Integrating waste valorization and symbiotic microorganisms for sustainable bioremediation of metal(loid)-polluted soils.

Remediation strategies for metal(loid)-polluted soils vary among the wide range of approaches, including physical, chemical, and biological remediation, or combinations of these. In this study, we assessed the effectiveness of a set of soil remediation treatments based on the combined application of inorganic (marble sludge) and organic amendments (vermicompost, and dry olive residue [DOR] biotransformed by the saprobic fungi Coriolopsis rigida and Coprinellus radians) and inoculation with arbuscular mycorrhizal fungi (AMFs) (Rhizophagus irregularis and Rhizoglomus custos). The treatments were applied under greenhouse conditions to soil residually polluted by potentially toxic elements (PTEs) (Pb, As, Zn, Cu, Cd, and Sb), and wheat was grown in the amended soils to test the effectiveness of the treatments in reducing soil toxicity and improving soil conditions and plant performance. Therefore, we evaluated the influence of the treatments on the main soil properties and microbial activities, as well as on PTE availability and bioaccumulation in wheat plants. Overall, the results showed a positive influence of all treatments on the main soil properties. Treatments consisting of a combination of marble and organic amendments, especially biotransformed DOR amendments, showed the greatest effectiveness in improving the soil biological status, promoting plant growth and survival, and reducing PTE availability and plant uptake. Furthermore, AMF inoculation further enhanced the efficacy of DOR amendments by promoting the immobilization of PTEs in soil and stimulating the phytostabilization mechanisms induced by AMFs, thus playing an important bioprotective role in plants. Therefore, our results highlight that biotransformed DOR may represent an efficient product for use as a soil organic amendment when remediating metal(loid)-polluted soils, and that its application in combination with AMFs may represent a promising sustainable bioremediation strategy for recovering soil functions and reducing toxicity in polluted areas.

Ecotoxicological Assessment of Polluted Soils One Year after the Application of Different Soil Remediation Techniques.

The present work evaluated the influence of eight different soil remediation techniques, based on the use of residual materials (gypsum, marble, vermicompost) on the reduction in metal(loid)s toxicity (Cu, Zn, As, Pb and Cd) in a polluted natural area. Selected remediation treatments were applied in a field exposed to real conditions and they were evaluated one year after the application. More specifically, five ecotoxicological tests were carried out using different organisms on either the solid or the aqueous (leachate) fraction of the amended soils. Likewise, the main soil properties and the total, water-soluble and bioavailable metal fractions were determined to evaluate their influence on soil toxicity. According to the toxicity bioassays performed, the response of organisms to the treatments differed depending on whether the solid or the aqueous fraction was used. Our results highlighted that the use of a single bioassay may not be sufficient as an indicator of toxicity pathways to select soil remediation methods, so that the joint determination of metal availability and ecotoxicological response will be determinant for the correct establishment of any remediation technique carried out under natural conditions. Our results indicated that, of the different treatments used, the best technique for the remediation of metal(loid)s toxicity was the addition of marble sludge with vermicompost.

Fungal Endophytes Enhance Wheat and Tomato Drought Tolerance in Terms of Plant Growth and Biochemical Parameters.

Drought is a major threat to plant growth in many parts of the world. During periods of drought, multiple aspects of plant physiology are negatively affected. For instance, water shortages induce osmotic imbalance, inhibit photosynthesis, decrease nutrient uptake, and increases the production of reactive oxygen species (ROS). In this context, it is necessary to develop sustainable strategies for crops that would help mitigate these conditions. In previous studies, endophytic Zopfiella erostrata strains were found to extensively colonize plant roots, forming a profuse melanized mycelium in the rhizosphere, which could be involved in improving water uptake and nutrient mineralization in plants. The aim of this study is to evaluate the effect of different strains of Z. erostrata on stress mitigation in wheat and tomato plants grown under water deficit conditions. General plant growth variables, as well as physiological and biochemical parameters, related to oxidative status were determined. Our data demonstrate that inoculation with both Zopfiella strains had a very significant effect on plant growth, even under water deficit conditions. However, we observed an even more pronounced impact, depending on the plant and strain involved, suggesting a certain degree of plant/strain compatibility. The biochemical aspects, the accumulation of proline, the oxidative damage to lipids, and the activity of antioxidant enzymes varied considerably depending on the endophyte and the plant evaluated.

