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Pamidimarri D. V. N Sudheer,윤주현,Sushma Chauhan,강택진,최권영 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.6
In this study, the production of 9-(nonanoyloxy) nonanoic acid from oleic acid was investigated. The whole cell biotransformation of oleic acid includes OhyA (hydratase), ADH (alcohol dehydrdogenase), and BVMO (Baeyer-Villiger Monooxygenase) enzymes consecutively. BVMOs are known to catalyze oxidative cleavage of long chain aliphatic ketones (e.g., 2-decanone, 10-ketooctadecanoic acid). However, the enzymes are difficult to overexpress in a soluble form in microorganisms. Thereby, this study has focused on screening and functional expression of the BVMOs in Escherichia coli. Initially BVMOs were selected by protein sequence analysis and were examined for their ability to express in soluble and active form to generate 9-(nonanoyloxy)nonanoic acid from oleic acid. Secondly various optimization strategies of inducer concentrations, co-expression with molecular chaperones, and different media conditions were investigated. Among the 9 BVMOs screened, three BVMOs were found to produce the target product and among these, Di_BVMO3 isolated from Dietzia sp. D5 was found to be best. Further, the soluble expression of Di_BVMO3 was enhanced by adding phosphoglycerate kinase as N-terminal fusion tag. The whole cell biotransformation with fusion enzyme resulted in 3 ~ 5-fold enhancement in product formation compared with the non-fusion counterpart. Final productivity up to 105.3 mg/L was achieved. Besides Di-BVMO3, other two new BVMOs of Rh_BVMO4 from Rhodococcus sp. RHA1 and AFL838 from Aspergillus flavus NRRL3357 were screened for production of 9-(nonanoyloxy)nonanoic acid and could be used for whole cell biotransformation reaction of other long chain ketones.
Sudheer, Pamidimarri D.V.N,Seo, Dahee,Kim, Eun-Joo,Chauhan, Sushma,Chunawala, J.R.,Choi, Kwon-Young Elsevier 2018 Enzyme and microbial technology Vol.119 No.-
<P><B>Abstract</B></P> <P>Production of (Z)-11-(heptanoyloxy)undec-9-enoic acid from recinoleic acid was achieved by whole-cell biotransformation by <I>Escherichia coli,</I> utilizing crude glycerol as the sole carbon source. Whole-cell biotransformation resulted in ∼93% conversion of the substrate ricinoleic acid to (Z)-11-(heptanoyloxy)undec-9-enoic acid. We replaced the inducer-dependent promoter system (T7 and Rhm promotors) with a constitutive promoter system. This resulted in successful expression of ADH, FadL, and E6-BVMO, without costly inducer addition. Efficacy evaluation of the whole-cell biotransformation by inducer-free system by five different <I>E. coli</I> strains revealed that the highest product titer was accumulated in <I>E. coli</I> BW25113 strain. The engineered inducer-free system using crude glycerol as the sole carbon source showed competitive performance with induction systems. Optimized conditions resulted in the accumulation of 7.38 ± 0.42 mM (Z)-11-(heptanoyloxy)undec-9-enoic acid, and when 10 mM substrate was used as feed concentration, the product titer reached 2.35 g/L. The inducer-free construct with constitutive promoter system that this study established, which utilizes the waste by-product crude glycerol, will pave the way for the economic synthesis of many industrially important chemicals, like (Z)-11-(heptanoyloxy)undec-9-enoic acid.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Conversion of recinoleic acid into (Z)-11-(heptanoyloxy)undec-9-enoic acid. </LI> <LI> BVMO-ADH-FadL expressing <I>E. coli</I> biotransformation system. </LI> <LI> Induction-free biotransformation system development. </LI> <LI> Waste by-product crude glycerol utilization as sole carbon source. </LI> </UL> </P>
Y-doped zinc oxide (YZO) nanoflowers, microstructural analysis and test their antibacterial activity
Sharma, S.K.,Sudheer Pamidimarri, D.V.N.,Kim, D.Y.,Na, J.G. Elsevier 2015 Materials Science and Engineering C Vol.53 No.-
Self-assembled 3D flower-like yttrium-doped zinc oxide (YZO) microstructures composed of nanorods were prepared by hydrothermal-precipitation, and tested their antibacterial activity. The morphological, structural, and compositional properties of YZO nanoflowers were characterized by various techniques, which confirmed a well-crystallized wurtzite hexagonal phase. X-ray photoelectron spectroscopy (XPS) of YZO nanopowder showed the 3d core level spectra of yttrium (Y), which formed by two components at about 158.2eV (3d<SUB>5/2</SUB>) and 160.4eV (3d<SUB>3/2</SUB>). The antibacterial activity of YZO nanoflowers were investigated using both gram-positive and gram-negative microorganisms. Enhancement in antibacterial activity was observed by the incorporation of yttrium (Y: 2at.%) of nanorod-based-flowers because of increased surface area. The prepared YZO nanocomposite showed potential as an antibacterial agent with applications in controlling the spread of infections and also the ability of fast antibacterial activity which can hinder the re-emergence of infection.
