为了筛选对铜绿微囊藻有溶藻活性的菌株,采用试管法筛选溶藻效果好的细菌,显微观察高效溶藻菌的溶藻作用方式,对其热稳定性、耐酸碱能力及紫外稳定性进行考察,并采用16S r DNA序列分析鉴定溶藻菌种类。共筛选获得7株具有溶藻效果的细菌...为了筛选对铜绿微囊藻有溶藻活性的菌株,采用试管法筛选溶藻效果好的细菌,显微观察高效溶藻菌的溶藻作用方式,对其热稳定性、耐酸碱能力及紫外稳定性进行考察,并采用16S r DNA序列分析鉴定溶藻菌种类。共筛选获得7株具有溶藻效果的细菌,其中F15菌株对铜绿微囊藻溶藻效果最好。菌株F15的溶藻活性物质为胞外产物,当其生长到对数期时,其胞外产物的溶藻效果达到最大,按体积比1∶6将其加入藻液,培养3 d后,铜绿微囊藻的去除率达55%以上。该溶藻活性产物对加热、酸碱及紫外线处理均具有较好的稳定性。16S r DNA序列分析表明,F15菌株与Bacillus cereus strain ATCC 14579同源性最高,达99%,被鉴定为蜡状芽孢杆菌。F15菌株溶藻效果好,稳定性高,具有开发成生物控藻菌剂的潜在价值。展开更多
We separated tertiary egg membrane (TGM) from 2- and 25-day-old eggs of cuttlefish Sepiella maindroni de Rochebrune, and revealed its ultrastructure, physical (solubility, barrier property) and biochemical (histo...We separated tertiary egg membrane (TGM) from 2- and 25-day-old eggs of cuttlefish Sepiella maindroni de Rochebrune, and revealed its ultrastructure, physical (solubility, barrier property) and biochemical (histology, histochemistry, nutritional components, bacteriostasis) characteristics. The results show that TGM could not be dissolved with natural seawater, alcohol, ether or hydrochloric acid (HC1), but it could be dissolved with 2-chloroethanol, diethylamine, and sodium hydroxide (NaOH). The black TGM was more effective in blocking off mud particulates, microorganisms (Chlorella vulgaris, Vibrio alginolyticus) and lighter than the white TGM. The elasticity of black and white TGMs was 1.8 N and 1.5 N, respectively. There were some ink particulates and rod-shaped bacteria in the black TGM. The nutritional components were different between black and white TGMs: Lipid content was lower and protein content was higher in the black TGM. TGM could also inhibit the growth of Vibrio alginolyticus.展开更多
Filtration and cross-flow ultrafiltration techniques were used to separate culture media of Prorocentrurn donghaiense at the exponential growth, stationary and decline stages into 〈0.45 μm filtrate, 100 kDa-0.45 μm...Filtration and cross-flow ultrafiltration techniques were used to separate culture media of Prorocentrurn donghaiense at the exponential growth, stationary and decline stages into 〈0.45 μm filtrate, 100 kDa-0.45 μm, 1%100 kDa and 1-10 kDa retentate and 〈1 kDa ultrafiltrate fractions. The fluorescence properties of different molecular weights of dissolved organic matter (DOM) were measured by excitation-emission matrix spectra. Protein-like and humic-like fluorophores were observed in the DOM produced by P. donghaiense. The central positions of protein-like fluorophores showed a red shift with prolonged growth duration, shifting from tyrosine-like properties at the exponential growth stage to tryptophan-like properties at the stationary and decline stages. The excitation wavelengths of protein-like fluorophores exhibited some change in the exponential growth and stationary stages with increased molecular size, but showed little change in the decline stage. However, the emission wavelengths in the decline stage exhibited a blue shift. Very distinct C type and A type peaks in humic-like fluorophores were observed. With a prolonged culture time, the intensities of both of the peaks became strong and the excitation wavelengths of peak A showed a red shift, while the A:C ratios fell. More than 94% of fluorescent DOM was in the lower than 1 kDa molecular weight fraction.展开更多
