Dr. Rajeev K Sukumaran

Rajeev Kumar Sukumaran
Professional Experience
  • Head, MPTD: CSIR-NIIST - 2019 onwards
  • Head, Biofuels and Biorefineries Section- 2015 onwards
  • Senior Principal Scientist: CSIR-National Institute for Interdisciplinary Science and Technology - 2018 onwards
  • Principal Scientist: CSIR-National Institute for Interdisciplinary Science and Technology - 2014-2018
  • Senior Scientist: CSIR-National Institute for Interdisciplinary Science and Technology - 2010-2014
  • Scientist C: CSIR-National Institute for Interdisciplinary Science and Technology - 2007 -2010
  • Scientist B: CSIR-National Institute for Interdisciplinary Science and Technology - 2004 -2007
  • Member Technical-Biotechnology solutions, at Bigtec Pvt Ltd Bangalore - 2001
Area of Expertise
  1. Lignocellulosic Ethanol and Biorefineries
  2. Fermentation Technology
  3. Cell and Molecular Biology
Technology Transfer

Technologies/Knowhow Transferred

  • Process for production of cellulase enzyme for paper pulp processing using solid state fermentation. Transferred to Industry

Processes/Products Developed

  • Cellulase Enzyme Blends for biomass hydrolysis
  • Process for production of cellulase enzyme for paper pulp processing using solid state fermentation
  • Process for production of beta glucosidase for biomass hydrolysis
  • Process for production of fungal spores under solid state fermentation
  • Process for production of Keratinase enzyme using waste chicken feather
Patents & Publications

Patents

  1. Flocculant Based Disinfection Process for Pathogenic Medical Waste Disposal. Shankar SP, Hareesh US, Parameswaran B, Sukumaran RK, Ajayaghosh A. PCT Application PCT/IN2021/050032, 2021. Indian Patent Application 202011039050, 2020. 13/01/2021
  2. Antibacterial Multi-Charged Metal Complexes and Coatings with Metal Nanoparticles Thereof. Shankar SP, Anjali N, Hareesh US, Suja P, Vijayan V, Pillai S, Sukumaran RK, Ajayaghosh A. Indian Patent Application 202111015509, 2021. 31-03-2021
  3. Disinfection and in situ Flocculation-Solidification Process for Pathogenic Medical Waste Disposal. Shankar SP, Nair SS, Radhakrishnakurup A, Vijayan V, Mohamed PAA, Hareesh US, Sukumaran RK, Savithri S, Devi SP, Ajayaghosh A. Indian Patent Application No. Temp./E-1/24389/2021-DEL, 2021 (PCT Pending). Filed 15 May 2021
  4. An Improved Disinfection/Solidification Process for Pathogenic Medical Waste Disposal. Shankar SP, Nair SS, Suja P, Hareesh US, Sukumaran RK, Savithri S, Devi PS, Ajayaghosh A. Indian Patent Application No. Temp./E-1/24367/2021-DEL, 2021 (PCT Pending). 15 May 2021

