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Evaluation of novel polyunsaturated fatty acid (PUFA) producing micro-heterotrophs for incorporation into aquaculture feeds

Project number: 1997-329
Project Status:
Completed
Budget expenditure: $205,077.00
Principal Investigator: Tom Lewis
Organisation: University of Tasmania (UTAS)
Project start/end date: 22 Jun 1997 - 31 May 2002
Contact:
FRDC

Need

Polyunsaturated fatty acids (PUFA) are essential components in aquaculture diets, where an artificial food chain must be established (Bottino 1974; Rimmer et al. 1994). For many larval, or fingerling aquaculture species, the provision of PUFA (especially the omega-3 fatty acids EPA, DHA, and the omega-6 fatty acid AA is critical, and must be provided from either a "live" diet, usually via rotifers (eg. Brachionus plicatilis) or brine shrimp (Artemia sp.) as intermediates (Ostrowski & Divakaran 1990, Mourene and Tocher 1993a,b; Bell et al 1995; Southgate & Lou 1995) or an artificial diet. As adults, many species of finfish are reared on artificial (pelletised) foods that must also contain PUFA.

Commercial sources of PUFA for use within the mariculture industry are currently restricted to certain fish oils and microalgal species which are, respectively, under threat of over-exploitation and expensive to produce (New and Csavas 1995, Tacon 1995). The recent discoveries of bacteria and fungi that synthesise PUFA provide a novel and timely opportunity to develop biotechnological processes for sustainable and relatively cheap PUFA production.

Particular opportunities arise from the recent isolation of the following organisms:

1) Antarctic bacteria that produce the n-3 fatty acids EPA and DHA, and the n-6 fatty acid AA. (Antarctic CRC and University of Tasmania)

2) Marine fungi that produce high levels of both DHA and EPA. (CSIRO Division of Marine Research)

Research combining skills and expertise in microbiology, cell culturing and manipulation, marine oils and lipid chemistry, biotechnology and aquaculture nutrition are required to take advantage of the industrial opportunity presented. Scientific advances can be made in each of these areas.

In microbiology there is a need to develop targeted, intelligent screening protocols to optimise recovery of bacteria with biotechnologically useful traits such as PUFA production. There is also a need to integrate current knowledge of factors which affect microheterotroph growth and metabolic processes into the development of techniques to optimise production of desired compounds. Research integration is expected to lead to the development of technology with which high productivity can be achieved while using cheap culture media.

The application of state-of-the-art techniques in lipid chemistry will be applied to qualitatively and quantitatively evaluate PUFA production by microheterotrophs. The biotechnological challenge will involve devising stable formulations of whole cells and/or their extracts, and to transfer this technology from laboratory-scale trials through pilot-scale to commercial production systems.

As discussed above, the potential Australian Bacterial Single Cell (BSC) product(s) in this application should be able to meet some or all of the requirement for n-3 and n-6 fatty acids of larval and adult aquaculture species. In addition, the BSC products should be also able to provide a good protein source, and may have the potential to improve the fatty acid profile of product flesh. Thus, the proposed Australian product may have the potential to replace a significant proportion of the fish meal and fish oil currently used.

Industrial advantage will be gained from the application of the scientific knowledge developed during this project, in the incorporation of PUFA-producing bacteria or products derived therefrom into aquaculture food-chains.

Objectives

1. To develop targeted screening programs for the isolation and characterisation of PUFA-producing bacteria and other microheterotrophs
2. To maximise PUFA production by manipulation of specific microheterotroph culture conditions
3. To develop product formulations, including PUFA enrichment of live feeds, as a basis for commercial production of suitable strains.
4. To conduct feeding trials, using formulations to be developed during this project, using Atlantic salmon larvae (finfish, artificial feed), Flounder larvae (finfish, live feed) and Prawns (crustacea, artificial feed) as test species
Environment
PROJECT NUMBER • 2014-241
PROJECT STATUS:
COMPLETED

Reassessment of intertidal macroalgal communities near to and distant from salmon farms and an evaluation of using drones to survey macroalgal distribution

The salmon farming industry has significantly expanded in South-eastern Tasmanian both in production and in number and location of farms. Along with this expansion has been an increasing concern from the general community about the effects of salmon farms on the environment. This includes a reported...
ORGANISATION:
University of Tasmania (UTAS)
Industry
PROJECT NUMBER • 2004-210
PROJECT STATUS:
COMPLETED

Aquafin CRC - Atlantic Salmon Aquaculture Subprogram: use of immunomodulation to improve fish performance in Australian temperate water finfish aquaculture

Before this project our knowledge of immune response in Amoebic Gill Disease (AGD) was fundamentally limited and more information was required to assess the potential for immunomodulators in the management of AGD. We confirmed that injection of bacterial DNA motif (CpG oligonucleotides) six...
ORGANISATION:
University of Tasmania (UTAS)
Environment
PROJECT NUMBER • 2004-215
PROJECT STATUS:
COMPLETED

Aquafin CRC - Atlantic Salmon Aquaculture Subprogram: establishment of challenge for AGD

This project has increased our knowledge of Amoebic Gill Disease, in particular about the pathogen and the dynamics of infection. We have described a new species of neoparamoeba, Neoparamoeba perurans, and showed that it has been consistently associated with AGD worldwide. Stocking...
ORGANISATION:
University of Tasmania (UTAS)
Environment
PROJECT NUMBER • 2015-024
PROJECT STATUS:
CURRENT

Managing ecosystem interactions across differing environments: building flexibility and risk assurance into environmental management strategies

Summary The overarching aim of this research was to provide an improved understanding of the environmental interactions of Atlantic Salmon farming and to provide recommendations to both government and industry on monitoring and management strategies that are appropriate to the level of risk...
ORGANISATION:
University of Tasmania (UTAS)
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