Microbiota Characterization of Compost Using Omics Approaches Opens New Perspectives for Phytophthora Root Rot Control

Phytophthora root rot caused by Phytophthora nicotianae is an economically important disease in pepper crops. The use of suppressive composts is a low environmental impact method for its control. Although attempts have been made to reveal the relationship between microbiota and compost suppressiveness, little is known about the microorganisms associated with disease suppression. Here, an Ion Torrent platform was used to assess the microbial composition of composts made of different agro-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67–75%) of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.This work was supported by LIFE project AGROWASTE (LIFE10/ENV/ES/469) http://ec.europa.eu/environment/life/

Beauveria bassiana (Hypocreales: Clavicipitaceae) Volatile Organic Compounds (VOCs) Repel Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae)

The entomopathogenic fungus Beauveria bassiana (Bb) is used to control the red palm weevil (RPW) Rhyncophorus ferrugineus (Oliver). Beuveria bassiana can infect and kill all developmental stages of RPW. We found that a solid formulate of B. bassiana isolate 203 (Bb203; CBS 121097), obtained from naturally infected RPW adults, repels RPW females. Fungi, and entomopathogens in particular, can produce volatile organic compounds (VOCs). VOCs from Bb203 were analyzed using gas chromatography-mass spectrometry (GC-MS). GC-MS identified more than 15 VOCs in B. bassiana not present in uninoculated (control) formulate. Both ethenyl benzene and benzothiazole B. bassiana VOCs can repel RPW females. Our findings suggest that B. bassiana and its VOCs can be used for sustainable management of RPW. They could act complementarily to avoid RPW infestation in palms.This work was supported by the Spanish Ministry of Science and Innovation AGL2015-66833-R project, the Universiti Kebangsaan Malaysia, and the Malaysia Ministry of Higher Education. Project was also partially supported by MUSA project (727624). The results of this paper have been filed for a Spanish Patent (P201631534)

A metabolomic approach to study the rhizodeposition in the tritrophic interaction: tomato, Pochonia chlamydosporia and Meloidogyne javanica

A combined chemometrics-metabolomics approach [excitation–emission matrix (EEM) fluorescence spectroscopy, nuclear magnetic resonance (NMR) and high performance liquid chromatography–mass spectrometry (HPLC–MS)] was used to analyse the rhizodeposition of the tritrophic system: tomato, the plant-parasitic nematode Meloidogyne javanica and the nematode-egg parasitic fungus Pochonia chlamydosporia. Exudates from M. javanica roots were sampled at root penetration (early) and gall development (late). EMM indicated that late root exudates from M. javanica treatments contained more aromatic amino acid compounds than the rest (control, P. chlamydosporia or P. chlamydosporia and M. javanica). 1H NMR showed that organic acids (acetate, lactate, malate, succinate and formic acid) and one unassigned aromatic compound (peak no. 22) were the most relevant metabolites in root exudates. Robust principal component analysis (PCA) grouped early exudates for nematode (PC1) or fungus presence (PC3). PCA found (PC1, 73.31 %) increased acetate and reduced lactate and an unassigned peak no. 22 characteristic of M. javanica root exudates resulting from nematode invasion and feeding. An increase of peak no. 22 (PC3, 4.82 %) characteristic of P. chlamydosporia exudates could be a plant “primer” defence. In late ones in PC3 (8.73 %) the presence of the nematode grouped the samples. HPLC–MS determined rhizosphere fingerprints of 16 (early) and 25 (late exudates) m/z signals, respectively. Late signals were exclusive from M. javanica exudates confirming EEM and 1H NMR results. A 235 m/z signal reduced in M. javanica root exudates (early and late) could be a repressed plant defense. This metabolomic approach and other rhizosphere -omics studies could help to improve plant growth and reduce nematode damage sustainably.This research was funded by the Spanish Ministry of Science and Innovation Grants AGL 2008-00716/AGR, AGL 2011-29297 and with a grant from the University of Alicante to N. Escudero (UAFPU2011)

Mejora en la docencia en biociencias mediante la metodología basada en resolución de problemas

La nueva metodología docente propuesta se basa en trabajar los conceptos de la asignatura de Bioquímica, en el Grado de Nutrición Humana y Dietética, mediante vídeos colgados en Youtube. Estos vídeos recogen la parte teórica de la asignatura, explicada mediante PowerPoint. En clase podemos trabajar cuestionarios sobre los diferentes temas. El objetivo es no centrar la clase teórica en la presentación de los diferentes temas que componen el temario de la asignatura. La presentación primera la hacemos mediante los vídeos, para poder centrar el valioso tiempo de las clases en profundizar en los contenidos mediantes cuestiones y otros puntos de interés, que van sugiriendo los propios alumnos. Los vídeos, en cierta forma, sustituyen a la clase magistral clásica. En resumen, la metodología docente se basa en un sistema de presentación de los temas online y una profundización de los contenidos en clase, buscando siempre la participación activa del alumnado, de forma que el profesor no sea sólo alguien que enseña una materia, sino que sea alguien que acompaña en el proceso de aprendizaje del alumno. La parte activa del aprendizaje se basa en el trabajo del alumnado y no en el profesor