Selected Publications

  1. Sukumaran RK, Christopher M, Kooloth Valappil P, Sreeja-Raju AR, Mathew RM, Sankar M, Puthiyamadam A, Adarsh VP, Aswathi A, Rebinro V, Abraham A, Pandey A. 2021. Addressing challenges in production of cellulases for biomass hydrolysis: Targeted interventions into the genetics of cellulase producing fungi. Bioresour. Technol. 329: 124746. https://doi.org/10.1016/j.biortech.2021.124746
  2. Kooloth-Valappil P, Christopher M, Sreeja-Raju A, Mathew RM, Kuni-Parambil R, Abraham A, Sankar M, Sukumaran RK. 2021. Draft genome of the glucose tolerant β-glucosidase producing rare Aspergillus unguis reveals complete cellulolytic machinery with multiple beta-glucosidase genes. Fungal Genet. Biol. 151: 103551. https://doi.org/10.1016/j.fgb.2021.103551
  3. Aswathi A, Pandey A, Madhavan A, Sukumaran RK. 2021. Chlorpyrifos induced proteome remodelling of Pseudomonas nitroreducens AR-3 potentially aid efficient degradation of the pesticide. Environ. Tech. Innov. 21: 101307. https://doi.org/10.1016/j.eti.2020.101307
  4. Sreeja-Raju A, Christopher M, Kooloth-Valappil P, Kuni-Parambil R, Gokhale DV, Sankar M, Abraham A, Pandey A, Sukumaran RK. 2020. Penicillium janthinellum NCIM1366 shows improved biomass hydrolysis and a larger number of CAZymes with higher induction levels over Trichoderma reesei RUT-C30. Biotechnol Biofuels 13: 196. https://doi.org/10.1186/s13068-020-01830-9
  5. Aswathi A, Pandey A, Sukumaran RK. 2019. Rapid degradation of the organophosphate pesticide–Chlorpyrifos by a novel strain of Pseudomonas nitroreducens AR-3. Bioresour. Technol. 292. 122025. https://doi.org/10.1016/j.biortech.2019.122025
  6. Kooloth-Valappil PK, Kuni-Parambil R, Abraham A, Christopher M, Sukumaran RK. 2019.Characterization of a glucose tolerant β-glucosidase from Aspergillus unguis with high potential as a blend-in for biomass hydrolyzing enzyme cocktails. Biotech. Lett. 41 (10): 1201-1211. https://doi.org/10.1007/s10529-019-02724-z
  7. Puthiyamadam A, Adarsh VP, Mallapureddy KK, Mathew A, Kumar J, Yenumala SR, Bhaskar T, Ummalyama SB, Sahoo D, Sukumaran RK. 2019. Evaluation of a wet processing strategy for mixed phumdi biomass conversion to bioethanol. Bioresour Technol. https://doi.org/10.1016/j.biortech.2019.121633
  8. Aravind Madhavan, Ashok Pandey, Rajeev K Sukumaran, 2017. Expression system for heterologous protein expression in the filamentous fungus Aspergillus unguis, Bioresour. Technol. 245:1334-1342. https://doi.org/10.1016/j.biortech.2017.05.140
  9. Meera Christopher, Anil K. Mathew, M. Kiran Kumar, Ashok Pandey, Rajeev K. Sukumaran, 2017. A biorefinery-based approach for the production of ethanol from enzymatically hydrolysed cotton stalks, Bioresour. Technol. 242: 178-183. https://doi.org/10.1016/j.biortech.2017.03.190
  10. Aravind Madhavan, Rajeev Kumar Sukumaran: 2016. Secreted expression of an active human interferon-beta (HuIFNβ) in Kluyveromyces lactis. Eng. Life Sci. 16(4):379-385. https://doi.org/10.1002/elsc.201500120
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Biography

Dr Rajeev K Sukumaran is the activity lead for Biofuel program of the Centre for Biofuels, Microbial Processes and Technology Division, CSIR-NIIST and was the coordinator of PAN-CSIR multi laboratory program on 2G Ethanol. He played the lead technical role in setting up of the 2G ethanol pilot plant at NIIST, which is the first of its kind in India, commissioned in 2012. He had his Masters and PhD in Biotechnology from Cochin University of Science and Technology, Kochi, India and a Post Graduate Diploma in Bioinformatics from Bigtec Pvt Ltd Bangalore. He started his career in Bigtec Pvt Ltd as Member Technical, Biotechnology Solutions, where he served as consultant to VMSRF (United Breweries Group R&D) on production of recombinant Human Insulin. He did his Post-Doctoral Studies at Mount Sinai School of Medicine (Now Ichan School of Medicine, Mount Sinai), New York on Molecular Immunology of Type I Diabetes, under Prof. Teodor Brumeanu, and later on at the Stem Cell Laboratory, Department of Obstetrics and Gynaecology, National University Hospital, Singapore, under Prof. Arfiff Bongso, where the work was on elucidating the molecular reasons for Human Embryonic Stem Cell Pluripotency. He joined CSIR-National Institute for Interdisciplinary Science and Technology in 2004 November and since then, is working on Biomass Conversion to Biofuels, and the facilitating technologies and science for lignocellulose conversion. His current interests are second generation biofuels, cellulase and other biomass hydrolysing enzymes, regulation of cellulase gene expression in filamentous fungi, heterologous protein expression in fungi and enzymes for speciality applications

Current Activities

  • Integrated Biorefinery processes
  • Biomass conversion to ethanol and chemicals through fermentative process
  • Cellulases, Beta glucosidases and other biomass hydrolyzing enzymes
  • Regulation of Cellulase Gene expression in filamentous fungi
  • Heterologous Protein Expression in Filamentous Fungi
  • Enzymes for glycosylation, and esterases for organic synthesis
  • Bioprocess development for enzyme production and other microbial products including process optimizations following the DOE concepts
  • Solid State Fermentation Process Development and Scale up
  • Xenobiotic degradation by bacteria - Implications and Mechanisms

