In the terrestrial animal feed industry the use of exogenous enzymes is a relatively common practice and today the global feed enzyme market is worth more than US$550 million. This saves the global feed market an estimated US$3-5 billion per year. To date the use of enzymes in aquaculture feeds has been limited, but interest is growing due to the increasing use of plant based protein ingredients and their by-products.

1. July | August 2012
Unlocking the hidden potential of plant
proteins using solid state fermentation
enzymes
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The International magazine for the aquaculture feed industry

2. FEATURE
Unlocking the hidden
potential of plant
proteins using solid state
fermentation technology
by John Sweetman1, Ioannis Nengas2 and Serge Corneillie3
I
n the terrestrial animal feed industry NSPs cannot be broken down by the digestive Alltech’s Bioscience Centers in Dunboyne,
the use of exogenous enzymes is a enzymes of many fish species especially the Ireland; Bangkok, Thailand; and Kentucky,
relatively common practice and today carnivorous ones. USA, have resulted in a $40 million state-of-
the global feed enzyme market is worth A wide range of anti-nutritional factors the-art production facility in Serdan, Mexico.
more than US$550 million. This saves the (ANFs) such as protease inhibitors, non- The SSF process involves the careful
global feed market an estimated US$3-5 digestible carbohydrates, lectins, saponins and selection of specific strains of naturally occur-
billion per year. To date the use of enzymes phytates may also be present in a number of ring fungi which have the ability to ferment
in aquaculture feeds has been limited, but plant derived materials such as legume seeds, a wide range of agricultural products such as
interest is growing due to the increasing use soybean meal, rapeseed meal etc. These can DDGS, corncob, palm kernel, wheat bran,
of plant based protein ingredients and their impede digestion in fish often decreasing rapeseed oil cake and soy bean. The selected
by-products. intestinal viscosity and bacterial loads which fungi are first propagated in a liquid media to
in turn affect the animals’ performance. These produce a large volume of inoculum which
The incorporation of Synergen™ (Alltech ANFs have therefore to be removed before is mixed with pre-sterilised selected solid
Inc., USA), a natural solid state fermenta- they can be incorporated in commercial feeds. substrate media to produce a mixture known
tion complex that improves profitability by The use of highly digestible and
maximizing nutrient release, has enabled the processed soybean meal such
fishmeal content of diets for several com- as low antigen SPC (soy pro-
table 1: Diet composition for Gilthead sea bream
mercial carnivorous fish species to be reduced tein concentrates) or proc-
by up to 65 percent. These diets have also essed corn gluten to replace Diet 1 2 3
maintained the same or achieved even better fish meal is possible but these Control natural Pre-treated
growth performance when compared to the highly processed ingredients complex with natural
high fishmeal diets. are expensive and the eco- complex
This article highlights the recent work nomic savings can therefore
carried out with Gilthead sea bream (Sparus be relatively low. Fish meal 25 25 25
aurata), red sea bream (Pagrus major), amber- Another solution for coun-
Soybean meal 40 40 40
jack (Serioli dumerili), pangasius catfish and terbalancing the digestibility
Wheat meal 16.7 16.65 16.65
Nile tilapia. problems of such ingredients is
to use enzymes that improve Corn gluten 5 5 5
Modern aquafeed challenges: substrate digestibility resulting Fish oil 13 13 13
maximising nutrient availability in higher nutrient availability Vit-Min 0.3 0.3 0.3
The economic success and sustainability of thus improving growth, food Synergen 0.05 0.05
aquaculture depends on minimising produc- conversion rates and there-
tion cost to maintain profitability, and feed fore economic efficiency.
table 2: effect of diet on the performance of Gilthead sea bream
generally comprises some 50 to 60 percent of Today a better under-
after 12 weeks.
