Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India.
PLoS One. 2012;7(3):e31498. doi: 10.1371/journal.pone.0031498. Epub 2012 Mar 5.
Bacteriocins are antimicrobial peptides that are produced by bacteria as a defense mechanism in complex environments. Identification and characterization of novel bacteriocins in novel strains of bacteria is one of the important fields in bacteriology.
METHODOLOGY/FINDINGS: The strain GI-9 was identified as Brevibacillus sp. by 16 S rRNA gene sequence analysis. The bacteriocin produced by strain GI-9, namely, laterosporulin was purified from supernatant of the culture grown under optimal conditions using hydrophobic interaction chromatography and reverse-phase HPLC. The bacteriocin was active against a wide range of Gram-positive and Gram-negative bacteria. MALDI-TOF experiments determined the precise molecular mass of the peptide to be of 5.6 kDa and N-terminal sequencing of the thermo-stable peptide revealed low similarity with existing antimicrobial peptides. The putative open reading frame (ORF) encoding laterosporulin and its surrounding genomic region was fished out from the draft genome sequence of GI-9. Sequence analysis of the putative bacteriocin gene did not show significant similarity to any reported bacteriocin producing genes in database.
We have identified a bacteriocin producing strain GI-9, belonging to the genus Brevibacillus sp. Biochemical and genomic characterization of laterosporulin suggests it as a novel bacteriocin with broad spectrum antibacterial activity.
细菌素是一种抗菌肽，由细菌在复杂环境中作为防御机制产生。在新型细菌菌株中鉴定和表征新型细菌素是细菌学的一个重要领域。
方法/发现：通过 16S rRNA 基因序列分析，将菌株 GI-9 鉴定为短芽孢杆菌属。由 GI-9 菌株产生的细菌素，即 laterosporulin，在最佳条件下培养的培养物上清液中使用疏水相互作用色谱法和反相 HPLC 从 culture 中纯化。该细菌素对广泛的革兰氏阳性和革兰氏阴性细菌具有活性。MALDI-TOF 实验确定该肽的精确分子量为 5.6 kDa，并且热稳定肽的 N 端测序显示与现有抗菌肽的低相似性。从 GI-9 的基因组草图序列中钓出编码 laterosporulin 的推定开放阅读框 (ORF)及其周围基因组区域。对推定的细菌素基因的序列分析显示与数据库中报道的任何产细菌素基因均无显着相似性。
我们已经鉴定出一种产细菌素的菌株 GI-9，属于短芽孢杆菌属。laterosporulin 的生化和基因组特征表明它是一种具有广谱抗菌活性的新型细菌素。
