Cultivation of green algae

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1 biology, technology and economy Annette Bruhn and Michael Bo Rasmussen Aarhus University National Center for Energy & Environment Silkeborg Denmark

2 Why cultivate green algae? Green tides Natural harvest Fertiliser Food- feed Biogas Cultivation Species composition Security of supply Quality

3 Why cultivate green algae? Food Aonori (Monostroma, Ulva), Codium, Caulerpa.. Feed Abalone (Ulva), finfish (Ulva), Shrimp (Ulva).. High value products Cosmetics (Ulva).. Bioremediation of wastewater Aquaculture (Ulva), agriculture (Freshwater algae, Ulva), municipal (Ulva) Energy Ulva, Chaetomorpha..

4 Biology of green algae 4500 species (Chlorophyta) Few species cultivated Distribution Global From above the tidal zone to 30 m depth Saline to fresh water Morphology Parenchymateous (foliose, tubular) (Ulva) Filamentous Unbranched (Chaetomorpha) Branched (Chladophora) Siphanous (pseudoparenchymatic - spongy )(Codium) Calcified (Halimeda) Algaebase (www. ). Van den Hoek 995.

5 Growth characteristics of green algae Ulva Growth rate % d - (Ulva),2 Photosyntetic tissue: 00% 2 Nutrient uptake K S (NH 4+ ) 4 µm 2 V max (NH 4+ ) 250 µmol/g/h 2 Codium Growth rate 4 % d - (Codium) 2 Photosyntetic tissue: 40% 2 Nutrient uptake K S (NH 4+ ).5 µm 2 V max (NH 4+ ) 28 µmol/g/h 3 Pedersen & Borum, Ramus & Venable, Gao & McKinley, 994.

Composition of green algae dry matter Water (87-90% of FW) Carbohydrates (up to 65% of DW) Storage (starch) 2 Structural (sulphated polydisperse heteropolysaccarides, xylans, mannans, cellulose) 2

6 Composition of green algae dry matter Water (87-90% of FW) Carbohydrates (up to 65% of DW) Storage (starch) 2 Structural (sulphated polydisperse heteropolysaccarides, xylans, mannans, cellulose) 2 water Protein (up to 44% of DW) 3 Lipid (-3.5% of DW) 4 Pigments Chlorophyll a and b Carotenoids Minerals / ash (7-32% of DW),5 Bruhn et al, Percival, Msuya & Neori, Holdt & Kraan, Lamare & Wing, 200.

7 Reproduction of green algae - natural Vegetative - fragmentation Spores (4 flagella) Sexual gametes (2 flagella) Isogamy Anisogamy Spore release/control Stress Tidal/lunar cycle,2 Mass spawning 3 Lüning, Lee, Clifton, 997 Example: Ulva life cycle

8 Reproduction of green algae - artificial Seed stocks from regeneration of isolated utricles (Codium) Protoplast technology (89 species (4/24/24) 2 Green algae promising (simple) Seed stock Selective breeding Protoplast fusion Enzymatic lysis of cell wall Regeneration of cell wall Mitosis Nanba et al, Reddy et al, Photos: courtesy of Algaebase and Dr. Reddy.

9 Cultivation open sea Purpose Food/feed industry (Japan, Korea, Philippines) Multi-purpose approach (Ulva in India) Ulva/Monostroma ropes/nets As Porphyra Japan, India Codium ropes 7. kg/m rope 2 (Equivalent to Laminaria yield 3 ) Calm waters FAO, Nanba et al, Edwards & Watson, 20.

10 Cultivation tanks/raceways Purposes Integrated MultiTrophic Aquaculture (IMTA),2 Biofilter Feed Energy test cultivations 3,4 High production 65 T DW/ha/y (South Africa ~ 35ºS) 74 T DW/ha/y (Florida~ 30ºN) 3 45 T DW/ha/y (Denmark~ 55ºN) 4 Bolton et al, Neori et al, Ryther et al, Bruhn et al, 20

11 Cultivation tanks/raceways Energy intensive 3 Water exchange,2 Mixing (air, paddlewheel) High stocking density Incoming light 3 Areal nutrient load 2 Vegetative growth Fragmentation Sporulation/disease 3,4 Ryther et al, Msuya & Neori, Bruhn et al, Bolton et al, 2009.

