Random Mutagenesis of the Aspergillus oryzae Genome Results in Fungal Antibacterial Activity.
Random Mutagenesis of the Aspergillus oryzae Genome Results in Fungal Antibacterial Activity.
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DOI：
10.1155/2013/901697
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发表时间：
2013
影响因子：
3.4
通讯作者：
Hayman JR
中科院分区：
文献类型：
--
作者：
Leonard CA;Brown SD;Hayman JR
多重耐药细菌会在医院和社区造成严重感染。需要开发新的药物来对抗耐药微生物。微生物来源的天然产品是目前最可用的抗生素的来源。我们推测米曲霉的随机诱变会导致抗菌化合物的分泌。为了解决这一假设，我们开发了一种筛选方法来鉴定在体外抑制耐甲氧西林金黄色葡萄球菌(MRSA)生长的单个米曲霉突变体。为了随机产生米曲霉突变菌株，用甲烷磺酸乙酯(EMS)处理孢子。在筛选中测试了3000多种经EMS处理的米曲霉培养物，其中一株菌株CAL220显示出形态和抗菌活性的变化。该菌株的培养上清液对甲氧西林敏感的金黄色葡萄球菌、MRSA和铜绿假单胞菌有抗菌活性，但对肺炎克雷伯菌和普通变形杆菌无抗菌活性。这项研究的结果支持了我们的假设，并表明所使用的筛选方法足以和适当地检测由米曲霉诱变产生的分泌型抗菌真菌化合物。由于米曲霉的基因组已经测序，并且有系统可用于该生物体的遗传转化，因此可以引入定向突变和随机突变来促进利用该系统发现新的抗菌化合物。
Multidrug-resistant bacteria cause severe infections in hospitals and communities. Development of new drugs to combat resistant microorganisms is needed. Natural products of microbial origin are the source of most currently available antibiotics. We hypothesized that random mutagenesis of Aspergillus oryzae would result in secretion of antibacterial compounds. To address this hypothesis, we developed a screen to identify individual A. oryzae mutants that inhibit the growth of Methicillin-resistant Staphylococcus aureus (MRSA) in vitro. To randomly generate A. oryzae mutant strains, spores were treated with ethyl methanesulfonate (EMS). Over 3000 EMS-treated A. oryzae cultures were tested in the screen, and one isolate, CAL220, exhibited altered morphology and antibacterial activity. Culture supernatant from this isolate showed antibacterial activity against Methicillin-sensitive Staphylococcus aureus, MRSA, and Pseudomonas aeruginosa, but not Klebsiella pneumonia or Proteus vulgaris. The results of this study support our hypothesis and suggest that the screen used is sufficient and appropriate to detect secreted antibacterial fungal compounds resulting from mutagenesis of A. oryzae. Because the genome of A. oryzae has been sequenced and systems are available for genetic transformation of this organism, targeted as well as random mutations may be introduced to facilitate the discovery of novel antibacterial compounds using this system.