Contents 1. Introduction 2. The P. pastoris expression system 2.1. The AOX1 promoter and alternative promoters 2.1.1 AOX1 promoter. 2.1.2. Strongly expressed alternative promoters. 2.1.3. Moderately expressed alternative promoters. 2.2. Host strains 2.2.1. Methanol utilization phenotype 2.2.2. Protease-deficient host strains 2.3. Expression vectors 3. Bioreactor process techniques for productio...

Improvements in technology for the production of microbial biomass from natural gas, which have been gaining importance recent years, require development and optimization energy-efficient bioreactor designs. The most advanced methods developing scaling up industrial biotechnological processes rely on detailed hydrodynamic modeling, addition to classical approaches, as main tool analysis large-s...

the possibility of applying membrane distillation to support the fermentation process was investigated. the capillary polypropylene membranes were assembled in the membrane modules. the studies were carried out using the standard solutions containing the compounds frequently occurring in the broths such as ethanol, citric, acetic and lactic acids, glycerol and 1,3-propanediol. the performance o...

Hydrodynamic forces in bioreactors can decisively influence extracellular matrix deposition in engineered cartilage constructs. In the present study, the reduced fluid shear, high-axial mixing environment provided by a wavy-walled bioreactor was exploited in the cultivation of cartilage constructs using polyglycolic acid scaffolds seeded with bovine articular chondrocytes. Increased growth as d...

The present article describes two novel flexible plastic-based disposable bioreactors. The first one, the WU bioreactor, is based on the principle of a wave and undertow mechanism that provides agitation while offering convenient mixing and aeration to the plant cell culture contained within the bioreactor. The second one is a high aspect ratio bubble column bioreactor, where agitation and aera...

BACKGROUND Large-scale muscle tissue engineering remains a major challenge. An axial vascular pedicle and perfusion bioreactor are necessary for the development and maintenance of large-scale engineered muscle to ensure circulation within the construct. We aimed to develop a novel experimental model of a large-scale engineered muscle flap from an existing rat groin fat flap. METHODS A fat fla...

Five landfills were analyzed to provide a perspective of current practice and technical issues that differentiate bioreactor and recirculation landfills in North America from conventional landfills. The bioreactor and recirculation landfills were found to function in much the same manner as conventional landfills, with designs similar to established standards for waste containment facilities. L...

Recently developed perfusion micro-bioreactors offer the promise of more physiologic in vitro systems for tissue engineering. Successful application of such bioreactors will require a method to characterize the bioreactor environment required to elicit desired cell function. We present a mathematical model to describe nutrient/growth factor transport and cell growth inside a microchannel biorea...

Several bioreactor systems are used for biological treatment of hydrogen sulfide. Among these, airlift bioreactors are promising for the bioconversion of hydrogen sulfide into elemental sulfur. The performance of airlift bioreactors is not adequately understood, particularly when directly fed with hydrogen sulfide gas. The objective of this paper is to investigate the performance of an airlift ...