College of Food Science and Technology, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Guangdong Provincial Engineering Technology Research Center of Seafood, Guangdong Province Engineering Laboratory for Marine Biological Products, Key Laboratory of Advanced Processing of Aquatic Product of Guangdong Higher Education Institution, Guangdong Ocean University, Zhanjiang, 524088, China.
Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, 116034, China.
World J Microbiol Biotechnol. 2023 May 15;39(8):196. doi: 10.1007/s11274-023-03643-y.
The antagonistic Bacillus amyloliquefaciens HY2-1 was a marine microbiology that was isolated previously from the seabed silt of Beibu Gulf in China by dual culture with Penicillium digitatum. As a continuous study, the present work focused on evaluating the antimicrobial activity, identifying the produced active components, and revealing the fermentation characteristics of B. amyloliquefaciens HY2-1, respectively. It was found that B. amyloliquefaciens HY2-1 exhibited a broad-spectrum antimicrobial activity against the tested seven phytopathogenic fungi and five pathogenic bacteria by producing Bacillus lipopeptides such as fengycin A (C to C homologues) and surfactin (C and C homologues). Morphological observation of P. digitatum under light microscope, scanning electron microscopy, transmission electron microscopy, and fluorescence microscope inferred that B. amyloliquefaciens exerted the antagonistic activity by damaging the fungal cell membrane, thus inhibiting the mycelium growth and sporification of phytopathogenic fungi. As a marine microbiology, our results showed that B. amyloliquefaciens could survive and metabolize even at the culture condition with 110 g/L of NaCl concentration, and the produced antimicrobial compounds exhibited excellent thermostability and acid-alkali tolerance. The dynamic models were further constructed to theoretically analyze the fermentation process of B. amyloliquefaciens HY2-1, suggesting that the synthesis of antimicrobial compounds was coupled with both cell growth and cell biomass. In conclusion, the marine lipopeptides-producing B. amyloliquefaciens HY2-1 showed a promising prospect to be explored as a biocontrol agent for plant disease control of crops and postharvest preservation of fruits and vegetables, especially due to its outstanding stress resistance and the broad-spectrum and effective antagonist on various phytopathogenic fungi.
拮抗细菌解淀粉芽胞杆菌 HY2-1 是一株海洋微生物，先前通过与青桔绿僵菌的混合培养从中国北部湾海底淤泥中分离得到。作为一项连续研究，本工作分别侧重于评估解淀粉芽胞杆菌 HY2-1 的抑菌活性、鉴定产生的活性成分、揭示其发酵特性。结果发现，解淀粉芽胞杆菌 HY2-1 通过产生丰原素 A（C 至 C 同系物）和表面活性剂（C 和 C 同系物）等芽孢杆菌脂肽，对测试的七种植物病原菌真菌和五种病原菌具有广谱抑菌活性。在光学显微镜、扫描电子显微镜、透射电子显微镜和荧光显微镜下观察青桔绿僵菌的形态，推断解淀粉芽胞杆菌通过破坏真菌细胞膜发挥拮抗作用，从而抑制植物病原菌的菌丝生长和孢子形成。作为一种海洋微生物，我们的结果表明，解淀粉芽胞杆菌即使在 110 g/L 的 NaCl 浓度的培养条件下也能存活和代谢，并且产生的抑菌化合物表现出出色的热稳定性和酸碱耐受性。进一步构建了动力学模型来从理论上分析解淀粉芽胞杆菌 HY2-1 的发酵过程，表明抑菌化合物的合成与细胞生长和细胞生物质都相关。总之，产海洋脂肽的解淀粉芽胞杆菌 HY2-1 有望作为一种生物防治剂，用于控制作物病害和果蔬的采后保鲜，特别是由于其出色的抗逆性和对各种植物病原菌的广谱和有效拮抗作用。
