Isolation of a thermophilic Meiothermus sp. strain JE2 and its infective phage vB_Msp_JE2 from Rajwadi hot spring, India

A thermophilic, red-pigmented aerobic bacteria designated as strain JE2 was isolated from the water sample of the Rajwadi hot spring. Bacterial strain JE2 was Gram-negative, rod-shaped that grew optimally at pH 7.5 and 60 degrees C. Molecular identification of the 16S rRNA sequence indicated that bacterial strain JE2 formed a coherent cluster with genus Meiothermus. Subsequently, a lytic bacteriophage designated as vB_Msp_JE2 was isolated from the Rajwadi hot spring that could be propagated using Meiothermus sp. strain JE2. One-step growth curve using Meiothermus sp. strain JE2 as host demonstrated a latent period of 70 min and a burst size of 20. Bacteriophage vB_Msp_JE2 was stable at pH 6.0 -8.0. Additionally, the phage was thermostable at 60 degrees C and was completely inactivated above 75 degrees C. Since, most microbial studies have been reported predominantly from the Himalayan geothermal province, the present study reports the association of a unique culturable pigmented thermophilic bacterial host and bacteriophage from Rajwadi hot spring present in the West coast geothermal province, India.