Marine Bacteria as Probiotics and Their

Applications in Aquaculture

Presented by:

Akram Najafi

History

• It is a composite of the Latin preposition pro ("for") and the

Greek adjective βιωτικός (biotic), the latter deriving from the

noun βίος (bios, "life").

• Introduction of the concept is generally attributed to Nobel

Prize recipient Elie Matchnikoff.

In 1907, he suggested that "the dependence

of the intestinal microbes on the food makes

it possible to adopt measures to modify the

flora in our bodies and to replace the harmful

microbes by useful microbes.

• The World Health Organization’s 2001 definition of probiotics

is "live microorganisms which, when administered in adequate

amounts, confer a health benefit on the host.

Types of bacteria in body

- 10 times of the whole body cells (10 14)

- 1.5 kg of whole body weight

- 35 to 50 % colon

- 60 % of fecal mass

- 300 to 1000 different species

- Useful bacteria = 85 % of whole intestine microorganisms

Probiotic bacteria may colonise the upper part of the intestine to

avoid the adhering of pathogens to the intestinal tract and may

help in digestion.

Bacteria

• Decrease of potentially pathogenic gastro-intestinal

microorganisms

• Reduction of lactose resistance by LAB

• Reduction of gastro-intestinal discomfort

• Strengthening of the immune system

• Improvement of the skin's function

• Nutrition absorption, vitamins, inorganic materials.

• Strengthening of the resistance to cedar pollen allergens

• Reduction of flatulence and bloating;

• The protection of DNA

• Protection of proteins and lipids oxidative damage

• Anticancer

Benefits of probiotics

The most important bacteria in probiotics

Bifidobacterium longum subsp. infantis

Saccharomyces boulardiiLactobacillus sp.

Two forms of consuming

• Powder

• Syrup

• Capsule

Probiotics in Iran

10 9 CFU

6 * 10 9 CFU1.5 * 10 10 CFU

Enriched foods

Milk Yakult

Kefir

Breakfast Cereal

Snack bar

Yogurt Kimchi

Chees Sauerkraut

Pickled vegetables

Prebiotic & Synbiotics

• Prebiotics are carbohydrates that cannot be digested by the human

body. They are food for probiotics. A prebiotic is a fiber such as

fructose oligosaccharide, galactose oligosaccharide, etc., and is

consumed that is intended to stimulate the microflora which is

already present in the large intestine.

• Synbiotics refer to nutritional supplements combining probiotics

and prebiotics in a form of synergism.

Good sources of prebiotics

AsparagusJerusalem artichokes Oatmeal

Aquaculture

• Aquaculture is the farming of aquatic

organisms such as fish, crustaceans,

molluscs, aquatic plants.

• Major constraints on successful

aquaculture production:

- bacterial & viral diseases & high

mortality

• Disinfection of the hatchery and rearing

facilities can cause loss in a stable

microbial balance through proliferation

of opportunistic bacteria that enter into

the system and thereby limit the natural

biological control of opportunistic

pathogens.

• New strategies: ban on antibiotic and growth promoters in

aquaculture practices.

• Developing novel dietary supplement strategies to produce health

and growth-promoting compounds in aquaculture as:

- Prebiotics

- Probiotics

- Symbiotics

- Phytobiotics

• Bacillus, Lactobacillus, Lactococcus, Enterococcus, Clostridium,

Leuconostoc, Pseudomonas, Vibrio, Aeromonas, Shewanella, yeasts

bacteriophages, unicellular algae have been studied for use as

probiotics in aquaculture.

• By manipulation of the gut/intestinal microbial environment, the

survival and health of the organism in intensive rearing system

could be improved.

Live microbial adjunct which has a

beneficial effect on the host by modifying

the host associated or ambient microbial

community, by ensuring improved use of

the feed or enhancing its nutritional value,

by enhancing the host response towards

disease, or by improving the quality of its

ambient environment.

Definition of Probiotics in aquaculture

Certain beneficial characteristics need to be present for a

microorganism to be a probiotic in aquaculture:

- They must isolate from the environment where the probiotic will be

applied and avoid risk of introduction of all autochthonous organisms to

the system.

- Show beneficial effect

- Be nontoxic or nonpathogenic to the host and to other living

organisms in the system such as phytoplankton.

Currently, a number of probiotics are

commercially available and have been

introduced in molluscan, shellfish, and fish as

feed additives and also in culture waters

Mechanism of probiotics

- Antagonism to pathogens

- Competitive exclusion for adhesion sites

- Ability to produce organic acids, hydrogen peroxide

- Metabolites like vitamins, enzymes, lysozyme, antimicrobials,

siderophores

- Modulation of host immunity and physiology

Probiotics as Immune Stimulants

Clostridium butyricum bacteria given

orally to rainbow trout have shown

increased phagocytic activity of

leukocytes & enhanced the resistance of

fish to Vibriosis.

Addition of Bacillus species (strain S11) to

tiger shrimp provided disease protection by

activating both humoral and cellular

immune defenses

Use of Lactobacillus rhamnosus or their cell

wall components as prophylactic factor to

low stress in Oreochromis niloticus has been

reported

Antiviral effects

Recently, it has been found that probiotics

have beneficial effects against viral infections

such as iridovirus in Epinephelus coioides.

It has been reported that strains of Vibrio sp.,

Aeromonas sp., Pseudomonas sp., and groups

of coryneforms isolated from freshwater

salmon hatcheries showed antiviral activity

(more than 50% plaque reduction) against

infectious hematopoietic necrosis virus

(IHNV)