Soluciones innovadoras basadas en la aplicación de pulsos eléctricos de alto voltaje para mejorar la extracción y liberación de compuestos de interés producidos por microorganismos

Los cultivos microbianos como las levaduras y las microalgas representan una fuente muy prometedora para obtener productos de alto valor como pigmentos. Además, algunos procesos de la industria alimentaria se basan en la liberación de ciertos componentes de microorganismos, como es el caso de la “crianza sobre lías” de los vinos, en el cuál las manoproteinas son liberadas de la pared celular de Saccharomyces cerevisiae. Aunque algunos de estos componentes de alto valor son liberados al medio durante el metabolismo normal, la mayoría permanecen dentro de las células. La recuperación de estos componentes que están encerrados intracelularmente debería ocurrir a través de un proceso de bio-refinería sostenible y verde en el que la técnica de desintegración celular usada para mejorar la eficiencia de la etapa de extracción juega un papel principal. Los Pulsos Eléctricos de Alto Voltaje (PEAV) es una tecnología no térmica que produce el incremento de la permeabilidad de la membrana citoplasmática al paso de iones y macromoléculas. Por lo tanto, el tratamiento de PEAV mejora el fenómeno de transferencia de masa a través de la membrana citoplasmática porque esta pierde su permeabilidad selectiva después del tratamiento. El objetivo de esta Tesis Doctoral fue evaluar el potencial de la tecnología de PEAV para mejorar la extracción de compuestos intracelulares de interés de levaduras y microalgas. Se estudió: la liberación de manoproteinas de la levadura S. cerevisiae, la extracción de carotenoides de la levadura Rhodotorula glutinis y la extracción de pigmentos como ficocianina, ficoeritrina y carotenoides de las microalgas: Artrosphira platensis, Porphyridium cruentum y Haematococcus pluvialis respectivamente. La electroporación de la membrana citoplasmática de S. cerevisiae desencadenó la autolisis y aceleró la liberación de manoproteinas de la pared celular de la levadura durante la incubación. La autolisis inducida por PEAV y la subsiguiente liberación de manoproteinas fue más rápida a altas temperaturas y pHs, y bajas concentraciones de etanol. La mejora de la liberación de manoproteinas por PEAV se asoció al hecho de que el tratamiento facilitó la liberación de enzimas de las vacuolas y el subsiguiente acceso de dichas enzimas a la pared celular. Se detectó una alta concentración de β-glucanasa y proteasa en el medio extracelular que contenía células de S. cerevisiae tratadas por PEAV en comparación con el control. Así mismo, los PEAV aceleraron la liberación de manoproteinas durante la “crianza sobre lías” del vino Chardonnay sin afectar negativamente a sus propiedades fisicoquímicas. Las manoproteinas liberadas de las células de S. cerevisiae tratadas por PEAV mostraron propiedades funcionales similares en el vino que las manoproteinas liberadas durante la autolisis natural. Por otro lado, la electroporación de biomasa fresca de levadura R. glutinis fue inefectiva para extraer carotenoides usando etanol como solvente. Sin embargo, la incubación durante 24 horas de las células electroporadas de R. glutinis en un medio acuoso permitió la extracción de carotenoides en etanol. Este efecto fue también observado cuando las células fueron liofilizadas después de la incubación en medio acuoso. La necesidad de la incubación en medio acuoso para la extracción de carotenoides fue atribuida a la acción de las esterasas que causarían la disociación de los carotenoides unidos a las estructuras celulares. Una alta concentración de esterasas, cuya actividad disminuyó en presencia de etanol, fue detectada en el medio extracelular que contenía células de R. glutinis tratadas por PEAV. Finalmente, los tratamientos de PEAV permitieron la recuperación de Cficocianina de biomasa fresca de la microalga A. platensis usando agua como solvente con mejor pureza que los extractos obtenidos usando molino de perlas. La eficacia de los tratamientos de PEAV en los rendimientos de extracción fue altamente dependiente de la temperatura de aplicación. Por otro lado, la electroporación de la microalga P. cruentum estuvo influenciada por la intensidad del campo eléctrico y el tiempo de tratamiento y permitió la extracción de ficoeritrina. La liberación de este pigmento de las células tratadas por PEAV al medio acuoso requirió en todos los casos un tiempo de demora que indicaría la necesidad de la disociación de la ficobiliproteina de las estructuras celulares, que se asumió que estaba relacionada con el efecto de la autolisis desencadenada por los PEAV. De forma similar a R. glutinis, la electroporación de la biomasa fresca de la microalga H. pluvialis fue inefectiva para extraer el carotenoide astaxantina usando etanol como solvente. Sin embargo, el tratamiento de PEAV de la biomasa fresca seguido de la incubación en el propio medio de crecimiento permitió la extracción de este compuesto en etanol. Como se detectó principalmente astaxantina en forma libre en los extractos en vez de formando ésteres, se pensó que también la actividad esterasa estaba involucrada en el efecto observado. <br /

