一种鳞翅目昆虫致病菌的鉴定

应用传统的细菌分类方法（形态观察、培养特征、染色反应、生理生化反应等）并结合Biolog细菌鉴定系统．将从死亡的黄野螟（Heortia vitessoides Moore）幼虫身上分离得到的一种昆虫致病菌鉴定为沙雷氏菌属的粘质沙雷氏菌（Serratia marcescens Bizio）。     

产玫瑰红色素粘质沙雷氏菌的分离鉴定及抑菌活性

旨在分离鉴定产玫瑰红色素菌株,及其分离菌株和色素对病原菌的生物拮抗作用。经形态观察、生理生化试验和16S rRNA序列分析对其进行鉴定,通过控制变量法确定最佳产色素的温度及光照条件,破裂菌体提取色素分析此菌株产色素的量和红色素的性质,采用滤纸片法研究对病原菌的拮抗作用。结果表明：（1）分离细菌Dse\|01菌株最终鉴定为粘质沙雷氏菌（Serratia marcescens）;（2）该菌在25～35 ℃条件下培养色素形成较早且颜色较深,30 ℃温度下产色素最佳,光照对其色素形成时间没有明显影响;（3）30 ℃ 150 r·min-1培养24 h,提取获得色素粗品确定为灵菌红素,产量达（567.90±7.77）mg·L-1;（4）分离菌株的全菌液、上清液、菌体和提取色素对病原性大肠杆菌、沙门氏菌均无拮抗作用,而全菌液、菌体和提取色素对金黄色葡萄球菌具有明显的抑制作用。     

海南瓜实蝇致病细菌的分离鉴定及杀虫活性测定

从海南自然感病死亡的瓜实蝇上分离到1株对瓜实蝇高毒力的致病性菌株BC-hn,对其生防潜能进行评估.通过形态学观察、生理生化测定和16S rDNA序列测定分析,确定菌株BC-hn为黏质沙雷氏菌Serratia marcescens;用1×108 cfu/mL的菌悬液接种瓜实蝇进行室内杀虫活性测定,研究结果表明接种7d后成虫的平均死亡率为81.2％;卵孵化抑制率为37.5％,幼虫平均死亡率为53.0％,对蛹羽化的抑制作用最小,平均死亡率24.0％.用浓度为1×104～1×108菌悬液处理瓜实蝇成虫,7d后的LC50为1.16×106 cfu/mL.对其他昆虫致病性测定发现,菌株BC-hn对菜蚜也有较高的致死作用,接种7d后的死亡率为60.0％,但对供试的斜纹夜蛾、菜青虫、玉米螟和黄粉虫的死亡率均低于10.0％.菌株BC-hn对瓜实蝇成虫的毒力高,并对昆虫具有一定的专化性,具有较高的防治潜力.     

Isolation and identification of Serratia marcescens Ha1 and herbicidal activity of Ha1 ‘pesta’ granular formulation

A total of 479 bacterial strains were isolated from brine(Bohai, Qinhuangdao City, Hebei Province, China). Bioassay results indicated that 4 strains named Ha1, Ha17, Ha38, and Ha384 had herbicidal activity. And strain Ha1 had the highest effective herbicidal activity. As a result, this study aims to identify strain Ha1, characterize its physiological and biological activities, evaluate the herbicidal activity of its metabolites, and develop a ‘pesta' formulation and assess its effectiveness on Digitaria sanguinalis. Ha1 was identified as Serratia marcescens based on 16 S r DNA sequencing. This strain has a flagellum, a diameter of 0.5 to 0.8 μm, and a length of 0.9 to 2.0 μm. The indole test shows positive results, and the catalase enzyme exhibits strong positive reactions. Results further showed that the inhibitory concentration(IC50) of the crude extracts to D. sanguinalis radicula and coleoptile were 3.332 and 2.828 mg m L–1, respectively. Both the suppression of D. sanguinalis and the cell viability of the Ha1 formulation in ‘pesta' were higher when stored at 4°C than at(25±2)°C. These results indicated that S. marcescens Ha1 can potentially be used as a biocontrol agent against D. sanguinalis.     

