Enzymatic Potential of Bacteria and Fungi Isolates from the Sewage Sludge Composting Process

The aim of this study was the isolation and characterisation of the fungi and bacteria during the composting process of sewage sludge under a semipermeable membrane system at full scale, in order to find isolates with enzymatic activities of biotechnological interest. A total of 40 fungi were isolated and enzymatically analysed. Fungal culture showed a predominance of members of Ascomycota and Basidiomycota division and some representatives of Mucoromycotina subdivision. Some noticeable fungi isolated during the mesophilic and thermophilic phase were Aspergillus, Circinella, and Talaromyces. During the maturation phase, some lignin modifying enzyme producers, like Purpureocillium, Thielavia, Bjerkandera, or Dichotomyces, were found. Within this group, Thielavia and Bjerkandera showed high activity with production of laccases and peroxidases. In the bacterial culturome, a total of 128 strains were selected and enzymatically analysed. Bacillales, Actinomycetales, Pseudomonadales, and Lactobacillales were the orders most represented in culture-bacteria. Bacillus pumilus, B. stratosphericus, B. safensis, and Pseudomonas formosensis were the species most e cient in enzyme production, particularly peroxidases, polyphenol oxidases ammonifying activity, and amylases. These results showed that sewage sludge composting piles could represent a source of microorganisms which have adapted to adverse conditions.Junta de Andalucía RNM-7370 CTM2017-84332-RJunta de Andalucía RYC-2013-1248

First Report of in Vitro Biological Agent to Biocontrol of Date Palm Stipe Rot Affected by Fusarium brachygibbosum by Using Pergularia tomentosa L., Aqueous Extract

Palm (Phoenix dactylifera L.) is a specie cultivated in Mauritania. The present study is focus on the potential of the aqueous extract of the Pergularia tomentosa L., as biological control agent against Fusarium brachygibbosum, the main agent of the date palm stipe rot disease in Mauritania. Fungal pathogen was isolated from symptomatic date palm stipe rot disease in Mauritania. The morphological characterization and the molecular identification by sequencing ITS1, ITS2 5.8 RNAr region showed homology of 98% with Fusarium brachygibbosum strain UOA/HCPF 16982 s during in vitro tests on leaves performed to verify its phytopathogenicity. the inhibitory effect of aqueous extract of Pergularia tomentosa L. on the phytopathogenic isolate (Fusarium brachygibbosum) of date palm, on mycelial growth and spore germination was observed. In fact, in vitro on PDA, mycelial growth ranged from 39.23 to 67.7 %, depending on the concentration of the aqueous extract of P. tomentosa. The aqueous extract showed a reduction of spore germination varying from 5.3 to 23.8 %. The minimum inhibitory concentrations varied from 1 to 100 mg/ml. the various extracts give high antioxidant activities exhibited by DPPH assay. Multivariant analysis by PCA plot and the heatmap were done, to evaluate the correlation between the tested parameters. These results suggest the use of Pergularia tomentosa L., extract as a biological agent to control and reduce damage caused by Fusarium brachygibbosum.National Agency for Scientific Research and Innovation in Mauritani

Changes in soil carbon and nitrogen accessibility with the application of biochars with different morphological and physical characteristics

Purpose The recent literature indicates that, depending on the feedstocks and pyrolysis temperature, biochar can be a good source of nutrients. On the contrary, some biochars are not good sources of available carbon and other nutrients, but their porous structure seems to be a suitable microenvironment for microbial colonization. We investigated the response of soil biological parameters, microbial biomass carbon and nitrogen (MBC and MBN), in relation to mobile N species. Material and methods Five different biochars were produced at different temperatures (300, 350, 400, 450, and 500 °C) from the same feedstock (woodchips). The physicochemical and morphological characteristics of the individual biochar samples were described, and incubation was carried out with the application of 2% biochar to two different soil types (luvisol and fluvisol). Results and discussion The addition of 2% biochar did not change the pH in the slightly acid soils used in the experiment, in spite of the alkaline character of biochar. The increasing amounts of total and nitrate-available nitrogen during the experiment are probably related to changes in soil microbial activity. The amount of soluble carbon was constant during the experiment, confirming its stability in the soil, most likely because of the high amount of lignin in the feedstock. The influence of biochar on the soil microbiome was determined on the basis of the concentrations ofMBC andMBN. Microbial biomass was increased in both soils treated with biochar produced at lower temperatures. Conclusions The physicochemical characteristics of the biochar as well as the sorption behavior of N-NO3 − and N-NH4 + indicate that at a pyrolysis temperature of 400 °C, biochar properties change substantially. However, these findings are only valid for biochar produced from woodchips, and the long-term effects of biochar application on soil properties need to be investigated in further studies

