一种由质粒编码的葡萄球菌素的特性

从５８株具不同质粒谱的抗生素抗药性金黄色葡萄球菌中经筛选得菌株８５０４１．它所产生的抗菌活性物质能抗热７５～８０℃１ｈ；对蛋白分解酶敏感，包括胰蛋白酶、蛋白酶Ｅ、蛋白酶Ｂ．Ｐ，抗ＤＮａｓｅ及ＲＮａｓｅ；抗菌谱显示，在４株葡萄球菌类中只对金黄色葡萄球菌２０９Ｐ有抗菌活性，而对４株肠道菌及枯草芽胞杆菌无作用．据此认为，该抗菌物质属细菌素（葡萄球菌素）．用ＳＤＳ及４３℃处理产细菌素菌株，进行质粒消除试验及其质粒ＤＮＡ琼脂糖凝胶电泳，证明菌株８５０４１有一个Ｍｒ≈２４．４×１０６的产细菌素质检．     

Microbiological evaluation of 4-(6-chloro-7H-purin-8-ylamino)-3-nitro-chromen-2-one with a comparison to antibacterial activity of standard drugs

Nucleophilic substitution of 4-chloro-3-nitro-2-oxo-2H-chromen-2-one 3 by 6-chloro-7H-purin-2-ylamine (a), yielded the corresponding 4-(6-chloro-7H-purin-8-ylamino)-3-nitro-chromen-2-one 4. The chemical structure of synthesized compound was characterized using IR and NMR spectra, and elemental analyses. The purified synthesized compound 4 was tested at concentrations 1, 3, 5 mg/ml for its antibacterial activity against three bacterial cultures: Staphylococcus aureus, Escherichia coli, and Bacillus cereus. The antibacterial activity of synthesized compound was compared to antibacterial activity of standard antibiotics cephalexine and streptomycin.     

溶藻细菌DC21的分离、鉴定及其溶藻特性

从云南滇池中分离得到一株溶藻细菌DC21,经鉴定为葡萄球菌属的1种(Staphylococcussp.),可溶解铜绿微囊等9种藻.试验表明,经过滤、离心沉降及高温灭菌处理的滤液,均能强烈抑制铜绿微囊藻的生长,说明其溶藻作用的因子之一为该菌的胞外分泌物,且这种物质具有热稳定性.细菌DC21使藻的光合作用受到抑制;在试验的第1d,受试藻的超氧物歧化酶及过氧化氢酶活性显著增高,但在第7d,这两种抗氧化保护酶的活性显著下降;受试藻的丙二醛含量明显增高,说明该菌促使其发生了膜脂过氧化.     

Urban stormwater disinfection, quality variability during storage and influence on the freshwater algae: Implications for reuse safety

Stormwater reuse is one of the most important ways to mitigate water resource shortage. However, urban stormwater contains many bacteria species, which threaten the reuse safety. Therefore, stormwater disinfection is highly needed. Although disinfection has been widely conducted in the drinking water and reclaimed water, it is rarely carried out for stormwater. This study collected the roof stormwater and undertook chlorination disinfection. Two typical bacteria, Escherichia coli (E. coli) and Staphylococcus aureus (S.aureus) were selected in this study to investigate the disinfection efficiency. It is found that bacteria species present in the stormwater had an important influence on disinfection efficiency while the original stormwater quality did not show an obvious affect. However, when the disinfected stormwater was stored, the stormwater quality was highly variable during its storage process and the variability was affected by bacteria species. The S.aureus containing stormwater showed a high variability of quality and S.aureus significantly regrew. However, the E.coli containing stormwater quality had a relatively low variability and E.coli did not significantly regrew. Additionally, it is noted that after storage, the dissolved form of stormwater was more positive to the freshwater algae's growth while the particulate form (including bacteria and other particulate matters) was less. This implies that a further treatment such as filtration is needed before the stored stormwater is recharged into receiving waters in order to remove particulate forms. These research outcomes can provide useful insight to effective stormwater disinfection and ensure reuse safety.