Estudio de la variabilidad genética y organización cromosómica en el hongo fitopatógeno "Botrytis Cinerea"

La presente memoria de Tesis Doctoral consta de 4 objetivos. En el primero de ellos se determinó las distintas poblaciones de hongos filamentosos presentes en los viñedos del marco vitivinícola de Jerez se estudió la influencia de la inoculación de una cepa de laboratorio de Botritis cinerea, obtenida tras el aislamiento sucesivo de conidios producidos in vitro a partir de un aislado de campo, sobre la micobiota propia de la vid. Los géneros de hongos filamentosos aislados en la viña fueron Aspergillus, Botrytis, Cladosporium y Penicillium, siendo Aspergillus y Cladospoium los mayoritarios y con comportamientos diferentes en cada año de muestreo, mientras que botrytis y Penicillium fueron más regulares y minoritarios. La inoculación de la viña modificó el desarrollo de la micobiota propia de la vid, así como el desarrollo de las cepas silvestres de Botrytis. Como segundo objetivo analizar la patogenicidad de B, cinerea asi como estudiar el control genético de este carácter en el cruzamiento entre dos cepas sexualmente compatibles, con el fin de contribuir al control racional de la enfermedad causada por este patógeno, denominada Podredumbre gris. El cruzamiento establecido ha dado lugar a cepas con niveles de virulencia muy diferentes, los cuales pueden ser empleados en retrocruzamientos e incluso en estudios comparativos que aporten nuevos datos sobre los mecanismos de patogenicidad de este hongo. En el tercer objetivo se realizó la caracterización molecular de numerosas cepas de B, cinerea y se evaluó al efecto que tien la reproducción sexual en la variabilidad genética del patógeno. El análisi de cariotipo electroforético puso de manifiesto que la reproducción sexual contriubuye considerablemente a la variabilidad de la especie y que es un proceso que tiene lugar en la naturaleza con mayor frecuencia de lo observado hasta el momento. Por último se realizó la estimación del número de cromosomas del patógeno así como el estudio de su variabilidad genética mediante la aplicación de la técnica denominada "telomeri fingerprinting". La aplicación de esta técnica y el análisis de cluster reveló un alto grado de variabilidad en B, cinerea y estableción entre 8 y 11 el número de cromosomas presentes en esta especie

Development of a novel engineered stone containing a CuO/SiO2 nanocomposite matrix with biocidal properties

Building materials decay is caused by the combination of chemical, physical and biological aspects. Therefore, the development of innovative multifunctional building materials is an alternative to reduce their impact. This can be achieved by post-treatments or by direct changes in the fabrication of synthetic materials, such as engineered stone. The aim of this work is to develop a new type of engineered stone by using a CuO/SiO2 nanocomposite matrix, synthetized via sol–gel, as a binder and quartz particles of different grain size as aggregate. The use of a sol–gel route allows creating an amorphous SiO2 structure chemically compatible with the quartz aggregates, while CuO nanoparticles are added for their biocidal properties. The new materials present anti-fungal properties against yeast and Aspergillus carbonarius spores, a high surface hardness, thermal resistance and an appropriate impact resistance for their use in flooring and claddings, although their mechanical strength is overall lower than a resin-matrix engineered stone. The proportion of CuO in the matrix and water content modify the sol–gel kinetics and quartz sedimentation, which have an impact on the structure and mechanical properties

Development of vinegar obtained from lemon juice: Optimization and chemical characterization of the process

A research on the production of lemon vinegar directly from lemon juice was conducted. For the alcoholic fermentation, two different strains of Saccharomyces cerevisiae, as well as two types of cultures (submerged culture and yeasts immobilized in alginate beads) were used. A microbiological control was also implemented during this stage. Acetic fermentation variables were optimized for a semi-continuous process. The whole process was monitored by means of volatile (SBSE/GC-MS), polyphenolic composition (UPLC-DAD), and sensory analysis was also conducted for the optimization procedure. The best conditions for alcoholic fermentation were obtained when Saccharomyces cerevisiae var. bayanus strain was used under a submerged culture, where a content of 13.53 mL ethanol/100 mL of wine was obtained. With regards to acetic fermentation, the use of an unloading volume of 33.33% of the total volume produced lemon vinegar in 20–24 h with an acidity of 13.29 g/100 mL of vinegar (expressed as acetic acid). The chemical monitoring of the process demonstrated that the majority of volatile compounds and polyphenols studied decreased during alcoholic and acetic fermentations. Multivariate statistical analysis such as principal component analysis allowed the classification of the samples according to the matrix (juice, wine and vinegar)