Design of Bio-Absorbent Systems for the Removal of Hydrocarbons from Industrial Wastewater: Pilot-Plant Scale

The objective of this study was the development and design of a treatment system at a pilot-plant scale for the remediation of hydrocarbons in industrial wastewater. The treatment consists of a combined approach of absorption and biodegradation to obtain treated water with sufficient quality to be reused in fire defense systems (FDSs). The plant consists of four vertical flow columns (bioreactors) made of stainless steel (ATEX Standard) with dimensions of 1.65 × 0.5 m and water volumes of 192.4 L. Each bioreactor includes a holder to contain the absorbent material (Pad Sentec polypropylene). The effectiveness of the treatment system has been studied in wastewater with high and low pollutant loads (concentrations higher than 60,000 mg L−1 of total petroleum hydrocarbons (TPH) and lower than 500 mg L−1 of TPHs, respectively). The pilot-plant design can function at two different flow rates, Q1 (180 L h−1 ) and Q2 (780 L h−1 ), with or without additional aeration. The results obtained for strongly polluted wastewaters showed that, at low flow rates, additional aeration enhanced hydrocarbon removal, while aeration was unnecessary at high flow rates. For wastewater with a low pollutant load, we selected a flow rate of 780 L h−1 without aeration. Different recirculation times were also tested along with the application of a post-treatment lasting 7 days inside the bioreactor without recirculation. The microbial diversity studies showed similar populations of bacteria and fungi in the inlet and outlet wastewater. Likewise, high similarity indices were observed between the adhered and suspended biomass within the bioreactors. The results showed that the setup and optimization of the reactor represent a step forward in the application of bioremediation processes at an industrial/large scale.Compañía Logística de Hidrocarburos S.

High-Throughput Microbial Community Analyses to Establish a Natural Fungal and Bacterial Consortium from Sewage Sludge Enriched with Three Pharmaceutical Compounds

Emerging and unregulated contaminants end up in soils via stabilized/composted sewage sludges, paired with possible risks associated with the development of microbial resistance to antimicrobial agents or an imbalance in the microbial communities. An enrichment experiment was performed, fortifying the sewage sludge with carbamazepine, ketoprofen and diclofenac as model compounds, with the aim to obtain strains with the capability to transform these pollutants. Culturable microorganisms were obtained at the end of the experiment. Among fungi, Cladosporium cladosporioides, Alternaria alternata and Penicillium raistrickii showed remarkable degradation rates. Population shifts in bacterial and fungal communities were also studied during the selective pressure using Illumina MiSeq. These analyses showed a predominance of Ascomycota (Dothideomycetes and Aspergillaceae) and Actinobacteria and Proteobacteria, suggesting the possibility of selecting native microorganisms to carry out bioremediation processes using tailored techniques.Spanish GovernmentEuropean Research Founds CTM2017-84332-RJunta de Andalucia B-RNM-204-UGR20Consejo Nacional de Ciencia y Tecnologia (CONACyT) 377965 739637Spanish Ministry of Universities (Maria Zambrano Program) - Next Generation EU (NGEU

Effect of Composting Under Semipermeable Film on the Sewage Sludge Virome

The addition of compost from sewage sludge to soils represents a sustainable option from an environmental and economic point of view, which involves the valorisation of these wastes. However, before their use as a soil amendment, compost has to reach the quality levels according to the normative, including microbial parameters. Viruses are not included in this regulation and they can produce agricultural problems and human diseases if the compost is not well sanitised. In this study, we carried out the analysis of the viral populations during a composting process with sewage sludge at an industrial scale, using semipermeable cover technology. Viral community was characterised by the presence of plant viruses and bacteriophages of enteric bacteria. The phytopathogen viruses were the group with the highest relative abundance in the sewage sludge sample and at 70 days of the composting process. The diversity of bacterial viruses and their specificity, with respect to the more abundant bacterial taxa throughout the process, highlights the importance of the interrelations between viral and bacterial communities in the control of pathogenic communities. These results suggest the possibility of using them as a tool to predict the effectiveness of the processThis research was conductedwith funding from Junta de Andalucía [Research project RNM-7370]. E. A. would like to thank the Ministry of Economy and Competitiveness (MINECO) and European Regional Development Fund (ERDF) funds [RYC-2013-12481]. We acknowledge financial support from the Slovenian Research Agency (research core funding no. P4-0092)

