Immobilized Frankia spores remained viable on dry storage and on restoration to medium regenerated active colonies

Abstract

Spores of Frankia strain ACN lAG, immobilized in calcium alginate beads, germinated to produce colonies that increased in protein content and showed nitrogenase activity. Air dried immobilized spores remained viable for at least 15 days in dry condition, making the storage and transport of Frankia strains easy. This also opens the possibility of using beaded spores as inocula.

Improving Casuarina growth and symbiosis with Frankia under different soil and environmental conditions—review

“…Pure culture a • Containing hyphae, vesicles, spores, or intact culture Borthakur et al (1996) • The correct inoculum ensures plant receipt of the effective strain resulting in increased plant biomass Sayed et al (2002b) • Spores are resistant to higher temperatures and desiccation and can be stored for future inoculation 3. Immobilized pure intact culture or specific cell type a • The same advantages of using pure culture in addition to easy handling and extended "shelf life" under different temperature and moisture conditions Kohls et al (1994) • Successful immobilizing agents for Frankia are calcium alginate and polyacrylamide gel (PAG) Borthakur et al (1996) Sayed et al (2002b, c) Sayed et al (2006 a The pure, immobilized, or liquid cultures may contain whole cell or specific cell types including hyphae, spores, or vesicles (164:1), indicating that the litter decomposition is limited by phosphorus (Yuehua and Yangyan 1990;Mailly and Margolis 1992;Mele et al 2004). The introduction of more effective nitrogen-fixing Frankia strains may therefore not improve soil fertility as nodulation itself is reduced by reducing phosphorus level (Yuehua and Yangyan 1990;Wall et al 2000).…”