Chini-Zittelli - Production and Use of Microalgae Biomass for Aquaculture Feeds
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Transcript of Chini-Zittelli - Production and Use of Microalgae Biomass for Aquaculture Feeds
“Production and Use of Microalgae Biomass for
Aquaculture Feeds”
G. Chini Zittelli, M.R. Tredici, E. Tibaldi, B.M. Poli, L. Rodolfi,
N. Biondi, A. Niccolai
Increase in population will
require at least 40 Mln additional
tonnes annually
Aquaculture….. A Growing Industry
Capture fisheries have
reached a maximum
exploitation level
Aquaculture has grown
rapidly over the last decades
40% of fish products
50% of the food fish supply
86%
Fish meal scarcity
Aquaculture feed dilemma: FISH MEAL/OIL
Aquaculture Fish meal/oil provision
Increase aquaculture production Increase demand of fish meal/oil
Heavy exploitation of fish resources
Fishmeal € 1.2-1.6/kg
Fishoil € 1.2/kg
Fish meal/oil supply declines and prices
increase
Million tons
Data FAO & IFFO
FISH MEAL/OIL PRODUCTION
HOWEVER
• Availability fluctuates (El NiÑo)
• Competition with traditional livestock
• Economically and environmentally unsustainable
Current Alternatives to Fish Meal
FISH MEAL/OIL
NEEDS TO BE PARTIALLY OR TOTALLY REPLACED
Corn
gluten
meal
Feather
meal
Microbia
l feed
ingredie
nts
MICROALGH
E
Poultry
by-
product
meal
Soybean
meal
Meat and
bone meal
Canola,
lupin meal
Aquafeeds Seaweed Seaweed
Ingredient Criteria
Replacement must have
High protein content
Good aminoacid balance
Good protein digestibility
High palatability
Source of PUFAs (EPA, DHA)
Source of antioxidants
Promising alternative source
• high content of good quality protein, vitamins, minerals and PUFAs
Canola,
lupin meal
Corn gluten
meal Meat and
bone meal
Soybean
meal
Aquafeed
Poultry
by-product
meal
Microbial
feed
ingredients
ne
w
General composition of commercially available feed ingredients and microalgae
(% of dry matter)
Commodity Crude
Protein
Total
Carbohydrate
Total
Lipid
Ash Gross
Energy
(MJ kg-1)
Fish meal 63 - 11 15.8 20.1
Poultry meal 58 - 11.3 18.9 19.1
Soybean 44 39 2.2 6.1 18.2
Wheat meal 12.2 69 2.9 1.6 16.8
Arthrospira sp. 58 17 7.5 8 19.8
Chlorella vulgaris 52 21 13.5 5 21.3
Tetraselmis sp. 53 13 19 14.4 22.3
Nannochloropsis sp. 28 14 39.3 14.8 24.5
Isochrysis (T-ISO) 46 12 32.7 9.2 21.6
Gracilaria sp.* 10 50 0.9 34 11.2
Ulva lactuca * 13 57 1 25 11.2
BALANCED
COMPOSITION
* Collected from natural habitat
THE MAJOR CHALLENGE: Microalgae biomass production COST
A further cost reduction of the algae biomass is necessary
Current production cost € 4/kg
Exceeds by 2-3 times the cost of fishmeal
and by 10-15 times that of soybean meal
KEY ISSUES
Strain
selection Low cost
cultivation process Low cost resources
CO2
Nutrients
water
Productivity
Robustness
Nutritional quality
Harvestability
Digestibility
Toxicity
€ 1-2/kg TARGET
Not easy
AIMS OF THIS WORK
To investigate the feasibility of producing microalgae biomass as aquafeed
• Selecting suitable microalgae strains
• Adopting low cost cultivation systems
• Reducing operational costs (mixing, cooling, fertilisers)