El escape room como técnica de estudio para la asignatura de Microbiología I

La motivación es un elemento fundamental para el aprendizaje del alumnado. Sin embargo, gran parte del contenido al que a veces se enfrentan no resulta motivante y genera una falta de implicación. En este sentido, las estrategias metodológicas deberán ir enfocadas estimular la motivación del alumnado. Una de las estrategias de innovación es la gamificación. Este enfoque se utiliza para aplicar los conocimientos adquiridos de manera lúdica en contextos que, a priori, no lo son. La gamificación es una estrategia didáctica que permite mejorar la motivación y, en consecuencia, la experiencia del aprendizaje haciéndolo más atractivo. El objetivo de este proyecto es aplicar la gamificación en la asignatura de Microbiología I del Grado de Farmacia como herramienta motivadora. Para ello, se llevará a cabo un escape room al final del primer cuatrimestre, una vez finalizado el contenido de la asignatura con fecha cercana la realización del examen final, dónde los alumnos previamente inscritos realicen esta prueba en grupos de 4 ó 5 personas con una duración de aproximadamente 20 minutos. El enigma del escape room irá enfocado a conceptos relativos a la asignatura, y se considerará como una actividad voluntaria dentro de la asignatura de Microbiología I. De este modo, se pretende usar la actividad del escape room como una herramienta de estudio previa al examen para afianzar y mejorar los conocimientos adquiridos durante la asignatura y la preparación por parte del estudiante para su evaluación en el examen final. Para valorar los efectos de esta actividad, se evaluará el rol de los alumnos durante el desarrollo de la misma, así como si ésta ha sido resuelta. También se analizará el impacto de esta actividad en la calificación del examen final. Los alumnos también valorarán esta actividad y una autoevaluación con respecto a su aprendizaje

Twitter as a Tool for Teaching and Communicating Microbiology: The #microMOOCSEM Initiative

Online social networks are increasingly used by the population on a daily basis. They are considered a powerful tool for science communication and their potential as educational tools is emerging. However, their usefulness in academic practice is still a matter of debate. Here, we present the results of our pioneering experience teaching a full Basic Microbiology course via Twitter (#microMOOCSEM), consisting of 28 lessons of 40-45 minutes duration each, at a tweet per minute rate during 10 weeks. Lessons were prepared by 30 different lecturers, covering most basic areas in Microbiology and some monographic topics of general interest (malaria, HIV, tuberculosis, etc.). Data analysis on the impact and acceptance of the course were largely affirmative, promoting a 330% enhancement in the followers and a >350-fold increase of the number of visits per month to the Twitter account of the host institution, the Spanish Society for Microbiology. Almost one third of the course followers were located overseas. Our study indicates that Massive Online Open Courses (MOOC) via Twitter are highly dynamic, interactive, and accessible to great audiences, providing a valuable tool for social learning and communicating science. This strategy attracts the interest of students towards particular topics in the field, efficiently complementing customary academic activities, especially in multidisciplinary areas like Microbiology.Versión del edito

Estudio de los procesos biológicos y de la estructura de las comunidades microbianas en el proceso de compostaje de lodos de depuradora de aguas residuales urbanas, en sistemas de membranas semipermea

