Chakraborty Kajal, Thilakan Bini, Raola Vamshi Krishna
Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North P.O., Post Box No. 1603, Cochin, 682018, Kerala, India.
Appl Biochem Biotechnol. 2018 Feb;184(2):716-732. doi: 10.1007/s12010-017-2562-9. Epub 2017 Aug 25.
A heterotrophic marine bacterium Bacillus amyloliquefaciens isolated from seaweed Padina gymnospora exhibited broad spectra of antibacterial activities against pathogenic bacteria Aeromonas hydrophila, Vibrio harveyi, Vibrio vulnificus, and Vibrio parahaemolyticus. The seaweed-associated B. amyloliquefaciens was recognized to possess functional type I polyketide synthase-1 (pks-1) gene, and was used to isolate four homologous compounds with polyketide frameworks. The compounds were characterized as 11-(15-butyl-13-ethyl-tetrahydro-12-oxo-2H-pyran-13-yl) propyl-2-methylbenzoate (1), 9-(tetrahydro-12-isopropyl-11-oxofuran-10-yl)-ethyl-4-ethoxy-2-hydroxybenzoate (2), 12-(aminomethyl)-11-hydroxyhexanyl-10-phenylpropanoate (3), and 7-(14-hydroxypropan-13-yl)-8-isobutyl-7,8-dihydrobenzo[c]oxepin-1(3H)-one (4) by comprehensive nuclear magnetic resonance and mass spectroscopic experiments. The compounds 1-4 displayed significant antibacterial activities against clinically important pathogens V. parahaemolyticus and V. vulnificus (inhibitory zone diameter of ≥15 mm, 100 mcg on disk). The electronic and hydrophobic parameters appeared to hold a conspicuous part in directing the antibacterial properties of the compounds. This study revealed seaweed-associated B. amyloliquefaciens as potential source of antimicrobial polyketides for pharmaceutical applications.
从海草裸叶藻中分离出的一株异养海洋细菌解淀粉芽孢杆菌，对致病性嗜水气单胞菌、哈维氏弧菌、创伤弧菌和副溶血性弧菌表现出广谱抗菌活性。与海草相关的解淀粉芽孢杆菌被认为具有功能性I型聚酮合酶-1（pks-1）基因，并被用于分离四种具有聚酮骨架的同源化合物。通过综合核磁共振和质谱实验，将这些化合物鉴定为11-（15-丁基-13-乙基-四氢-12-氧代-2H-吡喃-13-基）丙基-2-甲基苯甲酸酯（1）、9-（四氢-12-异丙基-11-氧代呋喃-10-基）-乙基-4-乙氧基-2-羟基苯甲酸酯（2）、12-（氨基甲基）-11-羟基己基-10-苯基丙酸酯（3）和7-（14-羟基丙基-13-基）-8-异丁基-7,8-二氢苯并[c]氧杂环庚三烯-1（3H）-酮（4）。化合物1-4对临床上重要的病原体副溶血性弧菌和创伤弧菌表现出显著的抗菌活性（圆盘上100微克时抑菌圈直径≥15毫米）。电子和疏水参数似乎在指导化合物的抗菌性能方面起着显著作用。这项研究揭示了与海草相关的解淀粉芽孢杆菌是制药应用中抗菌聚酮化合物的潜在来源。
