Commercial development of sweet proteins derived from African plants could be worth millions if new, natural sweeteners can bite into the (US) $2 billion low-calorie sweetener market.(1)
Research on intensely sweet proteins is not new, but recent breakthroughs may improve prospects for commercial development.
Most industry researchers admit that naturally sweet berries from the African plants mentioned below have been used for centuries by local African communities to sweeten food and beverages. Not surprisingly, patent claims by the biotech industry fail to recognize or reward these communities as a source of knowledge or innovation.
Researchers at Kirin Brewery (Japan) report in the May, 1997 issue of Nature Biotechnology that they have successfully coaxed genetically engineered yeast cells to produce the sweet protein monellin at levels exceeding the yields of monellin from serendipity berries, the West African plant (Dioscoreophyllum cumminisii) from which the protein is naturally extracted.
Thaumatin, a sweet protein derived from West Africa's Thaumatococcus danielli, is already marketed by Tate & Lyle (UK) under the brand name Talin. Xoma, a US biotech company, claims that it can produce the thaumatin protein using recombinant DNA technology at a cost that will compete with extraction from the natural plant source.
Miraculin, derived from the miracle fruits" of a West African plant, Richardella dulcifica, is a taste-altering protein that turns a sour taste to a sweet one. Researchers at BioResources International (USA) are cultivating miracle fruits and hope to purify the protein via genetic engineering.
Sweet Protein Native Plant Source Relative Sweetness (sucrose=1) US Patents Company or University
Thaumatin Thaumatococcus danielli (West Africa) 3,000 4,011,206 5,464,770 Tate & Lyle (UK) Xoma Corp.
Monellin Dioscoreophyllum cumminisii (West Africa) 3,000 3,998,798 others pending Univ. of Penna. Kirin Brewery
Brazzein or Pentadin Pentadiplandra brazzeana (Gabon-Central Africa) 2,000 5,527,555 5,346,998 5,326,580 Univ. of Wisconsin
Miraculin Richardela dulcifica (West Africa) n/a ? BioResources Intl.
1 Information in this article is gleaned, in part, from: Robert Dansby, "Sweet Science: Over expression of Monellin in Yeast," Nature Biotechnology, Vol. 15, May, 1997, pp. 419-420."