the total cost in intensive culture. Traditionally standing of how enzymes
Pre-treated
fishmeal has been the preferred ingredient work in animal feeds and the natural
Control with natural
due to its high protein content, favourable increasing evidence of their complex
complex
amino acid and mineral profiles, oil and other ability to improve feed quality,
benefits. Its replacement with plant based pro- shown in the last 10 years,
tein ingredients has been brought about by has allowed a more flexible Initial weight (g) 31,11±0,65 30,77±1,37 31,65±0,80
the increasing cost of fishmeal, its limited avail- approach by feed formulators. final weight (g) 84,04±5,76 95,57±3,57 100,75±1,90
ability and the requirement to ensure that this FCr 1,45±0,13a 1,18±0,01b 1,13±0,02b
expanding industry remains both financially Solid State
SGr 0,83±0,05a 0,94±0,07b 0,97±0,04b
profitable and environmentally sustainable. Fermentation
Values are means of three replicates expressed with the standard
Plant derived feed ingredients however Technology
deviation between tanks. Values with common superscripts
have several limitations. Non starch polysac- Alltech has pioneered demonstrate no significant differences among groups (p<0.05)
charides (NSPs) are a complex group of the production of SSF tech-
Specific growth rate (SGR) = (ln final weight - ln initial
polysaccharides which act as energy storage nologies for the animal feed
weight)*100/days
carbohydrates in grains and seed. While they industry. Eight years of col-
may provide a cheap source of dietary energy laborative research between Feed conversion ratio (FCR) = feed consumed g / weight increase g
32 | InternAtIonAl AquAFeed | July-August 2012

3. FEATURE
Figure 1. Feed conversion ratio (a) and Specific
growth rate (b) of the Gilthead sea bream fed
different diets
table 3: experimental diet composition for red sea bream.
1 2 3 4 5 6
Ingredients FM50 FM20 Ft FtP Fte0.05 Fte 0.1
anchovy meal 50 20 20 20 20 20
Innovative and proven
Soybean meal 0 18 18 18 18 18
Corn gluten meal 5 23 23 23 23 23
yeast products
Fish oil 5 5 5 5 5 5 in aquaculture
Soybean oil 5 7.4 7.4 7.4 7.4 7.4
Consistent products supported by
Ca(H2Po4)2 1 1 1 1 1 1
the Lesaffre group experience and
taurine - - 0.2 0.2 0.2 0.2 its unique know-how in biotechnology
Phytase - - - - - -
and nutrition;
(IU/g) - - - 1000 - - Selected strains and controlled production;
natural complex - - - - 0.05 0.1
Designed to solve nutritional
others* 34 25.6 25.4 25.2 25.35 25.3 and sanitary issues;
others: Starch, vitamin premix and wheat flour
Dedicated range of products:
live yeast, yeast cell wall, yeast extract
as ‘Koji’. Under strict aseptic conditions the effective over a
and enriched yeast.
Koji is then evenly distributed onto trays and wide range of feed
introduced into environmentally controlled processing condi-
SSF culture chambers for up to five days. tions.
During this time the fungus grows rapidly,
breaking down the fibrous and non-fibrous Carnivorous
portions of the chosen substrate. Doing so fish: Gilthead
dramatically changes the nutritional profile sea bream
of the material and results in the generation At the Institute
of products that can be used to reformulate of Aquaculture of
diets. On day five, the Koji is extracted and the Hellenic Centre
the by-product is dried. for Marine research
rformance
Wellbeing, the source of pe
The product from the Alltech SSF proc- an experiment was
ess, Synergen™, allows for a more flexible performed in which
approach to feed formulation through the approximately 31 g
inclusion of by-products or by reducing nutri- juvenile Gilthead sea
ent constraints in the diet. It has also been bream were fed 3 For more information: contactlfa@lesaffre.fr
shown, through animal performance, to remain different diets (Table
July-August 2012 | InternAtIonAl AquAFeed | 33

4. FEATURE
that requires only obtained by the low fishmeal diets con-
table 4: effect of dietary treatment on the performance of red sea bream after
additional taining Synergen. The lowest growth and
12 weeks.
