Probiotic Assign

8/4/2019 Probiotic Assign

1/13

PROBIOTIC

PROBIOTIC IN AQUACULTURE


2/13

INTRODUCTION

Aquaculture has become an important economic activity in many countries. In large-scale

production facilities, where aquatic animals are exposed to stressful conditions, problems relatedto diseases and deterioration of environmental conditions often occur and result in serious

economic losses. Prevention and control of diseases have led during recent decades to a

substantial increase in the use of veterinary medicines. These amounts of antibiotics have exerted

a very strong selection pressure towards resistance among bacteria, which have adapted to thissituation, mainly by a horizontal and promiscuous flow of resistance genes (SCAN, 2003).

Resistance mechanisms can arise one of two ways: chromosomal mutation or acquisition of

plasmids. The use of probiotics or beneficial bacteria, which control pathogens through a varietyof mechanisms, is increasingly viewed as an alternative to antibiotic treatment.

WHAT IS A PROBIOTICS?

The term probiotics is generally used to denote bacteria that promote the health of otherorganisms. Lilley and Stillwell (1965) described them as substances secreted by onemicroorganism, which stimulated the growth of another.

An expert with the Joint Food and Agriculture Organization of the United Nations/World Health

Organization (FAO/WHO), stated that probiotics are live microorganisms, which whenconsumed in adequate amounts, confer a health benefit for the host (FAO/WHO, 2001).

Verschuere et al. (2000) suggested the definition a live microbial adjunct which has a beneficial

effect on the host by modifying the host-associated or ambient microbial community, byensuring improved use of the feed or enhancing its nutritional value, by enhancing the hostresponse towards disease, or by improving the quality of its ambient environment

Irianto and Austin (2002) thus a probiotic is an entire or components of a micro-organism that isbeneficial to the health of the host.

MECHANISM OF ACTION

Probiotic strains have been shown to inhibit pathogenic bacteria both in vitro and in vivo

through several different mechanisms.

some possible benefits linked to the administering of probiotics have been suggested as:

1. Competitive exclusion of pathogenic bacteria2. Source of nutrients and enzymatic contribution to digestion3. Direct uptake of dissolved organic material mediated by the bacteria4. Enhancement of the immune response against pathogenic microorganisms


3/13

5. Antiviral effects.6. Interaction with phytoplankton

1. Competitive exclusionBacterial antagonism is a common phenomenon in nature, therefore, microbial interactions play

a major role in the equilibrium between competing beneficial and potentially pathogenicmicroorganisms.

Probiotics competive in three ways:

A. Competition for Adhesion sitesB. Competition for NutrientsC. Production of Inhibitory compounds.

A. COMPETITION FOR ADHESION SITESProbiotics Organisms compete with the pathogens for the adhesion sites and food in the gut

epithelial surface and finally prevent their colonization. Adhesion capacity and growth on or inintestinal or external mucous has been demonstrated in vitro for fish pathogens like Vibrioanguillarum andAeromonashydrophila ( Krovacek, 1987).

B. COMPETITION FOR NUTRIENTS:Probiotics utilizes nutrients which may be consumed by pathogens microbes. Competition fornutrients can play an important role in the composition of microbiota of the intestinal tract orambient environment of the cultured aquatic organism.

C. PRODUCTION OF INHIBITORY COMPOUNDSProbiotic bacteria releases a variety of chemical compounds that are inhibitory to both gram positive and gram negative bacteria. These includes bacteriocines, sideropheres, lysozymes,

proteases hydrogen peroxides etc. lactic acid bacteria are known to produce compounds such asbacteriocins that are inhibitory to other microbes.

The first report of the existence in seawater of bacteria with an inhibitory effect against a Vibriosp. has been attributed to Gaixa (1889).

In aquaculture, Thalassobacter utilis, has shown inhibitory effects against Vibrio anguillarum.The use ofVibrio alginolyticus strains as a probiotics has been recommended to increase survivaland growth of white shrimp (Litopenaeus vannamei) post-larvae in Ecuadorian hatcheries.


