Science Journal of Biotechnology

September 2014, Volume 2014, ISSN:2276-6375

Author(s) 2014. This work is distributed under the Creative Commons Attribution 3.0 License.

Research Article


Molecular and Culture-Based Analyses of Soil Bacteria in Ngere Tea Catchment Area of Murang'a County, Kenya

Eliud Nalianya Wafula*, Johnson Kinyua1, Daniel Kariuki1, Anne Muigai2, Romano Mwirichia3 and Tom Kosgei Kibet*

1Department of Biochemistry , Jomo Kenyatta University of Agriculture and Technology
2Department of Botany, Jomo Kenyatta University of Agriculture and Technology
3Institute for Biotechnology Research, Jomo Kenyatta University of Agriculture and Technology P.O Box 62000-00200 Nairobi, Kenya

Accepted 12 August, 2014, 2014; Available Online 12 September, 2014.

doi: 10.7237/sjbt/105


The objectives of this study were to isolate, characterise and identify groups of bacteria that are associated with soil quality in tea growing areas of Ngere. Thirty eight isolates were obtained using two categories of media, namely dilute nutrient broth agar and Tryptone soy agar. Ngere tea soils had the pH range of 3.9 to 5.0. The isolates were characterized using cultural and biochemical techniques. The Gram staining showed that 53% of the isolates were Gram positive while 47% were Gram negative, and they grew well at pH ranging from 5 6.5 and temperature range of 25oC to 35oC. Identification was done by Polymerase Chain Reaction (PCR) amplification of the 16S rDNA region, sequencing and phylogenetic analysis. Analysis of partial sequences using Blast showed that 56% were from the genus Bacillus,with similarities between 92% and 100%, 18% belonged to the genus Pseudomonas with similarities of 99 %. Other genera such Burkholderia, Chryseobacterium and Acinetobacter constituted 26% with similarity between 91% and 99%. Based on this study, the presence of isolates such as D5, D16, S31, D2, and S23 could indicate that they can be used both as bio control agents for weeds and biopesticides. These have the ability to produce bioactive compounds which can be used as replacements for synthetic pesticides that are active against fungal pathogens such as root rot fungi which frequently affects tea roots. Furthermore, presence of isolates: D61, D19, S30, D1, D78, D13, S55, D60, D79,and S48, among others, and the high percentage of organic carbon content, strongly suggested the extent of fertility of these soils because these isolates are an important element in mineral recycling, hence they can be used as indicators of soil health / biosensors or biofertilizers.

Keywords: Soil quality, Tea, Bacteria and Phylogenetic analysis