Application of dry olive residue-based biochar in combination with arbuscular mycorrhizal fungi enhances the microbial status of metal contaminated soils.

Biochar made-up of dry olive residue (DOR), a biomass resulting from the olive oil extraction industry, has been proposed to be used as a reclamation agent for the recovery of metal contaminated soils. The aim of the present study was to investigate whether the soil application of DOR-based biochar alone or in combination with arbuscular mycorrhizal fungi (AMF) leads to an enhancement in the functionality and abundance of microbial communities inhabiting metal contaminated soils. To study that, a greenhouse microcosm experiment was carried out, where the effect of the factors (i) soil application of DOR-based biochar, (ii) biochar pyrolysis temperature (considering the variants 350 and 500 °C), (iii) soil application dose of biochar (2 and 5%), (iv) soil contamination level (slightly, moderately and highly polluted), (v) soil treatment time (30, 60 and 90 days) and (vi) soil inoculation with Funneliformis mosseae (AM fungus) on ß-glucosidase and dehydrogenase activities, FA (fatty acid)-based abundance of soil microbial communities, soil glomalin content and AMF root colonization rates of the wheat plants growing in each microcosm were evaluated. Biochar soil amendment did not stimulate enzyme activities but increased microbial abundances. Dehydrogenase activity and microbial abundances were found to be higher in less contaminated soils and at shorter treatment times. Biochar pyrolysis temperature and application dose differently affected enzyme activities, but while the first factor did not have a significant effect on glucosidase and dehydrogenase, a higher biochar dose resulted in boosted microbial abundances. Soil inoculation with F. mosseae favored the proliferation of soil AMF community and increased soil glomalin content as well as rates of AMF root colonization. This factor also interacted with many of the others evaluated to significantly affect soil enzyme activities, microbial abundances and AMF community. Our results indicate that the application of DOR-based biochar along with AMF fungi is an appropriate approach to improve the status of microbial communities in soils with a moderate metal contamination at short-term.

Inoculation of Indigenous Arbuscular Mycorrhizal Fungi as a Strategy for the Recovery of Long-Term Heavy Metal-Contaminated Soils in a Mine-Spill Area.

Symbiotic associations with arbuscular mycorrhizal fungi (AMF) offer an effective indirect mechanism to reduce heavy metal (HM) stress; however, it is still not clear which AMF species are more efficient as bioremediating agents. We selected different species of AMF: Rhizoglomus custos (Custos); Rhizoglomus sp. (Aznalcollar); and Rhizophagus irregularis (Intraradices), in order to study their inoculation in wheat grown in two soils contaminated with two levels of HMs; we tested the phytoprotection potential of the different AMF symbioses, as well as the physiological responses of the plants to HM stress. Plants inoculated with indigenous Aznalcollar fungus exhibited higher levels of accumulation, mainly in the shoots of most of the HM analyzed in heavily contaminated soil. However, the plants inoculated with the non-indigenous Custos and Intraradices showed depletion of some of the HM. In the less-contaminated soil, the Custos and Intraradices fungi exhibited the greatest bioaccumulation capacity. Interestingly, soil enzymatic activity and the enzymatic antioxidant systems of the plant increased in all AMF treatments tested in the soils with both degrees of contamination. Our results highlight the different AMF strategies with similar effectiveness, whereby Aznalcollar improves phytoremediation, while both Custos and Intraradices enhance the bioprotection of wheat in HM-contaminated environments.

Implications of mycoremediated dry olive residue application and arbuscular mycorrhizal fungi inoculation on the microbial community composition and functionality in a metal-polluted soil.