Artificial Intelligence: A Promising Tool for Application in Phytopathology

Artificial intelligence (AI) is revolutionizing approaches in plant disease management and phytopathological research. This review analyzes current applications and future directions of AI in addressing evolving agricultural challenges. Plant diseases annually cause 10–16% yield losses in major crops, prompting urgent innovations. Artificial intelligence (AI) shows an aptitude for automated disease detection and diagnosis utilizing image recognition techniques, with reported accuracies exceeding 95% and surpassing human visual assessment. Forecasting models integrating weather, soil, and crop data enable preemptive interventions by predicting spatial-temporal outbreak risks weeks in advance at 81–95% precision, minimizing pesticide usage. Precision agriculture powered by AI optimizes data-driven, tailored crop protection strategies boosting resilience. Real-time monitoring leveraging AI discerns pre-symptomatic anomalies from plant and environmental data for early alerts. These applications highlight AI’s proficiency in illuminating opaque disease patterns within increasingly complex agricultural data. Machine learning techniques overcome human cognitive constraints by discovering multivariate correlations unnoticed before. AI is poised to transform in-field decision-making around disease prevention and precision management. Overall, AI constitutes a strategic innovation pathway to strengthen ecological plant health management amidst climate change, globalization, and agricultural intensification pressures. With prudent and ethical implementation, AI-enabled tools promise to enable next-generation phytopathology, enhancing crop resilience worldwide

Influence of the total concentration and the profile of volatile fatty acids on polyhydroxyalkanoates (PHA) production by mixed microbial cultures

Polyhydroxyalkanoates (PHAs) production from lignocellulosic biomass using mixed microbial cultures (MMC) is a potential cheap alternative for reducing the use of petroleum-based plastics. In this study, an MMC adapted to acidogenic effluent from dark fermentation (DF) of exhausted sugar beet cossettes (ESBC) has been tested in order to determine its capability to produce PHAs from nine different synthetic mixtures of volatile fatty acids (VFAs). The tests consisted of mixtures of acetic, propionic, butyric, and valeric acids in the range of 1.5–9.0 g/L of total acidity and with three different valeric:butyric ratios (10:1, 1:1, and 1:10). Experimental results have shown a consistent preference of the MMC for the butyric and valeric acids as carbon source instead other shorter acids (propionic or acetic) in terms of PHA production yield (estimated in dry cell weight basis), with a maximum value of 23% w/w. Additionally, valeric-rich mixtures have demonstrated to carry out a fast degradation process but with poor final PHA production compared with high butyric mixtures. Finally, high initial butyric and valeric concentrations (1.1 g/L and 4.1 g/L) have demonstrated to be counterproductive to PHA production.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was supported by the project CTM2016-79071-R (Spanish Ministry of Economy, Industry and Competitiveness) and financed by the Spanish State Research Agency ("Agencia Estatal de Investigacion" (AEI)) and by the European Regional Development Fund (ERDF) and by grant from the Program for the Promotion and Impulse of Research and Transfer of the University of Cadiz (Ref: IRTP04_UCA)

Anti-fouling nano-Ag/SiO2 ormosil treatments for building materials: The role of cell-surface interactions on toxicity and bioreceptivity

Protective coatings with hydrophobic or biocide properties are commonly employed to prevent biofouling of building materials exposed to the environment. Although the factors affecting bioreceptivity of the base materials are well known, the influence of the coating and/or biocide agent surface properties on the interaction with the cell surface is often overlooked. As such, a proper understanding of these interfacial interactions can help improve their anti-fouling effectiveness. This work studies a multifunctional superhydrophobic/biocide treatment, containing surface engineered Ag/SiO2 nanoparticles embedded in an organically modified silica matrix, focusing on determining the effect of the cell-nanoparticle interactions and surface properties on its effectiveness against algal fouling. The modification of SiO2 with positively charged groups increased the interaction of the biocide with the cell walls through electrostatic forces, while at the same time it promotes cell aggregation. The hydrophobic matrix decreases initial colonization due to its lower roughness and water absorption, although surface free energy measurements indicated an increase of the cell-surface adhesion force as polarity of the cell wall decreased. A Cassie-Baxter wetting regime on the superhydrophobic surfaces decreased effective contact area and adhesion force, though this state was quickly lost under exposure to the culture

Studying the influence of surface properties on the cell attachment and anti-fouling capacity of Ag/SiO2 superhydrophobic coatings for building materials

Anti-fouling coatings are a common solution for the protection of porous building materials from the effects of microbial colonization over their functionality and durability. Usually, this is achieved through the incorporation of biocides or the passive control by reducing bioreceptivity. Superhydrophobic surfaces are considered a promising strategy due to their reported capacity for reducing cell adhesion, but their affinity to non-polar substances may decrease their effectiveness under the right circumstances (e.g. organic contamination, cell walls with hydrophobic domains). The combination of these surfaces with active biocides may compensate these drawbacks, however, a close contact with the microorganisms is necessary to promote their effect. This work studies the factors that determine the anti-fouling capacity of a coating, tested on porous building materials, that combines superhydrophobic surface with a nanostructured Ag/SiO2 biocide agent. Special attention is paid to understanding to which extent the cell-surface interactions modulate the initial cell attachment to the surface and the biocidal effect. To this end, the electrostatic forces and surface energy balance were considered using different reference bacteria and a yeast. The results indicate that the hydrophobic character of the surface favors the cell attachment and the biocide agent may be unable to fully compensate this effect for all microorganisms. In addition, changes in micro and nano roughness seem to play an equally significant role. Overall, this study aims to provide a theoretical and experimental insight to assist in the future design of anti-fouling coatings tailored to the organisms responsible of fouling processes