4/13

So competitive exclusion of potential pathogenic bacteria effectively reduces or eliminates theneed for antibiotic prophylaxis in intensive larviculture systems.

2. Source of nutrients and enzymatic contribution to digestionIt has been suggested that microorganisms have a beneficial effect in the digestive processesof aquatic animals. In fish, it has been reported that Bacteroides and Clostridium sp. havecontributed to the host's nutrition, especially by supplying fatty acids and vitamins (Sakata,

1990).

Prieur et al (1990) observed that some bacteria may participate in the digestion processes ofbivalves by producing extracellular enzymes, such as proteases, lipases, as well as providing

necessary growth factors.

Dall and Moriarty (1983) reported that microbiota may serve as a supplementary source of

food and microbial activity in the tract digestive may be a source of vitamins or essentialamino acids.

3. Influence on water qualityIt has been reported that gram positive bacteria especially Bacillus sp. Improve water quality by converting the organic matter back to carbon dioxide into the environment. During the production cycle, high levels of gram-positive bacteria can be minimize the buildup ofdissolved and particulate organic carbon.Dalmin et al (2001) reported that use ofBacillus sp. improved water quality, survival andgrowth rates and increased the health status of juvenile Penaeus monodon and reduced thepathogenic vibrios.

4. Enhancement of the immune responseProbiotic stimulate the hosts specific immunity and non specific immunity. Some of the

bacteria like Lactic acid bacteria (LAB) increase the resistance to enteric infection. The

mechanism of immune stimulation is yet not known, but specific cell wall components or cell

layers may act as adjuvants and increase humoral immune response.Sakai et al(1995) demonstrated that oral administration ofClostridium butyricum bacteria to

rainbow trout enhanced the resistance of fish to vibriosis, by increasing the phagocytic

activity of leucocytes.

Nikoskelainen et al. (2003) showed that administration of a lactic acid bacterium

Lactobacillus rhamnosus (strain ATCC 53103) at a level of 105 cfu g1 feed, stimulated the

respiratory burst in rainbow trout (Oncorhynchus mykiss).

5. Antiviral effectsSome bacteria have antiviral effect, but the mechanism which these bacteria do is not known.

Kamei et al (1988) reported that strains ofPseudomonas sp., Vibrios sp.,Aeromonas sp., andgroups of coryneforms isolated from salmonid hatcheries, showed antiviral activity against

infectious hematopoietic necrosis virus (IHNV) with more than 50% plaque reduction.


5/13

6. Interaction with phytoplanktonProbiotics bacteria have a significant algicidal effect on many species of microalgae

particularly of red tide plankton. Bacteria antagonistic towards algae would be undesirable in

green water larval rearing technique in hatchery where unicellular algae are cultured and

added, but would be advantageous when undesired algae species developed in the cultureperiod.

SILENT FEATURE OF PROBIOTICS

1. The probiotic should be non pathogenic and non toxic to the host ,

2. It should be accepted by the host, e.g. through ingestion and potential colonization andreplication within the host,

3. It should reach the location where the effect is required to take place,

4. It should actually workin vivo as opposed to in vitro findings,

5. It should preferably not contain virulence resistance genes or AB resistance genes.

6. It should be capable of exerting beneficial influence on the host organism ( increase growthand / or disease resistance)

7. it should be capable of surviving and metabolizing in the gut environment ( resistant to low pH

and organic acids)8. It should be capable of remaining viable for a longer period under storage and field conditions.

9. It should be capable of stimulating the immune system.

10. It should be able to modify the microbial component of water such that the pathogenicmembers are reduced through competitive exclusion.

11. It should be able to efficiently breakdown the organic load with least consumption of

dissolved oxygen.