facilities and highest FCR were obtained with diet 2 (low
treatments
therefore it fishmeal). Adding taurine alone or taurine /
Parameter FM50 FM20 Ft FtP Fte0.05 Fte 0.1 would need a phytase to the low fishmeal diet improved
change in the the performance but this performance was
Final body weight (g) 71.5c 49.8a 55.2ab 59.7ab 74.5c 67. 8bc production still much lower than the high fishmeal diet
line. Since or the Synergen treated groups.
Weight gain(g) 57.7b 35.9a 40.4ab 59.7ab 59.9b 53.7b
the results Adding higher amounts of the natural
SGr (%/day) 1.96c 1.52a 1.57ab 1.70ab 1.94c 1.87c
obtained from complex (1 kg of Synergen/tonne) did not
FCr 1.12a 1.30b 1.27b 1.25b 1.16ac 1.21ac the ‘natural further improve the results. These results
Feed intake (g/day) 64.7a 46.6b 51.2ab 56.6ab 69.6a 64.9a complex’ show clearly that highly carnivorous fish
a,b Means differ P<0.05. diet have no (RSB) can be fed with low fishmeal levels
significant dif- and that ordinary plant proteins can be used
1) in triplicate at a water temperature of 18 ± ference from the ‘pre-treated with natural if appropriate ingredients are added.
2 °C. The sea bream were fed with a control complex’ diet, this indicates that the natural Field trials in Japan with red sea bream
diet (1) with a moderate 25 percent fishmeal complex can be effectively added directly to have confirmed these results. In commercial
inclusion and two other diets in which a the ingredient mix. The ‘natural complex’ diet cages, red sea bream performed better
portion of the wheat meal was replaced by gave an improvement of 18 percent in FCR when Synergen was incorporated in the diet
Synergen, incorporated at 0.05%. In diet 2, and a 13 percent improvement in SGR when with an increased SGR (0.70% when com-
‘Natural complex’, Synergen was incorpo- compared to the control diet. pared to 0.55% in the control group) and a
rated into the whole ingredient mix prior to Currently industrial trials and commercial final weight gain of 175 g which was greater
extrusion while in diet 3, ‘Pre-treated with application are underway. Based solely on than the 138 g achieved by the control
the improvement in FCR, a groups. The FCR was 21 percent lower in
return on investment of 1: the fish fed the diet incorporating Synergen
43 can be expected when and the feed efficiency of the Synergen
Synergen is added in this incorporated diet was also improved. (86.6
manner for this species with versus 68%). Amberjack (Serioli dumerili)
additional increased profit also showed similar growth results growing
benefits to be added from from 2.2 kg to 2.6 kg (without Synergen) or
the growth rate improve- 3.1 kg (with Synergen).
ments.
Pangasius and tilapia
Figure 2: Growth of red sea bream fed different diets
Carnivorous fish: It is strongly believed that omnivo-
Red sea bream rous and herbivorous fish can digest plant
Improved growth rates proteins better than carnivorous fish and
have also been achieved therefore do not need additional ingredi-
by Satoh et al. (2011) with ents in their diets. However the inclusion of
juvenile red sea bream. In Synergen in diets for fish species such as tra
this case red sea bream, and basa catfish and tilapia has resulted in
of approximately 13.5 g significantly improved growth and lowered
were fed six different diets significantly the FCR in both low and high
(Table 3). A high fish- fishmeal diets.
