Suitability of the shaking flask for oxygen supply to microbiological cultures期刊界 All Journals 搜尽天下杂志传播学术成果专业期刊搜索期刊信息化学术搜索

按检索

Suitability of the shaking flask for oxygen supply to microbiological cultures

Authors:	H -J Henzler M Schedel

Institution:	(1) Bayer AG, W-5600 Wuppertal, Germany

Abstract:	Due of its simplicity the shaking flask is used in serial studies, e.g. in the screening for secondary metabolites or in the optimization of fermentation processes. Experimental investigations in these small bioreactors are often the first step in developing a large-scale fermentation process.Movement of the flask should produce sufficient mixing, supply of oxygen, and removal of carbon dioxide. In the case of fluids with low or moderate viscosity, gas transport is the most important aspect. This publication summarizes data necessary to calculate the gas transport. These data are derived from the consideration of the gas diffusions through the cotton plug as well as from the substance transport between the gas and liquid phases. As a result suitable fermentation conditions can be selected. Finally, the performance limits of the shaking flask are illustrated using the example of the oxygen supply in a Streptomyces tendae fermentation.List of Symbols A _s Cross section of plug - A Surface area of liquid in flask - a A/V _F specific phase interface area - c Concentration - c ^* Saturation concentration - c Plug diffusion term - D Widest diameter of flask - $\mathbb{D}_x ,\mathbb{D}_y ,\mathbb{D}_z$ Diffusion coefficients in multicomponent gas mix tures - $\mathbb{D}_{xy} ,\mathbb{D}_{xz} ,\mathbb{D}_{yz}$ Diffusion coefficients in binary gas mixtures - $\mathbb{D}_{\text{F}}$ Diffusion coefficient of oxygen in the liquid - d Diameter of neck of flask - e Eccentricity - G Volume-based mass flow - G _m Maximum volume-based mass flow - g Acceleration due to gravity - h Height coordinate - ¯H Mean height of plug - Hy p _i/c ^, Henry constant - K Consistency index - k D _xy/D _xz, Ratio of diffusion coefficients in binary gas mixtures - k _M Monod constant - k _L a Mass transport coefficient: gas/liquid - M Molecular weight - m Flow exponent - n Speed of shaking - p Pressure - p _i Partial pressure of gas component i - q Area-based flow of volume - R $= {{q_{{\text{CO}}_{\text{2}} } } \mathord{\left/ {\vphantom {{q_{{\text{CO}}_{\text{2}} } } {q_{{\text{O}}_{\text{2}} } }}} \right. \kern-\nulldelimiterspace} {q_{{\text{O}}_{\text{2}} } }}$ , respiration ratio - Sc $= {v \mathord{\left/ {\vphantom {v {\mathbb{D}_{\text{F}} }}} \right. \kern-\nulldelimiterspace} {\mathbb{D}_{\text{F}} }}$ , Schmidt number - T Absolute temperature - V Flask volume - V _F Volume of liquid in flask - w Velocity of the Stefan flow - x, y, z* Ratios of the partial pressures of the gases O₂, CO₂, N₂ - Rate of shear - Dynamic viscosity of the liquid - Kinematic viscosity of the liquid - Density of the liquid - _x, $\varrho _{{\text{O}}_{\text{2}} }$ Density of O₂ gas - Surface tension Indices 0 State in gas volume of shaking flask - 1 State in outside air - G Gas volume - x, y, z O₂, CO₂, N₂

Keywords:
本文献已被 SpringerLink 等数据库收录！

设为首页 | 免责声明 | 关于勤云 | 加入收藏