DEPARTMENT OF EXTREMOPHILIC BACTERIAx - Institute of ...

tomatoedgeBiotechnology

Feb 20, 2013 (4 years and 6 months ago)

178 views

DEPARTMENT OF EXTREMOPHILIC BACTERIA






Head:

Associate Professor Margarita Kambourova, PhD

Tel: +359 2

979

e
-
mail:
margikam@microbio.bas.bg



1958

Born July 22, 1958, Sofia

1981

Diploma, Faculty of
Biology, Sofia State University

1986

PhD in Micribiology, Institute of Microbiology, BAS

1986

Research Scientist, Institute of Microbiology

1996
-
1997

The Royal Society Postdoctoral fellow, Department of Biological Sciences, Heriot
-
Watt
University, Edinb
urgh, UK

2001

DFG Postdoctoral fellow, Technische Microbiologie, Technische Universitat, Hamburg,
Germany

2002

DFG Postdoctoral fellow, Technische Microbiologie, Technische Universitat, Hamburg,
Germany

2003

Associated Professor. Institute of
Microbiology, BAS

2004

Head of Department of Extremophilic Bacteria, Institute of Microbiology, BAS

2004

NATO fellow,Institute of Protein Biochemistry, CNR, Naples, Italy

Teaching

Since 1996

Faculty of Information Technologies, Specialty
Bioinformatics, Sofia University






STAFF


Alexandra Tonkova
, PhD, Associate Professor

Anna Derekova
, PhD, Research Scientist

Ivanka Bojadzhieva
,
PhD, Research Scientist

Iva Tomova
, PhD, Research Scientist

Nadja Kirilova
, MS, Research Assistant

Nikolina Atanasova
, MS, Research Assistant

Tzvetina Kitayska,

MS, Research Assistant

Iva Ivanova,

MS, Research Assistant



Main Reserch Topics



Biodiversity of extremophilic bacteria
. The application of the molecular
approach for characterization of the biodiversity in microbial communities
has lead to basic changes in our opinion about the extent of our knowledge
on the organism world. Bulgaria is rich in thermal springs, representin
g the
natural ecosystem for thermophilic microorganisms. New, cultivation
-
independent methodologies as well as classical microbiological and
biochemical approaches are used for searching of unknown
microorganisms which could hardly be assigned to the same
phylogenetic
units with the previously isolated by cultivation techniques organisms.



Biosynthetic capacity of extremophilic microorganisms to synthesize
biotechnologically valuable enzymes.
These

organisms have been
identified as industrially important due

to the production of thermostable
enzymes. Regulation of enzyme synthesis is investigated in batch and
continuous cultures. Producers of different hydrolases were isolated:
α
-

and β
-
amylases, cyclo dextrin gluacno transferase, glucosidase,
pullulanase, in
ulinase, pectinase, xylanase, lipase, protease, gellan
-
lyase
et al. Optimal schemes for purification of the enzymes with maximum yield
were created. Substrate specificities of enzymes, physico
-
chemical
parameters of action, kinetic constants of enzyme reac
tions, influence of
different inhibitors, detergents and organic solvents on enzyme activities
were investigated.



Biosynthesis of bacterial exopolysaccharides from thermophilic
bacteria.
Synthesized by thermophilic bacteria exopolysaccharides
express unus
ual thermostability and could be successfully used as
viscosifiers and plastifiers in pharmaceutical industry and as gelling agents
in food industry.

A polysaccharide with
very high biological activity was
isiolated. It increased the lethal dose of avarol
almost 20 fold.



Immobilization of synthesized enzymes and of cell
-
producers
for their
more effective application as industrial biocatalysts. The cells were
immobilized by entrapment in different gels and hybrid nanomaterials

or
attachment to membranes. Enzymes were immobilized by physical
absorption, cross
-
linking and ion
-
binding. The application of the
biocatalysts received in polycyclic and


continuous processes proved the
effectiveness of immobilization.





Ongoing Proje
cts



I.


International projects



Advanced Fluorescence Sensors for Detection of Hazardous Agents. Project
supervisor: S. D’Auria (Italy), Project leader: M. Kambourova. NATO
Collaborative Linkage Grant N.CBP.EAP.CLG.9824372006
-
2008.



