BACKGROUND Heterologous production of natural products in Escherichia coli has emerged as an attractive strategy to obtain molecules of interest. Although technically feasible most of them are still constrained to laboratory scale production. Therefore, it is necessary to develop reasonable scale-up strategies for bioprocesses aiming at the overproduction of targeted natural products under indu...

Recent work has identified ethanol toxicity as a major factor pre­ venting continuous production of ethanol at the concentrations ob­ tainable in batch culture. In this paper we investigate the use of a con­ tinuous two-stage bioreactor design to circumvent toxic effects of ethanol. Biomass is produced via continuous culture in the first stage reactor in which ethanol concentrations are either ...

This paper deals with the modelling and control of semi-batch reactor used for chromium sludge regeneration process. A comparison of three process control approaches is presented. Usual PID controller without online identification (OI) and adaptive PID controller were adapted to semi-batch rector process in our previous studies. In this study the two-degrees-of-freedom (2DOF) controller is deve...

In this study; variation of effluent BOD5’s (Se) with reaction time (tr) in Sequencing Batch Reactor (SBR) unit for textile industry wastewater treatment plant and effective parameters on this variation have been researched. Determination of appropriate reaction time (tr) is an important value for design and operation of activated sludge unit. An appropriate kinetic equation for Sequencing Batc...

The purpose of this work was to examine the settling properties of activated sludge from a sequencing batch reactor (SBR). The experiments were carried out in a bench-scale reactor, fed with wastewater from the University of Olsztyn treatment plant. Concentrations of the examined activated sludge varied between 2.5 and 6.0 kg SS m. Laboratory analyses of the sludge comprised: sludge concentrati...

The nutrient removal using microalgae in wastewater has received more attention in the last years. Due to the optical loss of wastewater, the reactors for algae used in wastewater treatment, have a small depth and they need large surfaces (like open ponds). In this study it is proposed a novel photobioreactor with an internal illumination using LED lights and Plexiglas End-Lighten rods. The lig...

human granulocyte-colony stimulating factor (hg-csf) cdna was expressed in the methylotrophic yeast pichia pastoris under the control of the alcohol oxidase (aox1) promoter. an expression vector for hg-csf secretion was constructed using vector ppic9. higher levels of hg-csf was obtained using a p. pastoris mut+ (methanol utilization fast) phenotype. the effects of environmental factors such as...

A process comprising two-step fed-batch cultivation has been investigated for the production of ectoines using the halophilic bacterium Halomonas boliviensis DSM 15516(T). The first cultivation was performed under optimal conditions for cell growth and resulted in cell mass concentration of about 41 g l(-1) after 24 h of cultivation. During the second cultivation at higher salt concentration, a...

The present study was designed for the production and optimization of the C12-C14 sophorolipid, using the yeast Candida bombicola ATCC-22214. The fermentation was carried under fed-batch culture conditions i.e., maintaining 15% coconut oil and 10% glucose as hydrophobic and hydrophilic carbon sources, respectively. A maximum yield 54.0 g/L (in 234 h) was achieved. A significant antimicrobial ac...