Expertise

  • Enzyme and Microbial Technology
  • Bioprocess Development and Optimization
  • Cell and Molecular Biology
  • Large Scale Gene Expression Data Analyses
  • DOE concepts in bioprocess optimization
  • Basic and Applied Microbiology
Alumni

]

Prajeesh Dr. Prajeesh KV (Former Ph. D Student, Year of Award - 2021)
Prajeesh’s PhD work was on understanding the mechanism of regulation of biomass hydrolysing enzymes in Aspergillus unguis, a rare fungus producing glucose tolerant beta-glucosidase (GT-BGL); through genome sequencing and transcriptome profiling. The study could identify key regulatory pathways involved in the regulation of BGL and also resulted in the successful cloning and expression of the GT-BGL protein. The information gained by this study would be useful in the design of more efficient and glucose tolerant enzymes for biomass conversion applications.
Aswathi Dr. Aswathi A (Former Ph. D Student, Year of Award - 2021))
Dr Aswathi explored the resistance of microbes to the organophosphate pesticide chlorpyrifos.
Selim Dr. Selim Ashoor (TWAS Post-Doctoral Fellow, 2018-19)
Ayman Dr. Ayman Saligh Omar Idris (Former Ph. D Student, Year of Award - 2018)
Anil Dr. Anil Mathew (Contract Researcher - 2014-16; Post-Doctoral Fellow 2017-19)
Amith Dr. Amith Abraham (Post-Doctoral Fellow, 2015-18)
Aravind Dr. Aravind Madhavan (Former Ph. D Student, Year of Award - 2016)
Vani Dr. Vani Sankar (Former Ph. D Student, Year of Award - 2015)
Sabeela Dr. Sabeela Beevi U (Former Ph. D Student, Year of Award - 2015)
Deepthy Dr. Deepthy Alex (Former Ph. D Student, Year of Award - 2015)
Lalitha Dr. Lalitha Devi Gottumukkala (Former Ph. D Student, Year of Award - 2014)
Rajasree Dr. Rajasree KP (Former Ph. D Student, Year of Award - 2014)
Abraham Dr. Abraham Mathew
Reeta Dr. Reeta Rani Singhania

 

Academic Qualification
  • MSc Biotechnology: Cochin University of Science and Technology, Kochi, India
  • PhD: Biotechnology: Cochin University of Science & Technology, Cochin India
  • Post Graduate Diploma in Bioinformatics: Bigtec Pvt Ltd, Bangalore
  • Post-Doctoral
    i. Mount Sinai School of Medicine, (Currently -Icahn School of Medicine, Mount Sinai) New York
    ii. Stem Cell Lab, National University Hospital, Singapore
Team

