A Correlative Evaluation of Morphology and Rheology of Aspergillus terreus during Lovastatin Fermentation

Pradeep Srivastava,Kamakshi Gupta,P. K. Mishra 한국생물공학회 2007 Biotechnology and Bioprocess Engineering Vol.12 No.2

Lovastatin, a secondary metabolite, was produced by fermentation process using Aspergillus terreus in an internal loop airlift reactor. It is a highly aerobic fermentation process. Biomass concentration and cell morphology were evaluated and observed to contribute significantly to the high viscosity and pseudoplastic non-Newtonian behavior of the broth. Typical morphological changes over 10 days in the fermentation broth were studied. The viscosity increased from the start of the fermentation with an increasing cell mass content, reached to a maximum of 60 N/m2·s at 160 h and then declined after the branching of the hyphae with the formation of arthrospores. Rheological parameters like consistency index and fluidity index were evaluated. The consistency index was observed to increase from 9.8 to 66.85 N/m2, while fluidity index decreased from 0.69 to 0.48 s1 during 10 days of lovastatin production. A correlation between growth and consistency index of the broth has been evaluated.

Recovery of copper from a surface altered chalcopyrite contained ball mill spillage through bio-hydrometallurgical route

Sandeep Panda,Pradeep Chandra Rout,Chinmaya Kumar Sarangi,Srabani Mishra,Nilotpala Pradhan,Umaballav Mohapatra,Tondepu Subbaiah,Lala Behari Sukla,Barada Kanta Mishra 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.3

Bioleaching studies for chalcopyrite contained ball mill spillages are very scarce in the literature. We developeda process flow sheet for the recovery of copper metal from surface activated (600 oC, 15 min) ball mill spillagethrough bio-hydrometallurgical processing route. Bioleaching of the activated sample using a mixed meso-acidophilicbacterial consortium predominantly A. ferrooxidans strains was found to be effective at a lixiviant flow rate of1.5 L/h, enabling a maximum 72.36% copper recovery in 20 days. Mineralogical as well as morphological changesover the sample surface were seen to trigger the bioleaching efficiency of meso-acidophiles, thereby contributing towardsan enhanced copper recovery from the ball mill spillage. The bio-leach liquor containing 1.84 g/L Cu was purified throughsolvent extraction using LIX 84I in kerosene prior to the recovery of copper metal by electrowinning. Purity of thecopper produced through this process was 99.99%.

A Correlative Evaluation of Morphology and Rheology of Aspergillus terreus during Lovastatin Fermentation

Gupta, Kamakshi,Mishra, P.K.,Srivastava, Pradeep Korean Society for Biotechnology and Bioengineerin 2007 Biotechnology and Bioprocess Engineering Vol.12 No.2

Lovastatin, a secondary metabolite, was produced by fermentation process using Aspergillus terreus in an internal loop airlift reactor. It is a highly aerobic fermentation process. Biomass concentration and cell morphology were evaluated and observed to contribute significantly to the high viscosity and pseudoplastic non-Newtonian behavior of the broth. Typical morphological changes over 10 days in the fermentation broth were studied. The viscosity increased from the start of the fermentation with an increasing cell mass content, reached to a maximum of $60N/m^2{\cdot}s$ at 160 h and then declined after the branching of the hyphae with the formation of arthrospores. Rheological parameters like consistency index and fluidity index were evaluated. The consistency index was observed to increase from 9.8 to $66.85 N/m^2$, while fluidity index decreased from 0.69 to $0.48s^{-1}$ during 10 days of lovastatin production. A correlation between growth and consistency index of the broth has been evaluated.

Numerical modeling and prediction of adhesion failure of adhesively bonded composite T-Joint structure

Subhransu K Panda,Pradeep K Mishra,Subrata K. Panda 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.74 No.6

