Marine algae

Summary

Algal aspects

Algae are relatively undifferentiated organisms which, unlike plants, have no true roots, leaves, flowers or seeds. They are found in marine, freshwater and terrestrial habitats. Their size varies from tiny microscopic unicellular forms of 3-10 µm (microns) to large macroscopic multicellular forms up to 70 meters long and growing at up to 50 cm per day. Algae do not have water-conducting tissues, as they are, at some stage, surrounded by water, which is also important for reproduction by spores. The spores may be motile or non-motile. Most of the algae are photosynthetic organisms that have chlorophyll. Apart from chlorophyll, they contain additional pigments, which are the basis of classification.

Phytoplankton, seaweeds and symbiotic dinoflagellates (unicellular, biflagellate organisms) in corals and sea anemones are marine algae. Seaweeds are classified as Green algae (Chlorophyta), Brown algae (Phaeophyta), Red algae (Rhodophyta) and some filamentous Blue-green algae (Cyanobacteria). Most of the seaweeds are red (6000 species) and the rest known are brown (2000 species) or green (1200 species). Seaweeds are used in many maritime countries as a source of food, for industrial applications and as a fertilizer. Nori (Porphyra spp.), a Japanese red seaweed, is very popular in the Japanese diet, has a high protein content (25-35% of dry weight), vitamins (e.g. vitamin C) and mineral salts, especially iodine. Industrial utilization is at present largely confined to extraction for phycocolloids, industrial gums classified as agars, carrageenans and alginates. Agars, extracted from red seaweeds such as Gracilaria , are used in the food industry and in laboratory media culture. Carrageenans, extracted from red seaweeds such as ChondrusGymnogongrus, and Eucheuma among others, are used to provide particular gel qualities. Alginates are derivatives of alginic acid extracted from large brown algae such as Laminaria. They are used in printers’ inks, paints, cosmetics, insecticides, and pharmaceutical preparations. In the USA, alginates are used as stabilizers in ice cream and also as a suspending agent in milk shakes. In 1995, the estimated value of international seaweed gums market was $560 million dollars.

IP aspects

Northeastern University, in the United States, has filed a PCT application related to transformation of multicellular marine algae via Agrobacterium. Marine algae are defined by the applicants as non-angiosperm photosynthetic eukaryotic organisms that live in the ocean or in saline water. According to the disclosure, marine algae could serve as a source of valuable pharmaceutical compounds through genetic engineering. They naturally have a very high protein content and are easy to grow for biomass.

With respect to genetic transformation, the applicants claim to provide a stable method for genetic transformation of multicellular marine algae. The method comprises wounding the outer cell wall layer of an alga in order to facilitate the access of Agrobacterium T-DNA with a gene of interest. The transformation of algal cells takes place in an environment containing seawater to ensure the survival of the transformed algae. To exemplify their invention, the applicants describe the transformation of the red alga Porphyra, known as nori, for which worldwide production is estimated at $1.5 billion dollars annually.

Algae transformation – Specific Patent Information

Patent Number Title, Independent Claims and Summary of Claims Assignee
WO 2000/62601 A1

  • Earliest priority – 15 April 1999
  • Filed – 14 April 2000
  • OPI – 26 October 2000
Title – Agrobacterium-mediated genetic transformation of multicellular marine algae, resultant strains and their products

Claim 1A method for causing genetic transformation of multicellular marine algae, said method comprising:

A) culturing cells of a transformation-competent Agrobacterium species, said cells containing a Ti plasmid that contains a gene of interest;
B) wounding a multicellular marine algae to be transformed in a manner that is sufficient to penetrate at least the cuticle, or outer cell wall layer of said alga;
C) applying cells of said transformation-competent Agrobacterium species to wounded cells of said alga; and
D) co-culturing said applied cells of said Agrobacterium species with said wounded algal cells for a time sufficient to effect transformation of some of said algal cells.

Claim 20A stable transgenic multicellular marine algae, said alga comprising a DNA sequence coding for a gene foreign to said alga, wherein said alga is further capable of expressing said DNA sequence and of transferring said expressible DNA sequence to progeny of said alga.
Claim 22A transgenic strain of marine algae comprising and capable of expressing a DNA sequence coding for an antigen of a pathogenic microorganism or an antigenic determinant thereof, wherein said antigen or antigenic determinant thereof is capable of eliciting a secretory immune response in a human or other animal upon oral administration of cellular material from said algae.
Claim 23A transgenic strain of marine algae with enhanced disease resistance to marine fungi compared to a non-transformed said strain.
Claim 24
A transgenic strain of marine algae capable of producing a compound having an enhanced health benefit compared to a non-transformed said strain.
Claim 26A method for eliciting a secretory immune response in a human or other animal, said method comprising:

  • orally administering an effective amount of a composition comprising transgenic marine algae, or tissue thereof,
    wherein said transgenic algae, or algal tissue, comprise and are capable of expressing a DNA sequence coding for an antigen of a pathogenic microorganism or an antigenic determinant thereof,
    wherein said antigen or antigenic determinant thereof is capable of eliciting a secretory immune response in a human or other animal upon oral administration of cellular material from said algae.

The claims as filed of the present PCT application recite:

  • a method for the transformation of multicellular marine algae with Agrobacterium by
    • wounding the cuticle of the algae
    • applying competent Agrobacterium containing a gene of interest to the wounded alga; and
    • co-culturing both Agrobacterium and algal cells allowing enough time for the transformation process
  • a stable transgenic marine alga capable of expressing a foreign sequence and transferring such sequence to its progeny;
  • transgenic strains of marine algae comprising:
    • antigens as elicitors for human or animal immune response
    • resistance to marine fungi
    • a compound for health benefit
  • a method to elicit human or animal immune response by orally administering a transgenic alga or algal tissue containing an antigen that acts as an elicitor of an immune response.

Northeastern University

Remark The present PCT application has passed the deadline to enter national phase (30 or 31 months from filing depending on the country), therefore will not have any patents granted from this particular application.

Note: Patent information on this page was last updated on 9 February 2006.