Anaerobic digestion (AD) has been applied over the years for the treatment of a wide variety of organic streams. The advantages of this process over other biological treatments relate mainly to the low cost of bioreactors operation, when compared to aerobic processes, since AD-based treatments offer a cost-effective solution for the treatment of high-strength organic wastes, through economic re...

BACKGROUND Clostridium acetobutylicum possesses two homologous adhE genes, adhE1 and adhE2, which have been proposed to be responsible for butanol production in solventogenic and alcohologenic cultures, respectively. To investigate their contributions in detail, in-frame deletion mutants of each gene were constructed and subjected to quantitative transcriptomic (mRNA molecules/cell) and fluxomi...

The aim of the study was first to develop a simple and practical model of anaerobic digestion including sulphate-reduction in anaerobic ponds. The basic microbiology of our model consists of three steps, namely, acidogenesis, methanogenesis, and sulphate reduction. This model includes multiple reaction stoichiometry and substrate utilization kinetics. The second aim was to determine some kineti...

Leaves of Mangifera Indica (MI, mango leaves) and Manihot Utilissima (MU, cassava leaves) are available in tropical regions and are the most accessible vegetal wastes of Kinshasa, capital of Democratic Republic of Congo. These wastes are not suitably managed and are not rationally valorized. They are abandoned in full air, on the soil and in the rivers. They thus pollute environment. By contras...

Arginine is an important pH-elevating agent in the oral cavity. It has been incorporated in oral hygiene formulations to mitigate sensitivity and to prevent caries. In this investigation, the effects of sustained arginine dosing of dental plaque microcosms on bacteriological composition and pH were evaluated under controlled conditions. Plaque microcosms were established in constant-depth film ...

The purpose of this investigation is to study the effect 1) leachate recirculation (LR) and dilution (LD), 2) increment waste ratio, 3) co-digestion using poultry as co-substrate for enhancing acidogenesis process organic municipal solid (OMSW), thereby increasing medium chain fatty acids (MCFAs) production. results experiment carried in a batch pilot reactor show that LR increases hydrolysis w...

BACKGROUND Oleaginous microalgae contain a high level of lipids, which can be extracted and converted to biofuel. The lipid-extracted residue can then be further utilized through anaerobic digestion to produce biogas. However, long-chain fatty acids (LCFAs) have been identified as the main inhibitory factor on microbial activity of anaerobic consortium. In this study, the mechanism of LCFA inhi...

The paper proposes an observability analysis and estimation schemes for specific growth rates and biomass concentrations of the anaerobic digestion process. A 3-stage model of 5 dynamic states is assumed, describing the hydrolysis, acidogenesis and methanogenesis of two different populations of microorganisms (acidogenic and methanogenic). The main result is that the specific growth rates of th...