微生物學報Acta Microbiologica Sinica
48(4)：421~425; 4 April 2008
徐春光1,2, 梁秀梅2 , 黃英1*, 王黎明1, 崔慶峰1
(1 中國科學院微生物研究所, 微生物資源前期開發(fā)國家重點實驗室, 北京 100101)
(2 呼倫貝爾學院生命科學與化學學院, 呼倫貝爾 021008)
摘要：【目的】了解酸性土壤環(huán)境里中度嗜酸鏈霉菌的多樣性, 調查其物種資源,?！痉椒ā坑梅稚⒑筒钏匐x心法及選擇性分離培養(yǎng)基從14 份云南酸性土壤樣品中分離到367 株具有鏈霉菌培養(yǎng)特征的放線菌, 并進行了顏色分群,。從各顏色類群中選取代表菌株共97 株, 通過顯微形態(tài)觀察和pH 梯度生長實驗確定其中的中度嗜酸鏈霉菌。進一步從中篩選出16 株中度嗜酸鏈霉菌代表菌株, 進行16SrRNA 基因序列的相似性和系統(tǒng)發(fā)育分析, 并結合基因組DNA-DNA 相關性數據,。【結果】分離菌株歸為12 同的顏色類群, 其中80%屬于中度嗜酸鏈霉菌, 其代表菌株在系統(tǒng)發(fā)育樹上形成了8 個距離較遠且與已知種不同的進化分枝, 可能代表鏈霉菌屬內至少8 個不同的新基因種,?！窘Y論】用以上方法篩選出的中度嗜酸鏈霉菌可歸為8 個不同于已知種的進化群, 說明云南酸性土壤含有豐富多樣的中度嗜酸鏈霉菌新物種。
關鍵詞：中度嗜酸鏈霉菌; 16S rRNA 基因; 系統(tǒng)發(fā)育分析; 多樣性; 進化群
中圖分類號：Q939 文獻標識碼：A 文章編號：0001-6209 (2008) 04-0421-05
在酸性和偏酸性自然環(huán)境特別是土壤中, 中度嗜酸放線菌(pH 生長范圍4.5~7.5, 最適pH5.0~5.5)的數量遠遠超過嚴格嗜酸放線菌(pH 生長范圍3.5~6.5,最適pH4.5), 而鏈霉菌是其中的絕對優(yōu)勢菌群, 人們推斷中度嗜酸鏈霉菌在酸性土壤有機物質的降解和轉化過程中扮演著重要角色[1~4],。近年來國內外的研究[4, 5]表明, 酸性土壤中嗜酸稀有放線菌具有較豐富的種屬多樣性,。而對酸性環(huán)境中常見放線菌—鏈霉菌多樣性的研究, 更有可能發(fā)現新的抗真菌活性物質和在低pH 下有高活性的酶類, 并且對闡明它們的生態(tài)作用具有普遍意義[6, 7]。1991 年, Park 等[8]用5S rRNA 基因序列對專性嗜酸鏈霉菌,、中度嗜酸鏈霉菌和嗜中性鏈霉菌進行了系統(tǒng)發(fā)育學研究, 發(fā)現它們分別在進化樹上形成獨立分枝,。2003 年, Kim 等[9]利用分散和差速離心法從酸性土壤中分離到3 株專性嗜酸鏈霉菌, 并建立了鏈嗜酸菌新屬(Streptacidiphilus gen. nov.)。2004 年, Kim等[10]對一群中度嗜酸鏈霉菌的代表菌株KCTC 9926T進行了多相分類研究, 發(fā)現此菌株在鏈霉菌屬內形成一個單獨的分枝, 并將它所代表的菌群定為鏈霉菌屬的一個新種(Streptomyces yeochonensis sp. nov.),。我們從云南酸性土壤中分離純化到一批嗜酸鏈霉菌,通過表型特征和分子系統(tǒng)學分析, 對其中的中度嗜酸鏈霉菌的物種多樣性進行了研究,。
Isolation and Identification of the Temperate Bacteriophage from Isolated Strains of Streptococcus suis Serotype 2
Yuling Ma, Chengping Lu*, Hongjie Fan
(College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China)
Abstract: A PCR assay was developed to study the distributional characteristics of phage integrase gene in Streptococcus suis serotype 2 (SS2). A 323bp distinct DNA target can be amplified in 25 strains of virulent SS2, while can not be amplified in avirulent strain T15, 5 strains of other serotypes（SS1, SS7, SS9） and strains of group C Streptococcus strains from pigs, which suggested that the phage integrase gene may be related to the pathogenicity of SS2 and can be consider as a detection factor of the virulent gene of SS2. The sequencing and restriction endonuclease analysis of the PCR products were also done. Comparisons between the sequences of phage integrase gene with that of SS2 strain, showed a high homology with SS2 China strains 98HAH33, 05ZYH33 and North American strain 89.1591. Complete cell lysis was observed with SS2 virulent strains but not with avirulent strain T15 after the induction by mitomycin C. Electron microscopy analysis of the lysate from SS2 virulent strains HA9801 and ZY05719 revealed the presence of phage particles. The induced phage, named SS2-HA and SS2-ZY, both have a small isometric nucleocapsid approximately 50 nm in diameter and have no tail and is therefore a member of the Tectiviridae family. The phage integrase gene sequence of phage SS2-HA and SS2-ZY shared high homologue identities with virulent SS2 strains, which suggested that the phage integrase gene of SS2 has high specify. The temperate phage and phage integrase gene can only detected from SS2 virulent strains but not from avirulent strain, and the detection of phage integrase gene was related to the virulence-associate factors of SS2, such as the muramidase-released protein gene (mrp), which suggested that the temperate phage of SS2 may be related to the pathogenicity of SS2.
Keywords: Streptococcus suis type 2; temperate bacteriophage; induce
基金項目: 國家自然科學基金(30770002); 國家“973 項目”(2004CB719601)
*通訊作者。Tel/Fax: +86-10-64807311; E-mail: [email protected]
作者簡介: 徐春光(1978. ), 女, 內蒙古呼倫貝爾人, 呼倫貝爾學院生命科學與化學學院助教, 主要從事放線菌系統(tǒng)分類學研究,。
收稿日期: 2007-10-29; 修回日期: 2008-01-03
ISSN 0001-6209; CN11-1995/Q
全文下載：云南酸性土壤中度嗜酸鏈霉菌的多樣性
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