Biology Department, College of Science, Sultan Qaboos University, Al Khoud, Sultanate of Oman.
J Ind Microbiol Biotechnol. 2013 Jul;40(7):759-72. doi: 10.1007/s10295-013-1276-4. Epub 2013 May 5.
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.
在这项研究中，从高盐微生物垫中筛选了极端嗜盐和中度嗜热的微生物，以研究它们产生抗菌、抗硅藻、抗藻类和群体感应（QS）抑制化合物的能力。从微生物垫中分离出 5 株属于 Marinobacter 和 Halomonas 属的细菌菌株和 1 株属于 Haloterrigena 属的古细菌菌株。这些菌株能够在最大盐度为 22-25%和最高温度为 45-60°C 的条件下生长。来自菌株的己烷、二氯甲烷和正丁醇提取物抑制了至少 9 种人类病原体中的 1 种的生长。只有 Halomonas sp. SK-1 的上清液的正丁醇提取物抑制了微藻杜氏盐藻的生长。大多数分离物的提取物抑制了酰基高丝氨酸内酯产生菌和报告菌 Chromobacterium violaceum CV017 的 QS。Marinobacter sp. SK-3 的 QS 抑制二氯甲烷提取物的纯化导致了四种相关二酮哌嗪（DKP）的分离：环（L-Pro-L-Phe）、环（L-Pro-L-Leu）、环（L-Pro-L-异亮氨酸）和环（L-Pro-D-Phe）。使用 C. violaceum CV017 和缺乏 AHL 产生的基于大肠杆菌的 QS 报告基因（pSB401 和 pSB1075）测试了这些 DKP 的 QS 抑制特性。环（L-Pro-L-Phe）和环（L-Pro-L-异亮氨酸）抑制了 C. violaceum CV017 依赖 QS 的 violacein 产生。环（L-Pro-L-Phe）、环（L-Pro-L-Leu）和环（L-Pro-L-异亮氨酸）降低了 3-氧代-C6-HSL 诱导的报告基因大肠杆菌 pSB401 依赖 QS 的发光。我们的研究表明，来自高盐微生物垫的嗜盐和中度嗜热菌株具有产生生物技术相关化合物的能力，这些化合物可作为防污剂使用。