Fragility of Kardar-Parisi-Zhang universality class in the presence of temporally correlated noise

We study numerically a family of surface growth models that are known to be in the universality class of the Kardar-Parisi-Zhang equation when driven by uncorrelated noise. We find that, in the presence of noise with power-law temporal correlations with exponent θ, these models exhibit critical exponents that differ both quantitatively and qualitatively from model to model. The existence of a threshold value for θ below which the uncorrelated fixed point is dominant occurs for some models but not for others. In some models the dynamic exponent z(θ) is a smooth decreasing function, while it has a maximum in other cases. Despite all models sharing the same symmetries, critical exponents turn out to be strongly model dependent. Our results clearly show the fragility of the universality class concept in the presence of long-range temporally correlated noise.This work was supported by Grant No. PID2021-125543NB-I00 funded by MCIN/AEI/10.13039/501100011033/ (Spain) and by ERDF “A way of making Europe” by the European Union. E.R.-F. acknowledges support from the Margarita Salas postdoctoral program from Universidad Carlos III Madrid. A.A. was partially financed by Project No. EXA1143/23 of UNMDP (Argentina). J.M.A. acknowledges support from a JAEINT22_EX_1385 CSIC fellowship

Enhanced satellite analytics for mussel platform census using a machine-learning based approach

Mussel platforms are big floating structures made of wood (normally about 20 m × 20 m or even a bit larger) that are used for aquaculture. They are used for supporting the growth of mussels in suitable marine waters. These structures are very common near the Galician coastline. For their maintenance and tracking, it is quite convenient to be able to produce a periodic census of these structures, including their current count and position. Images from Earth observation satellites are, a priori, a convenient choice for this purpose. This paper describes an application capable of automatically supporting such a census using optical images taken at different wavelength intervals. The images are captured by the two Sentinel 2 satellites (Sentinel 2A and Sentinel 2B, both from the Copernicus Project). The Copernicus satellites are run by the European Space Agency, and the produced images are freely distributed on the Internet. Sentinel 2 images include thirteen frequency bands and are updated every five days. In our proposal, remote-sensing normalized (differential) indexes are used, and machine-learning techniques are applied to multiband data. Different methods are described and tested. The results obtained in this paper are satisfactory and prove the approach is suitable for the intended purpose. In conclusion, it is worth noting that artificial neural networks turn out to be particularly good for this problem, even with a moderate level of complexity in their design. The developed methodology can be easily re-used and adapted for similar marine environments

Lysozyme crystallization in hydrogel media under ultrasound irradiation

Sonocrystallization implies the application of ultrasound radiation to control the nucleation and crystal growth depending on the actuation time and intensity. Its application allows to induce nucleation at lower supersaturations than required under standard conditions. Although extended in inorganic and organic crystallization, it has been scarcely explored in protein crystallization. Now, that industrial protein crystallization is gaining momentum, the interest on new ways to control protein nucleation and crystal growth is advancing. In this work we present the development of a novel ultrasound bioreactor to study its influence on protein crystallization in agarose gel. Gel media minimize convention currents and sedimentation, favoring a more homogeneous and stable conditions to study the effect of an externally generated low energy ultrasonic irradiation on protein crystallization avoiding other undesired effects such as temperature increase, introduction of surfaces which induce nucleation, destructive cavitation phenomena, etc. In-depth statistical analysis of the results has shown that the impact of ultrasound in gel media on crystal size populations are statistically significant and reproducible.MCIN/AEI PID2020-118498GB-I00 PID2020-116261GB-I00 PID2020-115372RB-I00 MCIN/AEI/FEDER "Una manera de hacer Europa", Spain PID2019-106947RA-C22FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain) A-FQM-340-UGR20 P18-FR-3533 P18-RT-1653 BTEP-026-UGR1