12. It should help to reduce the BOD/COD levels and other obnoxious gases in the sediment.

13. It should be cheap, efficient and easily available.


6/13

SELECTION CRITERIA FOR PROBIOTICS

Method to select probiotic bacteria for the use in culture system should include the followingsteps:

yCOLLECTION OF BACKGROUND INFORMATIONBefore the start of research on the development of probiotics, the activities about the

culture practices and economics of the development should be studied. A close

knowledge of the rearing practices used in an aquaculture farm is necessary to determine

whether a probiotic application would be feasible or not.

y ACQUISITION OF PUTATIVE PROBIOTICSThe acquisition of good pool of candidate probiotic is of major importance in this

process. It is a vital in his process that the choice of the strain is made as a function of thepossible role of the probiotics to developed. There is no unequivocal indication that the

putative probiotics isolated from the host or from their ambient environment performbetter than isolates completely alien to the cultured species or those that originates from

a very different habitat.

y SCREENING OF PUTATIVE PROBIOTICSA common way to screen the candidate probiotics is to perform in vitro antagonism tests

in which pathogens are exposed to the candidate probiotic in liquid or in solid medium.Candidate probiotics can be selected based on the production of inhibitory compounds

like Bacteriocines, siderophores, or when in competition of nutrients. This is done with

extreme precautions.

y EVALUATION OF PATHOGENICITY OF SELECTED STRAINSProbiotic should not be pathogenic to the host and this should be confirmed prior to

acceptance. Therefore the host must be challenged under stressed and non stressedconditions. This can be done by adding probiotic to the cultured water.

y IN VIVO EVALUATIONThe effect of candidate probiotic should also be evaluated in vivo, in which the candidatespecies is introduced to the host under culture and then monitoring growth, survival and

physic-chemical parameters.

PREPARATION OF PROBIOTIC FOR AQUACULTURE

1. SCREENING OF POTENTIAL PROBIOTICIt is done to isolate the microbe from the culture and enhance its natural effects, favoring

their growth by adding some nutrients or distributing large quantities of them in culture.


7/13

2. SUITABLE CAREER OF PROBITICIt is done along with feed in pelleted, encapsulated and free concentrated forms to reachthe gut in sufficient numbers and to see see the viability of these for a longer period.

TYPES OF PROBIOTIC

Conventionally probiotics are applied through feed, but now a day they are also being applied tothe pond water or sediments. Based on their mode of action they are classified as

1. Feed probiotics2. Pond probiotics

FEED PROBIOTICS

Feed probiotics are those that are administered through feed. These finally find their way into thegut or gastrointestinal tracts of the cultured organism.

On reaching the gastro-intestinal tract the feed probiotics act though-

a. Suppression of bacterial pathogensb. Production of anti-bacterial compounds like organic acids, H2O2 and antibiotics by

anaerobic bacteria results in competitive exclusion of pathogenic strains from the guts ofthe host.

c. Production of special metabolites like vitamin B by many probiotic strain leads to betternutrient utilization and health condition.

d. Immunostimulation- several strains of Lactobacilli have some potential role inaugmenting the immune system of host.

e. Reduction of the potential availability of oxygen to pathogen.f. Detoxification of the metabolites produced by intestinal pathogens.

ADVANTAGES OF FEED POBIOTICS1. Promotion of growth2. Improved food conversion3. Prevention of intestinal disorder4. Pre-digestion of anti nutritional factor5. Avoidance of residual effect of antibiotic in tissue.

POND PROBIOTICS

Health of aquatic organism deteriorates rapidly with increasing environmental stress like low

DO, accumulation of ionized ammonia, nitrite, anoxic conditions and H2 S in the sediments. So


8/13

many microbial supplements can be used to mitigate such conditions which prevent their

establishment in ponds. Pond probiotics basically settles on the botton sediments and act fromthe bottom.

ACTTIONS OF POND PROBIOTIC

1. Biocontrol probiotic limit or eliminate the pathogenic biota through antagonisticproperties.

2. Bioremediation - probiotic maintain water quality through reduction in BOD or CODlevel. The responsible bacteria have capacity to breakdown complex organic matter tosimpler units and are also capable of oxidizing toxic element from water and render themharmless.

