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.

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.

Using multi-source data and decision tree classification in mapping vegetation diversity

Gaurav Shukla,Rahul Dev Garg,Pradeep Kumar,Hari Shanker Srivastava,Pradeep Kumar Garg 대한공간정보학회 2018 Spatial Information Research Vol.26 No.5

This study acknowledges the problem of land cover demarcation in diverse vegetation condition. The Normalized Difference Vegetation Index is used for the preparation of base map. Further identification of mix and incorrect classes was done using ground truth. Radar data in combination with optical indices are used. In different NDVI classes, rRV with additional criteria on Normalized Difference Water Index successfully demarcated waterlogged area, polarization ratio rRV/rRH and backscattering coefficient rRH are found suitable to separate bare land from dry grass land, sparse and dense scrub could be separated by - (rRV ? rRH)/2 and NDVI is efficient to identify dense vegetation. The study area is taken as Keoladeo National Park in Bharatpur, India. Statistical similarity between ground truth and classified class has been assessed using Jaccard coefficient (JC), Jaccard distance (JD), Dice coefficient (DC) and F-score. High similarity values of JC, JD, DC and F-score are achieved for all land cover types except bare land. Although, dry grassland showed low value of F-score; the reason could be low precision of class. The overall accuracy (87.17%), producer’s accuracy (86.39%), user’s accuracy (85.81%) and Kappa Coefficient (0.84) are also utilized to analyze performance of classifier.

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.

Strategies towards Orthopaedic Tissue Engineered Graft Generation: Current Scenario and Application

SaradaPrasanna Mallick,Zerihun Beyene,Dheerendra Kumar Suman,Abhimanyu Madhual,Bhisham Narayan Singh,Pradeep Srivastava 한국생물공학회 2019 Biotechnology and Bioprocess Engineering Vol.24 No.6

Even though degradation and damage to bone and cartilage tissue can be resolved naturally, but there is a great challenge to regenerate functional tissue due to multiple pathological conditions. To treat the diseased/ damaged bone and cartilage tissue as well as to improve or maintain its natural functions and structure, there are different strategies being developed for repair and regeneration of these tissues. Various innovative researches lead to remarkable improvement in clinical outcome of defective bone and cartilage treatments. Biomaterial based scaffolds which are capable of supporting cell growth and applied for replacement of tissue in vivo for both bone and cartilage. The review also delineates about the tissue engineering bioreactors for the recreation of frameworks to recellularise the graft in vitro by presenting them to physiologically significant mechanical or potentially hydrodynamic stimulation condition. This review summarizes and discusses the strategies for regeneration and repair of bone and cartilage tissue, current scenario and application.

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.

A Critical Aspect of Bioreactor Designing and Its Application for the Generation of Tissue Engineered Construct: Emphasis on Clinical Translation of Bioreactor

Aditya Anand,Sarada Prasanna Mallick,Bhisham Narayan Singh,Shikha Kumari,Dheerendra Kumar Suman,Satyavrat Tripathi,Divakar Singh,Pradeep Srivastava 한국생물공학회 2022 Biotechnology and Bioprocess Engineering Vol.27 No.4

Usage of bioreactors in the field of tissue engineering has played a significant role in enabling a controlled and reproducible change in the formation of damaged tissue on being provided with specific factors. Owing to the scarcity seen in providing sufficient donor organs for transplantation there is a huge requirement for large-scale production of artificial organs. This cannot be achieved by static culturing since it does not provide an invivo three-dimensional (3D) microenvironment therefore tissue engineering plays a vital role in the development of artificial tissues and organs as per the clinical demands whereas bioreactors have served a major role in providing the artificial microenvironment required by the cells to grow further into a tissue and then into an organ. By providing the specific biochemical cues and mechanoresponsive stimuli the bioreactors turn to be very effective in generating transplantable organs. Apart from performing studies in a controlled manner aimed at understanding biological and physicochemical effects, bioreactors also ensure the safe and reproducible production of tissueengineered constructs to achieve cost-effective large-scale production. The design criteria for bioreactors to be used in tissue engineering include optimal aspect ratio, proper aeration for the cells to proliferate, and agitation with reduced shear stress. The current review summarizes important aspects like Height/Diameter ratio or aspect ratio, shear stress, mechanical stress, aeration, agitation, oxygenation, etc. related to the design of tissue bioreactors, different types of bioreactors that are in use to date, and the reported pieces of literature to yield an overview on the existing concepts. It mainly focuses on the generation of 3D tissue constructs in various reactor systems specially designed for their culture and development along with their applications.

Late quaternary fluvial incision and aggradation in the Lesser Himalaya, India

Dosseto, Anthony,May, Jan-Hendrik,Choi, Jeong-Heon,Swander, Zachary J.,Fink, David,Korup, Oliver,Hesse, Paul,Singh, Tejpal,Mifsud, Charles,Srivastava, Pradeep Elsevier 2018 Quaternary science reviews Vol.197 No.-

<P><B>Abstract</B></P> <P>Reconstructing how rivers respond to changes in runoff or sediment supply by incising or aggrading has been pivotal in gauging the role of the Indian Summer Monsoon (ISM) as a geomorphic driver in the Himalayas. Here we present new chronological data for fluvial aggradation and incision from the Donga alluvial fan and the upper Alaknanda River, as well as a compilation of previous work. In addition to conventional OSL-SAR (Single-Aliquot Regenerative-Dose) dating method, we have tested and applied pulsed OSL (POSL) dating for quartz samples that include K-rich feldspar inclusions, which is expected to improve the applicability and validity of OSL ages in the Lesser Himalaya. For previously dated deposits, our OSL ages are shown to be systematically older than previously reported ages. These results suggest periods of aggradation in the Alaknanda and Dehradun Valleys mainly between ∼25 and 35 ka. This most likely reflects decreased stream power during periods of weakened monsoon. In addition, in-situ cosmogenic beryllium-10 was used to infer bedrock surface exposure ages, which are interpreted as episodes of active fluvial erosion. Resulting exposure ages span from 3 to 6 ka, suggesting that strath terraces were exposed relatively recently, and incision was dominant through most of the Holocene. In combination, our results support precipitation-driven fluvial dynamics, which regulates the balance between stream power and sediment supply. On a larger spatial scale, however, fluvial dynamics are probably not spatially homogeneous as aggradation could have been taking place in adjacent catchments while incision dominated in the study area.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Himalayan fluvial history is investigated by establishing a chronology of incision and aggradation. </LI> <LI> We dated alluvial fills using POSL and strath terraces with in-situ cosmogenic beryllium-10. </LI> <LI> Aggradation took place between ∼25 and 35 ka, reflecting decreased stream power during periods of weakened monsoon. </LI> <LI> Bedrock exposure ages span from 3 to 6 ka, suggesting that incision was dominant through most of the Holocene. </LI> <LI> Fluvial dynamics is mainly precipitation-driven, which regulates the balance between stream power and sediment supply. </LI> </UL> </P>