To evaluate the suitabilty of two marine microalgae biomass as alternative
dietary ingredient in aquafeed throught feeding experiments with sea bass
(Dicentrarchus labrax)
To assess the sustainability of the cultivation process evaluating the energy
balance in a pilot plant made of GWP photobioreactors
Main Characteristics
Selection of suitable strains
Robust and competitive
Easy to be cultivated
Highly productive under natural conditions
Large size and/or high sedimentation rate (easy to harvest)
Naturally rich in valuable compounds (proteins, PUFAs, vitamins)
Safe, no toxic
Easy to digest
Preferably autochthonous
RESULTS: Microalgae selection All microalgae were cultivated outdoors during summer in GWP II of 4.0 cm light-path
MICROALGHE Volumetric
productivity
(g L-1 d-1)
Protein
content
(% d.wt)
Major PUFAs
content
(% d.wt)
In vitro
digestibility
(% d.wt)
Tetraselmis suecica F&M-M33
0.66 ± 0.07
51.6 ± 5.8
EPA 0.40
ARA 0.05
41.1 ± 0.9
Isochrysis (T-ISO) F&M-M36 0.21 ± 0.08
49,6 4,0
DHA 1,1
51.8 ± 2.7
Phaeodactylum tricornutum
F&M-M40 0.56 35.8 ± 0.01 EPA 2.5 41.6 ± 4.5
Nannochloropsis oceanica F&M-
M24 0.21 ± 0.09 27.6 ± 2.1 EPA 3.5
ARA 0.6 41.8 ± 4.3
Chlorella sorokiniana F&M-M49
0.43
40.5 ± 4.4
- LA 1.8
26.4 ± 3.3
Chlorella sorokiniana IAM 212 0.42
38.2 ± 4.3
-
37.5 ± 1.7
Nostoc sphaeroides F&M-C117 0.15
27.9
-
58.9 ± 3.2
Arthrospira platensis M2
0.60
70.3± 0.01
- LA 1.5
73.5 ± 6.6
EPA: 0.4 %
VIT E : 0.13%
Proximate composition and EAA profile of T. suecica in comparison with conventional aquafeed ingredients
(% of dry matter)
Source Protein CHO Lipid Ash Crude fiber
Fish meal 60-75 1-4 5-20 10-25 1-3
Meat meal 55-60 19 2.10 15-18 2-3
Meat and bone meal 48-50 - 10-14 30-35 3.4
Poultry by-product meal 60-75 4-6 12-15 16-17 2
Soybean meal 52 - 2 6 5
Rapeseed meal 42 - 2 10 12
Cotton seed meal 46 - 7 7 15
Wheat flour 16 - 1.5 0.8 0.3
Tetraselmis sp. 53 13 19 14.4 -
WHY TETRASELMIS ?
• Robust MARINE microalga
• Productive
• Versatile
• High salinity growth
• Quite digestible (40%)
• Suitable nutritional quality
1.30 5.02 3.33 0.46 3.01 3.09 1.94 4.61 4.85 2.73 Poultry by-product meal
1.40 3.48 1.70 - 2.45 3.32 1.08 2.99 4.09 1.86 Tetraselmis sp.
0.37 0.64 0.68 - 0.46 0.90 0.56 0.35 1.13 0.49 Wheat flour
1.28 4.96 1.92 - 1.29 2.52 1.19 2.18 2.67 1.51 Cotton seed meal
1.19 2.49 2.11 - 1.78 1.73 1.09 2.52 2.94 1.71 Rapeseed meal
1.32 3.31 2.28 0.69 2.04 2.36 0.82 3.18 3.59 2.14 Soybean meal
1.04 4.78 2.70 0.46 2.03 2.24 1.4 3.86 3.32 1.69 Meat and bone meal
1.82 4.69 3.18 0.57 2.81 3.01 2.29 5.24 5.04 2.80 Fish meal
His Arg Val Trp Thr Phe Met+Cys Lys Leu Ile
Source
Essential aminooacids
Outdoor mass cultivation Low cost disposable Panel VS Open pond
Gap with commercial pond was almost closed in terms of reactor cost
*occupied area
620
3.9 70 54 % energy into the
biomass
0 460 228 Cooling
Energy requirement
(GJ ha-1 y-1)
50 580 Mixing
24 29 28 Land Areal Productivity
(g m-2 d-1)*
23-48
33 150 Cost (€ m-2)**
**occupied area
GWP I GWP II Raceway pond
620 580 50
* Summer productivity
in Tuscany
Microalgae-feed production in a 1ha GWP plant
At what ENERGY cost?
