Biomedical subjects

Sumana Bhattacharya

Publications and source records attributed to Sumana Bhattacharya.

10 recordsLinked to original sources

PubMed2005

Biotechnological storage and utilization of entrapped solar energy.

Our laboratory has recently developed a device employing immobilized F0F1 adenosine triphosphatase (ATPase) that allows synthesis of adenosine triphosphate (ATP) from adenosine 5'-diphosphate and inorganic phosphate using solar energy. We present estimates of total solar energy received by Earth's land area and demonstrate that its efficient capture may allow conversion of solar energy and storage into bonds of biochemicals using devices harboring either immobilized ATPase or NADH dehydrogenase. Capture and storage of solar energy into biochemicals may also enable fixation of CO2 emanating from polluting units. The cofactors ATP and NADH synthesized using solar energy could be used for regeneration of acceptor D-ribulose-1,5-bisphosphate from 3-phosphoglycerate formed during CO2 fixation.

Adenosine Diphosphate↗

PubMed2004

Cascade of bioreactors in series for conversion of 3-phospho-D-glycerate into D-ribulose-1,5-bisphosphate: kinetic parameters of enzymes and operation variables.

A novel scheme employing enzymatic catalysts is described enabling conversion of D-ribulose-1,5-bisphosphate (RuBP) from 3-phospho-D-glycerate (3-PGA) without loss of carbon. Bioreactors harboring immobilized enzymes namely, phosphoglycerate kinase (PGK), glycerate phosphate dehydrogenase, triose phosphate isomerase (TIM), aldolase, transketolase (TKL), phosphatase (PTASE/FP), epimerase (EMR) and phosphoribulokinase (PRK), in accordance with this novel scheme were employed. These reactors were designed and constructed based on simulations carried out to study their performance under various operational conditions and allowed production of about 56 +/- 3% RuBP from 3-PGA. This method of synthesis of RuBP from 3-PGA employing immobilized enzyme bioreactors may be used for continuous regeneration of RuBP in biocatalytic carbon dioxide fixation processes from emissions where RuBP acts as acceptor of carbon dioxide to produce 3-PGA, rendering the fixation process continuous.

Bioreactors↗

PubMed2004

Potential use of sugar binding proteins in reactors for regeneration of CO2 fixation acceptor D-Ribulose-1,5-bisphosphate.

Sugar binding proteins and binders of intermediate sugar metabolites derived from microbes are increasingly being used as reagents in new and expanding areas of biotechnology. The fixation of carbon dioxide at emission source has recently emerged as a technology with potentially significant implications for environmental biotechnology. Carbon dioxide is fixed onto a five carbon sugar D-ribulose-1,5-bisphosphate. We present a review of enzymatic and non-enzymatic binding proteins, for 3-phosphoglycerate (3PGA), 3-phosphoglyceraldehyde (3PGAL), dihydroxyacetone phosphate (DHAP), xylulose-5-phosphate (X5P) and ribulose-1,5-bisphosphate (RuBP) which could be potentially used in reactors regenerating RuBP from 3PGA. A series of reactors combined in a linear fashion has been previously shown to convert 3-PGA, (the product of fixed CO2 on RuBP as starting material) into RuBP (Bhattacharya et al., 2004; Bhattacharya, 2001). This was the basis for designing reactors harboring enzyme complexes/mixtures instead of linear combination of single-enzyme reactors for conversion of 3PGA into RuBP. Specific sugars in such enzyme-complex harboring reactors requires removal at key steps and fed to different reactors necessitating reversible sugar binders. In this review we present an account of existing microbial sugar binding proteins and their potential utility in these operations.

Journal Article↗

PubMed2004

Solubilization and concentration of carbon dioxide: novel spray reactors with immobilized carbonic anhydrase.

Novel spray reactors are described that employ immobilized biocatalyst (carbonic anhydrase), enabling concentration and solubilization of emitted CO(2) by allowing catalytic contact with water spray. The reactors were fed with simulated emission gas. The performance of the reactors was investigated with respect to operation variable: emission flow rate; gas composition in the emission stream; water flow rate; area-to-volume ratio of immobilized reactor core; and the enzyme load within the core. The reactors were also investigated for pressure drop and extractability of CO(2) from the emission with single vs. multiple reactors (of combined equal volume). The biotechnological process of solubilization and concentration of CO(2) from emission exhausts or streams occurring in the spray reactors could be coupled for further biochemical/chemical conversion of the concentrated CO(2).

