effect of dietary inclusion of seaweeds on intestinal proteolytic activity of juvenile sea bream,...
Post on 03-Apr-2018
216 Views
Preview:
TRANSCRIPT
-
7/29/2019 Effect of dietary inclusion of seaweeds on intestinal proteolytic activity of juvenile sea bream, Sparus aurata
1/6
March | April 2013Effect of dietary inclusion of seaweeds on
intestinal proteolytic activity of juvenile seabream, Sparus aurata
The International magazine for the aquaculture feed industry
International Aquafeed is published six times a year by Perendale Publishers Ltd of the United Kingdom.All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies,the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis ofinformation published.Copyright 2013 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any formor by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058
INCORPORAT ING
f Ish fARmING TeChNOlOGy
http://www.aquafeed.co.uk/http://www.aquafeed.co.uk/ -
7/29/2019 Effect of dietary inclusion of seaweeds on intestinal proteolytic activity of juvenile sea bream, Sparus aurata
2/6
In thelast years considerable attention
has beenpaidon the useofseaweeds
(SW)asapossibleingredientforaqua-feeds.Red,greenandbrownSWcanbe
takenfromtheirnaturalhabitatandbrought
to the shore by the action of winds and
tides. Otherwise, biomass can be obtained
from secondary and tertiary treatment of
effluents. Wastewater treatment utilising
photosynthetic organisms is an interest-
ing alternative to reduce
the ecological impact of
domestic, industrial or
aquaculture e ff luents .
Generally,high-qualityalgalbiomass is yielded from
algalcultivation,represent-
inganexcellentsourceof
hydrocolloids,carotenoids,
and bioactive substances,
which allows dif ferent
industrial applications. In
addition,thereiscurrently
an increas ing interest
for the potential of SW
in human and animal
nutrition.
Seaweed asingredientin aquafeeds
AlthoughnutritionalpropertiesofSWare
notaswellknownasarethoseoflandplant-
basedingredients,theirchemicalcomposition
maybecharacterisedbylowcontentinlipids,
moderate in protein, but rich in non-starch
polysaccharides, minerals and vitamins. Lipid
contents range from 0.3 to 7.2 percent,
althoughalgallipidsarerichinPUFAsuchasC20:5n3 (eicosapentaenoic acid, EPA) and
C22:6n3 (docosahexaenoicacid,DHA).The
proteincontributionisrangedfrom10to30
g/100 g dry weight, whichmay vary greatly
amongSWspecies,environmentalconditions
(especiallyundernitrogen-enrichedcondition)
andseason.
Thehighbiologicalvalueofalgalproteinsmakes algae suitable for inclusion both in
animalfeeds(especiallymarinespecies)andin
humandiets.Thehighcarbohydratecontent
(30to60%)isaverymarkedcharacteristicin
most SW, comprising mainly soluble carbo-
hydrates,likesugars,andpectins,alginicacid,
agar and carrageenan as well. Besides their
potential nutritional value, from a techno-
logicalpointofview,SWcanalsobeusedas
additivesinthefeedindustry,forinstance,as
excellentfeedagglutinants(improvingtexture
andwaterstabilityofpellets),orasattractants
(increasingfeedintake).
The effects of seaweeds on fish
SeveralstudieshaveprovedthatadditionofsmallamountofSWinaquafeedsresulted
in considerable positive effect on growth
performance and feed utilisation efficiency,
carcass quality, physiological activity, intesti-
nalmicrobiota, disease resistance,and stress
response(Valente et al.,2006).Nonetheless,
ithas been alsonotedin otherpublications
that high SW inclusion reduces fish growthandfeedefficiency.Fromtheliteratureavail-
ableitcanbedeductedthattheresponseof
animalstoSWseemstobedose-dependent
and species-specific. Moreover, certain sub-
stances with antinutritive activity may be
present in SW, like lectins, tannins, phytic
acid, and protease and amylase inhibitors
(Oliveiraet al.,2009).Such
antinutritionalfactorsmight
interferewithbioavailability
and/ordigestibilityofnutri-
ents.Specialemphasisshould
be focused on protease
inhibitors. Binding of pro-
tease inhibi tors to pro-
teolyt ic enzymes causes
the pancreas to secrete
largeramountsofdigestive
enzymestoovercomethe
negative effects of inhibi-
tors on the digestion of
dietary protein. This fact
can lead to decreased
weightgain,andpancreatic
hypertrophy in some fish
species. For this reason,
studies aimed to include
SW in aquafeeds must also bring up their
possible effects on fish digestive physiology.
Todate,thereisscarceliteratureanalysingif
SW inclusion causes negative consequences
ondigestivephysiologyoffish.
