TY - JOUR
T1 - Quorum-sensing inhibitory compounds from extremophilic microorganisms isolated from a hypersaline cyanobacterial mat
AU - Abed, Raeid M.M.
AU - Dobretsov, Sergey
AU - Al-Fori, Marwan
AU - Gunasekera, Sarath P.
AU - Sudesh, Kumar
AU - Paul, Valerie J.
N1 - Funding Information:
The work of SD was supported by a Sultan Qaboos University (SQU) internal grant IG/AGR/FISH/12/01, by a HM Sultan Qaboos Research Trust Fund SR/AGR/FISH/10/01 and by the George E. Burch Fellowship in Theoretical Medicine and Affiliated Sciences at the Smithsonian Institution (USA). SD acknowledges Professor Ricardo Coutinho (IEAPM, Arraial do Cabo, Brazil) and the program science without frontiers (CNPq). RA would like to thank the Hanse-Wissenschaftskolleg (HWK), Institute for Advanced Study, Germany, for their support. The authors acknowledge help with QS bioassays by Dr. Max Teplitski (University of Florida, USA) and with strain isolation by Mrs. Samiha Al Kharusi. This is contribution No. 910 of the Smithsonian Marine Station at Fort Pierce.
PY - 2013/7
Y1 - 2013/7
N2 - In this study, extremely halophilic and moderately thermophilic microorganisms from a hypersaline microbial mat were screened for their ability to produce antibacterial, antidiatom, antialgal, and quorum-sensing (QS) inhibitory compounds. Five bacterial strains belonging to the genera Marinobacter and Halomonas and one archaeal strain belonging to the genus Haloterrigena were isolated from a microbial mat. The strains were able to grow at a maximum salinity of 22-25 % and a maximum temperature of 45-60 C. Hexanes, dichloromethane, and butanol extracts from the strains inhibited the growth of at least one out of nine human pathogens. Only butanol extracts of supernatants of Halomonas sp. SK-1 inhibited growth of the microalga Dunaliella salina. Most extracts from isolates inhibited QS of the acyl homoserine lactone producer and reporter Chromobacterium violaceum CV017. Purification of QS inhibitory dichloromethane extracts of Marinobacter sp. SK-3 resulted in isolation of four related diketopiperazines (DKPs): cyclo(l-Pro-l-Phe), cyclo(l-Pro-l-Leu), cyclo(l-Pro-l-isoLeu), and cyclo(l-Pro-d-Phe). QS inhibitory properties of these DKPs were tested using C. violaceum CV017 and Escherichia coli-based QS reporters (pSB401 and pSB1075) deficient in AHL production. Cyclo(l-Pro-l-Phe) and cyclo(l-Pro-l-isoLeu) inhibited QS-dependent production of violacein by C. violaceum CV017. Cyclo(l-Pro-l-Phe), cyclo(l-Pro-l-Leu), and cyclo(l-Pro-l-isoLeu) reduced QS-dependent luminescence of the reporter E. coli pSB401 induced by 3-oxo-C6-HSL. Our study demonstrated the ability of halophilic and moderately thermophilic strains from a hypersaline microbial mat to produce biotechnologically relevant compounds that could be used as antifouling agents.
AB - In this study, extremely halophilic and moderately thermophilic microorganisms from a hypersaline microbial mat were screened for their ability to produce antibacterial, antidiatom, antialgal, and quorum-sensing (QS) inhibitory compounds. Five bacterial strains belonging to the genera Marinobacter and Halomonas and one archaeal strain belonging to the genus Haloterrigena were isolated from a microbial mat. The strains were able to grow at a maximum salinity of 22-25 % and a maximum temperature of 45-60 C. Hexanes, dichloromethane, and butanol extracts from the strains inhibited the growth of at least one out of nine human pathogens. Only butanol extracts of supernatants of Halomonas sp. SK-1 inhibited growth of the microalga Dunaliella salina. Most extracts from isolates inhibited QS of the acyl homoserine lactone producer and reporter Chromobacterium violaceum CV017. Purification of QS inhibitory dichloromethane extracts of Marinobacter sp. SK-3 resulted in isolation of four related diketopiperazines (DKPs): cyclo(l-Pro-l-Phe), cyclo(l-Pro-l-Leu), cyclo(l-Pro-l-isoLeu), and cyclo(l-Pro-d-Phe). QS inhibitory properties of these DKPs were tested using C. violaceum CV017 and Escherichia coli-based QS reporters (pSB401 and pSB1075) deficient in AHL production. Cyclo(l-Pro-l-Phe) and cyclo(l-Pro-l-isoLeu) inhibited QS-dependent production of violacein by C. violaceum CV017. Cyclo(l-Pro-l-Phe), cyclo(l-Pro-l-Leu), and cyclo(l-Pro-l-isoLeu) reduced QS-dependent luminescence of the reporter E. coli pSB401 induced by 3-oxo-C6-HSL. Our study demonstrated the ability of halophilic and moderately thermophilic strains from a hypersaline microbial mat to produce biotechnologically relevant compounds that could be used as antifouling agents.
KW - Antimicrobial, extreme halophiles
KW - Biofouling
KW - Cyanobacterial mats
KW - Diketopiperazines
KW - Quorum-sensing inhibition
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U2 - 10.1007/s10295-013-1276-4
DO - 10.1007/s10295-013-1276-4
M3 - Article
C2 - 23645384
AN - SCOPUS:84879209549
SN - 1367-5435
VL - 40
SP - 759
EP - 772
JO - Journal of Industrial Microbiology and Biotechnology
JF - Journal of Industrial Microbiology and Biotechnology
IS - 7
ER -