| 摘要: |
| 广东南岭森林土壤中蕴藏着丰富的生物资源，但对其中的可培养细菌种类仍缺乏系统了解。本研究采用贫营养型的R2A培养基和富营养型的TSA培养基对南岭森林土壤中细菌进行了分离，获得细菌408株，分别从属于厚壁菌门、变形菌门、放线菌门和拟杆菌门的35属。其中的优势类群为厚壁菌门，占分离总数量的71%。在属水平，芽胞杆菌及其近缘属为优势类群。除芽胞杆菌外，假单胞菌、伯克霍尔德氏菌、草酸杆菌科Collimonas属和罗丹诺杆菌科Dyella属是分离获得的主要类群。R2A培养基在分离革兰氏阴性的变形菌门菌株方面表现出一定的偏好性，而TSA培养基分离得到的更多为快速生长的芽胞杆菌及其近缘的革兰氏阳性细菌。发现了15属的菌株具有一定的水解酶活性，大多表现出对淀粉和牛奶的水解活性，对有机磷的水解性能优于对无机磷的水解。降解纤维素的菌株则主要集中于芽胞杆菌及其近缘属中。发现了潜在新物种26株，分布于芽胞杆菌、Dyella、类芽孢杆菌等9属中。本研究仅使用了两种营养类型的培养基，进一步借助培养组学技术有望能更加全面反映南岭森林土壤中的可培养微生物多样性。 |
| 关键词: 森林土壤 可培养细菌 芽胞杆菌 优势类群 变形菌门 |
| DOI：10.14188/j.ajsh.2020.05.014 |
| 分类号:Q938 |
| 基金项目:广东省重点领域研发计划项目（2018B020205001）；广东省省级科技计划项目（2018B030324001） |
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| Diversity of culturable bacteria isolated from forest soils in the Nanling National Nature Reserve， Guangdong Province |
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LI Jiali, CHEN Wendi, FENG Guangda, ZHOU Yang, LIU Yang, CHEN Meng, ZHU Honghui
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State Key Laboratory of Applied Microbiology of Southern China/Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application， Guangdong Institute of Microbiology， Guangzhou 510070， Guangdong， China
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| Abstract: |
| Microbial resources are abundant in forest soils of the Nanling National Nature Reserve in Guangdong Province， but the culturable bacteria are still rarely known. In this study， bacterial strains were isolated and cultured from the forest soils of Nanling by using the R2A （oligotrophic type） and TSA （eutrophic type） media. A total of 408 strains were obtained which were affiliated to 4 phyla （Firmicutes， Proteobacteria， Actinobacteria and Bacteroidetes） and 35 genera， respectively. The dominant group of isolates was Firmicutes， accounting for 71 % of the total amounts. In the genus distribution， the isolates were dominated by Bacillus and its closely related genera. Besides the Bacillus group， Pseudomonas， Burkholderia， Collimonas and Dyella in the phylum Proteobacteria were also the major groups in the obtained strains. The species of isolates between two different nutrient type media showed significant differences and Gram-negative strains preferred R2A medium while fast grown Gram-positive strains such as Bacillus and its closely related genera preferred TSA medium. The isolates from 15 genera showed activity in hydrolyzing different substrates. Most the genera showed positive reactions in hydrolyzing starch and skim milk. The isolates showed more hydrolytic activity on organic phosphorus than that on inorganic phosphorus. Most of cellulose hydrolysis isolates were affiliated to Bacillus and its closely related genera. A total of 26 strains which might belong to potential novel species were found in the isolates and they were assigned into 9 different genera such as Bacillus， Dyella， Paenibacillus. In this study， only two media of different nutrient types were adopted for the bacterial isolation from Nanling forest soil and it is expected that the culturable microbial diversity in Nanling forest soil can be presented more comprehensively by using new culturomics techniques. |
| Key words: forest soil culturable bacterium Bacillus dominant group Proteobacteria |