Occurrence of tetracyclines and sulfonamides in manures, agricultural soils and crops from different areas in Galicia (NW Spain)

Antibiotics released to the environment are causing public health and sustainability concerns. Taking that into account, we studied the presence of tetracyclines (Tetracycline, Oxytetracycline, Chlortetracycline and Doxycycline) and sulfonamides (Sulfadiazine, Sulfamethazine, Sulfachlorpyridazine and Sulfamethoxypyridazine) in manures, soils and crops from Galicia (Spain), where a high number of cattle, pig and poultry farms exist. We used the HPLC-MS/MS technique to analyze 40 samples of cattle, pig and poultry manure, as well as 65 soil samples, and 27 vegetation samples. The presence of antibiotics was detected in 42% of the manures, 17% of the soils and 44% of crop samples, with maximum concentrations of 106.0 mg kg−1 for individual antibiotics in manures and 0.6 mg kg−1 in soils and plants. The simultaneous presence of several antibiotics was infrequent in soils (only three soils presented two or three antibiotics), and more common in manures and plants, some of them with up to five antibiotics. Pig slurries showed the highest antibiotic concentrations, as well as the highest number of different antibiotics. Crops fertilized with these slurries also showed the highest number of different antibiotics. Antibiotics were detected in 71% of grass and corn samples, and in 33% of wheat grain samples, while they were not detected in potato samples. These results can be very relevant taking into account potential environmental and public health repercussions of antibiotics in soil and water, as well as antibiotics uptake and accumulation in plants, and subsequent incorporation to the food chain.This work was supported by the Spanish Ministry of Economy and Competitiveness [grant numbers CGL2015-67333-C2-1-R and CGL2015-67333-C2-2-R]. M. Conde-Cid holds a pre-doctoral contract (FPU15/0280, Spanish Government). The sponsor had not involvement in study design; in the collection, analysis and interpretation of data; in the writing of the report, and in the decision to submit the article for publication.S

Review and analysis of computational techniques and methods for body condition score estimation on cows

BCS (del inglés "Body Condition Score") es un método utilizado para estimar las reservas de grasa corporal y el balance energ´ético acumulado de las vacas. El BCS influye significativamente en la producción de leche, reproducción y salud de las vacas. Es por ello, que es importante monitorear este valor para lograr una mejor respuesta animal, pero resulta ser una tarea costosa en tiempo y subjetiva, realizada generalmente de manera visual por evaluadores expertos. Estos problemas conducen la motivación de varios estudios, que han tratado de automatizar el BCS de vacas lecheras aplicando técnicas de análisis de imágenes y aprendizaje automático. En este documento se analizan dichos estudios, señalando sus principales ventajas y desventajas, las que permiten además identificar nuevas oportunidades de investigación y desarrollo para mejorar el proceso general de automatización del BCS.BCS (Body Condition Score) is a method used to estimate body fat reserves and accumulated energy balance of cows. BCS heavily influences milk production, reproduction, and health of cows. Therefore, it is important to monitor BCS to achieve better animal response, but this is a time-consuming and subjective task performed oftentimes visually by expert scorers. These problems are the motivation behind several studies, which have tried to automate BCS of dairy cows by applying image analysis and machine learning techniques. This work analyzes these studies pointing out their main advantages and drawbacks, which allow us in turn to identify new research and development opportunities to improve overall automatic BCS estimation.Sociedad Argentina de Informática e Investigación Operativ

Occurrence of tetracyclines and sulfonamides in manures, agricultural soils and crops from different areas in Galicia (NW Spain)