0.6 ENERGY OUTPUT
799 GJ ha-1 y-1
ENERGY INPUT
1340 GJ ha-1 y-1
The energy output
BIOMASS OUTPUT
36 t ha-1 y-1
The energy input
It is the total energy requirement
to run the plant
EMBODIED ENERGY: GWP, piping,
blowers, pumps and centrifuges
410 GJ ha-1 y-1
ENERGY OF FERTILIZERS: N and P
at 100% efficiency of use
152 GJ ha-1 y-1
ENERGY FOR OPERATION: Mixing (bubbling) 547
Cooling 90
Harvesting 141
TOTAL: 778 GJ ha-1 y-1
X
BIOMASS CALORIC CONTENT
22 MJ kg-1
Tetraselmis suecica
Tuscany (Italy) location
Wet biomass
Natural seawater and CO2 from flue-gas
Mixing reduced by 50% during the night
1 ha GWP II plant: total volume 315 m3 – 1250 m2 occupied land area
Real data from our experimental facilities in Italy
Assumptions for energy
analysis
Negative energy balance
Major energy costs
Embodied energy(30%)
Mixing (40%)
Fertilizers and harvesting (11%)
A protein yield of 18 t ha-1 y-1 is attainable
20 times higher than soya yield
Mode of improvement
Suitable location
+
Photovoltaic integration
Cultivation with low cost nutrients
Fertilizers and CO2 represent an important cost in algae biomass production
• 11% of total energy cost
• 20% of operating energy cost
Must be replaced by “inexpensive” raw
material
In our experiments
poultry manure
has been tested with
T. suecica cultures
• CO2 from flue-gas
• Nutrients from wastes
VP
(g L-1 d-1)
AP
(g m-2 d-1)
Control 0.27 0.10 16.7 5.83
Poultry
manure
0.25 0.04 15.4 2.12
• 7% lower productivity
• Depigmetation and higher bacterial
load
• Batch regimen
• PE sheet cover to avoid dilution by
rain water (10% decrease in total
solar radiation)
• 300 mL of poultry manure extract
were added every two days
NI = 52 mg L-1
P-PO4 = 4.7 mg L-1
Outdoor experiment
0
0.4
0.8
1.2
1.6
2
0 1 2 3 4 5 6
Time (day)
Bio
ma
ss
co
nc
en
tra
tio
n (
g d
.wt
L-1
)
Control Poultry manure
SI = 16.9 MJ m-2 d-1
Feeding experiments
A study was carried out to evaluate growth response, feed
utilization and fillet composition of sea bass (Dicentrarchus
labrax) fed diets including graded levels of dried
T. suecica
Isochrysis sp. (T-ISO)
. All diets were formulated using organic ingredients
9 groups/tank x 3 test diets
250 l tanks
FIBW (72 g)
Feeding period: 63 days
CONT TETRA10 TETRA20
Initial body weight (g) 69.4 69.6 69.5
Final body weight (g) 117.7 118.3 116.1
SGR (%) 0.84 0.84 0.81
Feed intake (g/d/fish) 1.04 1.07 1.05
FCR (Feed/ weight
gain)
1.35 1.41 1.43
Sea bass juveniles growth performance and
feed utilization as affected by dietary
algae inclusion
Tetraselmis trial
Dietary algae inclusion affected apparent
digestibility coefficients (ADCs)
evaluated in vivo
CONT TETRA20
ADC (%)
Protein 95.3 a 93.3 b
Lipid 99.3 a 79.7 b
Organic matter 89.1 a 87.4 b
Diet ingredients
(g/kg)
Cont TETRA
10
TETRA
20
Fish meal 548 493 439
Wheat Gluten meal 100 100 100
Soy bean meal 90 90 90
T. suecica dry powder 0 80 160
Wheat meal 120 93 66
