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Biotransformation of Flavone by CYP105P2 from Streptomyces peucetius
( Niraula ),( Narayan Prasad ),( Saurabh Bhattarai ),( Na Rae Lee ),( Jae Kyung Sohng ),( Tae Jin Oh ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.8
Biocatalytic transfer of oxygen in isolated cytochrome P450 or whole microbial cells is an elegant and efficient way to achieve selective hydroxylation. Cytochrome P450 CYP105P2 was isolated from Streptomyces peucetius that showed a high degree of amino acid identity with hydroxylases. Previously performed homology modeling, and subsequent docking of the model with flavone, displayed a reasonable docked structure. Therefore, in this study, in a pursuit to hydroxylate the flavone ring, CYP105P2 was co-expressed in a two-vector system with putidaredoxin reductase (camA) and putidaredoxin (camB) from Pseudomonas putida for efficient electron transport. HPLC analysis of the isolated product, together with LCMS analysis, showed a monohydroxylated flavone, which was further established by subsequent ESI/MS-MS, A successful 10.35% yield was achieved with the whole-cell bioconversion reaction in Escherichia coli. We verified that CYP105P2 is a potential bacterial hydroxylase.
Niraula Sarbjeet,Rose Meaghan,Chang Woo-Suk 한국미생물학회 2022 The journal of microbiology Vol.60 No.10
Microbial communities in the rhizosphere play a crucial role in determining plant growth and crop yield. A few studies have been performed to evaluate the diversity and co-occurrence patterns of rhizosphere microbiomes in soybean (Glycine max) at a regional scale. Here, we used a culture-independent method to compare the bacterial communities of the soybean rhizosphere between Nebraska (NE), a high-yield state, and Oklahoma (OK), a low-yield state. It is well known that the rhizosphere microbiome is a subset of microbes that ultimately get colonized by microbial communities from the surrounding bulk soil. Therefore, we hypothesized that differences in the soybean yield are attributed to the variations in the rhizosphere microbes at taxonomic, functional, and community levels. In addition, soil physicochemical properties were also evaluated from each sampling site for comparative study. Our result showed that distinct clusters were formed between NE and OK in terms of their soil physicochemical property. Among 3 primary nutrients (i.e., nitrogen, phosphorus, and potassium), potassium is more positively correlated with the high-yield state NE samples. We also attempted to identify keystone communities that significantly affected the soybean yield using co-occurrence network patterns. Network analysis revealed that communities formed distinct clusters in which members of modules having significantly positive correlations with the soybean yield were more abundant in NE than OK. In addition, we identified the most influential bacteria for the soybean yield in the identified modules. For instance, included are class Anaerolineae, family Micromonosporaceae, genus Plantomyces, and genus Nitrospira in the most complex module (ME9) and genus Rhizobium in ME23. This research would help to further identify a way to increase soybean yield in low-yield states in the U.S. as well as worldwide by reconstructing the microbial communities in the rhizosphere.
Niraula, M.,Adhikari, S.,Lee, D.Y.,Kim, E.K.,Yoon, S.J.,Dhungel, S.K.,Lee, W.,Shrestha, N.K.,Han, S.H. North Holland ; Elsevier Science Ltd 2014 Chemical physics letters Vol.593 No.-
Self-organized Titania nanotubes grown on a titanium foil by anodization is loaded with Ag<SUB>3</SUB>PO<SUB>4</SUB> using successive ionic layer adsorption and reaction method. The hybrid heterojunction nanostructure film thus prepared is investigated for visible light induced photocatalytic decomposition of azo-dye and compared with the bulk Ag<SUB>3</SUB>PO<SUB>4</SUB> film deposited on a Ti-substrate. The results demonstrate that the hybrid heterostructure exhibits much better photocatalytic performance due to the higher photostability.
Malla, S.,Niraula, N.P.,Liou, K.,Sohng, J.K. G. Fischer 2010 MICROBIOLOGICAL RESEARCH Vol.165 No.4
The resistance genes drrABC from Streptomyces peucetius ATCC 27952 were cloned into the pIBR25 expression vector under a strong ermE* promoter to enhance doxorubicin (DXR) production. The recombinant expression plasmids, pDrrAB25, pDrrC25 and pDrrABC25, were constructed to overexpress drrAB, drrC and drrABC, respectively, in S. peucetius ATCC 27952. The recombinant strains produced more DXR than the parental strain: a 2.2-fold increase with pDrrAB25, a 5.1-fold increase with pDrrC25, and a 2.4-fold increase with pDrrABC25. We also studied the relative ratios of doxorubicin, daunorubicin and ε-rhodomycinone produced in these recombinant strains.
Malla, Sailesh,Niraula, Narayan Prasad,Liou, Kwangkyoung,Sohng, Jae Kyung Elsevier 2009 Journal of bioscience and bioengineering Vol.108 No.2
<P><B>Abstract</B></P><P>To enhance doxorubicin (DXR) production, the structural sugar biosynthesis genes <I>desIII</I> and <I>desIV</I> from <I>Streptomyces venezuelae</I> ATCC 15439 and the glycosyltransferase pair <I>dnrS/dnrQ</I> from <I>Streptomyces peucetius</I> ATCC 27952 were cloned into the expression vector pIBR25, which contains a strong <I>ermE⁎</I> promoter. The recombinant plasmids pDnrS25 and pDnrQS25 were constructed for overexpression of <I>dnrS</I> and the <I>dnrS/dnrQ</I> pair, whereas pDesSD25 and pDesQS25 were constructed to express <I>desIII/desIV</I> and <I>dnrS/dnrQ–desIII/desIV</I>, respectively. All of these recombinant plasmids were introduced into <I>S. peucetius</I> ATCC 27952. The recombinant strains produced more DXR than the <I>S. peucetius</I> parental strain: a 1.2-fold increase with pDnrS25, a 2.8-fold increase with pDnrQS25, a 2.6-fold increase with pDesSD25, and a 5.6-fold increase with pDesQS25. This study showed that DXR production was significantly enhanced by overexpression of potential biosynthetic sugar genes and glycosyltransferase.</P>
( Ariungerel Mandakh ),( Narayan Prasad Niraula ),( Eung Pil Kim ),( Jae Kyung Sohng ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.12
Pantothenate kinase (PanK) catalyzes the first step in the biosynthesis of the essential and ubiquitous cofactor coenzyme A (CoA) in all organisms. Here, we report the identification, cloning, and characterization of panK-sp from Streptomyces peucetius ATCC 27952. The gene encoded a protein of 332 amino acids with a calculated molecular mass of 36.8 kDa and high homology with PanK from S. avermitilis and S. coelicolor A3(2). To elucidate the putative function of PanK-sp, it was cloned into pET32a(+) to construct pPKSP32, and the PanK-sp was then expressed in E. coli BL21(DE3) as a His-tag fusion protein and purified by immobilized metal affinity chromatography. The enzyme assay of PanK-sp was carried out as a coupling assay. The gradual decrease in NADH concentration with time clearly indicated the phosphorylating activity of PanK-sp. Furthermore, the ca. 1.4-fold increase of DXR and the ca. 1.5-fold increase of actinorhodin by in vivo overexpression of panK-sp, constructed in pIBR25 under the control of a strong ermE* promoter, established its positive role in secondary metabolite production from S. peucetius and S. coelicolor, respectively.