Fungi constitute one of the life kingdoms. Fungi are eukaryotic (eu=true; karyon=nucleus) organisms with a cell wall like plants, but they do not have chlorophyll. Fungi are not able to ingest their food like animals do, nor can they manufacture their own food the way plants do. Instead, fungi feed by absorption of nutrients from the surrounding environment. They accomplish this by growing through and within the substrate on which they are feeding.
Fungi are divided into two big groups: yeasts and moulds. Yeasts are solitary rounded forms that reproduce by making more rounded forms through mechanisms such as budding or fission. Moulds, on the other hand, have bodies composed of thread-like long cells called hyphae. Thus, moulds are also known as filamentous fungi. The filamentous cells are connected end-to-end and grow in a branching fashion forming a network called mycelium. The mycelium that grows over and within a substrate that is used as a source of nourishment is called vegetative mycelium. In the life cycle, the vegetative mycelium may give rise to a large organized reproductive structure called fruit body, which bears the reproductive cells or spores and is produced solely for the release of spores.
In taxonomic terms, moulds are present in all five divisions of Eumycota (Eu=true; mycota=fungus): Mastigomycotina (e.g. Phytophtora , Achlya), Zygomycotina (e.g. Rhizopus, Mucur), Ascomycotina (e.g. some species of Aspergillus, Neurospora ), Basidiomycotina (e.g. Agaricus, Pleurotus) and Deuteromycotina (e.g. Fusarium, Trichoderma).
Filamentous fungi or moulds are vital for the maintenance of ecosystems. By breaking down dead organic material, they continue the cycle of nutrients through ecosystems. Some of them act as plant pathogens causing severe crop losses from disease and post-harvest food spoilage. In the reagent industry and medicine areas, filamentous fungi are the source of commercial enzymes, organic acids, and numerous drugs such as antibiotics (e.g. penicillin, cefalosporin). Among filamentous fungi are highly appreciated edible fungi such as Agaricus bisporus, the popular cultivated mushroom; Pleurotus spp., the "oyster mushroom", Tuber spp., "truffles", and Morchella spp., "Morels", among others. Thus, in many areas, the industrial production of genetically engineered fungi has tremendous potential.
The selected patents and patent applications presented in this section are directed to transformation of moulds or filamentous fungi with Agrobacterium.
There are two institutions that have filed patent applications related to Agrobacterium-mediated transformation of filamentous fungi: Unilever N.V., in The Netherlands, has a granted United States patent and several applications around the world, and The Penn State Research Foundation, in the United States, has a PCT and a United States patent application.
Unilever's invention is directed to a transformed mould with A. tumefaciens having a vector containing an expressible gene between T-DNA borders. Although the Penn State 's invention also refers to the transformation of a mould, which the inventors called filamentous fungi, they limit the invention to a particular tissue to be transformed: the fruit body tissue of a filamentous fungi. Unilever does not claim the transformation of any tissue in particular, and their claims are therefore broader in that respect. In addition, some of the claims filed in the Penn State's applications are also directed to the transformation of a particular filamentous fungus: Agaricus bisporus , the cultivated mushroom.
- There is an overlap between the inventions as both refer to transformation of any filamentous fungi or mould with Agrobacterium. However, the invention disclosed by Penn State Research Foundation is more defined as it encompasses a particular fungal tissue to be transformed.
- It remains to be seen whether the claims as filed in the applications by Penn State Research Foundation are granted as filed. Unilever's United States patent is fairly broad, however, and may pose freedom to operate problems if the species A. tumefaciens is used for transforming any mould.
The information contained in this page was believed to be correct at the time it was collated. New patents and patent applications, altered status of patents, and case law may have resulted in changes in the landscape. CAMBIA makes no warranty that it is correct or up to date at this time and accepts no liability for any use that might be made of it. Corrections or updates to the information are welcome. Please send an email to firstname.lastname@example.org.