TY - JOUR
T1 - Cyanobacterial mats from hot springs produce antimicrobial compounds and quorum-sensing inhibitors under natural conditions
AU - Dobretsov, Sergey
AU - Abed, Raeid M.M.
AU - Al Maskari, Sultan M.S.
AU - Al Sabahi, Jamal N.
AU - Victor, Reginald
N1 - Funding Information:
Acknowledgements The work of SD was supported by the Sultan Qaboos University (SQU) internal grant IG/AGR/FISH/09/03 and by the HM Sultan Qaboos Research Trust Fund SR/AGR/FISH/10/01. The authors acknowledge Dr. Alban Ramette from the Max-Planck Institute for training RA on ARISA technique and Prof. Stjepko Golubic (Boston University) and Katarzyna Palinska (ICBM, Oldenburg, Germany) for microscopic identification of cyanobacteria. Mrs. Yulia Plakhotnikova is thanked for her help in sampling and Dr. Abbas Khan for extract preparation.
PY - 2011/12
Y1 - 2011/12
N2 - Polar (water) and non-polar (ethyl acetate) extracts from the cyanobacterial layer (top 1-3 mm) of four hot spring microbial mats in the Sultanate of Oman were tested for their antibacterial, antidiatom and quorum-sensing inhibitory activities under natural conditions. The chemical composition of the active extracts was analysed using gas chromatography-mass spectrometry (GC-MS). Cyanobacteria within these mats were identified by direct microscopy while the total bacterial community composition was compared using automated ribosomal intergenic spacer analysis (ARISA). Only the extracts from Bowshar and Nakhl mats showed antibacterial properties against Bacillus sp., Micrococcus luteus, Shigella sonnei, Salmonella enterica and Klebsiella pneumoniae. All tested extracts inhibited the growth of the benthic diatom Amphora coffeaeformis. Extracts from Bowshar, Rustaq and Nakhl inhibited quorum-sensing of the reporter strains Chromobacterium violaceum CV017 and Agrobacterium tumefaciens NTL4. The highest bioactivity was recorded for ethyl acetate extracts from Nakhl mats, which had the lowest number of operational taxonomic units (OTUs). Using GC-MS, 74 chemical compounds were obtained, however with different distribution among the four mat extracts (similarity <43%). Various cyanobacteria, belonging mainly to Chroococcus, Phormidium, Leptolyngbya, Spirulina and Lyngbya were detected in the different mats, and each mat had its unique bacterial community, as confirmed by ARISA profiles. We conclude that antimicrobial and quorum-sensing inhibitory compounds can be produced by hot spring mat microorganisms under natural conditions and the differences in these compounds could be attributed to the differences in the mats' bacterial composition as well as the physical-chemical conditions of the springs.
AB - Polar (water) and non-polar (ethyl acetate) extracts from the cyanobacterial layer (top 1-3 mm) of four hot spring microbial mats in the Sultanate of Oman were tested for their antibacterial, antidiatom and quorum-sensing inhibitory activities under natural conditions. The chemical composition of the active extracts was analysed using gas chromatography-mass spectrometry (GC-MS). Cyanobacteria within these mats were identified by direct microscopy while the total bacterial community composition was compared using automated ribosomal intergenic spacer analysis (ARISA). Only the extracts from Bowshar and Nakhl mats showed antibacterial properties against Bacillus sp., Micrococcus luteus, Shigella sonnei, Salmonella enterica and Klebsiella pneumoniae. All tested extracts inhibited the growth of the benthic diatom Amphora coffeaeformis. Extracts from Bowshar, Rustaq and Nakhl inhibited quorum-sensing of the reporter strains Chromobacterium violaceum CV017 and Agrobacterium tumefaciens NTL4. The highest bioactivity was recorded for ethyl acetate extracts from Nakhl mats, which had the lowest number of operational taxonomic units (OTUs). Using GC-MS, 74 chemical compounds were obtained, however with different distribution among the four mat extracts (similarity <43%). Various cyanobacteria, belonging mainly to Chroococcus, Phormidium, Leptolyngbya, Spirulina and Lyngbya were detected in the different mats, and each mat had its unique bacterial community, as confirmed by ARISA profiles. We conclude that antimicrobial and quorum-sensing inhibitory compounds can be produced by hot spring mat microorganisms under natural conditions and the differences in these compounds could be attributed to the differences in the mats' bacterial composition as well as the physical-chemical conditions of the springs.
KW - ARISA
KW - Bioactivity
KW - Cyanobacteria
KW - Hot springs
KW - Microbial diversity
KW - Microbial mats
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U2 - 10.1007/s10811-010-9627-2
DO - 10.1007/s10811-010-9627-2
M3 - Article
AN - SCOPUS:80855147627
SN - 0921-8971
VL - 23
SP - 983
EP - 993
JO - Journal of Applied Phycology
JF - Journal of Applied Phycology
IS - 6
ER -