| 摘要: |
| 微囊藻水华是最为常见的有害水华。在水华中的微囊藻细胞大多聚集为群体,群体状态对维持其生态优势至关重要。将微囊藻分散成单细胞状态,可削减其竞争优势,作为控制水华的手段。本实验以细菌多糖黄原胶和水华微囊藻(Microcystis flos-aquae)胞外多糖为唯一碳源,筛选出了5株具有利用微囊藻胞外多糖能力的细菌,通过共培养研究了这些菌对单细胞状态的水华微囊藻(M. flos-aquae)胞外多糖和群体状态的惠氏微囊藻(M. wesenbergii)群体状态的影响。结果显示,对于水华微囊藻,其中4株细菌能够明显地降低胞外多糖的粘度；对于惠氏微囊藻,5株细菌均能显著减小藻群体,并能抑制其生长。这5株菌经16S rDNA鉴定均属于假单胞菌属。研究的结果显示,分离获得的菌株有用于防控微囊藻水华的可能性。 |
| 关键词: 微囊藻 群体 多糖降解菌 胞外多糖 水华 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（31971561、31370217） |
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| Screening of bacteria for extracellular polysaccharide degradation and its effect on colonial size of Microcystis |
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Yu Xiaoli, Li Anli, Wang, Li Jianhong
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School of Life Sciences, Nanjing Normal University
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| Abstract: |
| Microcystis bloom is the most common harmful bloom. Microcystis cells in bloom aggregate into colonies, and the colonial form is crucial for maintaining their ecological advantage. Dispersing Microcystis into the unicellular form can decrease their competitive advantage and use as a means to control the bloom. In this experiment, five polysaccharide-degrading bacteria (PDB) with the ability to decompose the extracellular polysaccharides of Microcystis were screened by using bacterial polysacchrides xanthan gum or the extracellular polysaccharides of M. flos-aquae as the sole carbon source. Effects of the bacteria on the extracellular polysaccharides of unicellular strain M. flos-aquae, and on the colonial size of colonial strain M. wesenbergii were observed by co-culture. The results showed that four strains of bacteria were able to significantly reduce the viscosity of extracellular polysaccharides of M. flos-aquae. All five strains were able to reduce the colonial size and inhibit the growth of M. wesenbergii. The PDB were identified to the genus Pseudomonas by 16S rDNA. This study showed that the PDB have the potential to control Microcystis bloom. |
| Key words: Microcystis colony polysaccharide-degrading bacteria extracellular polysaccharides bloom. |
