The role of some ecological and physiological factors in Frankia

Abstract

Three isolates were obtained !!•om ( •asuarina equisetifiJ/ia root nodules collected from different locations in Qena, Egypt The isolation methods used were differential filtration and nodule fragmentation. The investigated isolates were desi nated as SVI :02060 I, SVU020602. and SVU02060J. Microscopic observations confirmed the production of typical hw!lda characteristics namely: hyphae, vesicles and sporangia with non-motile spores

The effect of temperature on growth of f<i•aukia isolates was investigated for both 1-l-aukia isolates SVI '02060 I and SVI 1020603 The optimum growth tor the isolates was obtained at 28 "C and decreased as temperature increases However the isolates testerl were still growing at 40 "C. Growth was measured as the increase in protein content Htglml' 1 }

Growth curve of five infective hw1kia isolates. UGL020601q. UGL020602q. l'(iL02060 1q, ORS021 00 I and ORS02260 I was determined by measuring growth as protein content ([1g/ml' 1 } under both static and stirring conditions. (jmwth was measured afier nne day and then every week and up to seven weeks for i'iw!lda grown under static

conditions, and after 2 days and then every third day up to 14 days for