Current Members

Meena Meena Sankar (PhD Student)
Meena joined CSIR NIIST as Project Assistant to work on heterogeneous carbon catalysts for biomass hydrolysis and later on, for developing enzymatic processes for saccharification of multiple biomass feedstock, for bioethanol production. She was awarded the CSIR Senior Research Fellowship in April 2017 and joined for Ph.D. Her PhD work is on developing efficient enzyme cocktails for biomass saccharification through blending of heterogeneous enzyme preparations and deciphering the synergistic functioning of multiple biomass hydrolyzing enzymes and accessory proteins. She is working on the correlation between biomass structural features and the productive enzyme binding on them leading to efficient hydrolysis. She is also collaborating with the computational modelling and simulation group to develop rapid non-destructive IR spectroscopic methods for biomass characterization. She is also involved in cellulase production and purification from potent fungal strains.
Athira Athira Raj SR (PhD Student)
Athira completed her integrated BS-MS (Life Sciences Major) from IISER Thiruvananthapuram in 2015 and joined the Biofuels Group for PhD after qualifying the CSIR-JRF NET. Athira investigates the mechanism of production and regulation of cellulase enzymes in Penicillium janthinellum. She has demonstrated the superiority of the fungus in biomass hydrolysis (In comparison to Trichoderma reesei) is resulting from an enhanced level of carbohydrate active enzymes (CAZYmes) and better control of induction. He has also discovered unique transcription factors that could hold the key to understanding the regulation of cellulase expression in the fungus. Her work aims to generate knowledge of the regulatory mechanisms, which would aid genetic modification of the fungus for improved cellulase production.
Meera Meera Christopher (PhD Student)
Meera joined the Biofuels Group, MPTD after her M. Tech (Biotechnology) from SRM University, and worked in the Centre for Biofuels Project, where her work was on developing efficient biomass hydrolysis and fermentation processes. She joined for Ph. D after qualifying the CSIR-SRF. Her research focusses on deciphering the lignocellulose-degrading enzyme system of Penicillium sp., genetic modifications to develop hyper-cellulolytic strains and formulating improved cellulase cocktails for biomass hydrolysis. Through genomics, transcriptomics and proteomic approaches she is deciphering the control networks involved in cellulase regulation in the model organism - Penicillium janthinellum. She is also developing an expression system for this fungus using efficient regulatory elements identified through transcriptome studies, for secreted expression of heterologous proteins
Anoop Anoop P (PhD Student)
I have completed my Masters in Biotechnology from Kerala Agricultural University and had worked in Industry and in various projects before joining the Biofuel Group. My research goal is to understand cellulase production using lignocellulosic biomass and its use for fuels and value-added chemicals. The study targets optimization of the cellulase production process using submerged fermentation and its scale-up. Proteome level studies are targeted to understand the role of various cellulolytic and accessory enzyme activities in aiding hydrolysis of specific biomass substrates. This data would be used for creating models to predict components for tailored enzyme blends.
Adarsh Adarsh VP (PhD Student)
My research work is focused on Consolidated bioprocessing (CBP) for bioethanol production filamentous fungi”. Lignocellulosic biomass is one of the promising raw materials for the bioethanol production, but the operation is still challenging due to the cost of enzymes needed for biomass hydrolysis and lack of strategies for by-product valorization. CBP, where a single organism performs the biomass hydrolysis and ethanol fermentation does away with separate hydrolysis and fermentation operations and the addition of enzymes. Filamentous fungi are natural degraders of biomass and several of them are capable of ethanol production. My study focuses on a deeper understanding of the growth and ethanol production by a model filamentous fungus, towards developing a process for ethanol production using biomass as substrate, eliminating the need for an enzymatic hydrolysis step.
Athulya Athulya A (PhD Student)
The main objective of my work is to study the degradation of organophosphate pesticides by a soil isolate - Pseudomonas nitroreducens AR-3 (One of the fastest chlorpyrifos (CP) degraders reported), towards developing this organism as a bioinoculant for soil bioremediation. Organophosphates a highly toxic group of pesticides with their potential toxicity to non-target organisms including humans. Our studies have revealed that upon exposure to CP, there is a reprograming of the proteome in the organism, and there is a coordinated expression of several xenobiotic degradation pathways including some responsible for antimicrobial resistance. This is alarming as it implies that the stimulation of the microorganisms with a xenobiotic may enhance its resistance towards another, which could even be an antimicrobial in clinical use. We are trying to understand this cross-resistance mechanisms, in addition to organophosphate degradation as a soil bioremediation method

 

Projects

Major Projects Operated

Current

Sl. No Title of Project Funding agency Participating Agencies/Collaborator
1 Process Development for enzymatic production of Ascorbic Acid  2 glucoside CSIR CSIR-NIIST
2 Developing magnetic nanoparticle immobilized enzyme catalysts for biofuel applications. (Indo-Portuguese exchange program) DST CSIR-NIIST, University of Lisbon, Portugal