Evaluating the effect of seaweedson digestive proteases
Inarecentstudy,weevaluatedtheeffectofinclusionoftwoSWasdietaryingredients
onintestinalproteolyticactivityofjuvenilesea
bream.Gracilaria cornea(GR)andUlva rigida
(UL)werechoseninthepresentstudyowing
to its fast growth, low-cost production and
Effect of dietary inclusion
of seaweeds on intestinal
proteolytic activity of juvenile
sea bream, Sparus aurata
by Mara Isabel Sez, Toms Martnez and Javier Alarcn,Universidad de Almera-CEIA3, Spain
Figure 1: Detail of experimental feeds. UL-25percent (above) and control (below)
38 | IntenAtIonA AquAFeed | March-April 2013
FEATURE
-
7/29/2019 Effect of dietary inclusion of seaweeds on intestinal proteolytic activity of juvenile sea bream, Sparus aurata
3/6
successfulintegratedcultureinfish-farmefflu-
ents.BiomasswasobtainedfromtheMarine
Biotechnology Centre (ULPGC, Spain). SW
werecultivatedin750Lsemicircularfibreglass
tanks filled with seawater plus the fishpond
effluentsofapilotaquaculturesystem(11m 3
withanoptimaldensityofSparus aurataof20
kgm-3,andawaterrenovationrateof68
volday-1).RedandgreenSWwerewashed
withseawater,sun-driedfor48hours,groundandsievedthrough0.1mmsievebeforebeing
usedasadietaryingredient.
Dry algal biomass was incorporated into
six experimental diets (40% crude protein
and 12% crudelipid) atincreasing levels (5,
15 and 25%). A feed without SW served
as a control diet. Feeds were made at the
UniversityofAlmeria-CEIA 3facilities(Service
of Experimental Diets; http://www.ual.es/
stecnicos_spe).Every experimental feedwas
randomly assigned to triplicate group of
fifteenseabreamjuveniles(15.4ginitialbody
weight). Fish were fed by hand twice per
day (9:00and17:00) ata rateof 3percent
of their body weight for 70 days. At the
endofthetrial,fishwerekilledaccordingto
the requirements of the Directive 2010/63/
UE, and digestive tract was removed, and
thenprocesses toobtainenzymaticextracts.
Intestinal proteases were analysed by two
differentapproaches:a) quantifyingthe level
ofintestinalproteolyticactivity,andb)visual-
izing the profile of intestinal proteases in
zymograms(Alarcnet al.,1998).Inaddition,
thepresenceofproteaseinhibitorsinSWwastestedaccordingtoAlarcnet al.(1999).
Checking the presence ofprotease inhibitors in SW
Resultsrevealedthe presenceofprotease
inhibitors in SW.
Dose-response
curves showed
that UL contained
substances able to
reduce digestive
proteolytic activity
in sea bream (up
to77%),whereasa
negligible inhibition
by GR was found
(4%). Obvious dif-
ferences in the
kinetic of inhibition
of protease activity
werefoundforUL.
Equation defining
such curvemay be
used topredictthe
expected percent-
age of reduction
in protease activ-
ity, once proteaseactivityinthediges-
tive tract and the
amount of feed ingested are known. For
instance,inthecaseof40gseabream,total
proteaseactivityreleasedafteramealisaround
1,300units.Thosefishthatconsumed0.5gof
afeedcontaining15percentofUL,showeda
ratiomgULperunit ofactivityof50,which
determined a
reduction nearly
40percentinthe
activity of diges-
tive proteases.
Fortunately, fish
havemechanisms
to compensate
theeffectof die-
taryantinutrients.
Zymograms
obtained after
electrophoretic.
separation of
proteinsisause-
ful tool toknow
indetailthetype
of inhibition
caused by pro-
tease inhibitors.
From the zymo-
gram, it is clear
that Ulva pro-
duces a general-
ised inhibition in
alkaline proteas-
esofseabream.
On the contrary
Gracilariadidnotaffectanyofthe
activebands.
The same
results were
observed after
incubationofdigestiveproteaseswithextracts
oftheexperimentaldiets.Themeaninhibition
ranged from 11 to 48 percent. In general,
UL-supplemented feeds showed inhibition
values higher than the GR-supplemented
diets,whichdidnotexceed16percent.For
ULdiets,itwasfoundthatpercentageofinhi-
bitionwaspositivelycorrelatedwiththeSW
inclusion level, whichagreeswith theabove
mentioned dose-response curve. Inhibition
producedbyGRfeedscannotbeassociated
totheuseof thisSW.