PROBIOTIC STRAINS STUDIED IN AQUACULTURE

1. FISH EGGS AND LARVAEThe spawning and early life stages of fish larvae may have profound implications for the

dynamics of microbial communities. These communities can also be influenced by inorganic and

organic compounds. Immediately after hatching process, fish larvae come into contact with theirimmediate environment that provides colonization by a wide variety of microorganism.

The composition of microbiota is influenced by many factors including the availability of

nutrients, animal physiology and immunological factors. Under normal conditions, one of the

basic physiological functions of the resident microbiota is that it functions as a microbial barrieragainst microbial pathogens and as a complement to the establishment of digestive enzymes.

During the initial feeding period, it is possible to manipulate the establishment of an artificialdominance of a determined group of bacteria in the fish-associated microbiota by adding aspecific strain.

Example, . A significant increase in the mean weight and survival rate of turbot larvae (S.maximus) fed rotifers enriched in lactic acid bacteria and these strains provided a significantprotection against a pathogenic Vibrio compared to control larvae (Gatesoupe, 1994).

2. FISH JUVENILES AND ADULTIt is found that a commercially prepared bacterial mixture ofBacillus spp. mixed into the rearingwater increased survival and production of channel catfish (Ictalurus punctatus).A strain ofCarnobacterium sp. previously isolated from the intestine of Atlantic salmon, was

effective at controlling infections caused byA. salmonicida, Vibrio ordalii, and Yersinia ruckeriin fry and fingerling salmonids, applied at 5 107 cells g1 of feed .


9/13

Cultures of Aeromonas hydrophila, Vibrio fluvialis, Carnobacterium sp. and an unidentified

gram-positive coccus, have been beneficial for rainbow trout when these strains wereadministered as food additives, since their application reduced significantly the impact offurunculosis by competitive exclusion and enhanced cellular immunity in the fish.

It has been reported that the presence of antifungal effects from various strains of probiotics. Forexample, a strain isolated from fresh water, Aeromonas media (strain A199) in culture of eels

( Anguilla australis Richardson), presented antagonistic activity against Saprolegnia sp.,supressing the growth of this opportunistic pathogen.

3. CRUSTACEANIn a study of tiger shrimp, the inoculation of Bacillus S11, a saprophytic strain, resulted in

greater survival of the post-larvalP. monodon that were challenged by pathogenic luminescent

bacterial culture. A mixture ofLactobacillus spp. isolated from chicken gastrointestinal tracts has

improved the growth and survival rates of juvenile P.

monodon when fed these strains for 100days

CONSTRAINTS OF PROBIOTIC USE

The major constraints of probiotic are

1. LEACHING Probiotic strains used in the feed may not be available to host due toleaching, therefore standardization of dose is essential.

2. SURVIVAL Many bacterial strains not survive in feed preparation and they lose theirviability when exposed to high temperature and pressure of the extruder.

3. HIGH ORGANIC LOAD - High organic load in the bottom sediments may reduce theefficacy of the bioremediator.

4. DOSAGES Depending on the water and sediment status exact dosages need to becalculated for every set of different conditions.


10/13

CONCLUSION

Probiotic have been successfully used in aquaculture to enhance both internal and external microbialenvironment. However a great deal of research is needed to make it successfully proposition.

First of all it is necessary to understand the nature of competition between species or strain. Secondly fateof probiotic organism in the rearing medium and in gastrointestinal tract should be answered. Thirdly

there is a need for future studies to determine the best possible method of adminstration of probiotic. Themechanism by which the bacterial treatment influences the fish survival cannot be explained from data

collected therefore further initiatives to define the potential benefits of these treatecosystem is

essential.ments to aquaculture production and further derterminig their mechanism of action in pond


11/13

REFERENCES

L. Verschuere, H. Heang, G. Criel, P. Sorgeloos and W. Verstraete, Selected bacterialstrains protectArtemia spp. from the pathogenic effects ofVibrio proteolyticus CW8T2,

Applied and Environmental Microbiology66 (3) (2000), pp. 11391146.