文摘为了筛选对铜绿微囊藻有溶藻活性的菌株,采用试管法筛选溶藻效果好的细菌,显微观察高效溶藻菌的溶藻作用方式,对其热稳定性、耐酸碱能力及紫外稳定性进行考察,并采用16S r DNA序列分析鉴定溶藻菌种类。共筛选获得7株具有溶藻效果的细菌,其中F15菌株对铜绿微囊藻溶藻效果最好。菌株F15的溶藻活性物质为胞外产物,当其生长到对数期时,其胞外产物的溶藻效果达到最大,按体积比1∶6将其加入藻液,培养3 d后,铜绿微囊藻的去除率达55%以上。该溶藻活性产物对加热、酸碱及紫外线处理均具有较好的稳定性。16S r DNA序列分析表明,F15菌株与Bacillus cereus strain ATCC 14579同源性最高,达99%,被鉴定为蜡状芽孢杆菌。F15菌株溶藻效果好,稳定性高,具有开发成生物控藻菌剂的潜在价值。
基金Supported by the National Natural Science Foundation of China (No 40646030, 40776076)the Changjiang River Scholar and Innovative Research Team in university (No IRT0734)+4 种基金Key Scientific Research Project of Education Ministry of China (No207045)Key Project of Science and Technology of Zhejiang Province (No 2006C130402007C120762009R10012)K.C. Wong Magna Fund in Ningbo University
文摘We separated tertiary egg membrane (TGM) from 2- and 25-day-old eggs of cuttlefish Sepiella maindroni de Rochebrune, and revealed its ultrastructure, physical (solubility, barrier property) and biochemical (histology, histochemistry, nutritional components, bacteriostasis) characteristics. The results show that TGM could not be dissolved with natural seawater, alcohol, ether or hydrochloric acid (HC1), but it could be dissolved with 2-chloroethanol, diethylamine, and sodium hydroxide (NaOH). The black TGM was more effective in blocking off mud particulates, microorganisms (Chlorella vulgaris, Vibrio alginolyticus) and lighter than the white TGM. The elasticity of black and white TGMs was 1.8 N and 1.5 N, respectively. There were some ink particulates and rod-shaped bacteria in the black TGM. The nutritional components were different between black and white TGMs: Lipid content was lower and protein content was higher in the black TGM. TGM could also inhibit the growth of Vibrio alginolyticus.
基金Supported by the High Technology Research and Development Program of China (863 Program) (Nos 2006AA09Z180 and 2004AA639790)the National Natural Science Foundation of China (No 40106013)the National Basic Research Program of China (973 Program) (No 2001CB409703)
文摘Filtration and cross-flow ultrafiltration techniques were used to separate culture media of Prorocentrurn donghaiense at the exponential growth, stationary and decline stages into 〈0.45 μm filtrate, 100 kDa-0.45 μm, 1%100 kDa and 1-10 kDa retentate and 〈1 kDa ultrafiltrate fractions. The fluorescence properties of different molecular weights of dissolved organic matter (DOM) were measured by excitation-emission matrix spectra. Protein-like and humic-like fluorophores were observed in the DOM produced by P. donghaiense. The central positions of protein-like fluorophores showed a red shift with prolonged growth duration, shifting from tyrosine-like properties at the exponential growth stage to tryptophan-like properties at the stationary and decline stages. The excitation wavelengths of protein-like fluorophores exhibited some change in the exponential growth and stationary stages with increased molecular size, but showed little change in the decline stage. However, the emission wavelengths in the decline stage exhibited a blue shift. Very distinct C type and A type peaks in humic-like fluorophores were observed. With a prolonged culture time, the intensities of both of the peaks became strong and the excitation wavelengths of peak A showed a red shift, while the A:C ratios fell. More than 94% of fluorescent DOM was in the lower than 1 kDa molecular weight fraction.