“Clarification peculiarities of disrupted microorganism suspension by the method of cross-flow microfiltration”

Author, institution: Darius Mažeika, Kaunas University of Technology

Science area, field: Technological Sciences, Chemical Engineering

The Doctoral Dissertation is available at the library of Kaunas University of Technology (K. Donelaičio St. 20, Kaunas).

Scientific Supervisor:

Assoc. Prof. Dr. Zenonas VALANČIUS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T).

Scientific Consultant:

Prof. Dr. Jolanta LIESIENĖ (Kaunas University of Technology, Physical Sciences, Chemistry – 03T).

Dissertation Defence Board of the Chemical Engineering Science Field:

Prof. Dr. Rimantas Petras VENSKUTONIS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T) – chairman;

Prof. Dr. Habil. Zigmuntas Jonas BERESNEVIČIUS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T);

Assoc. Prof. Dr. Rima KLIMAVIČIŪTĖ (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T);

Dr. Arūnas LAGUNAVIČIUS (Thermo Fisher Scientific Baltics, Physical Sciences, Biochemistry – 04P);

Prof. Dr. Jolanta SEREIKAITĖ (Vilnius Gediminas Technical University, Technological Sciences, Chemical Engineering – 05T).

Official opponents:

Prof. Dr. Saulutė BUDRIENĖ (Vilnius University, Physical Sciences, Chemistry – 03P);

Prof. Dr. Habil. Juozas Vidas GRAŽULEVIČIUS (Kaunas University of Technology, Technological Sciences, Chemical Engineering – 05T).

Annotation:

The majority proteins that are manufactured in biotechnology are intracellular. The manufacturing of soluble intracellular proteins consists of several steps: biosynthesis, cell disruption, clarification of cell lysate and purification by implementing various chromatographic techniques. Separation of soluble proteins from cell debris is an inherently difficult operation usually performed by centrifugation or filtration. One of the alternative methods is cross-flow microfiltration which becomes increasingly popular. However, membrane fouling during the process is one of the major disadvantages of this technology.

The aim of this work is to examine the influence of various factors on the cross-flow microfiltration of the suspension of disrupted microorganisms and to optimize the clarification of disrupted N. corallina, N. denitrificans, T. aquaticus YT-1, A. luteus, B. amyloliquefaciens H, K. pneumoniae, M. spp ir C. Polymorphus cells. The efficiency of the process and macromolecule yields was analyzed. The influence of disruption method, pump flow rate, biomass concentration, pH, ionic strength, detergents, cationic polymers and resins on cross-flow microfiltration of disrupted microorganism suspension was examined. Conditions for clarification of disrupted cell suspension by cross-flow microfiltration were determined and the 750 kDa membrane was shown to be the most efficient. Flocculation with polyethyleneimine had the highest influence on the cross-flow microfiltration.