meal diet with 50 percent In recent trials, by Hung and Kim (2007),
anchovy meal was fed as a a comparison was made between a 15
control and five other diets percent fishmeal diet and a five percent
all with low fishmeal inclu- fish meal diet (65% reduction) with added
Figure 3: Growth of Amberjack with and without sion (20%) but to which Synergen (200 or 500 g per tonne feed)
Synergen
different components were to both diets. They demonstrated that
added (taurine, taurine and irrespective of the diet used (low or high
natural complex’, the plant ingredients were phytase enzyme, taurine and Synergen). In fish meal) the addition of the natural com-
hydrolyzed with the Synergen for four hours these diets the fishmeal was replaced with plex resulted in dramatic improvements in
at 40 °C prior to extrusion. ordinary corn gluten and soybean meal, performance parameters. Growth reached
The diet whose ingredients were pre- which are cheaper and industrially available approximately double that of the diet with-
treated by hydrolysing them with Synergen ingredients. out the enzyme present. Tra catfish grew
before the extrusion gave slightly better but Diet 2 was low fishmeal, diet 3 was low from 14 g to 36 g (without Synergen) or 70
not significantly different results than the fishmeal and taurine, diet 4 low fishmeal and g (with Synergen) while Basa catfish grew
diet which incorporated Synergen as a sup- taurine and phytase enzyme, diet 5 was low from 6 g to 57 g (without Synergen) or 82
plemented ingredient, mixed directly with fish meal and taurine and 500 g Synergen/ g (with Synergen).
the rest of the ingredients. Both these diets tonne feed and diet 6 low fishmeal and Similar results have been recorded for Nile
performed significantly better than the control taurine and 1 kg of Synergen/tonne feed. Tilapia in which a zero percent fishmeal diet
diet with improved growth, SGR and FCR The best performance was obtained with was used as the control diet where growth
(Table 2 and Figure 1). the positive high fishmeal diet (best growth from 3 g to 21 g occurred without Synergen
Pre-treatment of raw materials in com- and lowest FCR). Comparable growth and and to 35 g (with Synergen).
mercial feed production units is a procedure performance to the high fishmeal diet was This indicates that supplementing the low
34 | InternAtIonAl AquAFeed | July-August 2012

6. metals were analysed for five farms over two three international standards for tilapia farming, i.e. Sustainable Fisheries Partnership
croppings (10 months). The study helped BAP, GlobalGAP, and ASC, was held in Haikou Website: www.sustainablefish.org FEATURE
and high fish meal diets with the natural com- References
plex has enhanced the availability of dietary
Hung LT and TNH
nutrients and compensated for the poorer Kim. 2007. Reducing
quality of the raw ingredient characteristics fish meal utilization in
in the low fishmeal diet so improving overall Pangasius Catfish feeds
dietary performance. through application of
enzymes. Presented
Conclusion at Asian Pacific
The application of this SSF technology in Aquaculture 2007,
this manner opens the door more flexible Hanoi, Vietnam, 5-8
August 2007.
feed formulation and allows the incorpo-
ration of lower cost vegetable protein Satoh S, Hanini I, Sarker
substitutes such as simple soybean meal and MSA, Haga Y, Ohkuma T
corn gluten. Improved nutrient availability and H Nakayama 2011.
impacts directly growth and performance so Effect of Taurine, Phytase
increasing dietary efficiency both in terms of and enzyme complex
supplementation to
cost and environmental impact. The savings
low fish meal diet on
in fishmeal usage addresses consumer con-
growth of juvenile red
cerns and sustainability issue in the industry. sea bream Pagrus major.
There is still much to learn about these Presented at World
complex interactions but the indicators Aquaculture 2011, Natal,
show the potential of this technology. ■ Brazil, 6-10 June 2011.
1Alltech Aqua, 28200 Lixouri, Kefalonia, Greece
2Institute of Aquaculture, Hellenic Centre of Marine
Research, Agios Kosmas, Elliniko, 16610 Athens, Greece
3Alltech Japan, Shiba-Koen 2-3-27, Minato, Tokyo 105-
0011, Japan
July-August 2012 | InternAtIonAl AquAFeed | 27
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July-August 2012 | InternAtIonAl AquAFeed | 35

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