Effect of seaweed on digestiveproteases of sea bream
Digestiveenzymeswereaffectedbydiets,
asfishhaddifferentenzyme activitylevel of
alkaline proteases after 70 days of feeding
experimental diets. In general, a decrease
in alkaline protease activity was evidenced
whenfeedsincludedULorGR.Inparticular,
the proteolytic activities of fish fed Ulva
supplemented-feeds were significantly lowerthan those of fish fed on control diet. The
presence of protease inhibitors in SWmay
be the reason of the progressive decrease
intheproteolyticactivityinfishfeddietwith
increasing levels of Ulva meal. Supporting
this hypothesis, it has been confirmed that
aqueousextractsofUlvamealinhibitalkaline
proteasesofS. aurata.Moreover,thedropin
Figure 2: Dose-response curves obtained when differentamounts of SW meal (0 to 300 g) were incubated with a
fixed amount of proteolytic activity (1 U) in the inhibitoryassay. Protease inhibition was expressed as the percentage ofreduction in proteolytic activity. Such curves are a simple way
to evaluate how hypothetical variations in the inclusion of
SW might affect sea bream digestive proteases
March-April 2013 | IntenAtIonA AquAFeed | 39
FEATURE
REGISTER NOWfor FREE entrance at
www.viv.net
VIVRussia2013May 21-23, 2013 | Moscow, Russia
Opening the gates to the
Russian Feed to Meat trade.
Special themes
i i i i i l i i i i
i i l il .
http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/http://www.gepro.de/ -
7/29/2019 Effect of dietary inclusion of seaweeds on intestinal proteolytic activity of juvenile sea bream, Sparus aurata
4/6
thelevelofalkalineprotease activitywasnot
accompanied by a decrease of fish growth
andfeedutilization,sinceallfishgrewequally
(unpublished data). Santigosa et al. (2008)
reportedasimilarfindingwhentroutwerefed
ondietsincludingplantproteins.
On the other hand, the ana lysi s of
zymograms revealed that the pattern of
intestinal proteases was not modified by
inclusion ofSW. Allsea breamspecimens
showed the same number and distr ibu-
tion of active fractions as in control group
(afterelectrophoreticalseparation,thepat-
tern of intestinal proteases in this speciesis characterized by five groups of active
bands). These results confirmed that the
typeofalkaline proteases secreted into the
intestinal lumen was notmodified by any
of experimental diets. The existence of a
compensation mechanism against dietary
protease inhibitors in juvenile sea bream
hasbeenpreviouslyprovedbySantigosaet
al.(2010),whofoundsimilarresultswhen
fish were fed diets with soybean trypsin
inhibitor.
According tothe results,it isclear that
the amount of the pancreat ic proteases
secretedintotheintestinallumeninjuvenile
S. aurataisaffectedbytheuseofSW,par-ticularlyUlva.Nevertheless,itisalsoevident
that these ingredientsdidnot cause qualita-
tive changes in the composition of alkaline
proteases, given that all fish showed the
samepatternofproteolyticenzymesintheir
intestines, and thatgrowth performance of
fishwasnotaffected,asdeducedfromthein
vivofeedingtrial.
Conclusions
In vitroproteaseinhibitionassaysareause-
fultooltoassessthepresenceofantinutrients
inSWwithpotentialuseinaquafeeds.Based
on the results of this study, SW, especially
Ulva rigida, have antinutritive factors able to
inhibitdigestiveproteasesofS. aurata.Feeding
juvenile S. aurata on seaweed-based diets
decreased the amount of proteolytic activ-
ity secreted intothe intestine. However, the
inclusion of SWdoes not alter the pattern
of proteolytic enzymes in sea bream, which
reveals a compensating mechanism in this
species.Researchisbeingcurrentlyconducted
toassess theeffectofSWonotherdigestive
enzymes, intestinal microbiota, blood andtissue metabolites, and intestine and liver
histologyafter 70daysof feedingSW-based
diets. Further research is needed in order
to known the impact of SW in a long-term
feedingassay.
References
AlarcnFJ,DazM,MoyanoFJandAbellnE.
(1998)Characterizationandfunctionalproperties
ofdigestiveproteasesintwosparids;gilthead
seabream(Sparus aurata)andcommondentex
(Dentex dentex).FishPhysiolBiochem.19:257-267.
Alarcn,FJ,Moyano,FJandDaz,M.(1999).
Effectofinhibitorspresentinproteinsourceson
digestiveproteasesofjuvenileseabream( Sparus
aurata).AquaticLivingRes.12:233-238.
Oliveira,MN,Ponte-Freitas,AL,Urano-Carvalho,AF,
Taveres-Sampaio,TM,Farias,DF,Alves-Teixera,DI,
Gouveia,ST,Gomes-Pereira,JandCastro-Catanho
deSena,MM.(2009)Nutritiveandnon-nutritive
attributesofwashed-upseaweedsfromthecoast
ofCear,Brazil.FoodChem.11:254-259.
