Procedimiento de obtención de abono líquido orgánico rico en sustancias húmicas a partir de compost de origen vegetal

Número de publicación: ES2286917 A1 (01.12.2007) También publicado como: ES2286917 B1 (01.11.2008) Número de Solicitud: Consulta de Expedientes OEPM (C.E.O.) P200402011 (11.08.2004)Obtención de un producto líquido rico en sustancias húmicas mediante un procedimiento sencillo, rápido y extrapolable a nivel industrial y cuya aplicación a nivel agrícola sea satisfactoria. La obtención de dicho abono se ha llevado a cabo gracias a la optimización del proceso de extracción de las sustancias húmicas presentes en muestras de compost de origen vegetal. Las condiciones óptimas en las que se llevó a cabo dicho proceso implicaron altos valores de pH (> 10) y temperaturas superiores a 100°C. La aplicación del producto obtenido bajo tales condiciones, a nivel agrícola, ha mostrado aspectos de enorme interés tanto desde el punto de vista del desarrollo vegetal como en relación a las características del suelo o de la microbiota asociada a dicho sustrato.Universidad de Almerí

Compost Quality and Sanitation on Industrial Scale Composting of Municipal Solid Waste and Sewage Sludge

Municipal solid waste and sewage sludge are produced in large quantities that are often managed through industrial composting treatment. Because of their origin, composition, and complexity, ensuring adequate stabilization of the organic matter, and sanitation of fecal contaminants during composting is of the utmost significance, and difficult to achieve on an industrial scale. In this study, the operations of six industrial composting facilities that process municipal solid waste and sewage sludge were evaluated from the point of view of the sanitation achieved and the quality of the compost produced. In addition, the results were compared using the model of industrial compost from green waste. Differences between the plants were ascribable to operations other than composting systems. High phytotoxicity and fecal contamination above legislation thresholds were found in compost produced from municipal solid waste. In contrast, compost from sewage sludge were more stable and mature than those produced from green waste, and also had an adequate level of sanitation. The raw material and operational factors are of great relevance to obtain a stable, mature, and pathogen-free compost

Industrial Composting of Sewage Sludge: Study of the Bacteriome, Sanitation, and Antibiotic-Resistant Strains

Wastewater treatment generates a huge amount of sewage sludge, which is a source of environmental pollution. Among the alternatives for the management of this waste, industrial composting stands out as one of the most relevant. The objective of this study was to analyze the bacterial population linked to this process and to determine its effectiveness for the reduction, and even elimination, of microorganisms and pathogens present in these organic wastes. For this purpose, the bacteriome and the fecal bacteria contamination of samples from different sewage sludge industrial composting facilities were evaluated. In addition, fecal bacteria indicators and pathogens, such as Salmonella, were isolated from samples collected at key stages of the process and characterized for antibiotic resistance to macrolide, β-lactam, quinolone, and aminoglycoside families. 16S rRNA phylogeny data revealed that the process clearly evolved toward a prevalence of Firmicutes and Actinobacteria phyla, removing the fecal load. Moreover, antibiotic-resistant microorganisms present in the raw materials were reduced, since these were isolated only in the bio-oxidative phase. Therefore, industrial composting of sewage sludge results in a bio-safe final product suitable for use in a variety of applications

Biopriming of cucumber seeds using actinobacterial formulas as a novel protection strategy against Botrytis cinerea

This work highlights the ability of various actinobacterial formulas, to control the incidence of gray-mold caused by Botrytis cinerea in cucumber seedlings. Protocols applied aimed at the preliminary characterization of the actinobacterial collection and the biopolymers used as carriers were very useful for predicting their phytotoxic, phytostimulating and biopesticidal capacity. First, the phytostimulatory or phytotoxic potential of 3 biopolymers at 3 different concentrations and a collection of 10 actinobacteria were analyzed by calculating the germination index in cucumber seeds by seed dipping (biopriming). In general, two-member consortia and independent actinobacteria previously selected reached a phytostimulant effect on cucumber seedlings after their application by biopriming. Likewise, the selected actinobacteria were characterized, sole and in co-cultures, according to its ability to inhibit the growth of B. cinerea by dual culture bioassays. Finally, after selecting the most effective actinobacterial formulas, a preventive gray-mold bioassay was performed based on cucumber seed biopriming. The strains A5 and A7, in axenic and co-culture, showed to be the most efficient strains against the in vitro growth of B. cinerea. Seed biopriming strategy with actinobacterial formulas revealed a remarkable promoter effect in the early stages of plant development and after the infection with the phytopathogen fungus was remained. Definitely, the microbial formulas used in this work showed a phytostimulant and biopesticide character, laying the foundations for subsequent studies that allow a deeper scrutiny of the mechanisms of action that grant the specialization of the effect that occurs between beneficial microorganisms and specific plant hosts

Enzymatic profiles associated with the evolution of the lignocellulosic fraction during industrial-scale composting of anthropogenic waste: Comparative analysis

In the new European Waste Law, composting is proposed as one of the best options to properly manage organic waste of anthropogenic origin. Currently, the massive generation of this type of waste, as well as its heterogeneity, makes difficult in many cases control this process of degradation on an industrial scale. In this work, 15 facilities were selected based on 5 types of organic waste: Urban Solid Waste, Vegetable Waste, Sewage Sludges, Agrifood Waste and “Alpeorujo”. The samples were collected in different thermal phases. The results revealed very different physicochemical and enzymatic profiles, as well as different degrees of humification depending on the process and the raw materials. However, parameters such as β-glucosidase, amylase, lignin/holocellulose ratio and humification rate showed similar trends in all cases. All of them could act as important indicators to evaluate the quality of a composting process, despite the heterogeneity of the starting materials

