| 摘要: |
| 【目的】从温泉的底泥中分离、鉴定能产生免疫增强活性胞外代谢产物的嗜高温菌，并对其胞外代谢产物的免疫增强活性和抗病性进行研究。【方法】通过菌株个体形态、菌落形态和生理生化特性，初步排除从陕西西安东大温泉的底泥分离菌株中的重复菌株；以白细胞吞噬活性、白细胞杀菌活性、血清溶菌酶和血清SOD活性为指标进一步筛选获得目的菌株，采用个体形态、群落形态、生理生化特性和分子生物学方法对目的菌株进行初步鉴定；通过大孔吸附树脂浓缩活性成分，硅胶柱层析，以白细胞吞噬活性、白细胞杀菌活性、血清溶菌酶和血清SOD活性、免疫相关基因转录水平和免疫保护率为参考指标，活性追踪分离获得该菌株的主要活性物质。【结果】筛选到1株嗜高温菌株XA-4，鉴定为Anoxybacillus flavithermus。XA-4的代谢产物能显著增强鲤的非特异性免疫功能，流分B是株菌XA-4代谢产物中活性成分的主要浓缩物，可显著提高鲤的外周血白细胞吞噬活性、白细胞杀菌活性、血清溶菌酶和血清SOD活性，上调免疫相关基因转录水平，对鲤的免疫保护率达66.67%。【结论】菌株XA-4及其免疫增强物质的粗提物有较好的免疫增强活性，很有可能开发成为一种新的鱼类免疫增强剂。 |
| 关键词: 免疫增强剂 免疫保护 鲤 嗜高温菌 细胞因子 RQ-PCR |
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| 基金项目:陕西省教育厅产业化中试项目“绿色无公害微生物发酵饲料添加剂产业化”（2010JC22）；陕西省科技厅农业攻关项目“陕南特色生物资源利用与新产品开发”（2009K01 25） |
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| Isolation,determination and immunostimulatory effects of a specific thermophilac strain on carp,Cyprinus carpio |
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| Abstract: |
| 【Objective】This paper intends to determine the bioactiuity and enhancement on non-specific immunity and survival of secondary metabolite of strain SX-4 on carp(Cyprinus carpio).【Method】A thermophilic strain SX-4 able to produce immunostimulatory metabolite was isolated from sludge sample of hot spring and identified by comparison with 16S rRNA sequences (99% of homology) as Anoxybacillus flavithermus.【Result】Through bioactivity-guided fractionation of methanol extract from its cell-free culture,one bacterial extract with the capacity of improving the non specific immune responses and disease resistance (relative percent survival=66.67%) was obtained.【Conclusion】There is a possibility of using this extract as a better natural immunostimulant,which could have a promising role in aquaculture to prevent diseases and disease outbreaks. |
| Key words: immunostimulant immune protection carp Cyprinus carpio thermophiles cell factor RQ-PCR |