Santigosa,E,Snchez,J,Mdale,F,Prez-Snchez,J
andGallardo,MA.(2008).Modificationsofdigestive
enzymesintrout(Onchorynchus mykiss)andsea
bream(Sparus aurata)inresponsetodietary
fishmealreplacementbyplantproteinsources.
Aquaculture252:68-74.
Santigosa,E,SezdeRodigraez,MA,Rodiles,A,
GarcaBarroso,FandAlarcn,FJ.(2010).Effectof
dietscontainingapurifiedsoybeantrypsininhibitor
ongrowthperformance,digestiveproteasesand
intestinalhistologyinjuvenileseabream( Sparus
aurataL.).AquacultureRes.41:e187-e198.
Valente,LMP,Gouveia,A,Rema,P,Matos,J,Gomes,
EFandPinto,IS.(2006)Evaluationofthree
seaweedsGracilariabursa-pastoris,Ulva rigida
andGracilaria corneaasdietaryingredientsin
Europeanseabass(Dicentrarchus labrax)juveniles.
Aquaculture252:85-91.
Figure 4: Inhibition of seabream intestinal proteases
after incubation of extractswith solutions prepared using
experimental diets containing 5,15 and 25 percent of Ulva (UL)
and Gracilaria (GR) meal
Figure 5: Total alkaline protease activity measured in extracts of sea bream fed
different experimental diets containing graded levels of SW
Figure 3: Inhibition ofintestinal proteolytic enzymes
by Gracilaria corneaandUlva rigida meal. Qualitative
analysis: visualization ofinhibition of active fractions in
zymograms
MoreinforMation:
Mara Isabel Sez Casado
Email: msc880@ual.es
40 | IntenAtIonA AquAFeed | March-April 2013
FEATURE
-
7/29/2019 Effect of dietary inclusion of seaweeds on intestinal proteolytic activity of juvenile sea bream, Sparus aurata
5/6March-April 2013 | IntenAtIonA AquAFeed | 41
FEATURE
ASIAN GATEWAYTO ANAQUATIC WORLD OF WONDER
www.aquarama.com.sgFor more information, please contact:
Iman Tam aquarama-sg@ubm.com
co-located with
The 4th International Pet
& Accessories Exhibition
SANDS EXPO AND
CONVENTION CENTERMARINA BAY SANDS SINGAPORE
VENUE
CHANGE
SANDS EXPO AND
CONVENTION CENTERMARINA BAY SANDS SINGAPORE
Central Ofce and Orders
Jess Aprendiz, 19. 1 A-B 28007 Madrid
T. +34 915 014 041 norel@norel.es www.norel.es
VisitNOREL
Boothat
VIVASIA
2013
H105.G108
Ecobiol AquaPathogenic bacteria antagonist
Enhances friendly intestinal microflora
Improves Feed Conversion Ratio and growth
Helps mantain optimal health status
Reduces mortality in the ponds
Controls water quality
http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.norel.es/http://www.yara.com/ -
7/29/2019 Effect of dietary inclusion of seaweeds on intestinal proteolytic activity of juvenile sea bream, Sparus aurata
6/6
www.aquafeed.co.uk
LINKS
Seethefullissue
VisittheInternationalAquafeedwebsite
ContacttheInternationalAquafeedTeam
SubscribetoInternationalAquafeed
Transforming aquaculture
production using
oxygenation systems
Nutritional benefits of
processed animal proteinsin European aquafeeds
Towards aquafeeds with
increased food security
Bioenergetics application in aquaculture nutrition
Volume 16 I ssu e 2 2013 - mARC H | APR I l
INCORPORAT ING
fIsh fARmING TeChNOlOGy
Thisdigitalre-printispartoftheMarch|April2013editionofInternational
Aquafeedmagazine.
Contentfromthemagazineisavailabletoviewfree-of-charge,bothasafull
onlinemagazineonourwebsite,andasanarchiveofindividualfeaturesonthedocstocwebsite.
Pleaseclickheretoviewourotherpublicationsonwww.docstoc.com.
Topurchaseapapercopyofthemagazine,ortosubscribetothepaper
editionpleasecontactourCirculationandSubscriptionsManageronthelink
above.
INFORMATIONFORADVERTISERS-CLICKHERE
http://www.aquafeed.co.uk/http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/http://www.aquafeed.co.uk/contact.phphttp://www.aquafeed.co.uk/subscriptions.phphttp://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/iaf1102http://www.docstoc.com/profile/Perendalehttp://www.aquafeed.co.uk/advertising.phphttp://www.aquafeed.co.uk/advertising.phphttp://www.docstoc.com/profile/Perendalehttp://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/subscriptions.phphttp://www.aquafeed.co.uk/contact.phphttp://www.aquafeed.co.uk/http://www.aquafeed.co.uk/iaf1102http://www.aquafeed.co.uk/
top related