中国农业科学 ›› 2012, Vol. 45 ›› Issue (18): 3792-3800.doi: 10.3864/j.issn.0578-1752.2012.18.012

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

草酸青霉菌I1的cDNA文库构建及其溶磷相关基因的筛选

 唐超西, 龚明波, 李顺鹏, 朱昌雄   

  1. 1.中国农业科学院农业环境与可持续发展研究所,北京 100081
    2.中国农业科学院农业资源与农业区划研究所,北京 100081
    3.南京农业大学生命科学学院/农业部农业环境微生物工程重点开放实验室,南京 210095
  • 收稿日期:2012-01-19 出版日期:2012-09-15 发布日期:2012-05-17
  • 通讯作者: 通信作者龚明波,Tel/Fax:010-82108689;E-mail: gongcaas@163.com; 通信作者朱昌雄,Tel/Fax:010-82105987;E-mail: zhucx120@163.com
  • 作者简介:唐超西,Tel/Fax:010-82108689;E-mail:tangchaoxi240@163.com
  • 基金资助:

    中央级公益性科研院所基本科研业务费中国农科院资源区划所专项资金(2011-10)、水体污染控制与治理国家科技重大专项巢湖项目农业面源课题(2009ZX07103-002)

Construction of cDNA Library of Penicillium oxalicum I1 and Screening of Phosphate-Dissolving Related Gene

 TANG  Chao-Xi, GONG  Ming-Bo, LI  Shun-Peng, ZHU  Chang-Xiong   

  1. 1.中国农业科学院农业环境与可持续发展研究所,北京 100081
    2.中国农业科学院农业资源与农业区划研究所,北京 100081
    3.南京农业大学生命科学学院/农业部农业环境微生物工程重点开放实验室,南京 210095
  • Received:2012-01-19 Online:2012-09-15 Published:2012-05-17

摘要: 【目的】构建草酸青霉菌I1的cDNA文库,筛选溶磷相关基因。【方法】利用SMART技术构建草酸青霉菌I1的初级cDNA文库,通过难溶磷培养基筛选具有溶磷能力的转化子,测序并进行生物信息学分析。在难溶磷液体培养基中,进行转化子对溶液pH值、可溶磷含量的影响和产有机酸试验。【结果】成功构建了草酸青霉菌I1的初级cDNA文库,其库容量约为5.29×106 cfu•mL-1,重组率为99%;利用难溶磷固体培养基筛选,得到具有溶磷圈的转化子48个,其中转化子I-4的cDNA序列全长536 bp,为一个新的序列,基因编码氨基酸残基序列长129 n.t。转化子E. coli HST08 I-4在液体难溶磷培养基中培养,提高了有机酸的表达量,并增加了有机酸的种类,在培养12 h后,开始产生乙酸,24 h后,溶液中产生乳酸、苹果酸和α-酮戊二酸,培养36 h,溶液pH值由6.32降到3.69,可溶磷含量达到0.1076 mg•mL-1。【结论】从草酸青霉I1中筛选到一个溶磷相关基因pstI。

关键词: 草酸青霉菌, cDNA文库, 溶磷相关基因, 有机酸

Abstract: 【Objective】The objective of this study is to obtain phosphate-dissolving related genes from cDNA library of Penicillium oxalicum I1. 【Method】 A primary cDNA library of P. oxalicum I1 was constructed using SMART (switching mechanism at 5′ end of RNA transcript) technique. Transformants with phosphate-dissolving activities were screened on the insoluble phosphate medium, and the sequence of the bioinformation was analysed. To study the phosphate-dissolving mechanisms of the cloned gene, the changes of the pH value, the soluble phosphate content and the production of organic acids were analyzed in the insoluble phosphate liquid medium inoculated with the transformants harboring the phosphate-dissolving gene. 【Result】A cDNA library of P. oxalicum I1 was successfully constructed. Titer tests showed that the content of constructed P. oxalicum I1 cDNA library reached 5.29×106 cfu•mL-1, in which the percentage of recombinants was 99%. Forty-eight transformants with phosphate-dissolving activities were screened on the solid medium with insoluble phosphate. The corresponding gene in one of these transformants was identified. The full length cDNA of transformant I-4 was 536 bp, encoding a predicted protein with 129 amino acid residues. The expression of phosphate-dissolving gene in E. coli could enhance organic acids secretion and improve the phosphate solubilizing activity. It was found that acetic acid was secreted in 12 h, and lactic acid, malic acid and α-ketoglutarate were secreted in 24 h. The transformant I-4 decreased the pH value of medium from 6.32 to 3.69 and released soluble phosphate up to 0.1076 mg•mL-1 in 36 h. 【Conclusion】A phosphate-dissolving related gene, designated pstI, was screened from the cDNA library of P. oxalicum I1.

Key words: Penicillium oxalicum, cDNA library, phosphate-solubilizing related gene, organic acid