Adaptation of a microbial consortium to pelagic Sargassum modifies its taxonomic and functional profile that improves biomethane potential.

In recent years, pelagic Sargassum has invaded the Caribbean coasts, and anaerobic digestion has been proposed as a sustainable management option. However, the complex composition of these macroalgae acts as a barrier to microbial degradation, thereby limiting methane production. Microbial adaptation is a promising strategy to improve substrate utilization and stress tolerance.

Energy-saving pretreatments affect pelagic Sargassum composition and DNA metabarcoding reveals the microbial community involved in methane yield.

Sargassum spp. flood the Caribbean coastline, causing damage to the local economy and environment. Anaerobic digestion (AD) has been proposed as an attractive option for turning macroalgae into valuable resources.

Methane Production of spp. Biomass from the Mexican Caribbean: Solid-Liquid Separation and Component Distribution.

In the last decade, spp. seaweed species have caused massive flooding on the Caribbean Sea coasts. These seaweed species have a high content of recalcitrant compounds, such as insoluble fibers and polyphenols, which generate low methane yields in anaerobic digestion (AD).

Synergy of the Tropical Earthworm Pontoscolex corethrurus and Oil Palm Bagasse in the Removal of Heavy Crude Oil.

The tropical endogeic earthworm Pontoscolex corethrurus, a non-standard species used in ecotoxicity, has been found in crude oil-contaminated habitats. We estimated the removal of total hydrocarbons from heavy crude "Maya" oil on an artificially contaminated soil with a median lethal concentration of P. corethrurus and an addition of oil palm bagasse.

Physiological stabilization, community characterization, and nitrogen degradation dynamics in an anammox consortium from estuarine sediments.

Anammox is a cost-effective and sustainable process for nitrogen removal; however, the production of a physiologically stable inoculum is a critical point in the start-up process. In this work, estuarine sediments were used as incubation seeds to obtain cultures with stable anammox activity. Assays were performed in batch cultures fed with stoichiometric amounts of ammonium and nitrite, analyzing physiological response variables and the microbial community.

2-Chlorophenol consumption by cometabolism in nitrifying SBR reactors.

Cometabolic consumption of 2-chlorophenol (2-CP) by a nitrifying sludge was evaluated in two SBR reactors fed with 60 mg 2-CP-C/L and different initial ammonium concentrations (100, 200, 300, 400, and 500 mg NH-N/L). Irrespectively to the increase in ammonium concentration and throughout the operational cycles, the sludge achieved a complete nitrification in 14 days, accounting for ammonium consumption efficiencies close to 99% and nitrate production yields between 0.93 and 0.

Sensitivity of the Endogeic Tropical Earthworm Pontoscolex corethrurus to the Presence of Heavy Crude Oil.

Contamination of soil with petroleum is common in oil-producing areas across the tropical regions of the world. There is limited knowledge on the sensitivity of endogeic tropical earthworms to the contamination of soil with total petroleum hydrocarbons (TPH) present in crude oil. Pontoscolex corethrurus is a dominant species in tropical agroecosystems around oil-processing facilities.

Rheological behavior of physicochemical sludges during methanogenesis suppression and hydrogen production at different organic loading rates.

This study investigated the rheological behavior of raw physicochemical sludges and sludges that were digested at different organic loading rates (OLRs) (1, 5, 10 and 15 gVS L(-1) d(-1)) during methanogenesis suppression to produce hydrogen anaerobically. The Herschel-Bulkley model was used to describe the rheology of these sludges with specific properties. The results indicate that the Herschel-Bulkley model adequately described the rheology (τ0 ≠ 0) of this type of fluids (R(2) > 0.

Dynamics of a microbial community exposed to several concentrations of 2-chlorophenol in an anaerobic sequencing batch reactor.

The aim of this study was to contribute to the knowledge on the dynamic of the microbial community involved in anaerobic degradation of different concentrations of 2-chlorophenol (2CP, from 28 to 196 mg 2CP-C/L) and a mixture of 2CP and phenol (from 28 to 196 mg phenol-C/L) and its relationship with the respiratory process in two anaerobic sequencing batch reactors (ASBR). The dynamic of the microbial community was evaluated by denaturant gradient gel electrophoresis (DGGE) and ecological indices (S and J indices). The respiratory process was evaluated by means of substrate consumption efficiency, biogas yield, and specific consumption rates as response variables.

Influence of organic loading rate on methane production in a CSTR from physicochemical sludge generated in a poultry slaughterhouse.

The influence of the increase of the organic loading rate (OLR) on methane production in a continuous stirred-tank reactor (CSTR) from physicochemical sludge generated in a poultry slaughterhouse was evaluated. Total solid (TS) to obtain OLR of 1, 5, 10 and 15 g VS L(-1) day(-1), with hydraulic retention times of 29, 6, 6 and 4, respectively, were conditioned. The results showed a decrease in pH levels and an increase in the theoretical volatile fatty acids (VFA).

Effect of phenol and acetate addition on 2-chlorophenol consumption by a denitrifying sludge.

Chlorophenols are widely distributed in the environment. Various strategies have been used to improve their biological elimination under anaerobic conditions; however, such information is still scarce. The aim of this study was to evaluate in batch assays the consumption of 2-chlorophenol (2-CP) by a denitrifying sludge and the influence of acetate or phenol as co-substrates in the 2-CP consumption.

2-Chlorophenol consumption and its effect on the nitrifying sludge.

The kinetic behavior of a nitrifying sludge exposed to 2-chlorophenol (2-CP) was evaluated in batch culture. The assays were performed using a stabilized nitrifying sludge. In control assays with (mg L(-1)): NH(4)(+)-N (100) and NaHCO(3)(-)-C (250), the substrates were consumed in 8h, the ammonium consumption efficiency was 99% and the NO(3)(-) yield higher than 0.

Acetate enhances the specific consumption rate of toluene under denitrifying conditions.

Toluene is usually present in the environment as a contaminant along with other carbon sources which may influence its removal. In this work we studied the effect of a readily consumable carbon source such as acetate on toluene mineralization under denitrifying conditions. Continuous and batch cultures with stabilized denitrifying sludge were carried out.