Valorization of microalgal extracts obtained by pulsed electric - - PowerPoint PPT Presentation
PEF4Alg Biotics Valorization of microalgal extracts obtained by pulsed electric fjeld in lactic acid fermentation Aleksandra DjUKI-VUKOVI 1 , Dragana MLADENOVI 1 , Christian GUSBETH 2 , Ljiljana MOJOVI 1 1 Department of Biochemical
Aleksandra DjUKIĆ-VUKOVIĆ 1, Dragana MLADENOVIĆ 1, Christian GUSBETH 2, Ljiljana MOJOVIĆ 1
1Department of Biochemical Engineering and Biotechnology, Faculty of Technology and
Metallurgy, University of Belgrade, Serbia
2Karlsruhe Institute of Technology, Institute for Pulsed Power and Microwave
Technology, Germany
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1000 L photobioreactor , KIT
CO 2
minerals
H2O Biodiesel Not enough! More products to make it economically viable
Pulsed Electric Field – PEF treatment
Institute for Pulsed Power and Microwave Technology
of adequate strength and duration on eukaryotic and prokaryotic cells causing increase in cell membrane permeability, if increase in transmembrane voltage surpasses certain value
Miklavčič, 2014, Electroporation based technologies and treatments
Microalgae biomass
Lipids Protein s Aqueous PEF treatment Ethanolic extraction
Release of small water soluble components Nutrients recycling Valorization of released components
1.
Water soluble proteins Valorization
2. Lipids Biofuel 3. Anaerobic digestion Thermo -chemical conversion
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Process scheme from IHM/KIT
lactic acid + probiotics
FERMENTATION
Lactobacillus rhamnosus Lactobacillus paracasei
PEF obtained aqueous fraction of microalgae Lactobacillus rhamnosus Lactobacillus paracasei lactic acid As chemical As preservative As monomer for poly(lactic) acid
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Centrifugation: 10000 g, 6 minutes and resuspended – adjusting conductivity
PEF treatment
Supplementation with fermentable sugars
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FERMENTATION
Recommended number of viable cells in probiotics 106-109 CFU/g
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0h 24h 2 4 6 8 10
logN Time (h)
Antimicrobial activity of lactic acid Against:
enteritidis
aureus
Resistance to gastrointestinal stress (low pH, pepsin, pancreatin, bile salts)
Gastric juice Intestinal juice
Antibiotic resistance Resistance to:
n
in
n Suseptibility to:
etracycline
Antioxidant activity
intact cells intracellular cell free extracts
Important probiotic characteristics
bacteria
Strain LA concentration LA yield LA productivity Stereoselectivity
24.24 g/L 85% 1.01 g/Lh > 97% L-lactic acid
27.3 g/L 91% 1.14 g/Lh > 97% L-lactic acid
Not significant changes were observed in free amino nitrogen concentration!
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b e f
e f e r m e n t a t i
L . p a r a c a s e i L . r h a m n
u s c
t r
10 20 30 40 50 60 70 80 90 100
ABTS, %
b e f
e f e r m e n t a t i
L . p a r a c a s e i L . r h a m n
u s c
t r
10 20 30 40 50 60 70 80 90 100
DPPH, %
ABTS DPPH
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Before fermentat ion L. paracasei L. rhamnosu s contro l Before fermentat ion L. paracasei L. rhamnosu s contro l
Chlorella vulgaris – FDA approved for human nutrition
– GRAS status Lyophilisation Fermented extracts Can be performed in open fermentation mode – avoiding thermal sterilisation or filtration But… changes in colour, oxidation, temperature, pH … After the LA fermentation high antioxidant activity in fermented extracts Food additive - probiotics centrifugation solids liquid Lactic acid extraction
Department of Biochemical Engineering and Biotechnology Faculty of Technology and Metallurgy University of Belgrade Serbia
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Ministry of Education, Science and Technological Development of Republic of Serbia