Metal-polluted soils represent hostile environments affecting the composition and functions of soil microbial communities. This study evaluated the implication of combining the mycoremediated dry olive residue (MDOR) amendment application with the inoculation of the arbuscular mycorrhizal fungi (AMF) Funneliformis mosseae in restoring the quality, composition, and functionality of soil microbial communities. To achieve this aim, a mesocosms experiment was set up that included three variations: i) with and without application of Penicillium chrysogenum-10-transformed MDOR (MDOR_Pc), and Chondrosterum purpureum-transformed MDOR (MDOR_Cp) amendments; ii) with and without F. mosseae inoculation; and iii) 30-day and 60-day soil treatment time. As a result of this combined treatment, changes in the soil labile organic C and N fractions were observed throughout the experiment. Increases in the abundance of phospholipid fatty acids (PLFAs) for bacteria, actinobacteria, and Gram- and Gram+ bacteria were also recorded at the end of the experiment. The addition of MDOR amendments boosted fungal and AM fungi communities. AM fungi root and soil colonization was also enhanced as the result of improvement nutrient turnover and spatial conditions caused by adding MDOR in combination with an inoculation of F. mosseae. The composition and functionality of microbial communities seemed to be an important ecological attribute indicating an apparently fully functional restoration of this metal-polluted soil and therefore suggesting the suitability of the combined MDOR and AM fungus treatment as a reclamation practice.

Enhancing laccase production by white-rot fungus Funalia floccosa LPSC 232 in co-culture with Penicillium commune GHAIE86.

To obtain enzymatic preparations with higher laccase activity levels from Funalia floccosa LPSC 232, available for use in several applications, co-cultures with six filamentous microfungi were tested. A laccase non-producing soil fungus, identified as Penicillium commune GHAIE86, showed an outstanding ability to increase laccase activity (3-fold as compared to that for monoculture) when inoculated in 6-day-old F. floccosa cultures. Maximum laccase production with the F. floccosa and P. commune co-culture reached 60 U/mL, or twice that induced by chemical treatments alone. Our study demonstrated that co-culture with soil fungi might be a promising method for improving laccase production in F. floccosa. Although the enhancement of laccase activity was a function of P. commune inoculation time, two laccase isoenzymes produced by F. floccosa remained unchanged when strains were co-cultured. These data are compatible with the potential of F. floccosa in agricultural applications in soil, whose enzyme machinery could be activated by soil fungi such as P. commune.

Risk element immobilization/stabilization potential of fungal-transformed dry olive residue and arbuscular mycorrhizal fungi application in contaminated soils.

The use of biotransformed dry olive residue (DOR) as organic soil amendment has recently been proposed due to its high contents of stabilized organic matter and nutrients. The potential of biotransformed DOR to immobilize risk elements in contaminated soils might qualify DOR as a potential risk element stabilization agent for in situ soil reclamation practices. In this experiment, the mobility of risk elements in response to Penicillium chrysogenum-10-transformed DOR, Funalia floccosa-transformed DOR, Bjerkandera adusta-transformed DOR, and Chondrostereum purpureum-transformed DOR as well as arbuscular mycorrhizal fungi (AMF), Funneliformis mosseae, inoculation was investigated. We evaluated the effect of these treatments on risk element uptake by wheat (Triticum aestivum L.) plants in a pot experiment with Cd, Pb, and Zn contaminated soil. The results showed a significant impact of the combined treatment (biotransformed DOR and AMF inoculation) on wheat plant growth and element mobility. The mobile proportions of elements in the treated soils were related to soil pH; with increasing pH levels, Cd, Cu, Fe, Mn, P, Pb, and Zn mobility decreased significantly (r values between -0.36 and -0.46), while Ca and Mg mobility increased (r = 0.63, and r = 0.51, respectively). The application of biotransformed DOR decreased risk element levels (Cd, Zn), and nutrient concentrations (Ca, Cu, Fe, Mg, Mn) in the aboveground biomass, where the elements were retained in the roots. Thus, biotransformed DOR in combination with AMF resulted in a higher capacity of wheat plants to grow under detrimental conditions, being able to accumulate high amounts of risk elements in the roots. However, risk element reduction was insufficient for safe crop production in the extremely contaminated soil.

