This study aimed to produce polyhydroxyalkanoates (PHAs) from organic wastes by mixed bacterial cultures using anaerobic-aerobic fermentation systems. Palm oil mill effluent (POME) was used as an organic source, which was cultivated in a two-step-process of acidogenesis and acid polymerization. POME was operated in a continuous flow anaerobic reactor to access volatile fatty acids (VFAs) for PH...

Apple pomace extract (APE) in aerobic variable fed batch culture under standardized fermentation parameters was evaluated for the production of baker’s yeast. The substrate was fed at a flow rate of 0.39 dm h to regulate fermentable sugar concentration between 1-2 % in bioreactor. An average specific growth rate of 0.24 h and cellular yield coefficient of 0.48 g/g sugar was obtained during bake...

Partial-nitritation anammox (PNA) is a novel wastewater treatment procedure for energy-efficient ammonium removal. Here we use genome-resolved metagenomics to build a genome-based ecological model of the microbial community in a full-scale PNA reactor. Sludge from the bioreactor examined here is used to seed reactors in wastewater treatment plants around the world; however, the role of most of ...

Designing large-scale stirred bioreactors with performance closely matching the one achieved in lab-scale fermenters presents continuous challenge. In this contribution, dynamic modelling of the aerobic biocatalytic conversion process in viscous batch stirred tank reactor is developed. Its operation is illustrated by simulation of the interaction of fluid flow, mass transfer and reaction releva...

A bioreactor system without a biomass-liquid separation unit is evaluated for its chemical oxygen demand (COD) removal and biomass retention capabilities under the nitrogen deficient and low F/M conditions that are known to produce bulking biomass. A fully oxygenated stream recycled from an external oxygenator delivers the oxygen to an upflow bioreactor in which a biomass zone is formed and mai...

Seventy-five aerobic heterotrophs have been isolated from a packed-column bioreactor inoculated with soil from Antarctica. The column was maintained at 10 degrees C and continuously fed with a casein-containing medium to enrich protease producers. Twenty-eight isolates were selected for further characterization on the basis of morphology and production of clearing zones on skim milk plates. Phe...

A new process consisting of a landfill bioreactor, partial-nitritation (PN) and the anammox process has been developed for landfill leachate treatment. In this study, the landfill bioreactor exhibited excellent performance in methane-rich biogas recovery, with a specific biogas yield of 0.47 L gas g(-1) COD and methane percentages of 53-76%. PN was achieved in the aerobic reactor by high free a...