Past

Sl. No Title of Project (* Projects with funding above 1Cr ) Funding agency Participating Agencies/Collaborator
1 Technology Assessment and integration of CSIR’s lignocellulosic ethanol programs/facilitating technologies for a feasible 2GE ethanol technology (PANCSIR-2GE) CSIR CSIR-IIP, CSIR-IICT, CSIR-CFTRI, CSIR-NCL, CSIR-NEERI, CSIR-CGCRI, CSIR-IITR, CSIR-CSMCRI
2 Development of a gene expression platform for heterologous protein production in the filamentous fungus Aspergillus unguis DBT  
3 Characterization of the major agro-residue biomass in India for assessment of their feedstock potential for biofuel applications TIFAC (DST) CSIR-IIP
4 Loktak Lake biomass (paragrass) based biorefinery for fuels and chemicals: value addition through biotechnological and thermochemical platform IBSD (DBT) CSIR-IIP, IBSD
5 Characterization, recombinant expression, process scale up and validation of selected hydrolases from native actinobacteria for commercial exploitation DBT ( Support program to JNTBGRI) JNTBGRI (Coordinating lab)
6 The Development of Stabilized Formulations of Biopesticides and Biofertilizers T Stanes & Co Coimbatore  
7 Centre for Biofuels, Phase II TIFAC (DST)  
8 Integrated technologies for Economically Sustainable Bio-Based Energy DST (AISRF) ICT -Mumbai (Coordinating lab) IOC, TERI, ICGEB (India)
QUT, UWA, Curtin Univ., CSIRO, NSW -Dept. of Primary Industries (Australia)
9 Large scale production process for beta glucosidase enzyme for biomass hydrolysis for Biorefineries CSIR  
10 Sorghum stover based Biorefinery for Fuels and Chemicals MNRE CSIR- IICT, TERI, MNNIT
11 Glycerol based Carbon Acid Catalyst for the production of Ethanol and value added chemicals DST NIIST, IICT
12 Development of commercially viable biotech products - PGA, LA and Cellulase Thermax India Ltd, Pune  
13 Pre-treatment of Rice Straw for Bioenergy DSM India Pvt Ltd  
14 India country report on second generation biofuels International Energy Agency France  
15 Centre for Biofuels TIFAC (DST)  
16 Liquid and gaseous biofuels from biomass CSIR  
17 Construction and Screening of environmental DNA libraries for novel beta-lactamase inhibitors and lipases DBT  
18 Conversion of cellulose and hemi-cellulose into sugars and ethanol CSIR-NMITLI NCL, IICB, IMTECH, MKU, DU, IITB, IIIM
19 Isolation and cloning of glucose tolerant β-glucosidase from fungal isolate BTCF-5 and the cbh1 control elements from Trichoderma reesei, and studies on the properties of the enzyme DST  

 

Research Areas

Research

Second Generation Ethanol (2G Ethanol/Bioethanol):

At the Centre for Biofuels, we have been working on integrated cellulosic ethanol process for more than a decade. The process has moved on from laboratory scale to pilot, and a pilot plant which can handle about 80 kg of biomass per day was established in the NIIST Campus. We coordinated PAN-CSIR 2G ethanol program bringing together 9 leading CSIR labs where individual unit operations were addressed by different labs with the appropriate expertise. The activities at NIIST mainly focuses on developing efficient and cost-effective enzymes for biomass hydrolysis, ethanol and inhibitor tolerant yeasts for fermentation of biomass hydrolysates, energy efficient and effective pretreatment processes etc., while we work on almost all aspects of biomass conversion to ethanol. Current goal is to achieve commercial feasibility through efficient operation and valorization of by products (eg - Lignin and pentose sugars). We were the pioneers to do a systematic mapping of the surplus biomass availability in the country, published by TIFAC (DST) in 2009. Current work is focused on improved generic and biomass specific enzyme cocktails, facilitating technologies for biomass conversion and by product valorization, organism development for ethanol fermentation and fermentation for biomass to high value products etc. Through collaborative mode we are now working on IR methods for rapid characterization of biomass.

Res 2G Ethanol

Biomass hydrolyzing enzymes for Biorefineries

The most efficient method for biomass deconstruction to component sugars is the enzymatic hydrolysis. Currently the enzymatic hydrolysis step is considered as the most expensive step in a biomass to ethanol /chemicals process and despite the fact that worldwide there are a large number of efforts to develop cheap and highly efficient enzyme catalysts, this has not become a reality. We are working on developing new and highly efficient cellulase cocktails, based on enzyme blends for biomass hydrolysis. We are studying the cost reduction of cellulase production using cheap fermentation strategies like solid-state fermentation, making cheaper inducers, simplifying recovery steps and by genetically modifying cellulase-producing fungi. We use filamentous fungi like Trichoderma, Penicillium and Aspergillus as the source of cellulases and hemicellulases and are looking at various aspects of cellulase induction, large-scale production and blending. The enzyme blends created by us are capable of out-performing some of the current best preparations in the market for biomass conversion. Our cellulase preparation from Pencillium janthinellum and beta glucosidase preparation from Aspergillus niger have been successfully produced at pilot scale. A pilot scale (50kg/batch) Solid State Fermentation Facility (SSF/Koji Room) facility for enzyme production was established at NIIST to cater to enzyme production R &D and is currently being used for process scale up.