Análisis de las buenas prácticas de participación ciudadana en las unidades de gestión clínica del Servicio Andaluz de Salud / Analysis of good practices for inhabitant participation in the clinical management units of the Andalusian Health Service (Spain)

Objetivo: Conocer buenas prácticas de participación ciudadana en las unidades de gestión clínica (UGC) del Servicio Andaluz de Salud (SAS) y explorar factores percibidos por profesionales de UGC del SAS que pueden influir en la existencia y la distribución de buenas prácticas de participación ciudadana. Método: Estudio con metodología mixta realizado en Andalucía en dos fases (2013-2015). En la fase 1 (estudio cuantitativo) se realizó un cuestionario online a directores/as de UGC con una comisión de participación ciudadana constituida. En la fase 2 (estudio cualitativo) se realizaron entrevistas semiestructuradas a profesionales del SAS con experiencia en participación ciudadana. Se realizó un análisis descriptivo de la información cuantitativa y un análisis de contenido semántico de la cualitativa. Resultados: En la fase 1 participaron 530 UGC. Las prácticas de participación ciudadana implementadas con mayor frecuencia en las UGC están circunscritas a los niveles de información y consulta. Otras prácticas que suponen una mayor implicación y delegación ciudadana son secundarias. En la fase 2 se entrevistó a 12 profesionales. Los obstáculos identificados por los/las profesionales que pueden afectar a la distribución de buenas prácticas están relacionados con las creencias y las actitudes de la ciudadanía, los/las profesionales, el sistema sanitario y el contexto. Conclusiones: Las principales prácticas de participación ciudadana en las UGC están relacionadas con los niveles más básicos de participación. No se reconocen claramente la manera y los mecanismos que facilitarían el empoderamiento ciudadano en el sistema sanitario (AU)

Objective: To discover good practices for inhabitant participation in the clinical management units (CMUs) of the Andalusian Health Service (AHS) (Spain) and to explore the reasons perceived by CMU and AHS professionals that may influence the presence and distribution of those good practices among the CMU. Methods: Study with mixed methodology carried out in Andalusia (Spain) in two phases (2013-2015). Firstly, an online survey was delivered to the Directors of the CMUs which had set up an inhabitant participation commission. In a second phase, a qualitative study was carried out through semi-structured interviews with professionals from the Andalusian Health Service with previous experience in inhabitant participation. A descriptive analysis of the quantitative information and a semantic content analysis of the qualitative information were carried out. Results: 530 CMUs took part in the survey. The inhabitant participation practices more often implemented in the CMUs are those related to the informing and consultation levels. Twelve professionals were interviewed in the second phase. Other practices with higher inhabitant involvement and delegation are secondary. The barriers which were identified by professionals are related to the beliefs and attitudes of the inhabitants, the professionals, the health system and the environment. Conclusion: The main practices for inhabitant participation in the CMUs are related to the most basic levels of participation. The method and dynamics which facilitate inhabitant empowerment within the health system are not clearly recognized (AU)

[Analysis of good practices for inhabitant participation in the clinical management units of the Andalusian Health Service (Spain)]. / Análisis de las buenas prácticas de participación ciudadana en las unidades de gestión clínica del Servicio Andaluz de Salud.

OBJECTIVE: To discover good practices for inhabitant participation in the clinical management units (CMUs) of the Andalusian Health Service (AHS) (Spain) and to explore the reasons perceived by CMU and AHS professionals that may influence the presence and distribution of those good practices among the CMU. METHODS: Study with mixed methodology carried out in Andalusia (Spain) in two phases (2013-2015). Firstly, an online survey was delivered to the Directors of the CMUs which had set up an inhabitant participation commission. In a second phase, a qualitative study was carried out through semi-structured interviews with professionals from the Andalusian Health Service with previous experience in inhabitant participation. A descriptive analysis of the quantitative information and a semantic content analysis of the qualitative information were carried out. RESULTS: 530 CMUs took part in the survey. The inhabitant participation practices more often implemented in the CMUs are those related to the informing and consultation levels. Twelve professionals were interviewed in the second phase. Other practices with higher inhabitant involvement and delegation are secondary. The barriers which were identified by professionals are related to the beliefs and attitudes of the inhabitants, the professionals, the health system and the environment. CONCLUSION: The main practices for inhabitant participation in the CMUs are related to the most basic levels of participation. The method and dynamics which facilitate inhabitant empowerment within the health system are not clearly recognised.

