Microbial Diversity in Two Egyptian Soils

Badr El-Din, Said; Radwan, Samir; Zidan, Wafaa; Zahra, Moawad

Microbial Diversity in Two Egyptian Soils

Document Type : Original Article

Authors

¹ Agricultural Microbiology Department, National Research Centre, Dokki, Cairo, Egypt

² Agricultural Microbiology Department, Faculty of Agriculture, Cairo University, Egypt

Abstract

Microbial DNA extracted from two soil samples collected from Beni-Suef and Kafr El-Sheikh were
subjected to PCR amplification with primers specific for 16S rDNA gene and cloned in linear pCR 2.1
plasmid vector. Recombinants were transformed into Escherichia coli competent cells. Sixty clone
inserts (30 from each soil sample) were sequenced and subjected to phylogenetic analyses. Forty
sequences of the sixty clones were affiliated with previously recognized bacterial groups. Thirty six of
these had closest relatives among cultured taxa and clustered primarily with three divisions containing
microrganisms commonly associated with soil: Proteobacteria, Gram-positive organisms, and
Cytophaga-Flexibacter-Bacteroides group. The results also showed the presence of one clone related to
Nirospira retrieved from Beni-Suef soil, one clone from Archaea kingdom retrieved from Kafr El-Sheikh
soil, and three clones affiliated to the newly described Holophaga-Acidobacterium phylum in both Beni-
Suef and Kafr El-Sheikh soils. Seven sequences grouped with known divisions but had closest relatives
among soil taxa known only from rDNA sequences analysis. Twelve clone sequences were distantly
related to known sequences. Many of these sequences may represent new bacterial divisions.

Keywords