Target photosynthetic products and chlorophyll

fluorescence

Biophysics Department

Biology faculty

Moscow State University

Andrey Rubin

hνhν

hν

CO2

N2, P

∆pH ATP

e-Chl∗

Fl

PS II e- e-

General scheme of photosynthetic processes

NADP

hν

2H2O4H++O2(газ)

H+

H+

Primary photosynthetic processes

Pool ATP

Nitrogen and sulfur deficiency

e-

e-

Normal

hν

PQ

Protein synthesis

Carbohydrate pool

Carbohydrate synthesis(Calvin cycle)

FdFd

Hydrogen evolution

Lipid synthesisbiofuel

CO2

Nitrogen and sulfur deficiency

Nitrogen deficiency

ATPase e-PS I

Nitrogen assimilation

Growth rate dependence on light intensity

General view of the annular reactors used for mass cultivation of Nannochloropsis sp. In the foreground, 50-cm annular reactors; in the background, 91-cm annular reactors (Zittelli et al., 2002).

Light intensity dependence on the distance from the light source in a biophotoreacter

10-2 с

10-11 s

10-6 s

Scheme of primary photosynthetic processes

10-4с

Test biophotoreactor. Early (left) and late

(right) stages of cell growth

PQ

PQH2

PQPQ

H2O

P680

QA

2H+ 1/2O2

Chl Chl

2H+

2H+ 2H+

Fd

Pc

bh

bl

FeSR

P700

FeSI

Chl

3H+

K+

Cl-

H+

NADPH

NADP+

ADP + Pi

ATP

+ +

_ _

lumen

stroma

Thylakoidmembrane

hν hνfluorescence

PS II PS I

ATP-synthase

bf

Q-cycle R-COO-

-OOC

-OOC

R-COO -

f

F0

F

Fm

0 1 10 t, cCalvin cycle

Photosynthetic pathways in chloroplasts

∆pH

Fm

Fv

Fo

P

SD

O

F

Fo

0 0.05 0.7 Time (s) 5

m

v

m

m

F

F

F

FFP =−= 0

Fluorescence induction curve

Photosynthetic efficiency

H2O PSII Qa Qb PSI .. CO2…* *

O2

hv hv

ChloroRespir.

-

!F (ns)!(-N2 , -P) starvation

O2-O2

*

excess

membranedestruction(DEATH)

signal

ATPΔpHqN

Car. cycle

P quenching*

photoprotection ? 8 20 day hours

3

2

1

0

Fv /Fm phytoplankton

Photooxidation and defense mechanisms

10-1 100 101 102

Production, mg·C · m-3 · day -1

Cal

cula

ted

prod

ucti

on (

from

F0 · F

V · I)

Correlation between phytoplankton productivities measured with

fluorometer and radiocarbon method

corr = 0.84717

0 2 4

0

2

4

6

0 2 4 6 0 2 4

Fm

F0

Fm

Fm

F0

F0

Dark-adapted fluorescence parameters F0 and Fm as a functionof time after adding 0 (a), 0.39 (b), or 0.78 (c) μM Cu2+ to

Chlorella

Time, h

a b c

Early diagnostics of heavy metal ions effects

Probabilities of the electron carriers Сi states

The initial probabilitiespi(0)=bi , i=1,…, l .

dp

dtp k p ki

j ji i ijj

l= −

=∑ ( ),

1

43214

322243113

2231322

11231

''

'

)'(

pkpkp

pkpkpkpkp

pkkkpkp

pkpkp

−=−++=

++−=−=

−

−

14321 =+++ pppp

Description of the states of complex C1C2

Scheme of the states of

Photosystem 2

Cl-chlorophyllPhe-pheophytitnQA,Qb – quinone

acceptors

7

Chl+

Phe -

QAQB -

y3

Chl +

PheQA -

QB -

y4

Chl*PheQA -

QB -

y6

ChlPheQAQB

2 -

Chl*PheQAQB

2-

Chl+

Phe -

QAQB

2-

Chl+

PheQA -

QB 2-

ChlPheQA -

QB 2-

Chl*PheQA -

QB 2-

Chl +

Phe-

QA -

QB 2-

z1 z2 z3 z4 z5 z6 z7

ChlPheQA

Chl*PheQA

Chl+

Phe -

QA

Chl+

PheQA -

ChlPheQA -

Chl*PheQA -

Chl+

Phe-

QA -

g1 g2 g3 g4 g5 g6 g7

2H s+

PQH2

2Hs+

PQH2

2Hs+

PQH2

2H s+

PQH2

2Hs+

PQH2

2H s+

PQH2

2H s+

PQH2

PQ PQ PQ PQ PQ PQ PQ

ChlPheQAQB -

y1

Chl+

Phe-

QA -

QB -

y7

ChlPheQA -

QB -

y5

Hl+

ChlPheQAQB

Chl*PheQAQB

Chl+

Phe -

QAQB

Chl+

PheQA -

QB

ChlPheQA -

QB

Chl*PheQA -

QB

Chl+

Phe-

QA -

QB

x1 x2 x3 x4 x5 x6 x7

Chl*PheQAQB -

y2

2 3 5 6

3332

31

302928

15 16 17

18

19 20

21 22 23 24 25 26 27

34 35 36 37 38 39 40

Hl+

4

Hl+

1

8 129 10 13

11

Hl+

14

PQPQH ⇔2

41

)( 66662222 gzyxgzyxkk

FL

F +++++++=

PGA

BPGA

GAP

Ru5P

RuBP

ATP

CO2

ATP

P8

P6

P0

X

P9

β

NADPH Q

P5

PS1

P4

ADP

ATP PS2

P3P2

H2O

P1

P7

F

α

(z)(s)