Risk element sorption/desorption characteristics of dry olive residue: a technique for the potential immobilization of risk elements in contaminated soils.

Olive oil production is one of the most relevant agroindustrial activities in the Mediterranean region and generates a huge amount of both solid and semi-solid wastes, the uncontrolled disposal of which might lead to serious environmental problems. Due to its organic matter and mineral nutrient content, the waste material can be applied to agricultural soil as a fertilizer. However, due to its high organic matter content, dry olive residue (DOR), commonly called "alperujo," has the potential to immobilize risk elements in contaminated soils. The main objective of this study was to assess the possible effect of DOR on sorption of risk elements such as cadmium (Cd), lead (Pb), and zinc (Zn) in the soil. A set of batch sorption experiments were carried out to assess the ability of DOR to adsorb Cd, Pb, and Zn where the effect of the preceding biotransformation of DOR by four species of fungi: Penicillium chrysogenum, Coriolopsis floccosa, Bjerkhandera adusta, and Chondrostereum purpureum was compared. The Freundlich and Langmuir sorption isotherms were calculated to assess the sorption characteristics of both transformed and non-transformed DOR. The results showed good potential sorption capacity of DOR, especially for Pb and to a lesser extent for Cd and Zn. Better sorption characteristics were reported for the biotransformed DOR samples, which are expected to show higher humification of the organic matter. However, the desorption experiments showed weakness and instability of the DOR-bound elements, especially in the case of Zn. Thus, future research should aim to verify the DOR sorption pattern in contaminated soil as well as the potential stabilization of the DOR element bounds where the increase of the pH levels of the DOR samples needs to be taken into account.

Exploring the potential of fungi isolated from PAH-polluted soil as a source of xenobiotics-degrading fungi.

The aim of this study was to find polycyclic aromatic hydrocarbon (PAH)-degrading fungi adapted to polluted environments for further application in bioremediation processes. In this study, a total of 23 fungal species were isolated from a historically pyrogenic PAH-polluted soil in Spain and taxonomically identified. The dominant groups in these samples were the ones associated with fungi belonging to the Ascomycota phylum and two isolates belonging to the Mucoromycotina subphylum and Basiodiomycota phylum. We tested their ability to convert the three-ring PAH anthracene in a 42-day time course and analysed their ability to secrete extracellular oxidoreductase enzymes. Among the 23 fungal species screened, 12 were able to oxidize anthracene, leading to the formation of 9,10-anthraquinone as the main metabolite, a less toxic one than the parent compound. The complete removal of anthracene was achieved by three fungal species. In the case of Scopulariopsis brevicaulis, extracellular enzyme independent degradation of the initial 100 µM anthracene occurred, whilst in the case of the ligninolytic fungus Fomes (Basidiomycota), the same result was obtained with extracellular enzyme-dependent transformation. The yield of accumulated 9,10-anthraquinone was 80 and 91 %, respectively, and Fomes sp. could slowly deplete it from the growth medium when offered alone. These results are indicative for the effectiveness of these fungi for pollutant removal. Graphical abstract ᅟ.

