Touraj Rahimi; Ali Niazi; Seyed Mohsen Taghavi; Esmaeil Ebrahimie; Shahab Ayatollahi; Tahereh Deihimi
Abstract
The isolation of native microorganism that produced biosurfactants in order to oil pollutants bioremediation and hydrophobic oil hydrocarbons availability inter soil texture has become important issues in bioremediation technology. Surfactin is one of the biosurfactants with more application that produced ...
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The isolation of native microorganism that produced biosurfactants in order to oil pollutants bioremediation and hydrophobic oil hydrocarbons availability inter soil texture has become important issues in bioremediation technology. Surfactin is one of the biosurfactants with more application that produced by Bacillus subtilis strains could overcome these problems. Thus in this study, we investigated operon which involved in surfactin biosynthesis and its regulator comQXPA operon due to a high level of surfactin biosynthesis by B. subtilis MJ01 isolated from oil contaminated soil based on comparative genomics approaches. Surfactin operon localized and compared among six genomes of close relative strains and MJ01 indicated that missense point mutations on genes of surfactin operon were existence. These mutations affected NPRS protein AMP-binding domain that responsible to bind amino acid to correct the situation on surfactin peptide ring. It seems that lack of hemolytic and anti-microbial function of MJ01 surfactin was due to the creation of missense mutation and modifications in the surfactin biosynthesis NPRS enzyme structure. Moreover, srf genes expression regulated by comQXPA quorum sensing operon. MJ01 Quorum sensing operon rearrangement showed that part of the comQ gene was extended into comX gene and these genes had overlap region. Results suggested that in MJ01 genome has been occurred specific combination of QS genes organization. Despite high similarity of three genes comQXP among MJ01 with BEST7613 and other subtilis strains group, comA gene showed high identity with spizizenii strains group.
Tahereh Deihimi; Esmaeil Ebrahimie; Ali Niazi; Mansour Ebrahimi; Shahab Ayatollahi; Ahmad Tahmasebi; Touraj Rahimi; Moein Jahanbani Veshareh
Abstract
Applying microorganism in oil recovery has attracted attentions recently. Surfactin produced by Bacillus subtilis is widely used industrially in a range of industrial applications in pharmecutical and environmental sectors. Little information about molecular mechanism of suffactin compound is available. ...
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Applying microorganism in oil recovery has attracted attentions recently. Surfactin produced by Bacillus subtilis is widely used industrially in a range of industrial applications in pharmecutical and environmental sectors. Little information about molecular mechanism of suffactin compound is available. In this study, we performed promoter and network analysis of surfactin production genes in Bacillus subtilis subsp. MJ01 (isolated from oil contaminated soil in South of Iran), spizizenii and 168. Our analysis revealed that comQ and comX are the genes with sequence alterations among these three strains of Bacillus subtilis and are involved in surfactin production. Promoter analysis indicated that lrp, argR, rpoD, purr and ihf are overrepresented and have the highest number of transcription factor binding sites (TFBs) on the key surfactin production genes in all 3 strains. Also the pattern of TFBs among these three strains was completely different. Interestingly, there is distinct difference between 168, spizizenii and MJ01 in their frequency of TFs that activate genes involve in surfactin production. Attribute weighting algorithms and decision tree analysis revealed ihf, rpoD and flHCD as the most important TF among surfactin production. Network analysis identified two significant network modules. The first one consists of key genes involved in surfactin production and the second module includes key TFs, involved in regulation of surfactin production. Our findings enhance understanding the molecular mechanism of surfactin production through systems biology analysis.
