-bacterium when colonizing rice as an endophyte, showing a 30% increment in plant weight compared to non-inoculated plants. The cloning and expression of an acdS gene led to a recombinant strain, Azoarcus sp. CIB (pSEVA237acdS), possessing significant ACC deaminase activity (6716 nmol mg−1 h−1), constituting the first PGPB of the Rhodocyclaceae family equipped with this PGP trait. The recombinant CIB strain acquired the ability to protect inoculated rice plants from the stress induced by cadmium (Cd) exposure and to increase the Cd concentration in rice seedlings. The observed decrease of the levels of reactive oxygen species levels in rice roots confirms such a protective effect. The broad-host-range pSEVA237acdS plasmid paves the way to engineer PGPB with ACC deaminase activity to improve the growth of plants that might face stress conditions.This work was supported by grants BIO2016-79736-R and PCIN-2014-113 from the Ministry of Economy and Competitiveness of Spain; by a grant of Fundación Ramón-Areces XVII CN; and by Grants CSIC 2016 2 0E 093 and 2017 2 0I 015;. We also acknowledge the UHasselt Methusalem project 08M03VGRJ.Peer reviewe
Inoculated Seed Endophytes Modify the Poplar Responses to Trace Elements in Polluted Soil
Seed endophyte inoculation can enhance the plant tolerance to pollutants, which allows plant cultivation on trace element (TE) polluted soils. Methylobacterium sp. CP3 and Kineococcus endophyticus CP19 were tested in vitro for their tolerance to Zn and Cd and their plant growth promotion traits. The in vivo effects of bioaugmentation with individual strains or both strains were tested using two poplar cultivars, Populus deltoides x (P. trichocarpa x P. maximowiczii) ‘Dender’ and ‘Marke’, grown in TE polluted soil for six weeks. Methylobacterium sp. was found to grow on media enriched with 0.4 and 0.8 mM Cd, and both endophytes tolerated 0.6 and 1 mM Zn, due to the presence of genes involved in Zn and Cd tolerance and transport. Methylobacterium sp. showed an extracellular ion sequestration mechanism. Production of indole-3-acetic acid by Methylobacterium sp. and K. endophyticus, as well as phosphorus solubilization by Methylobacterium sp. were observed. Bioaugmentation with both endophytes increased the shoot length of Populus ‘Marke’ and enhanced the Mg uptake in both cultivars. Inoculation with Methylobacterium sp. reduced the bioaccumulation of Zn in ‘Marke’, conferring it an excluder strategy. Methylobacterium sp. and K. endophyticus seemed to improve the plant nutritional status, which can alleviate abiotic stress
Surgical results of cranioplasty with a polymethylmethacrylate customized cranial implant in pediatric patients: A single-center experience
OBJECTIVE: Cranioplasty is a reconstructive procedure used to restore skull anatomy and repair skull defects. Optimal skull reconstruction is a challenge for neurosurgeons, and the strategy used to achieve the best result remains a topic of debate, especially in pediatric patients for whom the continuing skull growth makes the choice of material more difficult. When the native bone flap, which is universally accepted as the preferred option in pediatric patients, is unavailable, the authors' choice of prosthetic material is a polymethylmethacrylate (PMMA) implant designed using a custom-made technique. In this paper the authors present the results of their clinical series of 12 custom-made PMMA implants in pediatric patients. METHODS: A retrospective study of the patients who had undergone cranioplasty at Gaslini Children's Hospital between 2006 and 2013 was conducted. A total of 12 consecutive cranioplasties in 12 patients was reviewed, in which a patientspecific PMMA implant was manufactured using a virtual 3D model and then transformed into a physical model using selective laser sintering or 3D printing. All patients or parents were administered a questionnaire to assess how the patient/parent judged the aesthetic result. RESULTS: Patient age at craniectomy ranged from 5 months to 12.5 years, with a mean age of 84.33 months at cranioplasty. The mean extension of the custom-made plastic was 56.83 cm2. The mean time between craniectomy and cranioplasty was 9.25 months. The mean follow-up duration was 55.7 months. No major complications were recorded; 3 patients experienced minor/moderate complications (prosthesis dislocation, granuloma formation, and fluid collection). CONCLUSIONS: In this patient series, PMMA resulted in an extremely low complication rate and the custom-made technique was associated with an excellent grade of patient or parent satisfaction on long-term follow up