Prokaryotic cells divide by a process known as

#Question id: 14297

#SCPH05 I Biotechnology

A two-stage chemostat system is used for production of secondary metabolite. The volume of each reactor is 0.5 m³; the flow rate of feed is 50 l h^{- 1}. Mycelial growth occurs in the first reactor; the second reactor is used for product synthesis. The concentration of substrate in the feed is 10 gl^-1. Kinetic and yield parameters for the organism are:

Assume that product synthesis is negligible in the first reactor and growth is negligible in the second reactor. Determine substrate concentrations entering the second reactor.

#Question id: 14300

#SCPH05 I Biotechnology

A 15-m ³ chemostat is operated with dilution rate 0.1 h^-1. A continuous steriliser with steam injection and flash cooling delivers sterilized medium to the fermenter. Medium in the holding section of the steriliser is maintained at 130⁰C The concentration of contaminants in the raw medium is 10⁵ ml^-l; an acceptable contamination risk is one organism every 3 months. The Arrhenius constant and activation energy for thermal death are estimated to be 7.5 × 10³⁹ h^-1 and 288.5 kJ gmol^{- 1}, respectively. The steriliser pipe inner diameter is 12 cm. At 130⁰C the liquid density is 1000 kg m^{- 3} and the viscosity is 4 kg m^{- 1} h^{- 1}. Assuming perfect plug flow, determine the length of the holding section.   __________________

#Question id: 14302

#SCPH05 I Biotechnology

Pseudomonas sp. has a mass doubling time of 2.4 h when grown on acetate. The saturation constant using this substrate is 1.3 g/l (which is unusually high), and cell yield on acetate is 0.46 g cell/g acetate. If we operate a chemostat on a feed stream containing 38 g/l acetate, find the Substrate concentration when the dilution rate is 0.8Dmax?

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