.M. Lilly and R.H. Stillwell, Probiotics: growth promoting factors produced bymicroorganisms, Science147 (1965), pp. 747748.

A. Irianto and B. Austin, Probiotics in aquaculture, Journal of Fish Diseases25 (2002),pp. 633642.

FAO/WHO, 2001. Report of a joint FAO/WHO expert consultation on evaluation ofhealth and nutritional properties of probiotics in food including powder milk with live

lactic acid bacteria. Crdoba, Argentina.

D.E. Gaixa, ber das verhalten einiger pathogener mikroorganismen in meerwasser, Z.Hyg. Infektionskr.6 (1889), pp. 162225 (in German).

Y. Kamei, M. Yoshimizu, Y. Ezura and T. Kimura, Screening of bacteria with antiviralactivity from fresh water salmonid hatcheries,Microbiol

.Immunol

.32

(1988), pp. 6773 W. Dall and D.J.W. Moriarty, Functional aspects of nutrition and digestion. In: L.H.

Mantel, Editor, The Biology of Crustacea, vol. 5, Internal Anatomy and Physiological

Regulation, Academic Press (1983). S. Nikoskelainen, A. Ouwehand, G. Bylund, S. Salminen and E.M. Lilius, Immune

enhancement in rainbow trout (Oncorhynchus mykiss) by potential probiotic bacteria

(Lactobacillus rhamnosus),Fish Shellfish Immunol.15 (2003), pp. 443452.

G. Prieur, J.L. Nicolas, A. Plusquellec and M. Vigneulle, Interactions between bivalvesmolluscs and bacteria in the marine environment, Oceanogr. Mar.Biol. Annu. Rev.28

(1990), pp. 227352.

SCAN, 2003. Opinion of the Scientific Committee on Animal Nutrition on the criteria forassessing the safety of microorganisms resistant to antibiotics of human clinical and

veterinary importance. European Commission Health and Consumer Protection

Directorate-General. T. Sakata, Microflora in the digestive tract of fish and shell-fish. In: R. Lesel, Editor,

Microbiology in Poecilotherms, Elsevier, Amsterdam (1990), pp. 171176.

M. Sakai, T. Yoshida, S. Astuta and M. Kobayashi, Enhancement of resistance tovibriosis in rainbow trout, Oncorhynchus mykiss (Walbaum) by oral administration of

Clostridium butyricum bacteria, J. Fish Dis.18 (1995), pp. 187190.

G. Dalmin, K. Kathiresan and A. Purushothaman, Effect of probiotics on bacterialpopulation and health status of shrimp in culture pond ecosystem, Indian J. Exp.Biol.39

(2001), pp. 939942. Krovacek K.. , Paris A., Ahne W., and Masson I. 1987. Adhesion of Aeromonas

hydrophilla and Vibrio anguillarum to fish cells and to mucus coated glass slides. FEMS

Microbiol. Lett. 42:85-89.


12/13

F.J. Gatesoupe, Lactic acid bacteria increase the resistance of turbot larvae, Scophthalmusmaximus, against pathogenic Vibrio,Aquat. Living Resour.7 (1994), pp. 277282.

J.D.Jameson. 2003. Role of probiotic in Aquaculture. Fishing chime 23 (9): 47-49. Probiotic role of Lactic acid bacteria in fish. Suman Kapila. Use of probiotic in aquaculture Arun Kumar Probotics- Snehasish Mishra, Priyabrata Pattnaik and Ayyapan. Concept of probiotic in Aquaculture S.Sauarbh.


13/13

SELECTION OF PROBIOTICS AS BIOCONTROL AGENTS IN AQUACULTURE.

Probiotic Assign

Documents

Transcript of Probiotic Assign