Towards a circular bioeconomy to produce methane by co-digestion of coffee and brewery waste using a mixture of anaerobic granular sludge and cattle manure as inoculum.

Coffee processing wastes, such as solid (pulp and husk) and wastewater, co-digested with industrial brewery wastewater, serve as excellent substrates for generating methane in the anaerobic digestion process. This study compared methane production using different compositions of cattle manure (CM) and granular sludge from an Upflow Anaerobic Sludge Blanket (UASB) reactor used in poultry wastewater treatment (GS). Four anaerobic batch reactors (500 mL) were assembled, A (50% CM and 50% GS), B (60% CM and 40% GS), C (70% CM and 30% of GS) and D (60% CM and 40% GS). Equal concentrations of substrates were added to all reactors: pulp and husk pretreated by hydrothermolysis (1 g L-1), coffee (10 g COD L-1) and brewery (1.5 g COD L-1) wastewaters. Assays A, B and C were supplemented with 2 g L-1 of yeast extract, except for assay D. The reactors were operated at 37 °C and pH 7.0. In assay B, the highest CH4 production of 759.15 ± 19.20 mL CH4 g-1 TS was observed, possibly favored by the synergistic interactions between cellulolytic bacteria Christensenellaceae_R-7_group and Methanosaeta archaea, as inferred by genes encoding enzymes related to acetoclastic methanogenesis (acetyl-CoA synthetase). Consequently, the electricity production potential of assay B (45614.08 kWh-1 year-1) could meet the energy demand of a farm producing coffee and beer, contributing to a positive energy balance concerning methane generation.

Anaerobic digestion of aqueous phase from hydrothermal liquefaction of Spirulina using biostimulated sludge.

Hydrothermal liquefaction is a process that converts wet biomass into biofuels, more specifically bio-crude oil. During the process, post hydrothermal liquefaction waste water (PHWW) is generated, rich in nutrient and organic matter, however potentially toxic. Anaerobic digestion of PHWW from Spirulina, was evaluated using biostimulated sludge as a strategy to optimize the process. The biostimulation was conducted in a sequential batch reactor fed with organic acids and methanol aiming at development of acetogenic and methanogenic microorganism. Anaerobic biodegradability batch assays were performed, with biostimulated sludge and with non-biostimulated sludge, using increasing PHWW concentrations. Biostimulated sludge were more favourable for reaching higher methane yields at higher organic matter concentrations in comparison to non-biostimulated sludge, presenting less inhibition at conditions tested. Biostimulation was a key process to select and favour potential microorganisms involved in specialized uptake of recalcitrant compounds, such as Mesotoga and Methanomethylovorans.

Effect of a probiotic beverage consumption (Enterococcus faecium CRL 183 and Bifidobacterium longum ATCC 15707) in rats with chemically induced colitis.

BACKGROUND: Some probiotic strains have the potential to assist in relieving the symptoms of inflammatory bowel disease. The impact of daily ingestion of a soy-based product fermented by Enterococcus faecium CRL 183 and Lactobacillus helveticus 416 with the addition of Bifidobacterium longum ATCC 15707 on chemically induced colitis has been investigated thereof within a period of 30 days. METHODS: Colitis was induced by dextran sulfate sodium. The animals were randomly assigned into five groups: Group C: negative control; Group CL: positive control; Group CLF: DSS with the fermented product; Group CLP: DSS with the non-fermented product (placebo); Group CLS: DSS with sulfasalazine. The following parameters were monitored: disease activity index, fecal microbial analyses, gastrointestinal survival of probiotic microorganisms and short-chain fatty acids concentration in the feces. At the end of the protocol the animals' colons were removed so as to conduct a macroscopical and histopathological analysis, cytokines and nitrite quantification. RESULTS: Animals belonging to the CLF group showed fewer symptoms of colitis during the induction period and a lower degree of inflammation and ulceration in their colon compared to the CL, CLS and CLP groups (p<0.05). The colon of the animals in groups CL and CLS presented severe crypt damage, which was absent in CLF and CLP groups. A significant increase in the population of Lactobacillus spp. and Bifidobacterium spp. at the end of the protocol was verified only in the CLF animals (p<0.05). This group also showed an increase in short-chain fatty acids (propionate and acetate). Furthermore, the intestinal survival of E. faecium CRL 183 and B. longum ATCC 15707 in the CLF group has been confirmed by biochemical and molecular analyzes. CONCLUSIONS: The obtained results suggest that a regular intake of the probiotic product, and placebo to a lesser extent, can reduce the severity of DSS-induced colitis on rats.

