明永冰川三株黄杆菌低温噬菌体的生物学特性研究

Biological Characteristics of Three Flavobacterium Cold-active Bacteriophages from Mingyong Glacier

对分离自明永冰川地区的3株黄杆菌低温噬菌体(MYSP03、MYSP08和MYTP08)的生物学特征开展了研究,采用氯化铯密度梯度离心法对3株低温噬菌体进行了纯化并系统比较了3株低温噬菌体的形态、宿主专一性、吸附速率、最佳感染复数及一步生长曲线等生物学特性。虽然3株低温噬菌体的宿主均为黄杆菌,但它们在形态及生物学特性上均表现不同。低温噬菌体MYSP03和08为头尾型噬菌体,呈复合结构,二者头部直径与尾管长度明显不同;噬菌体MYTP08与MYSP08形态差异较大,但它们都能感染同一宿主菌,MYTP08为复层噬菌体,衣壳直径为58 nm。噬菌体MYSP03、MYSP08和MYTP08分别在MOI为0.1、10和1时所产生的子代噬菌体数量最多,3株噬菌体的裂解量显著不同,其中MYTP08最大为137。

Biological characteristics of three Flavobacterium cold-active bacteriophages （MYSP03, MYSP08 and MYTP08） isolated from the Mingyong glacier area were investigated. Using CsC1 density gradient cen- trifugation, the phage particles were purified. Their morphology, host specificity, absorption rate, optimal MOI and one-step growth curve were determined, The results showed that three bacteriophages had different morphology and biological characteristics, although all their hosts belong to the genus Flavobacterium. The bacteriophage MYSP03 and MYSP08 were icosahedral phages with different size of head diameter and tail length. The morphologies of MYTP08 and MYSP08 were significantly different, but they could infect the same host cell. MYTP08 was a tectivirus, its capsid was about 58 nm in diameter. Furthermore, infection of the host cells by MYSP03 at an MOI of 0.1, MYSP08 at an MOI of 10, and MYTP08 at an MOI of 1, re- spectively, resulted in the maximum quantity of offsprings produced. Among them, MYTP08 had the highest burst size of 137.