Fish oil 104 106 107
Celite 15 15 15
Mineral & Vitamin mix 20 20 20
Binder 3 3 3
(P<0.05)
Only
10-20% FM protein
substitution
FIBW (140 g)
Feeding period: 121 days
88 Cont ISO 10 ISO 20
Initial body weight (g) 142 141.9 142.1
Final body weight (g) 285.4 287.7 286.3
SGR (%) 0.58 0.58 0.58
Feed intake (g/fish/d) 1.93 a 2.01 ab 2.03 b
FCR (Feed/ weight
gain)
1.68 1.69 1.76
Sea bass growth performance and feed
utilization as affected by dietary algae
inclusion Isochrysis trial
Dietary algae inclusion affected in vivo
apparent digestibility coefficients
(ADCs) and n-3 PUFAs content of the
fillet muscle
Cont ISO 10 ISO 20
ADC (%)
Protein 93.2 93.4 92.6
Lipid 92.4 a 91.7 a 87.6 b
Dry matter 78.4 76.7 75.3
Diet ingredients
(g/kg)
Cont T-ISO 10 T-ISO 20
Fish meal 550 500 450
Wheat Gluten meal 120 120 120
Soy bean meal extr. 80 80 80
T-ISO dry powder 0 70 140
Wheat meal 100 85 70
Fish oil 100 70 40
Palm oil 0 25 50
Celite 15 15 15
Mineral & Vitamin mix 20 20 20
Binder 15 15 15
FM sparing effect (protein basis) 0 10 20
Fish lipid sparing level (%) 0 15 30
Cont ISO 10 ISO 20
Total n-3 PUFAs 25.1 a 23.7 ab 22.8 b
Microalga
10-20% FM protein
substitution
Microalga + PO
20-50% FM/FO lipid
substitution
CONCLUSIONS
Tetraselmis can be a potential source of aquafeed ingredient
On an annual basis an average biomass productivity of 36 t ha-1 y-1 and a protein
yield of 18 t ha-1 y-1 can be attained in a 1-ha GWP plant in Tuscany (Italy)
Energy cost is to high and the energy balance still negative (0.6)
Tetraselmis production costs in GWP are higher than 5 € kg−1
Using open ponds as culture system, flue gas as CO2 source and wastes to
provide nutrients the cost of algal biomass could be reduced to € 2
Do not overlook: THE ABILITY TO GROW WITHOUT IMPACTING ON FRESHWATER
AND ARABLE LAND
This will never be possible with terrestrial plants
Significantly higher compared to soya crop
Major energy costs are embodied energy of GWP, mixing, fertilizers and harvesting
Commercialization of microalgae biomass as a feed commodity is not mature yet
Nutrients from poultry manure were satisfactorily used with productivity close to
that of control culture
The main advantages are
For feed/food use, legislation and sanitary aspects must be carefully evaluated
Large-scale production of marine nitrogen-fixing cyanobacteria could be an
interesting strategy
• In feeding experiments with sea bass T. suecica and Isochrysis (T-ISO) have
shown their potential to become an alternative dietary ingredient in aquafeed
• Highly substituted diets resulted in a decline in lipid ADC and in a reduced n-3
PUFA content in the edible fillet
• Techniques of cell disruption are being tested to increase digestibility
• Greenish skin pigmentation was observed
Our experiments with Nostoc sphaeroides were disappointing
►► cost reduction
►► possibility to reuse poultry waste difficult to dispose of