MICROALGAE CULTURE (2) BIO301 Dr Navid Moheimani - - PowerPoint PPT Presentation

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Aug 22, 2022 378 likes •708 views

MICROALGAE CULTURE (2) BIO301 Dr Navid Moheimani n.moheimani@murdoch.edu.au Types of limitation Type I Type II Limits to Growth Abiotic factors: - Light (quality, quantity) -Temperature - Nutrient - O 2 - CO 2 , and pH - Salinity - Toxic

SLIDE 1

MICROALGAE CULTURE (2)

BIO301 Dr Navid Moheimani n.moheimani@murdoch.edu.au

SLIDE 2

Types of limitation

Type I Type II

SLIDE 3

Limits to Growth

Abiotic factors:

Light (quality, quantity)
Temperature
Nutrient
O2
CO2, and pH
Salinity
Toxic Chemicals

Biotic factors:

Pathogens (bacteria, fungi, viruses)
Competition by other algae

Operational factors:

Shear produced by mixing
Dilution rate
Depth
Harvest frequency
Addition of bicarbonate

SLIDE 4

Types of limitation

a. Temperature
b. Light
c. Nutrient
d. CO2
e. Mixing

Type I Type II Type I Type II

SLIDE 5

Limits to Growth

Light (except for heterotrophic culture)
Temperature
Nutrients

– N (as nitrate, ammonia, urea) – P – Fe – Si (diatoms)

Supply of inorganic C (CO2/HCO3
)
Mixing (turbulence & shear)

SLIDE 6

Light, Temperature & Oxygen

SLIDE 7

(e) ec es eh

6CO2 + 12H2O 6H2O 6O2 C6H12O6 + +

PSII Fluorescence

SLIDE 8

Light

The Earth receives about 100W.m-2 from the Sun
Irradiance varies with wavelength

Solar spectrum as defined in ASTM G-173-03 [1] AM1.5 Solar spectrum in µ mole photons.s-1.m-2.nm-1

SLIDE 9

Light - PAR

Only 431W.m-2 of

this is Photosynthetically Active Radiation (PAR)

PAR portion of solar spectrum (in terms of µ mole photons)

SLIDE 10

Algae

Are plant like organisms
All algae contain Chlorophyll a,
Have oxygenic photosynthesis
Have no specialised organelles
Range from uni-cellular microalgae (<1µm) to multicellular macroalgae (up

to 60m)

Moist environments (marine, freshwater, soils, salt lakes)
Light (quality and quantity) is the main limiting factor
Many other factors also limit the growth
Low CO2
High O2
pH
Nutrients
Photosynthetic pigments are

– responsible for absorbing light

Absorption spectra for different pigments

SLIDE 11

Algae

If an alga such as Botryococcus with Chlorophylls a and b and β-

carotene, is used it is a reasonable approximation that only 160W.m-2 is required for this process

The remainder is not fully utilised.

SLIDE 12

What we propose:

SLIDE 13

Algae pond PV/Filter Electricity Use for plant

peration

SLIDE 14

Photosynthetic and respiratory rates of Botryococcus braunii

SLIDE 15

Effect of pond depth on P. carterae productivity:

SLIDE 16

Pleurochrysis carterae productivity – Perth, WA DW Lipid Productivity changes over the year CaCO3

SLIDE 17

Irradiance is critical for maximum productivity

SLIDE 18

Growth rates of two strains of Chlorella pyrenoidosa at different

temperatures. Strain 7-11-05 (O) and (x) Emerson strain at high

light Peak

SLIDE 19

Growth rates of two strains of Chlorella pyrenoidosa at different

temperatures. (,O) Strain 7-11-05 at high (O) and low ( ) light

Peak

SLIDE 20

Growth rate of Dunaliella viridis over a range of NaCl concentrations at three different temperatures. () 30°C; (O ) 26°C; ( ) 14°C

SLIDE 21

Oxygen Temperature Irradiance

SLIDE 22

Light, temperature and O2 on photosynthesis of Pleurochrysis carterae grown in (b) indoors under a controlled condition and at 25oC. White bars = low O2 and Grey bars = high O2

SLIDE 23

Cultivation period n Specific Growth rate (d-1) Productivity (g.L-1.d-1) Dry weight Lipid CaCO3 Un-heated pond 02/Jun/2003-01/Jul/2003 14b 0.083 0.0197 0.006 0.0019 02/Aug/2003-28/Sep/2003 18 0.312 0.057 0.018 0.0056 Heated ponda 02/Jun/2003-08/Jul/2003 20b 0.099 0.025 0.008 0.0025 02/Aug/2003-28/Sep/2003 19 0.315 0.063 0.021 0.0062

Lipid productivity increased by 15%

SLIDE 24

Gross photosynthesis (µmoles O2.µg Chl a-1.min-1)

20 40 60 80 100 120 140 160 180 200 (a)

Oxygen concentration (% air saturation)

20 40 60 80 100 120 140 160

Gross photosynthesis (µmoles O2.µg Chl a-1.min-1)

20 40 60 80 100 120 140 160 180 200 (b)

Skeletonema costatum

20oC ■ 23oC 26oC

1200 µmol photons.m-2.sec-1 2500 µmol photons.m-2.sec-1

SLIDE 25

Gross photosynthesis (µmoles O2.µg Chl a-1.min-1)

50 100 150 200 250 300 350 400 (a)

Oxygen concentration (% air saturation)

20 40 60 80 100 120 140 160

Gross photosynthesis (µmoles O2.µg Chl a-1.min-1)

50 100 150 200 250 300 350 400 (b)

Tetraselmis chuii

1200 µmol photons.m-2.sec-1 2500 µmol photons.m-2.sec-1

20oC ■ 23oC 26oC

SLIDE 26

Mixing & Turbulence

SLIDE 27

Growth of P. carterae in Biocoil in the Airlift design II (●), design III (○) and design IV (■), data are mean and range in design IV

SLIDE 28

SLIDE 29

Growth curve (—●—) and growth rate (▼) of P. carterae grown under different stirring speed conditions in a carboy type reactor

SLIDE 30

Nutrients

SLIDE 31

Effect of temperature and vitamins

Chaetoceros gracilis - Pavlova lutheri

SLIDE 32

What is the optimum pH and how much CO2 is required ?

pH µ Productivity Lipid content (d-1) (mg.L-1.d-1) Biomass Lipid Tetraselmis suecica

Unregulated 0.21±0.08 144±11.1 32±10.0 22% 8 0.24±0.07 193±10.3 44±11.1 23%

7.5 0.25±0.09 320±32.2 92±13.2 29%

7 0.23±0.02 246±21.2 60±12.0 24% 6.5 0.21±0.05 142±41.5 30±21.3 21%

Chlorella sp.

Unregulated 0.29±0.04 190±17.9 39±7.2 20% 8 0.30±0.03 203±12.2 44±18.2 22% 7.5 0.31±0.04 222±14.3 61±11.0 28%

7 0.40±0.04 407±05.5 99±16.7 24%

6.5 0.22±0.06 146±17.9 25±6.6 17% 6 0.17±0.09 120±17.9 22±7.2 18% 5.5 0.09±0.07 90±17.9 18±7.2 20%

Emiliania huxleyi Unregulated 0.98±0.01 310±2.3 61±0.2 20%

7.8 0.76±0.00 230±1.6 59±0.1 25%