This study is reported the adhesion failure in adhesive bonded composite and specifically for the T-joint structure. Three-dimensional finite element analysis has been performed using a commercial tool and the necessary outcomes are obtained via an eight noded solid element (Solid 185-element) from the library of ANSYS. The structural analysis input has been incurred through ANSYS parametric design language (APDL) code. The normal and shear stress distributions along different layers of the joint structure have been evaluated as the final outcomes. Based on the stress distributions, failure location in the composite joint structure has been identified by using the Tsai-Wu stress failure criterion. It has been found that the failure index is maximum at the interface between flange and web part of the joint (top layer) which indicates the probable location of failure initiation. This kind of failures are considered as adhesion failure and the failure propagation is governed by strain energy release rate (SERR) of fracture mechanics. The different adhesion failure lengths are also considered at the failure location to calculate the SERR values i.e. mode I fracture (opening), mode II fracture (sliding) and mode III fracture (tearing) along the failure front. Also, virtual crack closure technique (VCCT) principle of fracture mechanics steps is used to calculate the above said SERRs. It is found that the mode I SERR is more dominating compared to other two modes of failure for the joint considered. Finally, the influences of various parametric (geometrical and material) effect on SERR of the joint structure are evaluated and discussed in details.

Theoretical and experimental modal responses of adhesive bonded T-joints

Mani Chandra Kunche,Pradeep K. Mishra,Hari Babu Nallala,Chetan K. Hirwani,Pankaj V. Katariya,Subhransu Panda,Subrata K. Panda 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.29 No.5

The modal frequency responses of adhesive bonded T-joint structure have been analyzed numerically and verified with own experimental data. For this purpose, the damped free frequencies of the bonded joint have been computed using a three-dimensional finite element model via ANSYS parametric design language (APDL) code. The practical relevance of the joint structure analysis has been established by comparing the simulation data with the in-house experimental values. Additionally, the influences of various geometrical and material parameters on the damped free frequency responses of the joint structure have been investigated and final inferences discussed in details. It is observed that the natural frequency values increase for the higher aspect ratios of the joint structure. Also, the joint made up of Glass fiber/epoxy with quasi-isotropic fiber orientation indicates more resistance towards free vibration.

In-vitro Studies on Copper Nanoparticles and Nano-hydroxyapatite Infused Biopolymeric Composite Scaffolds for Bone Bioengineering Applications

Shikha Kumari,Abha Mishra,Divakar Singh,Chenzhong Li,Pradeep Srivastava 한국생물공학회 2023 Biotechnology and Bioprocess Engineering Vol.28 No.1

This research study deals with the development of copper nanoparticles (CN) and nano-hydroxyapatite (nHAP) infused chitosan (C) and gelatin (G) based nanocomposite scaffolds for bone tissue engineering applications. Human-origin osteoblast cells (MG-63) were seeded over the scaffolds to investigate the novel biomimetic extracellular matrix system. The scanning electron microscopy (SEM) showed an average pore size between 100-146 μm for all the C-G-nHAP-CN based scaffolds. The in-vitro degradation study showed 74-83% degradation for CN-based scaffolds. For 0.03% CN based scaffold degradation rate (84%) was very close to the control scaffold. Swelling ratio was highest for the chitosan scaffold and it was in the range between 5.25-5.93 mg/mL for other scaffolds. Compressive moduli were highest for 0.03% CN scaffold (3.32 MPa) which was relatively very high in comparison to C-G-nHAP scaffold with 2.4 MPa strength in a wet state. Stress-strain graphs also show the maximum displacement by 0.03% CN scaffold. The functional and structural analysis for the scaffolds showed the presence of nHAP in the scaffold and CN peaks within the composite structure. Differential scanning colorimetry testing showed reduced crystallinity in CN-based scaffolds with a melting temperature of 320ºC. Their 2D cell behaviour in the Electrical Cell Impedance System (ECIS) study showed maximum cell spreading and growth in 0.02% CN-based scaffold. The cell-seeded composite was tested for 3-(4,5-dimethylthiazolyl-2)-2,5- diphenyltetrazolium bromide (MTT), 4,6-diamidino-2- phenylindole (DAPI), and acridine orange and propidium iodide (AOPI) assay for testing its cytocompatibility for MG-63 cell line. Cell proliferation and cell spreading was observed by SEM in all the CN-based scaffolds. Alkaline phosphatase (ALP) activity was highest in 0.03% CN scaffold with 2.0 optical density (OD) value. Alizarin Red Stain (ARS) staining was performed to support this study. It can be statistically depicted that nHAP and 0.03% CNbased scaffold could be potential biomaterial for minor to severe bone-related tissue regeneration applications.

