摘要：Bacterial diversity and total viable counts of bacteria of the different soil samples from two different localities in Omdurman north region—Karary and Khor Omer sub-regions—were carried out. Soil physical and chemical characteristics (pH, EC, SP, solublecations: Na, K, Ca, Mg and anion P, organic carbon, total nitrogen and soil texture) in each studied sub-regions were measured. Qualitative analysis of microorganisms isolated from the studied soil samples reveals a total of more than eight different species of bacteria, of which two are unidentified. The six species are classified under Bacillus genera. In Omdurman north region soil samples, total bacterial counts ranged from 7.5 × 103 cfu·g﹣1 to 1 × 104 with a mean of 4 × 104 cfu·g﹣1. The quantitative data on microbial population recorded in the present study were analysed using two diversity indices. High Shannon-Weiner diversity index value for bacteria was obtained in Khor Omer sub-region (1.71261). Actinomyces spp. and Streptomyces spp. were the most abundant microorganisms identified in the two sub-regions. Total bacterial count in Karary soil was positively correlated with EC (r = 0.3868), clay (r = 0.1412), sand (r = 0.5891) and K (r = 0.0265) and negatively correlated with pH, silt, SP, Na, P, Ca, Mg, N and OC whereas the total bacterial count in Khor Omer soil was positively correlated with EC (r = 0.3973), clay (r = 0.1966), silt (r = 0.2116), Ca (r = 0.6733), Mg (r = 0.586) and OC (r = 0.2368) and negatively correlated with pH, sand, SP, Na, K, P and N. There were obvious differences in correlation coefficients among the selected criteria (37% of the total number of correlation coefficients were positively correlated between bacterial counts and soil physico-chemical properties whereas 63% of the total number were positively correlated between plant type and bacterial counts). The formulation of an appropriate national strategy in biotechnology should constitute an important, initial step towards the utilization and industrialization of microorganisms. The development of molecular techniques of microbial identification, coupled with traditional methods is promising areas for continued research.