Clima emocional y liderazgo en los equipos sanitarios de Andalucía / Emotional climate and leadership in health care teams Andalusian

Objetivo: Conocer cómo influye el tipo de liderazgo de equipo en la calidad del clima emocional, en los equipos sanitarios de Andalucía. Diseño: Estudio descriptivo, cuantitativo con 6440 profesionales de la medicina y enfermería de 481 Unidades de Gestión Clínica del Servicio Andaluz de Salud. Metodología: Cuestionario on line de elaboración propia, con 15 preguntas de clima emocional y liderazgo. Resultados: El liderazgo de equipo es bien valorado por el personal sanitario, acompañado de valores de clima emocional medio. La capacidad del líder de facilitar la participación de todos los profesionales en el equipo, así como de definir y comunicar los objetivos y tareas a realizar, incide positivamente en la calidad del clima emocional. Conclusiones: Es necesario impulsar las habilidades motivacionales y cognitivas de liderazgo, para conferir mayor protagonismo y reconocimiento al personal sanitario y favorecer la gestión compartida en los equipos de trabajo

Objective: To research the influence of the leadership on the quality of the emotional climate, in the health care teams in Andalusia. Design: Quantitative, descriptive study with 6440 physicians and nurses from 481 health management units included in the Andalusian Health System. Methods: On-line questionnaire with 15 questions about emotional climate and leadership. Results: The statistical analysis revealed the existence of a well-considered leadership and a medium valued emotional climate. Leaders' capacity to promote participation of all members in the work team, and his o her ability to define and communicate the objectives, functions and tasks, have a positive effect on the quality of the emotional climate. Discussion: It seems important to promote leaders' motivational and cognitive skills, in order to confer a protagonist role and a more active professional recognition to the health professionals and to stimulate a shared management

The effectiveness of various treatments in changing the nutrient status and bioavailability of risk elements in multi-element contaminated soil.

Potential changes in the mobility and bioavailability of risk and essential macro- and micro-elements achieved by adding various ameliorative materials were evaluated in a model pot experiment. Spring wheat (Triticum aestivum L.) was cultivated under controlled condition for 60 days in two soils, uncontaminated Chernozem and multi-element contaminated Fluvisol containing 4900 ± 200 mg/kg Zn, 35.4 ± 3.6 mg/kg Cd, and 3035 ± 26 mg/kg Pb. The treatments were all contained the same amount of sulfur and were as follows: (i) digestate from the anaerobic fermentation of biowaste, (ii) fly ash from wood chip combustion, and (iii) ammonium sulfate. Macro- and micro-nutrients Ca, Mg, K, Fe, Mn, Cu, P, and S, and risk elements Cd, Cr, Pb, and Zn were assayed in soil extracts with 0.11 mol/l solution of CH3COOH and in roots, shoots, and grain of wheat after 30 and 60 days of cultivation. Both digestate and fly ash increased levels of macro- and micro-nutrients as well as risk elements (especially Cd and Zn; the mobility of Pb decreased after 30 days of cultivation). The changes in element mobility in ammonium sulfate-treated soils appear to be due to both changes in soil pH level and inter-element interactions. Ammonium sulfate tended to be the most effective measure for increasing nutrient uptake by plants in Chernozem but with opposite pattern in Fluvisol. Changes in plant yield and element uptake in treated plants may have been associated with the higher proline content of wheat shoots cultivated in both soils compared to control. None of the treatments decreased uptake of risk elements by wheat plants in the extremely contaminated Fluvisol, and their accumulation in wheat grains significantly exceeded maximum permissible levels; these treatments cannot be used to enable cereal and other crop production in such soils. However, the combination of increased plant growth alongside unchanged element content in plant biomass in pots treated with digestate and fly ash suggests that these treatments have a beneficial impact on yield and may be effective treatments in crops grown for phytoremediation.

Potential of non-ligninolytic fungi in bioremediation of chlorinated and polycyclic aromatic hydrocarbons.

In previous decades, white-rot fungi as bioremediation agents have been the subjects of scientific research due to the potential use of their unspecific oxidative enzymes. However, some non-white-rot fungi, mainly belonging to the Ascomycota and Zygomycota phylum, have demonstrated their potential in the enzymatic transformation of environmental pollutants, thus overcoming some of the limitations observed in white-rot fungi with respect to growth in neutral pH, resistance to adverse conditions and the capacity to surpass autochthonous microorganisms. Despite their presence in so many soil and water environments, little information exists on the enzymatic mechanisms and degradation pathways involved in the transformation of hydrocarbons by these fungi. This review describes the bioremediation potential of non-ligninolytic fungi with respect to chlorinated hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) and also shows known conversion pathways and the prospects for future research.