Agri-food sludge management using different co-composting strategies: study of the added value of the composts obtained

The growth of the agri-food industry has resulted in a strong increase in its sludge generation. This type of waste is often produced in high amounts, concentrated in certain areas, and shows characteristics similar to those of municipal sewage sludge (except for the absence of heavy metals). Composting has been widely studied as a viable alternative for the treatment and recycling of municipal sewage sludge, but little information is currently available concerning the composting of agri-food sludge. Thus, the aim of this work was to increase our knowledge of how the vegetable-derived sludge produced by the agri-food sector can be managed using different co-composting strategies. The work was concerned mainly with the characteristics of the bulking agents used (type and particle size) and their effects on the development of the process and on the potential added value of the composts obtained. For this, four composting piles were prepared using agri-food sludge and two bulking agents (vine shoot prunings and pepper plant pruning waste) at two particle sizes (<1 cm and <3 cm). The evolution of the process and the final properties of the composts obtained were studied using classical analytical methods together with advanced instrumental methods (thermal analysis and excitation–emission matrix (EEM) fluorescence spectroscopy). In addition, their physical characteristics and potential suppression of phytopathogens (Fusarium oxysporum f. sp. melonis) were determined. The results showed differences according to the type and size of bulking agent, the mixtures with vine shoot prunings having a higher biodegradability, which was confirmed by thermogravimetry and EEM fluorescence spectroscopy. Melon plants grown in a mixture which included compost produced using vine pruning waste had a greater shoot weight than those grown on peat alone, while the mixture including compost derived from pepper pruning waste gave a shoot weight similar to that of peat-grown plants. Furthermore, the composts elaborated using vine shoot prunings had added value with respect to their use as growing media components for seedling production of melon, due to their suppression of F. oxysporum f. sp. melonis. Therefore, this study has shown that the nature of the bulking agent used is of major importance not only for the development of the composting process, but also for the final properties and potential added value of the end-products obtained.This research has been supported with the Spanish National ProjectAGL2014-52732-C2-1-R and the Life+ Project AGROWASTE LIFE10/ENV/ES/469

Thermogravimetry coupled with mass spectrometry successfully used to quantify polyethylene and polystyrene microplastics in organic amendments

The global consumption of plastic is growing year by year, producing small plastic pieces known as microplastics (MPs) that adversely affect ecosystems. The use of organic amendments (compost and manure) polluted with MPs affects the quality of agricultural soils, and these MPs can be incorporated into the food chain and negatively impact human health. Current European legislation only considers large plastic particles in organic amendments. There is no information regarding MP pollution. Thus, the development of a methodology to support future legislation ensuring the quality of agricultural soils and food safety is necessary. This proposed methodology is based on thermogravimetry coupled with mass spectrometry to quantify polyethylene and polystyrene (PE and PS) MPs through their mass spectrometry signal intensity of characteristic PE (m/z 41, 43 and 56) and PS (m/z 78 and 104) ions. This method has been validated with several organic amendments where the MP content ranged from 52.6 to 4365.7 mg kg−1 for PE-MPs and from 1.1 to 64.3 mg kg−1 for PS-MPs. The proposed methodology is a quick and robust analytical method to quantify MPs in organic amendments that could support new legislation.The authors thank the Spanish MICINN (PGC 2018-098363-B-I00) and the European Commission (FEDER/ERDF) for their funding as well as the Grupo operativo EI-AGRI Expedient N 20190020007482. The research was also funded by the RECOVER project (BBI H2020 grant agreement No 887648). The authors also wish to thank the Technological Research Assistance Service of the Technical University of Cartagena (Spain) for their help

Bioactive fractions from cantabrian anchovy (Engraulis encrarischolus) viscera

The potential of cantabrian anchovy (Engraulis encrarischolus) viscera as a source of bioactive compounds is of interest for both, pharmaceutical and food industries. Cantabrian anchovy guts and heads were freeze-dried, extracted with methanol and subjected to fractionation by solvent partitioning using hexane, ethyl acetate, and butanol. Fractions were tested for antimutagenic, antioxidant, antifungal, and antibacterial activity using the Ames test; DPPH, ABTS, and FRAP assays; the radial grown inhibition assay; and the microbroth dilution method, respectively. Five fractions were obtained from the anchovy gut methanolic extract, in addition to the hexane- (HF), ethyl acetate- (EAF), and butanol-soluble (BF) fractions, an aqueous-soluble fraction (ALF) and precipitated crystals (ACF) in this were also obtained. HF and EAF resulted to be antimutagenic, HF and ALF showed antifungal activity, BF and ACF showed the highest antioxidant potential, and HF and BF were antibacterial against several strains. Anchovy gut, which to the present study had not been reported for any bioactivity, has antimutagenic, antifungal, antioxidant, and antibacterial compounds, which need to be isolated for full characterization and study.Authors wish to acknowledge CONACyT for the financial support granted to Burgos-Hernández, A., (234469) and Rosas‑Burgos, E.C., (234051) to carry out a sabbatical-research staying at the Universidad Miguel Hernández de Elche at Orihuela, Alicante, Spain