Aerosols↗

PubMed2004

Uniformly oriented bacterial F0F1-ATPase immobilized on a semi-permeable membrane: a step towards biotechnological energy transduction.

The immobilization of F(0)F(1)-ATPase in uniform orientation is reported. The biotinylated and histidine-tagged subunits of the bacterial F(0)F(1)-ATPase complex were used for immobilization of the complex on artificial semi-permeable membranes resulting in 88+/-7.8 and 72+/-5.2% coupling of the enzymes. The immobilized enzymes retained over 90% activity. The immobilized ATPase/synthase was used for generation of ATP from ADP and P(i) at the expense of electrochemical potential energy. The re-usability, ratio of amount of enzyme immobilized to enzymic activity conferred on the membranes, ATP synthesized by assembled system and suitability of ATP generated for use in coupled enzymic reactions were determined.

Adenosine Diphosphate↗

PubMed2003

Metabolic networks of microbial systems.

In contrast to bioreactors the metabolites within the microbial cells are converted in an impure atmosphere, yet the productivity seems to be well regulated and not affected by changes in operation variables. These features are attributed to integral metabolic network within the microorganism. With the advent of neo-integrative proteomic approaches the understanding of integration of metabolic and protein-protein interaction networks have began. In this article we review the methods employed to determine the protein-protein interaction and their integration to define metabolite networks. We further present a review of current understanding of network properties, and benefit of studying the networks. The predictions using network structure, for example, in silico experiments help illustrate the importance of studying the network properties. The cells are regarded as complex system but their elements unlike complex systems interact selectively and nonlinearly to produce coherent rather than complex behaviors.

Journal Article↗

PubMed2003

Immobilization of D-ribulose-1,5-bisphosphate carboxylase/oxygenase: a step toward carbon dioxide fixation bioprocess.

Immobilization of D-ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from spinach leaves is described. This enzyme enables the fixation of carbon dioxide on a five-carbon sugar D-ribulose-1,5-bisphosphate (RuBP). Two different immobilization methods were employed: dicyclohexylcarbodiimide coupling on nylon membrane matrix and dimethylpimelimidate immobilization on protein A agarose. The reusability of immobilized enzymes, coupling efficiency, and temperature-activity relationship of soluble and immobilized Rubisco are presented. The immobilization imparted greater thermal and storage stability. The thermal deactivation rates of the immobilized enzymes were considerably lower than those of the soluble enzyme.

Carbon Dioxide↗

PubMed2003

Biochemical engineering: cues from cells.

Engineering principles are used in the exploitation of biocatalysts derived from cells. The purity of reagents, catalysts and maintenance of operation variables are extremely important for bioengineering systems. Any change in the purity of reagents or in operation variables usually leads to a dramatic decrease in productivity. Cellular systems, however, are able to work with relatively high impure conditions and increase their productivity in response to external signals. Thus the seemingly disordered 'bag of juice' or cytoplasm has more order and much higher order of integration than first appears. Learning the semantics of this paradoxical ability of order and integration would help bioengineers to understand and enhance productivity even using impure reagents.

Biomedical Engineering↗

PubMed2003

CO2 hydration by immobilized carbonic anhydrase.

The enzyme carbonic anhydrase (isoform II) from bovine and human erythrocytes was immobilized using different covalent coupling methods on inert matrices. Immobilized carbonic anhydrase may enable concentration of CO2 for Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase)-catalysed fixation in bioreactors. In the present study the activity of carbonic anhydrase with respect to hydration of CO2 using soluble and immobilized enzymes was determined. The stability of the immobilization matrix, the properties of the immobilized enzymes subjected to a variation in operation variables and the activity profile with respect to storage are reported. Immobilization imparted greater thermal and storage stability and enhanced reusability.

Animals↗

PubMedDate not supplied

A nonradioactive assay method for determination of enzymatic activity of D-ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco).

A sensitive and nonradioactive assay method for activity determination of Rubisco is described. The method is based on thin-layer chromatographic separation of 3-phosphoglycerate (3-PGA) and D-ribulose-1,5-bisphosphate (RuBP). This assay method allows the quantitative determination of Rubisco activity. Rates of carbon dioxide fixation on RuBP determined by this method were comparable to those obtained independently by other methods. This assay method is reproducible and relatively free from interference.

Carbon Radioisotopes↗