Shifts in soil chemical properties and bacterial communities responding to biotransformed dry olive residue used as organic amendment.

Dry olive residue (DOR) is a waste product derived from olive oil extraction and has been proposed as an organic amendment. However, it has been demonstrated that a pre-treatment, such as its transformation by saprophytic fungi, is required before DOR soil application. A greenhouse experiment was designed where 0 and 50 g kg(-1) of raw DOR (DOR), Coriolopsis floccosa-transformed DOR (CORDOR) and Fusarium oxysporum-transformed DOR (FUSDOR) were added to soil. Analyses of the soil chemical properties as well as the structure and relative abundance of bacterial and actinobacterial communities were conducted after 0, 30 and 60 days following amendment. The different amendments produced a slight decrease in soil pH and significant increases in carbon fractions, C/N ratios, phenols and K, with these increases being more significant after DOR application. Quantitative PCR assays of the 16S rRNA gene and PLFA analyses showed that all amendments favoured bacterial growth at 30 and 60 days, although actinobacterial proliferation was more evident after CORDOR and FUSDOR application at 60 days. Bacterial and actinobacterial DGGE multivariate analyses showed that the amendments produced structural changes in both communities, especially after 60 days of amendment. PLFA data analysis identified changes in soil microbial communities according to the amendment considered, with FUSDOR and CORDOR being less disruptive than DOR. Finally, integrated analysis of all data monitored in the present study enabled us to conclude that the greatest impact on soil properties was caused by DOR at 30 days and that soil showed some degree of resilience after this time.

Microbial diversity of a Mediterranean soil and its changes after biotransformed dry olive residue amendment.

The Mediterranean basin has been identified as a biodiversity hotspot, about whose soil microbial diversity little is known. Intensive land use and aggressive management practices are degrading the soil, with a consequent loss of fertility. The use of organic amendments such as dry olive residue (DOR), a waste produced by a two-phase olive-oil extraction system, has been proposed as an effective way to improve soil properties. However, before its application to soil, DOR needs a pre-treatment, such as by a ligninolytic fungal transformation, e.g. Coriolopsis floccosa. The present study aimed to describe the bacterial and fungal diversity in a Mediterranean soil and to assess the impact of raw DOR (DOR) and C. floccosa-transformed DOR (CORDOR) on function and phylogeny of soil microbial communities after 0, 30 and 60 days. Pyrosequencing of the 16S rRNA gene demonstrated that bacterial diversity was dominated by the phyla Proteobacteria, Acidobacteria, and Actinobacteria, while 28S-rRNA gene data revealed that Ascomycota and Basidiomycota accounted for the majority of phyla in the fungal community. A Biolog EcoPlate experiment showed that DOR and CORDOR amendments decreased functional diversity and altered microbial functional structures. These changes in soil functionality occurred in parallel with those in phylogenetic bacterial and fungal community structures. Some bacterial and fungal groups increased while others decreased depending on the relative abundance of beneficial and toxic substances incorporated with each amendment. In general, DOR was observed to be more disruptive than CORDOR.

Differences in the secretion pattern of oxidoreductases from Bjerkandera adusta induced by a phenolic olive mill extract.

