Zhang Xiaoling, Pan Zekang, Zhang Jinkai, Liu Bingqian, Yang Qiao
ABI Group, Phycosphere Microbiology Laboratory, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316022, China.
Microorganisms. 2025 May 24;13(6):1198. doi: 10.3390/microorganisms13061198.
Phycosphere niches host rich, unique microbial consortia that harbor complex algae-bacteria interactions with fundamental significance in underpinning most functions of aquatic ecological processes. Therefore, harvesting the uncultured phycobacteria is crucial for understanding the intricate mechanisms governing these dynamic interactions. Here, we characterized and compared microbial community composition of the phycosphere microbiota from six harmful algal bloom-forming marine dinoflagellates, spp., and their bacterial associations. Furthermore, based on a combinational enhanced cultivation strategy (CECS) procedure for the selected isolation for cultivable phycobacteria, a new yellow-pigmented bioactive bacterium designated ABI-6-9 was successfully recovered from cultivable phycobacteria of the highly toxic strain amtk4. An additional phylogenomic analysis fully identified this new isolate as a potential novel species of the genus within the family . The bioactivity evaluation observed that strain ABI-6-9 can significantly promote the cell growth of its algal host and altered the gonyautoxin accumulation profiles in the co-culture circumstance. Additionally, the bacterial production of active bioflocculanting exopolysaccharides (EPSs) by strain ABI-6-9 was also measured after culture optimization. Thus, these findings revealed the potential environmental and biotechnological implications of this new microalgae growth- promoting phycobacterium.
藻际生态位拥有丰富、独特的微生物群落，其中存在复杂的藻菌相互作用，这对于支撑水生生态过程的大多数功能具有根本意义。因此，获取未培养的藻际细菌对于理解控制这些动态相互作用的复杂机制至关重要。在此，我们对六种形成有害藻华的海洋甲藻及其细菌联合体的藻际微生物群的微生物群落组成进行了表征和比较。此外，基于一种用于可培养藻际细菌的组合强化培养策略（CECS）程序，从剧毒的 菌株amtk4的可培养藻际细菌中成功分离出一种新的黄色色素生物活性细菌，命名为ABI-6-9。进一步的系统基因组分析完全确定这种新分离物为 科 属的一个潜在新物种。生物活性评估表明，菌株ABI-6-9能显著促进其藻类宿主的细胞生长，并在共培养环境中改变了麻痹性贝毒的积累情况。此外，在优化培养后还测定了菌株ABI-6-9产生活性生物絮凝胞外多糖（EPS）的情况。因此，这些发现揭示了这种促进微藻生长的新藻际细菌潜在的环境和生物技术意义。
