Physiological activity of native and r-DNA microorganisms
Main researcher
: MARIĆ, VLADIMIR (150706) Assistants
ŠUŠKOVIĆ, JAGODA (40116)
STEHLIK-TOMAS, VESNA (44734)
RUNJIĆ-PERIĆ, VJERA (39790)
GRBA, SLOBODAN (14222)
HORVAT, PREDRAG (120253)
BLAŽEKA, BOŽIDAR (160643)
MARIĆ, VLADIMIR (28422)
BLAGOVIĆ, BRANKA (142202)
MEHAK, MILENA (51414)
NOVAK, SRĐAN (85892)
PAVUŠEK, IVANKA (35771)
JOHANIDES, VERA (18803)
MATOŠIĆ, SREĆKO (71284)
VRDOLJAK, MARIJA (53326)
RUPČIĆ, JASMINKA (70160)
KOLB, NADA (21694)
ZORIĆ, IVANA (146265)
ŠEHOVIĆ, ĐURĐICA (46376)
BRKIĆ, BLAŽENKA (900441)
Type of research: basic Duration from: 04/01/91. to 04/01/96. Papers on project (total): 171
Papers on project quoted in Current Contents: 39
Institution name: Prehrambeno-biotehnološki fakultet, Zagreb (58) Department/Institute: Department of Biochemical Engineering Address: Pierottijeva 6/IV City: 10000 - Zagreb, Croatia
Communication
Summary: In order to collect and extend the knowledge about the
influence of the environment on the physiological activity of native and
r-DNA microorganisms in the state of rest, growth and multiplication, the
research will be done on various techniques of cultivation, separation, and
application of microbial biomasses. Cell constituents will be defined that
can serve as indicators of the physiological activity of the cells in the
resting as well as in the growth phase. The influence of the nutrient
medium, type of process, specific rates (of growth, supstrate consumption
and product synthesis) in rich and poor media, as well as techniques for
separation, concentration and preservation of microbial biomasses on the
parameters of physiological activity will be explored. Based on these
parameters the stability of technological characteristics of r-DNA
microorganisms will be checked out in laboratory scale experiments on
production of microbial biomass and various metabolites. In addition,
chemical and physical techniques for plasmid stabilization will be
explored. On the basis of the results of this research the mathematical
model will be established to predict the physiological activity of the
wild-type and r-DNA microorganisms in the production of metabolites or use
of biomasses as potential starter cultures.
Research goals: During the growth microbial cell synthesis a simple
and a very complex compaunds. A synthesis is directed by enzymes which are
regulated by the control mechanisms coded in DNA. Therefore, a modern
biotechnology uses genetically modofied microorganisms. The aim of this
research was to cellect and extend the knowledge of the influence of the
environment on physiological activity of native and rDNA microorganism
during: a) The state of rest (maintain of microbial biomasses in fresh,
frozen or freeze-dried state), b) Growth and multiplication in aim of
biomass or metabolite production in batch, semicontinuous and continuous
process, c) Preparations and use of immobilized cells, d) Development of
the specific process of cultivation, recovery, drying or freeze-drying of
selected bacterial starter cultures (e.g. lactic and azotofixing bacteria),
e) Construction and study of new type of bioreactor for the cultivation of
microbial starter cultures. Expected results are: 1. definition of cell
constituents by whose presence or particular concentration the
physiological capability of resting or activly growing microbial cells is
determined (enabling, in such a way, the predictability of cells
application to potential microbial processes, 2. A practical stability
control of the technological characteristic of rDNA microorganisms, in
microbial production of biomass and different metabolites, 3. Comparison of
physiological activity and productivity of native and rDNA microorganisms
in production of biomass and metabolites, 4. Improved procedure of
laboratory production of selected microbial starter culture, 5. Laboratory
model of new type of horizontal tubular bioreactor and development of
multiparameter mathematical model. Other information about the project.