Exploration of a haloarchaeon, Halostagnicola larsenii, isolated from rock pit sea water, West Coast of Maharashtra, India, for the production of bacteriorhodopsin

• Published in: Journal of applied microbiology 2015-06, Vol.118 (6), p.1345-1356
• Main Authors: Kanekar, P.P, Kulkarni, S.O, Kanekar, S.P, Shouche, Y, Jani, K, Sharma, A
• Format: Article
• Language: English
• Subjects: Bacteria; Bacteriology; bacteriorhodopsin; Bacteriorhodopsins - genetics; Bacteriorhodopsins - metabolism; Biotechnology; coasts; Energy; genes; Geologic Sediments - microbiology; haloarchaea; Halobacteriaceae - classification; Halobacteriaceae - genetics; Halobacteriaceae - isolation & purification; Halobacteriaceae - metabolism; Halostagnicola larsenii; India; low saline environment; Microbiology; Molecular Sequence Data; Phylogeny; red rock; ribosomal RNA; RNA, Ribosomal, 16S - genetics; rock gardens; rock pit sea water; salinity; seawater; Seawater - microbiology; Sodium Chloride - metabolism
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/jam.12784

AIMS: The aim of the present investigation was to isolate haloarchaea from rock pit sea water, West Coast of India and to explore their potential in the production of bacteriorhodopsin (BR) which converts light energy into electrical energy. METHODS AND RESULTS: Haloarchaeal strains were isolated from rock pit sea water samples collected from Rock garden, Malvan, West Coast of India. Based on morphological, physiological and biochemical characteristics, and 16S rRNA gene sequencing, all the 11 strains were identified as Halostagnicola larsenii. All the strains require at least 1·5 mol l⁻¹NaCl for growth; grow optimally in the range of 3·5–5·2 mol l⁻¹NaCl. BR was detected in all the strains ranging from 0·035 to 0·258 g l⁻¹. All 11 strains showed conversion of light energy into electrical energy in the range of 0·7–44·2 mV, when exposed to sunlight. CONCLUSIONS: A haloarchaeon, Hst. larsenii is isolated from rock pit sea water and demonstrated to have BR that converted light energy into electrical energy. SIGNIFICANCE AND IMPACT OF THE STUDY: The present investigation is presumably the first report of the isolation of Hst. larsenii from low salinity environment and its potential in production of BR. The haloarchaeon could be explored for the generation of electrical energy.