Anaerobic degradation of anionic surfactants by indigenous microorganisms from sediments of a tropical polluted river in Brazil / Degradación anaeróbica de tensioactivos aniónicos en microorganismos autóctonos de los sedimentos de un río tropical contaminado en Brasil

Linear alkylbenzene sulfonate (LAS) is widely used in the formulation of domestic and industrial cleaning products, the most synthetic surfactants used worldwide. These products can reach water bodies through the discharge of untreated sewage or non-effective treatments. This study evaluates the ability of the microorganisms found in the Tietê river sediment to degrade this synthetic surfactant. The experiment was conducted in a bioreactor, operated in batch sequences under denitrifying conditions, with cycles of 24 hours and stirring at 150rpm, using 430mL of sediments and 1 070mL of a synthetic substrate consisting of yeast extract, soluble starch, sodium bicarbonate and sucrose. LAS was added at different concentrations of 15mg/L and 30mg/L. The reactor operation was divided into the biomass adaptation to the synthetic substrate without LAS and three experimental conditions: a) addition of 15mg/L of LAS; b) 50% reduction the co-substrate concentration and 15mg/L of LAS, and c) addition of 30mg/L of LAS and 100% co-substrate concentration. The results showed that the degradation efficiency of LAS was directly related to the addition of co-substrates and the population of denitrifying bacteria. The removal of LAS and nitrate can be achieved simultaneously in wastewater with low organic loads. The reduction in the co-substrates concentration was directly influenced by the number of denitrifying bacteria (2.2x10(13) to 1.0x10(8)MPN/gTVS), and consequently, LAS degradation (60.1 to 55.4%). The sediment microorganisms in the Tietê river can be used as an alternative inoculum in the treatment of wastewater with nitrate and LAS contamination.

El alquilbenceno sulfonato lineal (LAS) es el tensoactivo sintético más usado en todo el mundo en los produtos de limpeza domestica e industrial y puede llegar a las masas de agua a través de la descarga de aguas residuales sin tratamiento o con un tratamiento ineficaz. El objetivo del estudio consistió en evaluar la capacidad de la microbiota presente en el sedimento del río Tietê en la degradación del tensoactivo anionico - LAS. El experimento se llevó a cabo en un bioreactor de lotes secuenciales en condiciones de desnitrificación con ciclos de 24 horas, agitación de 150rpm, usando 430mL de sedimento y 1 070mL de sustrato sintético constituido por extracto de levadura, almidón soluble, bicarbonato de sodio y sacarosa. El LAS fue añadido a diferentes concentraciones de 15mg/L y 30mg/L. El funcionamiento del bioreactor se dividió en la adaptación de la biomasa con sustrato sintético sin LAS y tres condiciones experimentales: A) adición de 15mg/L de LAS; B) 15mg/L de LAS y reducción del 50% de la concentración del co-sustrato y C) 30mg/L de LAS y la concentración de 100% de co-substrato. Los resultados obtenidos muestran que la eficiencia en la degradación del LAS está directamente relacionada con la población de bacterias desnitrificadoras y que el sedimento del río Tietê se puede utilizar como inóculo en el tratamiento de LAS en condiciones desnitrificadoras. La población de bacterias fue capaz de degradar el LAS independiente de la fuente de carbón adicionada. La remoción de LAS y de nitrato se puede lograr simultáneamente en aguas residuales con una baja carga orgánica. La reducción de la concentración del co-sustrato fue influenciado directamente por la población de bacterias desnitrificantes (2.2x10(13) a 1.0x10(8)MNP/gTVS) y por lo tanto la degradación de LAS (60.1-55.4%). Los microorganismos en el sedimento del río Tietê se pueden usar como inóculo alternativo para el tratamiento de efluentes contaminados con nitrato y LAS.

Influence of support material on the immobilization of biomass for the degradation of linear alkylbenzene sulfonate in anaerobic reactors.

Two horizontal-flow anaerobic immobilized biomass reactors (HAIB) were used to study the degradation of the LAS surfactant: one filled with charcoal (HAIB1) and the other with a mixed bed of expanded clay and polyurethane foam (HAIB2). The reactors were fed with synthetic substrate supplemented with 14 mg l(-1)of LAS, kept at 30+/-2 degrees C and operated with a hydraulic retention time (HRT) of 12h. The surfactant was quantified by HPLC. Spatial variation analyses were done to quantify organic matter and LAS consumption along the reactor length. The presence of the surfactant in the load did not affect the removal of organic matter (COD), which was close to 90% in both reactors for an influent COD of 550 mg l(-1). The results of a mass balance indicated that 28% of all LAS added to HAIB1 was removed by degradation. HAIB2 presented 27% degradation. Molecular biology techniques revealed microorganisms belonging the uncultured Holophaga sp., uncultured delta Proteobacterium, uncultured Verrucomicrobium sp., Bacteroides sp. and uncultured gamma Proteobacterium sp. The reactor with biomass immobilized on charcoal presented lower adsorption and a higher kinetic degradation coefficient. So, it was the most suitable support for LAS anaerobic treatment.