Department of Microbiology, Faculty of Agriculture, Cairo University, Giza, Egypt.
Department of Botany, Faculty of Sciences, Cairo University, Giza, Egypt.
J Adv Res. 2013 Jan;4(1):13-26. doi: 10.1016/j.jare.2011.11.003. Epub 2012 Jan 9.
North Sinai deserts were surveyed for the predominant plant cover and for the culturable bacteria nesting their roots and shoots. Among 43 plant species reported, 13 are perennial (e.g. Fagonia spp., Pancratium spp.) and 30 annuals (e.g. Bromus spp., Erodium spp.). Eleven species possessed rhizo-sheath, e.g. Cyperus capitatus, Panicum turgidum and Trisetaria koelerioides. Microbiological analyses demonstrated: the great diversity and richness of associated culturable bacteria, in particular nitrogen-fixing bacteria (diazotrophs); the majority of bacterial residents were of true and/or putative diazotrophic nature; the bacterial populations followed an increasing density gradient towards the root surfaces; sizeable populations were able to reside inside the root (endorhizosphere) and shoot (endophyllosphere) tissues. Three hundred bacterial isolates were secured from studied spheres. The majority of nitrogen-fixing bacilli isolates belonged to Bacillus megaterium, Bacillus pumilus, Bacillus polymexa, Bacillus macerans, Bacillus circulans and Bacillus licheniformis. The family Enterobacteriaceae represented by Enterobacter agglomerans, Enterobacter sackazakii, Enterobacter cloacae, Serratia adorifera, Serratia liquefaciens and Klebsiella oxytoca. The non-Enterobacteriaceae population was rich in Pantoae spp., Agrobacterium rdiobacter, Pseudomonas vesicularis, Pseudomonas putida, Stenotrophomonas maltophilia, Ochrobactrum anthropi, Sphingomonas paucimobilis and Chrysemonas luteola. Gluconacetobacter diazotrophicus were reported inside root and shoot tissues of a number of tested plants. The dense bacterial populations reported speak well to the very possible significant role played by the endophytic bacterial populations in the survival, in respect of nutrition and health, of existing plants. Such groups of diazotrophs are good candidates, as bio-preparates, to support the growth of future field crops grown in deserts of north Sinai and irrigated by the water of El-Salam canal.
北西奈沙漠的主要植物覆盖层和其根部和茎部栖息的可培养细菌进行了调查。在所报告的 43 种植物中，有 13 种是多年生的（例如 Fagonia spp.、Pancratium spp.），30 种是一年生的（例如 Bromus spp.、Erodium spp.）。有 11 种植物具有根鞘，例如 Cyperus capitatus、Panicum turgidum 和 Trisetaria koelerioides。微生物分析表明：相关可培养细菌具有很大的多样性和丰富度，特别是固氮细菌（固氮菌）；大多数细菌居民具有真正的和/或假定的固氮性质；细菌种群沿着朝向根表面的密度梯度增加；大量的种群能够存在于根内（根际）和茎内（叶内）组织中。从研究的球体中分离出 300 个细菌分离物。大多数固氮杆菌分离物属于巨大芽孢杆菌、短小芽孢杆菌、多粘类芽孢杆菌、粘质沙雷氏菌、环状芽孢杆菌和地衣芽孢杆菌。肠杆菌科由聚集肠杆菌、阴沟肠杆菌、阴沟肠杆菌、华丽沙雷氏菌、液化沙雷氏菌和产酸克雷伯氏菌代表。非肠杆菌科种群富含 Pantoea spp.、Agrobacterium rdiobacter、Vesicularis 假单胞菌、恶臭假单胞菌、嗜麦芽寡养单胞菌、恶臭杆菌、少动鞘氨醇单胞菌和黄单胞菌 luteola。在许多测试植物的根和茎组织中报告了 Gluconacetobacter diazotrophicus。报告的密集细菌种群很好地说明了内生细菌种群在现有植物的生存、营养和健康方面可能发挥的重要作用。这类固氮菌是很好的候选生物制剂，可用于支持在北西奈沙漠种植的未来田间作物的生长，并利用 El-Salam 运河的水进行灌溉。
