Sporedannelse

Sporedannelse, or sporulation, is the process by which organisms produce spores. Spores are specialized, often highly resistant structures that enable survival under adverse conditions and dispersal to new environments. Sporulation occurs in a range of organisms, notably bacteria and fungi, and in some algae and plants as part of their life cycles.

In bacteria, sporulation typically refers to endospore formation, a developmental program initiated under nutrient limitation or other stress. One cell divides to form a forespore inside a mother cell, then the spore matures with protective layers, including a cortex and a spore coat and a dehydrated core rich in dipicolinic acid and small acid-soluble proteins. The mature endospore is dormant and highly resistant to heat, desiccation, and chemicals. Germination resumes growth when conditions become favorable, with water uptake and metabolic reactivation.

In fungi, sporogenesis includes both asexual and sexual routes. Asexual spores, such as conidia or sporangiospores, are produced by mitosis and enable rapid dispersal during favorable conditions. Sexual spores, produced after meiosis, occur in structures such as asci (ascospores) or basidia (basidiospores) and increase genetic diversity. Filamentous fungi commonly form conidiophores bearing conidia; basidiomycetes form basidia; ascomycetes form asci.

In algae and some plants life cycles alternate between haploid and diploid phases with spores produced by meiosis (sporic meiosis). Spore formation is thus a central mechanism for survival, dispersal, and genetic diversification across diverse life forms.

This topic has relevance in laboratory and clinical contexts, including spore-forming pathogens such as Bacillus and Clostridium species, spore-resistant food safety concerns, and the industrial use of spores in fermentation and biotechnology.