Write-up of research and development interests/focus, past and present goals:
Research and Development Interest
The research efforts of our group are directed towards application of biological sciences and engineering principles, at the interface of biological sciences and engineering, to understand and analyze bioprocesses for production/ modification of biomolecules. Product and process development is an integral part of biotechnology-based industries due to large range of biomolecules being proposed for commercial development. Most of these products are based on fermentation and hence, the issues of development and synthesis of processes that can produce and purify the product of interest in large quantities are becoming important, more so in case of protein and DNA based biopharmaceuticals as one moves from discovery phase through clinical trials and to commercialization. The way to achieve a biotech product at economical cost is either to develop completely new/improved product or to modify processes for the existing products against competitive market forces. Both scenarios call for optimized processes which needs concerted approach of metabolic engineering, synthetic biology and system biology in addition to inputs from chemistry, biology and chemical engineering. We follow an integrated approach towards this goal, some of which are summarized below:
(i) Biopharmaceuticals: Development of recombinant-DNA technology of microbial and mammalian cell culture has allowed the production of biopharmaceuticals, proteins and nucleotides, for use as human therapeutics. However, productivity and stability of the transfected gene of interest are two important criteria that determine the viability of a process. Our studies include various expression systems for the high-level recombinant protein production (expression type and levels, posttranslational modifications, and biological activity of the proteins such as therapeutic proteins, vaccines), regulatory issues and developing novel strategies for their production and purification. The investigations on the effects of various molecular and process parameters including medium constituents, dissolved oxygen concentration on specific yield and productivity of two important therapeutic proteins, staphylokinase and streptokinase, in Escherichia coli had led to production processes for these two proteins and process scale-up. As glycosylation is one of the major post translational modifications of proteins in mammals, attempts are being made to prolong the serum half life for glycoproteins such as erythropoietin, using a new approach of glyco-engineering in CHO cell systems. Efforts are also focused on development of novel antibodies using mammalian cell culture for both therapeutic and diagnostic applications and on the screening and production of novel antimicrobial peptides (AMPs) along with understanding their mechanism of action.
(ii) Nanomedicine: Since many biopharmaceuticals show lower bioavailability and stability in vivo, polymer particle based delivery provides an important option for solving many of these problems. We are studying polymer based formulation of nano/micro particles for delivery of therapeutic proteins, peptides, vaccines, antibodies and nucleotides, exploring the molecular mechanism of stability and improved structural integrity of these biomolecules during processing thus optimizing concentration of excipients and important process conditions to improve their efficacy and yield.
(B) Biofuels and Environmental Biotechnology:
The oil security, fluctuating oil prices and concern on environmental impact of fossil fuels have led efforts on development of renewable fuel alternatives. Our research efforts are focused on optimization of process engineering, fermentation technology and enzyme engineering to develop large scale processes for production of ethanol, the most common renewable fuel today, from molasses, starch and lignocellulogics using an improved yeast strain which is osmotolerant, thermotolerant and ethanoltolerant. As economical production of bioethanol from renewable cellulosic biomass largely depends upon the gainful utilization of all of its components for production of additional value added chemicals, production of xylitol, one such value added chemical, by potential yeasts is being explored using metabolic pathway engineering as a tool. Our research efforts were also directed towards the replacement of some of polluting chemical processes by biological/enzymatic ones such as those of Leather processing and work is initiated for production of biofuels using algal biomass.
(C) Bioprospecting and Industrial Biotechnology:
Enzymes have applications in many fields. The discovery of new microbial enzymes through extensive and persistent screening rom biodiversity rich regions of the country to isolate microbes capable of producing industrially important biomolecules including enzymes and other metabolites is an important goal of our efforts. Microbial alkaline proteases dominate the worldwide enzyme market, accounting for a two-thirds share and major application of this group of enzymes include detergent and leather processing. Leather manufacturing involves chemical processing of skin and our research efforts are to replace these chemicals with enzymes. Formulating fermentation and purification strategies based on studies of medium optimization, effects of physiological and process parameters, process development and scale of issues and synthesis of downstream processing steps had led to development of efficient large scale production processes for alkaline proteases and similar investigations on recombinant α –amylase, phytase, lipases and cellulases are completed/ on-going.
Significant recognition: Awards, fellowships, international funding of distinction, technologies transferred/licensed etc.:
• Jadavpur University medal for standing Ist in order of merit at B. Tech (F.T.B.E.), 1982.
• Long-Term Overseas Research Associateship from Department of Biotechnology, Government of India, 1996.
Technology transferred/licensed (as Project Leader/ Team Member)
• “High cell density fermentation and purification of recombinant streptokinase from intracellular milieu of Escherichia coli” licensed to Shasun Chemicals and Drugs, Chennai, India.
• “A process for the production of recombinant staphylokinase” licensed to M/S Strides ArcoLabs Limited, Bangalore, India.
• “A process for enhanced production of natural streptokinase using Streptococcus equisimilis” transferred to Cadila Pharmaceuticals Limited, Ahmedabad.
• “A process for production of alkaline proteases” licensed to Cadila Pharmaceuticals Limited, Ahmedabad, India and Celestial Labs Limited, Hyderabad, India.