Purification, characterization and crystalogtaphic analysis of a thermostable
gellan lyase, synthesized by originally isolated thermophilic aerobic bacterial
strain. Project supervisor:

Assoc. Prof. P. Hristova, Project leader:

M.
Kambourova. Grant BG 16/2
005. Joint research project between NFSR,
Bulgaria and Greece (2005
-
2008).



Production of exopolysaccharides from thermophilic bacteria, isolated from hot
springs in Bulgaria and Italy. Bilateral agreement between Bulg. Acad. Sci.
and CNR (2007
-
2009). Coor
dinator:

Assoc. Prof . M. Kambourova



Magnetic nano
-
materials for immobilization of bacterial cells and CGT
-
ase for
production of cyclodextrins. Bilateral agreement between Bulg. Acad. Sci. and
Czech Acad. Sci. P
-
43/20.11.2007

(2007
-
2009). Coordinator:

Ass
oc. Prof . A.
Tonkova



II.


Bulgarian projects



Isolation of alkalophilic bacilli from Bulgarian thermal springs and soils for
thermostable β
-
cyclodextrin glucanotransferase production. Project leader:

A.
Tonkova. Grant B
-
1521/05, NFSR, Bulga
ria (2005
-
2009).



Molecular characterization of phylogenetic diversity of the bacteria in hot
springs located in South
-
West Bulgaria by 16S rDNA analysis. Project leader:

M. Kambourova. Grant

B

1511/05
, NFSR, Bulgaria (2005
-
2009).



Regiospecific

synthesis of structured lipids for food and medicine catalysed by
immobilized lipase from
B. stearothermophilus

MC7. Project supervisor
:
M.
Guncheva, Institute of Organic Chemistry, BAS; Project leader:

A. Derekova,
MSc. Grant C
-
М
U, NFSR

1501/05
, Bulgaria

(2005
-
2008).



Molecular characterization (by 16S rDNA) of phylogenetic diversity of the
microorganisms in Bulgarian hot springs in the region of Velingrad (Central
Bulgaria). Isolation of novel microbial enzymes with biotechnological
importance
.
Project le
ader
:
M. Kambourova. National Programme Genomics,
NSFR, Bulgaria (2005
-
2009).



Investigation of new hybrid nanomaterials for obtaining biocatalysts by
immobilized whole prokaryotic and eukaryotic microbial cells. Project leader:
Assoc. Prof. P. Aleksieva. P
articipant from the Department of Extremophilic
Bacteria: D
-
r L. Kabaivanova. National Programme Nanomaterials.



Magnetic nano
-
materials for immobilization of CGT
-
ase and production of
gama
-

and beta
-
cyclodextrins. Bilateral agreement between Bulg. Acad. Sc
i.
and Czech Acad. Sci. P
-
43/20.11.2007

(2007
-
2009). Coordinator:

Assoc. Prof
. A. Tonkova.





Most Important Achievements



A moderate thermophilic bacterial strain
Bacillus sp.
UG
-
5B with
benzonitrilase activity was isolated from polluted industrial water
s. The
benzonitrile degradation was realized via nitrilase pathway. Due to the high
enzyme thermostability of free or immobilized cells as well as the broad
substrate specificity, the isolated strain,
Bacillus sp.
UG
-
5B could have a
potential application
in chemical synthesis or various detoxification
processes.



An effective synthesis of cyclodextrin glucanotransferase was realized by
magnetic biocatalysts containing cells of
Bacillus circulans

ATCC 21783
and enzyme with a high specific activity was obtain
ed.



New obligate alkalophilic
Bacillus

strains were isolated from Bulgarian
habitats and successfully used for cyclodextrin glucanotransferase
production.



A new isolated bacterial strain representing novel species,
Anoxybacillus
rupiensis
, was isolated f
rom Bulgarian hot spring.



The originally isolated from Bulgarian hot spring
Bacillus
stearothermophilus

strain was described as the only producer of
thermostable gellan lyase reported up to now. Its thermostability
determines the possibility for running i
ndustrial processes at temperature
higher than 60°C in which temperature gellan is soluble.



Recent Publications





Atanasova N., Petrova P., Ivanova V., Yankov D., Vassileva A., Tonkova A.
(
2008
).
Isolation of novel alkaliphilic
Bacillus

strains for
cyclodextrin glucanotransferase
production.
Appl Biochem Biotech

149, 155
-
167
.



Atanassova M
.,
Derekova A
.,
Mandeva R
.,
Sj
ø
holm C
.,
Kambourova M
.
(
2008
).
Anoxybacllus bogrovensis

sp. nov., a novel thermophilic bacterium isolated from Dolni
Bogrov’s hot spri
ng, Bulgaria
. I
nt
.
J
.
Syst
.
Evol
.
Microb
. 58 (10), 2330


2335
.



Chernev
,
G
.,
Samuneva
,
B
.,
Djambaski
,
P
.,
Kabaivanova
,
L
.,
Emanuilova
,
E
.,
Miranda
Salvado I
.
M
.,
Fernandes
,
M
.
H
.
V
.,
Wu
,
A
.
(
2007). Synthesis and structure of new
biomaterials containing
chitosan
.
Physics and Chemistry of Glasses:
European J. Glass
Sci Technol,
B48/3
, 147
-
150.



