Abstract: A human food product comprises a higher ploidy strain of Fungi imperfecti of which each parent has a genetic growth constraint not shared by the other parent. One parent is for example auxotrophic for two compounds selected from histidine, arginine, leucine and adenine and the other for the other two. The nucleic acid content of the strain is preferably less than 2% by weight. The strain may be made by killing a higher ploidy strain of Fungi imperfecti and simultaneously reducing its nucleic acid content to below 2% by weight by treatment with water. The process may include preparing a higher ploidy strain of edible Fusarium by culturing two auxotrophs thereof together in a medium containing nutrients permitting both to grow and then culturing organisms derived from such culture in minimal medium. The invention is applicable to the production of human food by culturing the strain in conditions such that reversion or partial reversion to the haploid form(s) is minimised.

Abstract: A human food product comprises a higher ploidy strain of Fungi imperfecti of which each parent has a genetic growth constraint not shared by the other parent. One parent is for example auxotrophic for two compounds selected from histidine, arginine, leucine and adenine and the other for the other two. The nucleic acid content of the strain is preferably less than 2% by weight. The strain may be made by killing a higher ploidy strain of Fungi imperfecti and simultaneously reducing its nucleic acid content to below 2% by weight by treatment with water. The process may include preparing a higher ploidy strain of edible Fusarium by culturing two auxotrophs thereof together in a medium containing nutrients permitting both to grow and then culturing organisms derived from such culture in minimal medium. The invention is applicable to the production of human food by culturing the strain in conditions such that reversion or partial reversion to the haploid form(s) is minimised.

Abstract: Filamentous microorganisms of improved properties, for example growth rate, may be obtained by culturing a sample of desired morphology until a substantial proportion of the culture diverges from that morphology, selecting an organism from the culture at that stage which exhibits the desired morphology and repeating the process with the selected microorganism. Furthermore, an isolated Fusarium graminearum having all of the characteristics of IMI 366464 and also possessing a greater morphological stability and growth rate than Fusarium graminearium strain IMI 145,425 is disclosed.