(u) (y)

(x)

days ofgrowth

α

β

γ

γβα

0 40 80

N1

PGA

BPGA

GAP

Ru5P

RuBP

ATP

CO2

ATP

P8

P6

P0

X

P9

β

NADPH Q

P5

PS1

P4

ADP

ATP PS2

P3P2

H2O

P1

P7

F

α

(z)(s)

(u) (y)

(x)

ΔpH

[ATP]ΔpH = s2

)1(1

)1()1()1(

][32

472 xyp

s

zypyupyxp

dt

dy

dt

Qd −−+

−−−+−==−

21

1

s+- electron flow rate dependence on ΔpH

2

2

csb

asyF

+−= - fluorescence

d D

dtk C D k D C k D C k C Dn n

[ ][ ][ ] [ ][ ] [ ][ ] [ ][ ]

−− +

−− + − +

−− += − − +2 2 1 1 1 1

[ ], [ ]D D+ − - concentrations of the mobile carrier in the oxidized and reduced forms;

- concentrations of the components of the complex;

ki - bimolecular rate constants.

[ ], [ ],[ ],[ ]C C C Cn n1 1+ − + −

⇒ ⇒

− −

[ .... ]С С С

k k

D

k k

n1 2

1 2

1 2

Interaction of the complex with the mobile

electron carrier D

vVA

KD KPe

n A

H p KHp n A ADPn Pn Keq e

n A Hn H pn A ATPn

ADPn PnKD K P

H p

KHp

n A ATPnKT

Hn

KHn e n

n A=

⋅⋅

⋅ ⋅⋅

⋅ ⋅ − ⋅− ⋅

⋅ ⋅

+⋅

⋅⋅

+ ⋅⋅

δ ϕ

ϕ

δ ϕ

( / )~

( / )

1

To describe the ATP synthesis we used the expression based on the minimal kinetic scheme of ATP synthesis-hydrolysis reaction:

Where ϕ=F⋅∆Ψ/RT .

( )

⋅+⋅

⋅

+

⋅−⋅⋅=

−

−

nH

npH

p

npHH

K

eH

K

eH

HeHeVv

nH

pH

H

ϕδϕδ

ϕϕδ

11

( )

⋅+⋅

⋅

+

⋅−⋅⋅=

−

−

nK

npK

p

npKK

K

eK

K

eK

KeKeVv

nK

pK

K

ϕδϕδ

ϕϕδ

11

The dependence of the proton leakage on the potential was considered according to the mechanism of ion transfer trough the three barrier channel :

The similar expression was used to describe K+ transfer ::

Transmembrane electrochemical potential +∆H

µ~

Kinetics of the variables of the model

Flow fluorimeter device

Dep

th, m

Chla, mg/m3

Distance, km

A

Dep

th, m

Fv/Fm, r.u.

Distance, km

B

Dep

th, m

T, oC

Distance, km

C

Phytoplankton concentration (Fo) (A) and photosynthetical activity (Fv/Fm)(B), as well as water temperature (C) in the cross section of Issik-Kul Lake (Tamga-Grigor’evka). Data were obtained with using submersible fluorometer in July 1999.

Investigation of the vertical distribution of phytoplankton in oligotrophic Issyk-Kul Lake showed a complex structure of phytoplankton, which is due to pronounced water stratification. The lowest values of the abundance and photosynthetic activity were found in the upper layer under conditions of a high solar irradiation and low content of mineral nutrients. High abundance and high activity of algal cells were found in the deep layers of the photic zone indicating the presence of active algae, adapted to low light condition.

Light intensity dependence on the distance from the light source in a biophotoreacter

Cyt С2

M

Photosynthetic reaction centerRb. sphaeroides

L

H

Heme4

CL

Ch

Heme3

Heme2

Heme1

CL

Ch

Bchl2

Bchl

BPheoL

QAQB

21Å

11Å

10Å

14Å

10Å

11Å

P

P*

hv

*2μs

<3ps

150ps

100μs

Fe

100fs

3ps

P+Bph-

BPheoM

Electron transfer in reaction centers

2

/10

Lm

kT

e

e

ε

ε

−

− >h

Space distribution of protein electron carriers in a membrane

Scene of the direct model

Equipotential surfaces calculated according to Poisson-Boltzmann equations

model

Oxidesed Рс Reduced cyt f

Ion strength - 100 mM, pH=7, εр-ра=80; εбелка =2; red -6.5 мВ, blue + 6.5 мВ;green – atoms of molecules. Dotted lines connect residueson Pc and Cytf that were used by simulation for calculation the distance between proteins

r1

r2

r4r3

Rate constant dependence on the membrane thickness