Chernev, G.
,
Samuneva, B.
,
Djambaski, P.
,
Ka
baivanova, L.
,
Emanuilova, E.
,
Miranda
Salvado, I.M.
,
Wu, A.

(
2008).
Synthesis

and

selected

properties

of

silicate

hybrids

containing

sepharose

Advanced Mater Res

39
-
40
, 53
-
56.



Chernev, G.
,
Samuneva, B.
,
Djambaski, P.
,
Kabaivanova, L.
,
Emanuilova, E.
,
Salvado,
I.M.M.
,
Fernandes, M.H.V.
,
Wu, A.

(
2008).
Synthesis

and

structure

of

new

biomaterials

containing

silica

and

ch
itosan

Phys Chem Glasses
B

49

(1), 11
-
14,



Deckers D., Masschalck B., Aertsen A., Van Tiggelen C., Atanassova M., Michiels C.W.

(
2004).
Periplasmic

Lysozyme Inhibitor Confers Lysozyme Resistance to
Escherichia
coli
.
CMLS,

Cell Mol Life Sci
.
61
, 1229


1237.



Deckers, D., Masschalck, B., Aertsen, A., Callewaert, L., Van Tiggelen, C., Atanassova,
M., Michiels, C.W. (2004). “Periplasmic

Lysozyme Inhibitor Contributes to Lysozyme
Resistance in
Escherichia coli
.
Cell Mol Life Sci
,
61
,. 1229


1237
.



Derekova, A.,


Sjøholm, C., Mandeva, R., Kambourova, M. (2007).
Anoxybacillus


rupiensis
sp. nov., a novel thermophilic bacterium isolated from Rupi
basin (Bulgaria).
Extremophiles


11
577
-
583.



Derekova, A., Mandeva, R., Kambourova M. (200
8
).
Phylogenetic diversity of
thermophilic carbohydrate degrading bacilli from Bulgarian hot springs.
World
J.
Microbiol. Biotechnol.

24 (9), 1697
-
1702.



Derekova
,
A
.,
Sjoholm
,
C
.,
Mandeva
,
R
.,
Michailova
,
L
.,
Kambourova
,
M
. (2006).
Biosynthesis of a thermostable gellan lyase

by newly isolated and characterized strain of
Geobacillus stearothermophilus
98.
Extremophiles
,
10

(4), 321
-
326.



Groudieva
,
T
.,
M
.
Kambourova
,
H
.
Yusef
,
M
.
Royter
,
R
.
Grote
,
H
.
Trinks
,
G
.
Antranikian
.
(
2004). Diversity and cold
-
active hydrolytic enzymes of culturable bacteria associated
with Arctic sea ice, Spitzbergen.
Extremophiles

8
, 475
-
488.



Guncheva, M.
,
Zhiryakova, D.
,
Radchenkova, N.
,
Kambourova, M.

(
2008).
Acidolysis

of

Tripalmitin

with

Oleic

Acid

Catalyzed

by

a

Newly

Isolated

Thermostable

Lipase.

J. Am.
Oil Chem. Soc.
,
85
, 129
-
132.



Guncheva, M.
,
Zhiryakova, D.
,
Radchenkova, N.
,
Kambourova, M.

(2007).
Effect

of

nonionic

detergents

on

the

activity

of

a

thermostable

lipase

from

Bacillus

stearothermophilus

MC7.

J Mol. Catal B: Enzym

49

(1
-
4), 88
-
91.



Guncheva, M.
,
Zhiryakova, D.
,
Radchenkova, N.
,
Ka
mbourova, M.

(2009).
Properties

of

immobilized

lipase

from

Bacillus

stearothermophilus

MC7.

Acidolysis

of

triolein

with

caprylic

acid.

World Journal of Microbiology and Biotechnology

(in press).



Kabaivanova, L., Dobreva E., Emanuilova, E.,

Chernev, E.,
Samuneva, B., Salvado, I.
(2006). Synthesis, structure and application of new hybrid nanomaterials for cell
immobilization.
Minerva Biotechnol,

18
, 23
-
29.



Kabaivanova, L., Dobreva, E., Dimitrov, P., Emanuilova, E. (
2005).
Immobilization of
cells
with nitri
lase activity from a thermophilic bacterial strain.


J Ind Microbiol Biotechnol
32
, 7
-
11.