Hydrolytic Activities of Hydrolase Enzymes from Halophilic Microorganisms
Jervian Johnson,Pamidimarri D. V. N Sudheer,양영헌,김윤곤,최권영 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.4
Biomass is normally processed using acidic or basic catalysts, which both have their drawbacks. One suitable alternative is the application of hydrolytic enzymes that can convert biomass into simpler molecules, which can be fermented and processed into biofuel. Hydrolytic enzymes include proteases, lipases, amylases, cellulases, mannanases, chitinases, and xylanases. To discover sources of these enzymes, 19 halophilic strains of microorganisms that are significantly resistant to high salt concentrations were analyzed. The objective of this research was to identify halophilic microorganisms that produce the target enzymes with high activities, and to characterize these enzymes according to their salt tolerances. The results obtained indicated that Pseudolateromonas phenolica, Micrococcus luteus, Pseudoalteromonas peptidolytica, Halomonas socia, Marinobacter maritimus, and Exiguobacterium aurantiacum strain 2 produced the highest protease, lipase, amylase, cellulase, mannanase, chitinase, and xylanase relative activities, respectively. Except for protease from P. phenolica, all the enzymes tested for salt resistance either maintained or increased their activities with increasing NaCl concentration.
Comparative Response of Callus and Seedling of Jatropha curcas L. to Salinity Stress
Kumar, Nitish,Kaur, Meenakshi,Pamidimarri, D.V.N. Sudheer,Boricha, Girish,Reddy, Muppala P. Institute of Forest Science 2008 Journal of Forest Science Vol.24 No.2
Jatropha curcas L. is an oil bearing species with many uses and considerable economic potential as a biofuel crop. Salt stress effect on growth, ion accumulation, contents of protein, proline and antioxidant enzymes activity was determined in callus and seedling to understand the salt tolerance of the species. Exposure of callus and seedling to salt stress reduced growth in a concentration dependent manner. Under salt stress Na content increased significantly in both callus and seedling whereas, differential accumulation in the contents of K, Ca, and Mg was observed in callus and seedling. Soluble protein content differed significantly in callus as compared to seedling, however proline accumulation remained more or less constant with treatments. The proline concentration was ~2 to 3 times more in callus than in seedling. Salt stress induced qualitative and quantitative differences in superoxide dismutase (SOD; E.C. 1.15.1.1) and peroxidase (POX; E.C. 1.11.1.7) in callus and seedling. Salt induced changes of the recorded parameters were discussed in relation to salinity tolerance.
Comparative Response of Callus and Seedling of Jatropha curcas L. to Salinity Stress
Nitish Kumar,Meenakshi Kaur,D.V.N. Sudheer Pamidimarri,Girish Boricha,Muppala P. Reddy 강원대학교 산림과학연구소 2008 Journal of Forest Science Vol.24 No.2
Jatropha curcas L. is an oil bearing species with many uses and considerable economic potential as a biofuel crop. Salt stress effect on growth, ion accumulation, contents of protein, proline and antioxidant enzymes activity was determined in callus and seedling to understand the salt tolerance of the species. Exposure of callus and seedling to salt stress reduced growth in a concentration dependent manner. Under salt stress Na content increased significantly in both callus and seedling whereas, differential accumulation in the contents of K, Ca, and Mg was observed in callus and seedling. Soluble protein content differed significantly in callus as compared to seedling, however proline accumulation remained more or less constant with treatments. The proline concentration was ~2 to 3 times more in callus than in seedling. Salt stress induced qualitative and quantitative differences in superoxide dismutase (SOD; E.C. 1.15.1.1) and peroxidase (POX; E.C. 1.11.1.7) in callus and seedling. Salt induced changes of the recorded parameters were discussed in relation to salinity tolerance.
Yokimiko David,Mary Grace Baylon,Sudheer D. V. N. Pamidimarri,Kei-Anne Baritugo,채철기,김유진,김태완,김민식,나정걸,박시재 한국생물공학회 2017 Biotechnology and Bioprocess Engineering Vol.22 No.2
Coal is one of the major sources of energy, fuel, and other related chemicals. The processes to utilize coal for energy, fuel and other chemicals such as coal combustion, liquefaction, carbonization, and gasification pose a great threat to the environment by emitting toxic particles and CO2 to the atmosphere. Thus, biological beneficiation of coal can be a good strategy to utilize coal with environmental sustainability. Here, we report the screening of microorganisms able to degrade or depolymerize coal. These host strains are potential candidates for the development of biological treatment process of coal. A total of 45 microbial strains were isolated from sludge enriched with coal and were identified based on 16S rRNA sequencing. Four strains of three genera, Cupriavidus sp., Pseudomonas sp., and Alcaligenes sp., were further characterized for their abilities to degrade coal. The degree of coal degradation was analyzed by measuring the increase in absorbance at 450 nm by UV spectroscopy. These microorganisms were also able to increase the pH of the culture media as a response to the acidic nature of coal. Laccase-like activity was also found in these strains when tested for RBBR dye degradation. Since biological degradation of coal through the use of microorganisms is a good alternative to chemical combustion of coal, microbial strains isolated in this study can be potential biological catalysts for coal conversion into valuable chemicals.