Development and characterization of microfiltration hollow-fiber modules for sterilization of fermentation media

Abstract

-Sterilization of fermentation medium involving heat may result in undesirable chemical reactions that alter nutrient concentration and yield products, which interfere in the fermentation performance. Sterilization of heat-sensitive compounds usually involves separate sterilizations of carbon source and nutrient solution. Membrane separation processes are an alternative to thermal processes, as they have many advantages such as the possibility of continuous and modular operation and the use of moderate temperatures. In this context, the objective of this work was the preparation of hollow-fiber membranes and the design of modules suitable for continuous sterilization of fermentation medium. The membrane with the best performance had a maximum pore diameter of 0.2 µm and a permeability of 42.9 L/m 2 .bar.h for a glucose/peptone/yeast extract medium. A module with 0.26 m 2 of permeation area was built with these membranes. This module was able to provide a permeate flow rate of 2.2 L/h using a pressure difference of 0.2 bar. The collected permeate was completely sterile, thus confirming the efficiency of this process.

Optimizing the operational conditions of a membrane bioreactor used for domestic wastewater treatment

“…The hollow-fiber polymeric membrane was fabricated by the Membrane Separation Process Laboratory (PAM) of COPPE/UFRJ, according to the methodology proposed by Faria et al (2002). The mean pore diameter was determined by images from a scanning electron microscope (JEOL JSM -5300).…”

Elaboration and characterization of low cost ceramics microfiltration membranes applied to the sterilization of plant tissue culture media

“…Autoclaving (steam sterilization) is the most common technique because of its low cost and ease of use [51]. However, the sterilization of culture medium involving heat may result in undesirable reactions [44,50,52]. As an example, many proteins, vitamins, and carbohydrates are thermolabile and may decompose during autoclaving.…”

Solvent recovery from soybean oil/n-hexane mixtures using hollow fiber membrane

“…Membrane technology has been increasingly adopted by the food industry, mainly for the clarification of juices, wines and beers and the concentration of milk proteins. The interest in the application of membrane separations in the processing of vegetable oils to replace some of the traditional steps has also been growing in the last decade (Baker, 2004;Coutinho et al, 2009;Sarmento et al, 2004;Shahidi, 2005) Membrane separation processes have advantages over conventional separation processes, including energy savings, the selectivity of the compounds obtained, the possibility of separation of thermolabile compounds, the simplicity of operating the system and a relatively easy scale up from lab to industrial scale (Faria et al, 2002;Shahidi, 2005). In contrast to the conventional refining process, the membrane process can be conducted at low temperatures, preserving the heat sensitive components of technological interest of the oil, such as natural antioxidants.…”