Antibiotics released to the environment are causing public health and sustainability concerns. Taking that into account, we studied the presence of tetracyclines (Tetracycline, Oxytetracycline, Chlortetracycline and Doxycycline) and sulfonamides (Sulfadiazine, Sulfamethazine, Sulfachlorpyridazine and Sulfamethoxypyridazine) in manures, soils and crops from Galicia (Spain), where a high number of cattle, pig and poultry farms exist. We used the HPLC-MS/MS technique to analyze 40 samples of cattle, pig and poultry manure, as well as 65 soil samples, and 27 vegetation samples. The presence of antibiotics was detected in 42% of the manures, 17% of the soils and 44% of crop samples, with maximum concentrations of 106.0 mg kg−1 for individual antibiotics in manures and 0.6 mg kg−1 in soils and plants. The simultaneous presence of several antibiotics was infrequent in soils (only three soils presented two or three antibiotics), and more common in manures and plants, some of them with up to five antibiotics. Pig slurries showed the highest antibiotic concentrations, as well as the highest number of different antibiotics. Crops fertilized with these slurries also showed the highest number of different antibiotics. Antibiotics were detected in 71% of grass and corn samples, and in 33% of wheat grain samples, while they were not detected in potato samples. These results can be very relevant taking into account potential environmental and public health repercussions of antibiotics in soil and water, as well as antibiotics uptake and accumulation in plants, and subsequent incorporation to the food chain.Ministerio de Economía y Competitividad | Ref. CGL2015-67333-C2-1-RMinisterio de Economía y Competitividad | Ref. CGL2015-67333-C2-2-

Dual-Tweezer Behavior of an Octapodal Pyrene Porphyrin-Based System as a Host for Fullerenes

Producción CientíficaThe incorporation of eight pyrene units in a single porphyrin core exhibits a great synergistic effect, resulting in high affinity toward C60 and C70. This octapyrene porphyrin is easily accessible by a straightforward two-step synthetic approach that involves an octuple Suzuki reaction. The new supramolecular platform can present single- or double-tweezer fullerene hosting behavior. The switch from double- to single-tweezer behavior is triggered by the simple coordination of Zn2+ to the porphyrin. Both the octapyrene porphyrin 2HPOP and its zinc metalloporphyrin analogue ZnPOP show very high affinity for C60 and C70, while simultaneously allowing the discrimination of C70 over C60 in a C60/C70 mixture. The use of 2HPOP and ZnPOP for the enrichment of real fullerene mixtures is also demonstrated.Ministerio de Economía, Industria y Competitividad (grants CTQ 2013-41067-P / PGC 2018-099470-B-100

Improving multipath routing of TCP flows by network exploration

Ethernet switched networks are widely used in enterprise and data center networks. However, they have some drawbacks, mainly that, to prevent loops, they cannot take advantage of multipath topologies to balance traffic. Several multipath routing proposals use link-state protocols and Equal Cost Multi-Path routing (ECMP) to distribute the load over multiple paths. But, these proposals are complex and prone to flow collisions that may degrade performance. This paper studies TCP-Path, a protocol that employs a different approach. It uses a distributed network exploration mechanism based on broadcasting the TCPSYN packet to identify and select the fastest available path to the destination host, on the fly. Our evaluation shows that it improves on ECMP by up to 70% in terms of throughput for elephant flows and by up to 60% in terms of flow completion time for mouse flows. Indeed, network exploration offers a better, yet simple alternative to ECMP-based solutions for multipath topologies. In addition, we also study TCP-Path for elephant flows (TFE), which restricts TCP-Path application to elephant flows to reduce the exploration broadcast overhead and the size of forwarding tables, thus improving its scalability. Although elephant flows represent a small fraction (about 5%) of total flows, they have a major impact on overall performance, as we show in our evaluation. TFE reduces both the overhead incurred during path setup and the size of the forwarding tables by a factor of almost 20. Moreover, it achieves results close to those obtained by TCPPath for elephant flows, especially when working with high loads, and yields significant improvements for all types of flow at medium and high load levels.Comunidad de MadridUniversidad de Alcal