Hydrogen-Atom Abstraction Reaction of CF₃CH₂OCF₃ by Hydroxyl Radical

Singh, Hari Ji,Mishra, Bhupesh Kumar,Rao, Pradeep Kumar Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.12

Theoretical investigations are carried out on the title reaction by means of ab-initio and DFT methods. The optimized geometries, frequencies and minimum energy path are obtained at UB3LYP/6-311G(d,p) level. Single point energy calculations are performed at MP2 and MP4 levels of theory. Energetics are further refined by calculating the energy of the species with a modified Gaussian-2 method, G2M(CC,MP2). The rate constant of the reaction is calculated using Canonical Transition State Theory (CTST) utilizing the ab-initio data obtained during the present study and is found to be $5.47{\times}10^{-12}\;cm^3\;molecule^{-1}s^{-1}$ at 298 K and 1 atm.

Synthesis and Biological Evaluation of Novel 2-[Substituted acetly]-amino-5-alkyl]-amino-5-alkyl-1,3,4-thiadiazoles

Shakya, Ashok K.,Mishra, Pradeep,Patnaik, G.K.,Shukla, Rakesh,Srimal, R.C. The Pharmaceutical Society of Korea 1998 Archives of Pharmacal Research Vol.21 No.6

Sixteen novel 2-substituted acetyl amino-5-alkyl-1,3,4-thiadiazol were synthesized and screened for their pharmacological activities. A few of the compounds namely 11, 12 and 16 showed anti-inflammatory activities comparable to phenylbutazone. Compound 12 also showed significan non-specific spasmolytic activity. Diuretic activity of compound 15 at a dose level of 90mg/kg p.o. was two fold higher compared to 50mg/kg p.o. of furosemide. Comparable diuresis was aso produced by compounds 9, 10, and 16.

Enhanced Continuous Production of Lovastatin Using Pellets and Siran Supported Growth of Aspergillus Terreus in an Airlift Reactor

Kamakshi Gupta,P. K. Mishra,Pradeep Srivastava 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.2

Lovastatin, a hypocholesterolemic agent, is a secondary metabolite produced by filamentous microorganism Aspergillusterreus in submerged batch cultivation. Lovastatin production by pellets and immobilized siran cells was investigated in an airlift reactor. The process was carried out by submerged cultivation in continuous mode with the objective of increasing productivity using pellet and siran supported growth of A. terreus. The continuous mode of fermentation improves the rate of lovastatin productionK=The effect of dilution rate and aeration rate were studied in continuous culture. The optimum dilution rate for pellet was 0.02 h-1 and for siran carrier was 0.025 h-1. Lovastatin productivity using immobilized siran carrier (0.0255 g/L/h) was found to be greater than pellets (0.022 g/L/h). The productivity by both modes of fermentation was found higher than that of batch process which suggests that continuous cultivation is a promising strategy for lovastatin production. Lovastatin, a hypocholesterolemic agent, is a secondary metabolite produced by filamentous microorganism Aspergillusterreus in submerged batch cultivation. Lovastatin production by pellets and immobilized siran cells was investigated in an airlift reactor. The process was carried out by submerged cultivation in continuous mode with the objective of increasing productivity using pellet and siran supported growth of A. terreus. The continuous mode of fermentation improves the rate of lovastatin productionK=The effect of dilution rate and aeration rate were studied in continuous culture. The optimum dilution rate for pellet was 0.02 h-1 and for siran carrier was 0.025 h-1. Lovastatin productivity using immobilized siran carrier (0.0255 g/L/h) was found to be greater than pellets (0.022 g/L/h). The productivity by both modes of fermentation was found higher than that of batch process which suggests that continuous cultivation is a promising strategy for lovastatin production.

Hydrogen-Atom Abstraction Reaction of CF3CH2OCF3 by Hydroxyl Radical

Hari Ji Singh,Bhupesh Kumar Mishra,Pradeep Kumar Rao 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.12

Theoretical investigations are carried out on the title reaction by means of ab-initio and DFT methods. The optimized geometries, frequencies and minimum energy path are obtained at UB3LYP/6-311G(d,p) level. Single point energy calculations are performed at MP2 and MP4 levels of theory. Energetics are further refined by calculating the energy of the species with a modified Gaussian-2 method, G2M(CC,MP2). The rate constant of the reaction is calculated using Canonical Transition State Theory (CTST) utilizing the ab-initio data obtained during the present study and is found to be 5.47 × 10‒12 cm3 molecule‒1s‒1 at 298 K and 1 atm.