Impact of Sequential Inoculation with the Non- Saccharomyces T. delbrueckii and M. pulcherrima Combined with Saccharomyces cerevisiae Strains on Chemicals and Sensory Profile of Rosé Wines

Controlled inoculations of non-Saccharomyces yeasts are becoming increasingly used to produce high-quality wines due to their enological potential. In this study, we evaluated the impact of sequential inoculation with the commercial non-Saccharomyces yeasts (Torulaspora delbrueckii and Metschnikowia pulcherrima) in combination with Saccharomyces cerevisiae on the chemical and sensory profile of rosé wines. Sequential inoculation with T. delbrueckii produced wines with an overall reduction in esters, mainly explained by the lower concentrations of ethyl esters of medium-chain fatty acids and isoamyl acetate. The lower ester concentrations of these wines were related to a reduction in fruity descriptors. An increase was observed, however, in other minor esters such as cinnamates and ethyl esters of branched acids. Zinc, ethyl isobutyrate, and ethyl dihydrocinnamate were selected as potential markers for this fermentation strategy. Sequential inoculation with M. pulcherrima resulted in rosé wines with an enhanced ester profile, reduced acetaldehyde, and increased anthocyans and tannins. Compared to the control wines fermented with S. cerevisiae, the changes observed in these wines were far subtler, especially for the volatile profile, sensory characteristics, and color parameters, with isobutyl hexanoate and isoamyl butyrate being selected as potential markers

Size matters: how periodicity and depth of LIPSS influences E. coli adhesion on ferritic stainless steel

Bacterial adhesion is a serious problem in the healthcare and food industries, causing health problems and economic losses. This study evaluates the generation of Laser-Induced Periodic Surface Structures (LIPSS) with different periodicities to reduce bacterial adhesion on ferritic stainless steels. LIPSS nanostructuring evolves from hydrophilic to hydrophobic with air exposure. Fresh samples with 870 nm LIPSS show nearly 50 % reduced E. coli adhesion, but this effect diminishes in stabilized samples. This effect on bacterial adhesion can be attributed to LIPSS periodicity being like bacterial size, which would allow bacteria to accommodate and provide a suitable environment for their adhesion. Our results show that, in stable samples when the LIPSS periodicity is around 400 nm, reductions by almost 30 % are achieved and this reduction reaches 35 % when periodicity is close to 270 nm. These results indicate that smaller spatial periods prevent bacteria from fitting into valleys, so they remain on the peaks, hindering bacterial adhesion. Additionally, deeper LIPSS produced by a higher Surface Density of Applied Energy (SDAE), enhance bacteria-material interaction and, thus, increases adhesion

In Vitro Studies of Endophytic Bacteria Isolated from Ginger (Zingiber officinale) as Potential Plant-Growth-Promoting and Biocontrol Agents against Botrytis cinerea and Colletotrichum

Agriculture currently confronts a multitude of challenges arising from the excessive utilization of chemical pesticides and the proliferation of phytopathogenic fungi strains that exhibit resistance to commonly employed active compounds in the field. Botrytis cinerea and Colletotrichum acutatum are phytopathogenic fungi that inflict substantial economic losses within agriculture and food due to their high impacts on crops both pre- and post-harvest. Furthermore, the emergence of fungal strains that are resistant to commercial fungicides has exacerbated this problem. To explore more environmentally sustainable alternatives for the control of these pathogens, an investigation into the endophytic bacteria associated with ginger (Zingiber officinale Rosc.) was conducted. The primary focus of this study involved evaluating their inhibitory efficacy against the fungi and assessing their potential for promoting plant growth. The endophytic bacteria genera Lelliottia, Lysinibacillus, Kocuria, Agrococcus, Acinetobacter, Agrobacterium, Zymobacter, and Mycolicibacterium were identified. All isolates showed remarkable in vitro antagonistic ability against B. cinerea (>94%) and C. acutatum (>74%). Notably, the Lelliottia amnigena J29 strain exhibited a notable proficiency in producing extracellular enzymes and indole compounds (IAA), solubilizing phosphate and potassium, and forming biofilm. Furthermore, the Lysinibacillus capsici J26, Agrococcus citreus J28, and Mycolicibacterium sp. J5 strains displayed the capacity for atmospheric nitrogen fixation and siderophore production. These findings underscore the agricultural and biotechnological potential of endophytic bacteria derived from ginger plants and suggest the feasibility of developing alternative approaches to manage these two phytopathogenic fungi