Chitosan Induces Plant Hormones and Defenses in Tomato Root Exudates

In this work, we use electrophysiological and metabolomic tools to determine the role of chitosan as plant defense elicitor in soil for preventing or manage root pests and diseases sustainably. Root exudates include a wide variety of molecules that plants and root microbiota use to communicate in the rhizosphere. Tomato plants were treated with chitosan. Root exudates from tomato plants were analyzed at 3, 10, 20, and 30 days after planting (dap). We found, using high performance liquid chromatography (HPLC) and excitation emission matrix (EEM) fluorescence, that chitosan induces plant hormones, lipid signaling and defense compounds in tomato root exudates, including phenolics. High doses of chitosan induce membrane depolarization and affect membrane integrity. 1H-NMR showed the dynamic of exudation, detecting the largest number of signals in 20 dap root exudates. Root exudates from plants irrigated with chitosan inhibit ca. twofold growth kinetics of the tomato root parasitic fungus Fusarium oxysporum f. sp. radicis-lycopersici. and reduced ca. 1.5-fold egg hatching of the root-knot nematode Meloidogyne javanica.This work was supported by AGL 2015 66833-R Grant from the Spanish Ministry of Economy and Competitiveness and H2020 MUSA 727624 European Project

Chemical, Thermal and Spectroscopic Methods to Assess Biodegradation of Winery-Distillery Wastes during Composting

The objective of this work was to study the co-composting process of wastes from the winery and distillery industry with animal manures, using the classical chemical methods traditionally used in composting studies together with advanced instrumental methods (thermal analysis, FT-IR and CPMAS 13C NMR techniques), to evaluate the development of the process and the quality of the end-products obtained. For this, three piles were elaborated by the turning composting system, using as raw materials winery-distillery wastes (grape marc and exhausted grape marc) and animal manures (cattle manure and poultry manure). The classical analytical methods showed a suitable development of the process in all the piles, but these techniques were ineffective to study the humification process during the composting of this type of materials. However, their combination with the advanced instrumental techniques clearly provided more information regarding the turnover of the organic matter pools during the composting process of these materials. Thermal analysis allowed to estimate the degradability of the remaining material and to assess qualitatively the rate of OM stabilization and recalcitrant C in the compost samples, based on the energy required to achieve the same mass losses. FT-IR spectra mainly showed variations between piles and time of sampling in the bands associated to complex organic compounds (mainly at 1420 and 1540 cm-1) and to nitrate and inorganic components (at 875 and 1384 cm-1, respectively), indicating composted material stability and maturity; while CPMAS 13C NMR provided semi-quantitatively partition of C compounds and structures during the process, being especially interesting their variation to evaluate the biotransformation of each C pool, especially in the comparison of recalcitrant C vs labile C pools, such as Alkyl /O-Alkyl ratio.This work was supported by a contract to MABM, Spanish Ministry of Economy and Competitiveness (Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+i) 2008-2011), co-funded by the EU through the Social Funds (contract reference PTQ-12-05655)

Valorization of date palm (Phoenix dactylifera L.) pruning biomass by co-composting with urban and agri-food sludge

In the Mediterranean countries, there is an increasing production of date palm wastes (Phoenix dactylifera L.), not only due to the raising production of date palm fruits, but also derived from the maintenance of urban and peri-urban green areas, especially in those affected by red palm weevil (Rhynchophorus ferrugineus). The management of this increasing volume of green wastes usually concludes with a controlled disposal that implies an important loss of resources, in terms of organic matter, nutrients and energy. In addition, the rise of wastewater generation and the incentive of the wastewater treatment processes have derived in an increase of the amount of the sludge produced, which makes difficult its management. This work studies the feasibility of co-composting palm wastes with sludge from the urban and agri-food sectors as alternative treatment to manage these organic waste streams and to obtain added-value compost. For this, four mixtures (P1, P2, P3 and P4) were prepared using as main component palm leave waste (PL) mixed with different types of sludge. In the piles P1, P2 and P3, sewage sludge (SS) was used as co-composting agent, while agri-food sludge (AS) was used in P4. Throughout composting, the thermal profile of the composting piles was assessed, as were physical, chemical, physico-chemical and maturity parameters. In addition, the changes in water-soluble organic matter were assessed using chemical analytical methods and the excitation–emission matrix (EEM) fluorescence spectroscopy. The results obtained showed the viability of the co-composting process to obtain end-products with adequate maturity degree and physical characteristics for their potential use as substrates, except for the salt contents that can limit their use in some agricultural sectors.This work has been financed by the Spanish Ministry of Economy and Competitiveness and by European Regional Development Funds (ERDF, “Una manera de hacer Europa”), in the framework of the project “Development of new resources and bioproducts based on residues of palmaceous species oriented to carbon sequestration and mitigation strategies, Palmresource” (Project AGL2013-41612-R)