• “A process for production of α-amylase by recombinant Bacillus subtilis” licensed to Cadila Pharmaceuticals Limited, Ahmedabad, India and Celestial Labs Limited, Hyderabad, India.
• “Recovery of copper from Malanjkhand oxide and sulphide ores through column leaching-solvent extraction–electrowinning” licensed to Hindustan Copper Limited, India. (IMMT, Bhubaneswar)
Selected list of Publications and Patents:
· Singh J, Vohra RM, Sahoo DK. 2001. Purification and characterization of two extracellular serine proteases from a newly isolated obligate alkalophilic Bacillus sphaericus. Journal of Industrial Microbiology and Biotechnology 26: 387-393.
· Sahoo DK, Agarwal GP. 2002. Effect of oxygen transfer on glycerol biosynthesis by an osmophilic yeast Candida magnoliae I2B. Biotechnology and Bioengineering 78: 545-555.
· Singh Jasvir, Vohra RM, Sahoo DK. 2004. Enhanced production of alkaline proteases by Bacillus sphaericus using fed-batch culture. Process Biochemistry 39: 1093-1101.
· Vats P, Sahoo DK, Banerjee UC. 2004. Studies on the production of phytases (myo-inositolhexakisphosphate phosphohydrolases) by Aspergillus niger van teigham in laboratory scale fermenter. Biotechnology Progress 20: 737-743.
· Sahoo DK, Gupta R. 2005. Evaluation of ligninolytic microorganisms for efficient decolorization of a small pulp and paper mill effluent. Process Biochemistry 40: 1573-1578.
· Goyal D, Sahoo DK, Sahni G. 2007. Hydrophobic interaction expanded bed adsorption chromatography (HI-EBAC) based facile purification of recombinant streptokinase from E. coli inclusion bodies. Journal of Chromatography B. 850: 384-391.
· Jhamb K, Jawed A, Sahoo DK. 2008. Immobilized chaperones: A productive alternative to refolding of bacterial inclusion body proteins. Process Biochemistry 41: 387-597.
· Goyal D, Sahni G. and Sahoo DK. 2009. Enhanced production of recombinant streptokinase inEscherichia coli using fed-batch cultivation. Bioresource Technology 100: 4468-4474.
· Rawat S, Suri CR, Sahoo DK. 2010. Molecular mechanism of polyethylene glycol mediated stabilization of protein. Biochemical and Biophysical Research Communications 392: 561-566.
· Rawat S, Kohli N, Suri CR, Sahoo DK. 2012. Molecular mechanism of improved structural integrity of protein in polymer based microsphere delivery system. Molecular Pharmaceutics 9: 2403-2414, 2012.
· Jhamb K, Sahoo DK. 2012. Production of recombinant proteins in Escherichia coli: effects of process conditions and chaperone co-expression on cell growth and production of xylanase. Bioresource Technology 123: 135-143, 2012.
· Pal S, Choudhary V, Kumar A, Biswas D, Mondal AK, Sahoo DK. 2013. Studies on xylitol production by metabolic pathway engineered Debaryomyces hansenii. Bioresource Technology, 147: 449-455.
· Chopra L, Singh G, Choudhary V and Sahoo DK. 2014. Sonorensin: an antimicrobial peptide, belonging to the heterocycloanthracin subfamily of bacteriocins, from a new marine isolate, Bacillus sonorensis MT93. Applied and Environmental Microbiology 80, 2981-2990.
· Chopra L, Singh G, Jena KK, Verma H, Sahoo DK. 2015. Bioprocess development for the production of sonorensin by Bacillus sonorensis MT93 and its application as a food preservative. Bioresouce Technology 175, 358-366.
· Loharch S, Jain K, Sahoo DK, Ashish, Madathil R and Parkesh R. 2015. EpiDBase: a manually curated database for small molecule modulators of Epigenetic Landscape. Database 03/2015; DOI: 10.1093/database/bav013.
· Rawat S, Gupta P, Kumar A, Garg P, Suri CR, Sahoo DK. 2015. Molecular mechanism of polyvinyl alcohol mediated prevention of aggregation and stabilization of insulin in nanoparticles. Molecular Pharmaceutics 12, 1018–1030.
. Chopra L, Singh G, Jena KK, Sahoo DK. 2015. Sonorensin: A new bacteriocin with potential of an anti-biofilm agent and a food biopreservative. Scientific Reports, 5 (Sci. Rep. 5, 13412; doi: 10.1038/srep134), 1-13.
• Pal S, Mondal AK, Sahoo DK. 2016. Molecular strategies for enhancing microbial production of xylitol. Process Biochemistry 51, 809-819 (doi:10.1016/j.procbio.2016.03.017).
• Mutreja R, Jariyal M, Pathania P, Sharma A, Sahoo DK, Suri CR. 2016. Novel surface antigen based impedimetric immunosensor for detection of Salmonella typhimurium in water samples. Biosensor and Bioelectronics. 85, 707-713 (doi:10.1016/j.bios.2016.05.079).
• Jasvir Singh, R.M. Vohra and D.K. Sahoo. Preparation of alkaline protease. (IN9901313-I1).
• Sahoo DK, Dikshit KL and Jawed A. Process for production of soluble staphylokinase using Escherichia coli (IN201200062-I1).