Simulation of integrated anaerobic digestion-gasification systems using machine learning models.

In this study, the anaerobic digestion model M-ADM1 was integrated with the gasification model T-ANN to form a set of integrated models that can efficiently simulate the biomass AD-GS integration technology. Biogas slurry is used as feedstocks to prepare biogas slurry fertilizer. Solid residue is used feedstocks for gasification reactions. Biogas and syngas from the gasification of solid residue are used for energy. In this process, carbon emission is regarded as an important index for the comprehensive evaluation and optimization of AD-GS integration process. This study found that when the anaerobic digestion duration was 0 to 15 days, the carbon emission reduction increased rapidly. The amount of carbon emission reduction peaks on day 15. The value of carbon emission reduction is 0.1828 gCO2eq. In addition, when FEAG reached the maximum value at 15 days of anaerobic digestion, the decreasing trend of FEAG rate change value started to become significant.

Development of a taxon-discriminating molecular marker to trace and quantify a mycorrhizal inoculum in roots and soils of agroecosystems.

Crop inoculation with Glomus cubense isolate (INCAM-4, DAOM-241198) promotes yield in banana, cassava, forages, and others. Yield improvements range from 20 to 80% depending on crops, nutrient supply, and edaphoclimatic conditions. However, it is difficult to connect yield effects with G. cubense abundance in roots due to the lack of an adequate methodology to trace this taxon in the field. It is necessary to establish an accurate evaluation framework of its contribution to root colonization separated from native arbuscular mycorrhizal fungi (AMF). A taxon-discriminating primer set was designed based on the ITS nrDNA marker and two molecular approaches were optimized and validated (endpoint PCR and quantitative real-time PCR) to trace and quantify the G. cubense isolate in root and soil samples under greenhouse and environmental conditions. The detection limit and specificity assays were performed by both approaches. Different 18 AMF taxa were used for endpoint PCR specificity assay, showing that primers specifically amplified the INCAM-4 isolate yielding a 370 bp-PCR product. In the greenhouse, Urochloa brizantha plants inoculated with three isolates (Rhizophagus irregularis, R. clarus, and G. cubense) and environmental root and soil samples were successfully traced and quantified by qPCR. The AMF root colonization reached 41-70% and the spore number 4-128 per g of soil. This study demonstrates for the first time the feasibility to trace and quantify the G. cubense isolate using a taxon-discriminating ITS marker in roots and soils. The validated approaches reveal their potential to be used for the quality control of other mycorrhizal inoculants and their relative quantification in agroecosystems.

In vitro propagation of a cuban Arbuscular Mycorrhizal Fungal strain and factible bacteria's association / Propagación in vitro de una cepa cubana de Hongos Micorrízicos Arbusculares y su factible asociación a bacterias

ABSTRACT In vitro root cultivation techniques based on modified root systems are often used in studies on Arbuscular Mycorrhizal Fungi (AMF). It is a simplified but powerful tool to investigate AMF root colonization and development of the extraradical mycelium. The aim of this study was to establish and characterize the in vitro culture of a Cuban strain of Rhizophagus irregularis (INCAM 11) by using transformed chicory roots. For that, superficially disinfected propagules of R. irregularis were co-culture with the hairy transformed chicory roots on Modified Strullu and Romand (MSR) medium during five months. Spore germination was observed 3-5 days after surface disinfection. The first contact between AMF hyphae and roots occurred 1 - 3 days after germination and a significant production of extensive extraradical mycelium was observed. New spore formation started within 21 - 25 days. After 5 months, 2000 spores could be observed per plate which were able to germinate, colonize, establish and reproduce again spores when associated to young transformed roots of chicory. The most frequent associated microorganism to the in vitro culture of INCAM 11 was isolated and identified as Paenibacillus sp.

RESUMEN Las técnicas de cultivo de raíces in vitro basadas en sistemas de raíces modificadas se utilizan a menudo en los estudios sobre hongos micorrízicos arbusculares (HMA). Es una herramienta simplificada pero poderosa para investigar la colonización de las raíces de los HMA y el desarrollo del micelio extrarradical. El objetivo de este estudio fue establecer y caracterizar el cultivo in vitro de una cepa cubana de Rhizophagus irregularis (INCAM 11) utilizando raíces transformadas de achicoria. Para ello, propágulos de R. irregularis desinfectados superficialmente fueron co-cultivados con las raíces transformadas de achicoria en medio Strullu y Romand modificado (SRM) durante cinco meses. La germinación de las esporas se observó 3-5 días después de la desinfección superficial. El primer contacto entre las hifas y las raíces se produjo entre 1 y 3 días después de la germinación y se observó una producción significativa de micelio extrarradical. La formación de nuevas esporas comenzó entre 21 - 25 días. Después de 5 meses, se pudieron observar 2000 esporas por placa que fueron capaces de germinar, colonizar, establecer y reproducir nuevas esporas cuando se asociaron a raíces jóvenes transformadas de achicoria. El microorganismo asociado frecuentemente al cultivo in vitro de INCAM 11 fue aislado e identificado como Paenibacillus sp.