El compostaje es un proceso viable para el tratamiento final de los lodos procedentes de la depuración del agua, en un contexto en el que la tendencia de este residuo tiende a incrementarse. Su uso final como enmienda en suelos representa una opción sostenible desde un punto de vista ambiental y económico y conforme con las nuevas políticas ambientales de reciclaje y revalorización de residuos. A pesar de existir numerosas tecnologías para el compostaje de lodos de depuradora, el empleo de cubiertas semipermeables representa una tecnología que permite el control de olores y el mantenimiento de la temperatura y humedad en el interior de la pila, lo que puede acelerar dicho proceso. Los microorganismos son los principales responsables, por lo que la monitorización de los cambios poblacionales y su interrelación con las variables operacionales puede representar una herramienta muy útil para optimizar estos procesos. En este trabajo se llevó a cabo el estudio de dos pilas de compostaje con lodos de depuradora a escala industrial. En ambas pilas se utilizó la tecnología de cubierta semipermeable conectada con un sistema de insuflación de aire, modificando únicamente los tiempos de compostaje. Se llevó a cabo la monitorización de los parámetros físico-químicos y microbiológicos, como la determinación de las actividades enzimáticas y el estudio de la diversidad microbiana (bacteriana, fúngica y vírica) tanto mediante técnicas dependientes como independientes de cultivo. Finalmente se realizó un cribado de la producción de enzimas extracelulares en los aislados bacterianos y fúngicos obtenidos con el fin de la obtención de enzimas de valor biotecnológico. Las variables físico-químicas revelaron una alta correlación entre la actividad microbiana y la diversidad, reflejadas en una intensa fase de degradación bajo la cubierta. La diversidad bacteriana y fúngica se vio influenciada principalmente por las altas temperaturas, que favorecieron a las comunidades termotolerantes. La comunidad vírica estuvo caracterizada por la presencia de virus de plantas y bacteriófagos de bacterias entéricas, sugiriendo el importante papel de los virus en el control de las comunidades patógenas.Composting is a viable process for the final treatment of sewage sludge, in a context in which these wastes tend to increase. The addition of compost in soil represents a sustainable option from an environmental and economic point of view. Likewise, this application is in agreement with new environmental policies of recycling and in the revaluation of waste. Despite the existence of numerous technologies for the composting of sewage sludge, the use of semipermeable covers represent a technology that allows the control of odors and the maintenance of temperature and humidity inside the system, which can accelerate the composting process. Microorganisms are the main responsible players of the biological transformation, thus, monitoring the changes in the microbial population and their interrelation with operational variables can represent a very useful tool to optimize these processes. In this work, we carried out the study of two composting piles with sewage sludge at industrial scale. Both piles used the semipermeable cover technology connected with an air insufflation system, and were tested under variable composting times. The monitored physical-chemical and microbiological parameters included the determination of enzymatic activities and the study of microbial diversity (bacterial, fungal and viral population). These variables were tracked by both dependent and independent culture technologies. Finally, the production of extracellular enzymes in bacterial and fungal isolates was studied to obtain enzymes of biotechnological value. Physico-chemical variables revealed high correlation between microbial activity and diversity, reflected in an intense phase of degradation under the semipermeable cover. The bacterial and fungal diversity was most influenced by the high temperatures, which favored thermotolerant communities. The viral community was characterized by the presence of plant viruses and bacteriophages of enteric bacteria. Results suggest the important role of viruses in the control of pathogenic communities.Tesis Univ. Granada.Este trabajo ha sido financiado por el Proyecto de Excelencia Motriz RNM 7370 de la Junta de Andalucía y se ha llevado a cabo dentro del Grupo RNM-270 de Microbiología Ambiental de la Universidad de Granada. La autora agradece el contrato predoctoral ofrecido por la Junta de Andalucía.Programa Oficial de Doctorado en Biología Fundamental y de Sistema

Assessment of bacterial and fungal communities in a full-scale thermophilic sewage sludge composting pile under a semipermeable cover

Bacterial and fungal communities in a full-scale composting pile were investigated, with sewage sludge and a vegetal bulking agent as starting materials. Bacillales and Actinomycetales were predominant throughout the process, showing significant abundance. Ascomycota was the predominant fungal phylum during the thermophilic phase, with a shift to Basidiomycota at the end of the process. The bulking material was the principal contributor to both communities by the end of the process, with a signal above 50%. The presence of genera, such as Pedomicrobium, Ureibacillus and Tepidimicrobium at the end of the process, and Chaetomium and Arthrographis in the maturation phase, showed an inverse correlation with indicators of organic matter stabilisation. A semipermeable cover was an effective technology for excluding pathogens. These results indicate that changes in the microbial population and their interrelation with operational variables could represent a useful tool for monitoring composting processes.This research was conducted with funding from Junta de Andalucía (Research project RNM-7370) and the Ministry of Economy and Competitiveness (MINECO) and European Regional Development Fund (ERDF), [CTM2017-84332-R] and [RYC-2013-12481] (Ramón y Cajal contract for EA). We would like to acknowledge the Environmental Microbiology Research Group (RNM-270) of the University of Granada, Spain