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一株耐Cd菌株的分离、鉴定及基本特性 被引量:13
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作者 李倩 张平 +3 位作者 廖柏寒 彭佩钦 梅金星 徐继敏 《微生物学报》 CAS CSCD 北大核心 2019年第1期11-24,共14页
【目的】从活性污泥中筛选耐镉(Cd)菌株,并研究其生长特性及对溶液中Cd^(2+)吸附的最佳条件,以期为重金属Cd污染水体的微生物修复提供菌株资源和应用技术参考。【方法】采用平板划线法,从活性污泥中分离、筛选、驯化出耐Cd菌株,通过16Sr... 【目的】从活性污泥中筛选耐镉(Cd)菌株,并研究其生长特性及对溶液中Cd^(2+)吸附的最佳条件,以期为重金属Cd污染水体的微生物修复提供菌株资源和应用技术参考。【方法】采用平板划线法,从活性污泥中分离、筛选、驯化出耐Cd菌株,通过16SrRNA基因序列分析及溶血试验、蛋白质毒素结晶试验进行初步鉴定,并采用单因素实验优化菌株的培养条件,通过正交实验确定菌粉吸附溶液中Cd^(2+)的最佳条件,同时利用SEM-EDS及FTIR分析探讨菌粉吸附Cd^(2+)的机理。【结果】经分离、驯化得到1株耐Cd细菌菌株,命名为H6,初步鉴定为蜡样芽孢杆菌(Bacilluscereus),最大Cd^(2+)耐受浓度为350 mg/L。菌株H6的最佳生长条件为:pH 6.0–8.0,温度28°C,转速120–210 r/min,接种量1%–5%;菌株H6在生长过程中,培养液pH值先稍微下降然后不断上升。菌粉吸附Cd^(2+)的正交优化条件为:菌粉用量0.125 g/L,吸附时间2 h,pH 5.0,温度30°C,此条件下吸附量为205 mg/g。SEM-EDS分析和红外光谱(FTIR)分析表明,在吸附过程中主要作用基团有羟基、羧基、羰基、酰胺基和烷基,此外,Ca^(2+)与Cd^(2+)发生了离子交换。【结论】从活性污泥中分离出的菌株H6,初步鉴定为蜡样芽孢杆菌(Bacillus cereus),是1株具有较强Cd^(2+)吸附能力的细菌菌株。 展开更多
关键词 蜡样芽孢杆菌 筛选与鉴定 生长条件 吸附
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Assessment of soil nematode diversity based on different taxonomic levels and functional groups 被引量:3
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作者 Jiangnan Li peiqin peng Jie Zhao 《Soil Ecology Letters》 CAS 2020年第1期33-39,共7页
Although soil nematode diversity has been used as an indicator of habitat characteristics and environmental change,the diversity of entire soil nematode communities has not been comprehensively evaluated at different ... Although soil nematode diversity has been used as an indicator of habitat characteristics and environmental change,the diversity of entire soil nematode communities has not been comprehensively evaluated at different taxonomic levels,or for different functional groups,or at a fine taxonomic level within functional groups.In this study,two taxonomic diversity indices,the Shannon-Wiener index(H′)and Simpson index(l),were used to evaluate the following:1)nematode diversity at different taxonomic levels for the whole community,2)nematode diversity of different functional groups,and 3)nematode generic diversity of functional groups in the following four land-use types:forage land,cropland,secondary forest,and grassshrubland.The results showed that significant differences in nematode diversity among landuse types were detected by assessment at the order level but not at the family or genus level.The results also showed that significant differences in nematode diversity were better revealed by assessment of trophic groups rather than cp groups.The generic diversities(H′)of omnivorous nematodes and cp3 nematodes also significantly differed among land-use types.Our results indicate that diversity at a high taxonomic level(i.e.,order)may be a more useful indicator than diversity at a low taxonomic level(i.e.,family or genus)of differences among land-use types.In addition,the functional group diversity(i.e.,trophic group,cp group,and the combination of these two groups)for the whole community and the taxonomic diversity within functional groups were useful indicators of differences among land-use types. 展开更多
关键词 BIODIVERSITY Soil nematodes Taxon diversity Functional group diversity INDICATOR
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