Kabaivanova
,
L
.,
Emanuilova
,
E
.,
Chernev
,
G
.,
Samuneva
,
B
.,
Djambaski
,
P
.,
Miranda
Salvado I
.
M
. (2007).
Comparative study of two types of hybrid biocatalysts applied

in a
biodegradation process
.
Minerva Biotechnol.,

19,
57
-
63.



Kabaivanova
,
L
.,
Emanuilova
,
E
., Dimitrov, P.,


Engibarov, S., Boyadzhieva, I., Dobreva,
E. (2008). Nitrile degradation by free and immobilized cells of the thermophile
Bacillus
sp.
UG
-
5B, isola
ted from polluted industrial waters.
World J
.
Microbiol
.
Biotechnol
.

2
,
2383

2388.



Kambourova, M.,


Mandeva, R., Fiume, I., Maurelli, L., Rossi, M., Morana, A. (2007).
Hydrolysis of xylan at high temperature by co
-
action of the xylanase from Anoxybacillus
flavithermus BC and the beta
-
xylosidase/alpha
-
arabinosidase from Sulfolobus
solfataricus Oalpha.
J. Appl. Microbiol.
.
102
, 1586

1593.



Kambourova, M., Mandeva, R., Dimova, D., Poli, A., Nicolau,s B., Tommonaro G. (
2009).
Production and characterization of a

microbial glucan, synthesized by
Geobacillus
tepidamans

V264 isolated from Bulgarian hot spring.
Carbohydrate Polymers,
(in press).



L. Callewaert, B. Masschalck, D. Deckers, D. Nakimbugwe, M. Atanassova, A. Aertsen,
C. W. (2005). Michiels “Purification of

Ivy, a lysozyme inhibitor from
E. coli
, and
characterization of its specificity for various lysozymes”
.

Enzyme Microb Tech,
2
,

205


211
.



Nakimbugwe, D.
,
Masschalck B.
,
Atanassova M.
,
Zewdie
-
Bos
ü
ner, A.
,
Michiels, C.W.
(
2006
).
Comparison of bactericidal
activity of six lysozymes at atmospheric pressure and
under high hydrostatic pressure
.

Int
.
J
.
Food Microbiol
.,
108
, 355
-
363
.



Nakimbugwe, D., Masschalck, B., Atanassova, M., Zewdie
-
Bosüner A., Michiels, C.W.
“Comparison of bactericidal activity of six lyso
zymes at atmospheric pressure and under
high hydrostatic pressure”.
Int
.
J
.
Food Microbiol
.,
No 108
,
pp.

355


363, 2006
.



Safarikova M., Atanasova N., Ivanova V., Weyda F., Tonkova A. (2007). Cyclodextrin
glucanotransferase

synthesis by semicontinuous cultivation of magnetic biocatalysts fron
cells of Bacillus circulans ATCC 21783.
Process Biochem,

42
, 1454
-
1459.



Samuneva
,
B
.,
Djambaski
,
P
.,
Kashchieva
,
E
.,
Chernev
,
G
.,
Kabaivanova
,
L
.,
Emanuilova
,
E
.,
Salvado
,
I
.
M
.
M
.,
Fernandes M
.
H
.
V
.,
Wu
,
A
. (2007).
Sol
-
gel synthesis
and structure of silica hybrid biomaterials

.
J
.
Non
-
Cryst
.
Solids
,
354/
2
-
9:733
-
740
.



Samuneva, B.
,
Djambaski, P.
,
Kashchieva, E.
,
Chernev, G.
,
Kabaivanova, L.
,
Emanuilova, E.
,
Salvado, I.M.M.
, (...),
Wu, A.

(
2008).
Sol
-
gel

synthesis

and

structure

of

silica

hybrid

biomaterials

J. Non
-
Cryst Solids

354

733
-
740.



Samuneva, B.
,
Kabaivanova, L.
,
Chernev, G.
,
Djambaski, P.
,
Kashchieva, E.
,
Emanuilova, E.
,
Miranda Salvado, I.M.
, (...),
Wu, A.

(
2008).
Sol
-
gel

synthesis

and

structure

of

silica

hybrid

materials

J Sol
-
Gel Sci Techn

48
, 73
-
79.



Vassileva A., Atanasova N., Ivanova V., Dhulster P., Tonkova A. (2007).
Characterization
of
cyclodextrin glucanotransferase from
Bacillus circulans

ATCC 21783 in terms of
cyclodextrin production.
Ann Microbiol,

57

(4) 609
-
615.



Vassileva, A., Beschkov, V., Ivanova, V., Tonkova, A. (2005). Continuous cyclodextrin
glucanoransferase production by fre
e and immobilized cells of
Bacillus circulans

ATCC
21783 in bioreactors.
Process Biochem
40,
3290
-
3295.