12 Cultivation lagoons/ponds Purposes Food (Caulerpa, Ulva) IMTA Feed or food Biofilter/temporary nutrient sink,3 Energy test cultivations 2 Production estimates 2-5 T WW/ha/y (Caulerpa, Phillipines) 4 27 T DW/ha/y (Ulva, Florida) 2 Standing stock estimates T DW/ha (Mexico) 3 Up to 3-4 T DW/ha (Italy) Bartoli et al, Ryther et al, Zertuche Gonzalez et al, FAO, 200

13 Cultivation - lagoons Non-energy intensive No aeration/mixing (Limited water exchange) Lower standing stock/biomass density Lower production Higher risk of crash of biomass Temperature, respiration, nutrient, light Threat to natural seagrass beds, nuisance near recreative areas Zertuche Gonzalez et al, 2009.

14 Cultivation - biofilter efficiency Aquaculture Agriculture Municipal Output Max clean water Max N/P removal Min energy cost Construction of system 2 Nielsen et al, Neori et al, 2003.

15 Cultivation biofilter capacity High N availability high N content high protein Amino acid composition OK Nielsen et al, FAO, 2008 Use of agricultural land 2 Animal feed Human feed Energy

16 Economy challenges and potentials Energy Feed High value products Bioremediation

17 Ethanol yield (L kg DW - ) Ethanol udbytte (L kg DW-) AARHUS UNIVERSITY Seaweed for bioethanol Lower theoretical potential (lower carbohydrate content) Pretreatment need for specific enzymes Fermentation of C5 sugars 0,6 0,5 0,4 0,3 0,2 0, 0 Hvede Halm (hvede) Majs a a a a a a Majs halm Sukkerrør Bagasse b/c Ulva Laminaria digitata d/e b Chaetomorpha a: Kim & Dale, b: Nielsen et al, c: Isa et al, d: Schiener, et al. Biomara, Skotland. e: Adams et al, 20

18 m 3 CH4 kg - VS AARHUS UNIVERSITY Seaweeds for biogas Inhibiton salt, sulphur Inoculum optimisation 0,4 0,35 0,3 0,25 0,2 0,5 0, 0,05 0 M. porifera a g A. nodosum a a a a a a S. latissima S. fluitans G. tikvahiae b Chaetomorpha sp. c d e e f U. lactuca Wheat straw Turf grass Manure a: Chynoweth, b: Habig, et al, 984. c: Nielsen et al, d: Bruhn, et al, 20. e: McKendry, et al, f: Møller et al, g: Møller, 20

19 Economy challenges and potentials Energy Bioethanol Biogas Feed aquaculture and agriculture Protein Pigments Bioactive polysaccarides Minerals Legislation on origin of nutrients High value products Bioremediation sustainabiltity of aquaculture

20 Summary cultivation of green algae Green algae grow fast high yields efficient in taking up nutrients relatively easy to grow achieve high protein concentrations Economy Energy not economically feasible alone Food, feed, bioremediation depend on location High value products Future potential Protein applications promising potential Multi purpose applications / biorefinery Pretreatment technology Minerals Carbohydrate Carbohydrate Protein Lipid

21 Thanks for your attention

SPATIAL VARIATION IN THE BIOCHEMICAL COMPOSITION OF SACCHARINA LATISSIMA

SPATIAL VARIATION IN THE BIOCHEMICAL COMPOSITION OF SACCHARINA LATISSIMA Bruhn A, Nielsen MM, Manns D, Rasmussen MB, Petersen JK & Krause-Jensen D 4 TH NORDIC ALGAE CONFERENCE GRENÅ 2014 BIOCHEMICAL VARIATION