ISOLATION AND CHARACTERIZATION OF NOVEL EXTREMELY HALOTHERMOPHILIC BACTERIUM, HALOMONAS CASEINILYTICA WN.1B.S, FROM WADI AN NATRUN, EGYPT

The purpose of the present study was to isolate microbial halothermophiles from hyper saline Al- Hamra Lakeat Wadi An Natrun, Egypt. Twenty eight bacterial isolates were obtained and the morphological and physiological properties in addition to enzyme activities were studied. Amongst those isolates, WN.1B.s was selected as the most potent isolate based on growth at high temperature (up to 65oC) and at high salt concentration (up to 34%, near saturation state).A phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate WN.1B.s had the highest sequence similarity with respect to type strains of Halomonas caseinilytica (97 %), Halomonas elongata (96 %), Halomonas eurihalina (95 %), Halomonas koreensis (95 %) and Halomonas halmophila (95 %).Based on physiological characteristics and16S rRNA sequence analysisthis isolate was identified as Halomonas caseinilyticaWN.1B.s which belonged to bacterial domain, class Gammaproteobacteria, order Oceanospirillales, family Halomonadaceae, Halomonas species. Enzyme screening for strain WN.1B.s showed that, the isolate secrete amylases, lipases, cellulases and pectinase enzymes under harsh conditions that may be useful in different industrial processes.