Comparative analysis of phytotoxicity and compost quality in industrial composting facilities processing different organic wastes

A comparative analysis of industrial composting facilities processing Vegetal Residues, Sewage Sludge, Municipal Solid Waste, Agri-food Waste or Olive Mill Waste was performed. The evolution of phytotoxicity during composting was analyzed by measuring the germination index. Physico-chemical parameters (pH, electrical conductivity, organic matter, reducing sugars, phenolic compounds, humic substances, soluble organic carbon, NeNH4 þ and NeNO3 - ) and heavy metals content were evaluated in final products. The material became non-phytotoxic at the cooling phase or at the end of composting in facilities processing Olive Mill Waste, Sewage Sludge, and Agri-food Waste. In facilities processing Municipal Solid Waste and Vegetal Residues, the material never lost phytotoxicity. All composts, except Municipal Solid Waste, fulfill requirements of the Spanish legislation for heavy metals content. Phytotoxicity was attributed to the high electrical conductivity and pH of the Vegetal Residues compost and heavy metal content of the Municipal Solid Waste compost. Germination index is recommended to track the performance of industrial composting. This work provides new insights for the better management of composting at the industrial scal

Revisiting the succession of microbial populations throughout composting: A matter of thermotolerance

Composting has been traditionally considered a process in which a succession of mesophilic and thermophilic microbial populations occurs due to temperature changes. In order to deepen in this model, 1380 bacterial and fungal strains (the entire culturable microbiota isolated from a composting process) were investigated for their ability to grow across a wide range of temperatures (20 to 60 °C). First, qualitative tests were performed to establish a thermal profile for each strain. Then, quantitative tests allowed ascertaining the extent of growth for each strain at each of the tested temperatures. The identity of the isolates enabled to position them taxonomically and permitted tracking the strains throughout the process. Results showed that 90% of the isolates were classified as thermotolerant (they grew at all tested temperatures). Only 9% and 1% of the studied strains showed to be strictly mesophilic or thermophilic, respectively. Firmicutes exhibited the greatest thermal plasticity, followed by Actinobacteria and Ascomycota. Most of the Proteobacteria and all Basidiomycota strains were also able to grow at all the assayed temperatures. Thermotolerance was clearly demonstrated among the composting microbiota, suggesting that the idea of the succession of mesophilic and thermophilic populations throughout the process might need a reassessment

Industrial composting of low carbon/nitrogen ratio mixtures of agri-food waste and impact on compost quality

The agri-food waste (AW) require amendments for composting to adjust nutritional and physicochemical deficiencies. The theoretical mixtures formulation is difficult to reach on an industrial scale. The main objective of this work was to evaluate to what extent the composition of AW-based mixtures determines the quality of the final compost produced at the industrial scale. Raw materials having the same AW share characteristics, irrespectively of the amendments added, but their compost were different. All the materials were biological stable at the cooling phase, and mature enough at the end, although the degree of humification did not match with the absence of phytotoxicity. The final compost had sufficient quality even though the AW-based raw materials have a low C/N ratio (< 20) and other characteristics such as high electrical conductivity (13 mS·cm−1 ) and pH (< 8.5) that are unfavorable for composting. The management operations during industrial composting correct the deficiencies of raw materials

Characterization of Thermophilic Lignocellulolytic Microorganisms in Composting

Composting involves the selection of a microbiota capable of resisting the high temperatures generated during the process and degrading the lignocellulose. A deep understanding of the thermophilic microbial community involved in such biotransformation is valuable to improve composting efficiency and to provide thermostable biomass-degrading enzymes for biorefinery. This study investigated the lignocellulose-degrading thermophilic microbial culturome at all the stages of plant waste composting, focusing on the dynamics, enzymes, and thermotolerance of each member of such a community. The results revealed that 58% of holocellulose (cellulose plus hemicellulose) and 7% of lignin were degraded at the end of composting. The whole fungal thermophilic population exhibited lignocellulose-degrading activity, whereas roughly 8–10% of thermophilic bacteria had this trait, although exclusively for hemicellulose degradation (xylan-degrading). Because of the prevalence of both groups, their enzymatic activity, and the wide spectrum of thermotolerance, they play a key role in the breakdown of hemicellulose during the entire process, whereas the degradation of cellulose and lignin is restricted to the activity of a few thermophilic fungi that persists at the end of the process. The xylanolytic bacterial isolates (159 strains) included mostly members of Firmicutes (96%) as well as a few representatives of Actinobacteria (2%) and Proteobacteria (2%). The most prevalent species were Bacillus licheniformis and Aeribacillus pallidus. Thermophilic fungi (27 strains) comprised only four species, namely Thermomyces lanuginosus, Talaromyces thermophilus, Aspergillus fumigatus, and Gibellulopsis nigrescens, of whom A. fumigatus and T. lanuginosus dominated. Several strains of the same species evolved distinctly at the stages of composting showing phenotypes with different thermotolerance and new enzyme expression, even not previously described for the species, as a response to the changing composting environment. Strains of Bacillus thermoamylovorans, Geobacillus thermodenitrificans, T. lanuginosus, and A. fumigatus exhibiting considerable enzyme activities were selected as potential candidates for the production of thermozymes. This study lays a foundation to further investigate the mechanisms of adaptation and acquisition of new traits among thermophilic lignocellulolytic microorganisms during composting as well as their potential utility in biotechnological processing