Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Probiotic Bacteria Shows Promise for Use in Shellfish Aquaculture

31.01.2012
The use of probiotic bacteria, isolated from naturally-occurring bacterial communities, is gaining in popularity in the aquaculture industry as the preferred, environmentally-friendly management alternative to the use of antibiotics and other antimicrobials for disease prevention.

Known to the public for their use in yogurt and other foods to improve human digestion and health, probiotic bacteria isolated from other sources can also be used to improve survival, nutrition and disease prevention in larvae grown in shellfish hatcheries.

Researchers at NOAA’s Milford Laboratory in Milford, Conn. have shown that naturally-occurring bacteria isolated from the digestive glands of adult eastern oysters (Crassostrea virginica) and northern bay scallops (Argopecten irradians irradians) may be used as potential probiotic candidates in oyster larviculture.

Two related research studies published in the Journal of Shellfish Research identify a new probiotic bacterium, designated OY15, which has been shown to significantly improve larval survival in pilot-scale trials during the first two weeks of life, the most critical stage for the organism when mortality rates are among the highest.

“We are cautiously optimistic that this probiotic candidate, OY15, will offer a number of significant benefits to the shellfish industry,” said Gary Wikfors, co-author of both studies and head of the Milford Laboratory’s Biotechnology Branch. “Commercial and public shellfish hatcheries can have low survival rates for shellfish seed during the first two weeks, so improving those survival rates and the health of the organisms beyond that point is a pretty significant step forward.”

Hatcheries produce shellfish seed to supplement natural seed, which is often limited by loss of habitat, contamination from pollution, climate change and other factors. Bacterial diseases caused mainly by pathogenic bacteria such as Vibrio are a major cause of mortality in hatchery shellfish, particularly at the very early larval stage. The result: significant financial losses to commercial growers and to production of farmed shellfish, which accounts for 25 percent of the total world aquaculture product.

Antimicrobial drugs approved for use in aquaculture in some countries, but not the US, have traditionally been used to treat bacterial diseases, but overuse of antibiotics can result in the development of resistant strains of bacterial pathogens. The use of probiotic bacteria has become increasingly popular for improved nutrition, healthy digestion and disease prevention and is used in human foods like yogurt and in pet foods.

As demand for environmentally-friendly aquaculture grows, the use of probiotics for disease prevention and improved nutrition in shellfish aquaculture is also growing. While a number of research studies have shown promise, development of probiotics that can be used in aquaculture is a multistep process requiring fundamental research and full-scale trials.

“The objective of the first part of this study was to isolate and evaluate new probiotic bacteria which, when incorporated into foods used in shellfish hatcheries, might significantly improve larval survival,” said co-author Diane Kapareiko, a microbiologist at the Milford Laboratory. The second part of the study was to test the new probiotic candidate on the survival of oyster larvae in pilot-scale trials during their first two weeks of life.

“We conducted a very cautious, step by step study, to identify the best candidates under a variety of scenarios," Wikfors said. "Our bench-scale challenge studies indicated that oyster larvae exposed to probiotic candidate OY15 had the highest survival rate, and that the survival of pathogen-challenged larvae was further improved by the presence of OY 15 compared to the pathogen alone. It is somewhat analogous to a human building up immunity to a certain organism by being exposed to it, but without the involvement of antibodies.”

The Milford scientists isolated 26 candidate probiotic bacteria from oysters and scallops of which 16 had an inhibitory effect against a known shellfish-larval pathogen (B183) of the Vibrio species of bacteria. Further screening for safe use in culturing the oyster larvae and their microalgal feed indicated which probiotic candidates would inhibit growth of the pathogen most effectively and therefore could confer a protective effect upon oyster larval survival.

Lab studies indicated that survival of two-day old oyster larvae during two-week pilot scale trials improved when supplemented with the probiotic candidate OY15 strain. Four treatments were conducted: a larval control with no bacteria, a pathogen control with larvae and pathogen B183 only, a probiotic control with larvae and probiotic candidate OY15 only, and a combination treatment comprised of larvae and both probiotic and pathogen.

“Our research focused on the critical first stage of larval growth, when mortality rates are among the highest,” Kapareiko said. Positive effects of probiotic candidate OY15 were found on the survival of oyster larvae (short term), on growth of phytoplankton used as larval feed, and upon oyster survival during pilot-scale larviculture conditions.

“This two-part study confirms that use of naturally-occurring probiotic bacteria confers protection to oyster larvae against bacterial disease and improves their survival,” Kapareiko said. “The results can be used as guidelines for isolating and screening other potential probiotic candidates for similar aquaculture applications, and provide the basis for developing functional foods for use in shellfish hatcheries that incorporate a naturally occurring, probiotic bacteria.”

NOAA Fisheries Service is dedicated to protecting and preserving our nation’s living marine resources and their habitat through scientific research, management and enforcement. NOAA Fisheries Service provides effective stewardship of these resources for the benefit of the nation, supporting coastal communities that depend upon them, and helping to provide safe and healthy seafood to consumers and recreational opportunities for the American public.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.

Shelley Dawicki | EurekAlert!
Further information:
http://www.noaa.gov

More articles from Life Sciences:

nachricht Cnidarians remotely control bacteria
21.09.2017 | Christian-Albrechts-Universität zu Kiel

nachricht Immune cells may heal bleeding brain after strokes
21.09.2017 | NIH/National Institute of Neurological Disorders and Stroke

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>