一株灵菌红素产生菌的分离及其色素分析

[目的]从土壤中筛选出灵菌红素产生菌,并对其色素组成进行分析。[方法]利用平板筛选土壤中产红色素细菌,通过生理生化试验进行初步鉴定,摇瓶发酵后提取色素,色素组分经柱色谱与薄层色谱分离纯化后以紫外-可见光吸收光谱（UV-Vis）与液质联用（LC/MS）技术进行分析。[结果]从南昌地区土壤中分离得到1株产红色素的细菌NS-17,生理生化特征与粘质沙雷氏菌（Serratia marc-escens）吻合,从发酵后的菌体中分离得到2个具有相似UV-Vis与LC/MS特征的色素组分,组分1分析结果与已报道的灵菌红素一致,组分2具有未见报道的碱性条件下特异性UV-Vis图谱。[结论]分离得到1株产灵菌红素的粘质沙雷氏菌NS-17,并从该菌中分离得到2个色素组分。     

On the role of sawdust in the development of mastitis in cows

Sawdust was aspirated into one of the teatcups of the milking unit by induced liner slip during milking of 10 cows, which were then slaughtered. Sawdust particles were recovered from the interior of the quarters, the teat skin and the inside of the liners corresponding to both treated and untreated teats, and from the milk claw and the bucket as well. Sterile sawdust was introduced into the teat cisterns of three quarters of one cow. Clinical mastitis developed. The investigation was initiated by an outbreak of Serratia-mastitis in a dairy herd and supports the view that the outbreak was caused by contaminated sawdust used as litter in combination with improper detachment of the milking units. Widening of the impact concept is propsosed.     

一株粘质沙雷氏菌对蔬菜常见害虫毒力的研究

从棉田中自然死亡的棉铃虫体上分离得到一株昆虫致病菌,经鉴定为肠杆菌科沙雷氏菌属粘质沙雷氏菌(Serratiam arcescens)。实验证明该菌对烟青虫(H eliothis assulta)、菜青虫(Pieris rapae)、棉铃虫(H elicoverpa arm igera)、小菜蛾(Plutellaxylostella)等蔬菜上常见的鳞翅目害虫具有一定的毒力作用。该昆虫致病菌对目标昆虫的毒力主要表现在造成昆虫停食、行动迟缓、对刺激反应迟钝、幼虫生长期缩短、提前化蛹、不能正常羽化等方面。     

罹病光肩星天牛幼虫分离菌株的16S rDNA系统发育分析

[目的]研究从罹病光肩星天牛[Anoplophora glabripennis(Motsch.)]幼虫刻槽中分离的菌株BH-1的16S rDNA系统发育及该菌株杀虫特性。[方法]常规细菌鉴定,将BH-1接种健康天牛后观察杀虫效果并通过设计特异引物扩增其16S rDNA序列,进行测序及同源性分析。[结果]用1010cfu/ml BH-1菌液接种2龄天牛幼虫8 d后致死率达72.7%。BH-1与GenBank收录的Serratia marcescens的16S rDNA序列的同源性达99.5%,同时结合细菌的部分常规鉴定结果,鉴定出BH-1菌株为粘质沙雷氏菌(S.marcescens)。[结论]BH-1的发现为天牛的生物防治提供了参考。     

黏质沙雷菌——实验教学用良好菌种

黏质沙雷菌在医药、环境污染的治理、化工等领域均具有一定的应用价值,适合在很多专业的微生物学实验课中应用;它所具备的菌体小、分布广、生长快、营养要求低等生物学特性又使其可应用于很多实验项目中;它独特的菌落＂饰变＂性质更能丰富微生物遗传学实验的教学内容。对黏质沙雷菌的独特性质及其在医药、环境污染治理、化工和其他领域的应用作一阐述。