The secretome of the white-rot fungus Bjerkandera adusta produced in synthetic Kirk medium was compared to that supplemented with an aqueous phenol-rich extract of dry olive mill residues (ADOR). Distinct changes in the protein composition of oxidoreductases, namely diverse class-II peroxidases and aryl alcohol oxidases were found. In the ADOR-supplemented medium (ASC), 157 distinct proteins were identified by the secretome analysis, whereas only 59 of them were identified without ADOR supplementation (Kirk medium culture; KM). Proteome analysis indicated that the number of peroxidases produced in ASC was more than doubled (from 4 to 11) compared to KM. Two short manganese peroxidases (MnP1 and MnP6) and one versatile peroxidase (VP1) represented 29% of the relative abundance (NSAF) in ASC. Two of them (MnP1 and VP1) were also detected in KM at a relative abundance (NSAF) of only 3%. Further peroxidases present in ASC were one lignin peroxidase (LiP2), one generic peroxidase (GP) and three dye-decolorizing peroxidases (DyPs). The relative abundance of DyPs and aryl alcohol oxidases (AAO) were lower in ASC in comparison to KM. In addition to peptide sequence analysis, the secretion of Mn(2+)-oxidizing peroxidases as well as AAOs were followed by enzyme measurement. The Mn(2+)-oxidizing activity increased nearly 30-fold (from 10 to 281Ul(-1)) after ADOR addition. Two enzymes responsible for that activity were successfully purified (BadVPI and BadVPII). To prove a potential involvement of these enzymes in the degradation of aromatic compounds, BadVPI was tested for its ability to degrade the recalcitrant dehydrogenated polymer (DHP, synthetic lignin). These results show that natural phenol-rich materials act as secretome-stimulating additives. Applying these substances enables us to investigate fungal degradation and detoxification processes and gives more insight into the complexity of fungal secretomes, e.g. of white-rot fungi.

Arbuscular mycorrhizal fungi alleviate oxidative stress induced by ADOR and enhance antioxidant responses of tomato plants.

The behaviour of tomato plants inoculated with arbuscular mycorrhizal (AM) fungi grown in the presence of aqueous extracts from dry olive residue (ADOR) was studied in order to understand how this symbiotic relationship helps plants to cope with oxidative stress caused by ADOR. The influence of AM symbiosis on plant growth and other physiological parameters was also studied. Tomato plants were inoculated with the AM fungus Funneliformis mosseae and were grown in the presence of ADOR bioremediated and non-bioremediated by Coriolopsis floccosa and Penicillium chrysogenum-10. The antioxidant response as well as parameters of oxidative damage were examined in roots and leaves. The data showed a significant increase in the biomass of AM plant growth in the presence of ADOR, regardless of whether it was bioremediated. The establishment and development of the symbiosis were negatively affected after plants were exposed to ADOR. No differences were observed in the relative water content (RWC) or PS II efficiency between non-AM and AM plants. The increase in the enzymatic activities of superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6) and glutathione-S-transferase (GST; EC 2.5.1.18) were simultaneous to the reduction of MDA levels and H2O2 content in AM root growth in the presence of ADOR. Similar H2O2 levels were observed among non-AM and AM plants, although only AM plants showed reduced lipid peroxidation content, probably due to the involvement of antioxidant enzymes. The results highlight how the application of both bioremediated ADOR and AM fungi can alleviate the oxidative stress conditions, improving the growth and development of tomato plants.

Effects of dry olive residue transformed by Coriolopsis floccosa (Polyporaceae) on the distribution and dynamic of a culturable fungal soil community.

Dry olive residue (DOR) is an abundant waste product resulting from a two-phase olive oil extraction system. Due to its high organic and mineral content, this material has been proposed as an organic soil amendment; however, it presents phytotoxic and microtoxic properties. Thus, a pretreatment is necessary before its application to soil. Among the strategies for the bioremediation of DOR is treatment with ligninolytic fungi, e.g. Coriolopsis floccosa. This work aimed to assess the diversity of culturable fungi in a soil of the southeast Iberian Peninsula and to evaluate the short-term impact of untransformed and C. floccosa-transformed DOR on soil mycobiota. A total of 1,733 strains were isolated by the particle filtration method and were grouped among 109 different species using morphological and molecular methods. The majority of isolates were ascomycetes and were concentrated among three orders: Hypocreales, Eurotiales and Capnodiales. The soil amendment with untransformed DOR was associated with a depression in fungal diversity at 30 days and changes in the proportions of the major species. However, when C. floccosa-transformed DOR was applied to the soil, changes in fungal diversity were less evident, and species composition was similar to unamended soil.