Gluconacetobacter diazotrophicus: a natural endophytic diazotroph of Nile Delta sugarcane capable of establishing an endophytic association with wheat

摘要: Gluconacetobacter- like diazotrophs were encountered as dense populations inside the root and stem tissues of sugarcane cultivated in ancient agricultural fields Nile Delta. Counts >105 cells g-1 recorded samples. The leaves contained a smaller population (<103 g-1). typical dark-orange colonies which developed on LGIP agar plates purified. Identification was performed with API microtube systems: 20E for Enterobacteriaceae 20NE non-Enterobacteriaceae. profiles local isolates closely related to those type culture Gluconacetobacter diazotrophicus (ATTC 49037). successfully reduced C2H2 produced appreciable amounts ethylene presence cane juice. This suggested that are strain G. diazotrophicus. Wheat seedlings inoculated number under gnotobiotic conditions. Both optical scanning electron microscopy showed endophytic spp. present all samples tested. They observed apparently intact enlarged epidermal cells, also tissues, indicating bacterium able migrate upward into shoot tissues. Although inoculation did not stimulate growth cereal plant, results obtained particularly interesting because this bacterial species capable colonizing internal wheat, considered natural host until now.