Res Biomass

Beta-Glucosidase (BGL)

BGL is the rate limiting enzyme in cellulose hydrolysis and it catalyses the final step of converting cellobiose to glucose. Since this enzyme is subject to feedback inhibition, biomass hydrolysis efficiencies are often dependent on the glucose concentrations that these enzymes can withstand without getting inhibited. Glucose tolerant enzymes can help in biomass conversion by allowing the hydrolysis reactions to proceed to a higher equilibrium, which will allow a higher final glucose concentration. We had isolated glucose tolerant BGLs from filamentous fungi (Aspergillus unguis and Byssoclamys fulva) both having a glucose inhibition constant (Ki) of 0.8M (~14% Glucose). The enzymes when blended to cellulase preparations would enhance hydrolysis efficiencies up to 30 %. Considering the importance of these enzymes, we cloned and expressed the gene for glucose tolerant BGL (GT-BGL) and is currently trying to decipher the mechanism of glucose tolerance, through structure function correlations.

Res BGL

Cellulase Gene Regulation in Filamentous Fungi

Fungi are important facilitators of carbon cycle on the globe through decomposition of plant biomass. The complete degradation of lignocellulosic biomass is a complex process that require synergistic action of several organisms in the soil of which fungi are unmistakably the most prominent. Fungi poses an arsenal of enzymes that act co-ordinately to breakdown lignocellulose. Breakdown of the cellulose polymer require a large group of enzymes which are mostly glycosyl hydrolases (eg. cellulases, hemicellulases) and several accessory proteins and auxiliary activities that include swollenins, lytic polysaccharide mono-oxygenases (LPMOs) etc. These are the very enzymes that we need for breaking down biomass in biorefineries for a renewable production of fuels (eg. ethanol, methanol, butanol) chemicals (eg. succinic acid, maleic acid) or materials (eg. Biopolymers like polyhydroxyakanoates) and are therefore of considerable research interest. Even today the cost of enzymes is the major bottle neck in biomass conversion technologies and improved production at competitive cost would be most advantageous for the success of biorefineries. However, in nature, the production of cellulases by filamentous fungi are tightly regulated by induction and repression mechanisms and circumventing this control is the key to enhanced production. This require better understanding of the regulation of cellulase genes in filamentous fungi, especially the induction and repression mechanisms. To date, most of the information available on the regulation of cellulase genes in fungi have come from studies on the model organism – Trichoderma reesei, the best known cellulase producer. Our group have been working with the fungi – Penicillium janthinellum (originally isolated at NCIM- CSIR-NCL, Pune), Aspergillus niger and Aspergillus unguis, the former a cellulase hyper producer superior to the best known cellulase producer T. reesei RUT C30, and the latter two, producers of beta glucosidase (BGL) which is the last enzyme in the cellulolytic cascade and the rate limiting one. Through genome, secretome and transcriptome analyses we have demonstrated that the increased number of CAZymes, higher BGL to cellulase ratio and higher induction levels accounts for the perceived superiority of P. janthinellum in hydrolysis of pretreated biomass. Also, it was discovered that the fungus harbours hitherto undescribed transcription factors and membrane transporters and signal transduction proteins that are co-ordinately regulated with cellulases. We have also found evidence for a Ca2+ dependent signalling in the regulation of glucose tolerant beta glucosidase in the rare fungus Aspergillus unguis. Our efforts are to understand deeper, the mechanisms of cellulase regulation so that we may be able to manipulate these control systems for better and more efficient production of biomass hydrolyzing enzymes for biorefinery applications

Res1

Heterologous protein expression in filamentous fungi

Protein expression in filamentous fungi is advantageous due to several reasons. Filamentous fungi are phylogenetically closer to humans compared to the currently used hosts for heterologous protein production, which will result in similar post-translational modifications and folding patterns. They can be cultivated on cheap biomass residues as carbon source thereby reducing production costs and increase the scales of operation; secretion systems are highly efficient allowing easy recovery of products etc. This is an area of immense importance also to the biofuel program since the large scale expression of enzymes like glucose tolerant BGL will help in developing cheaper enzymes. We have developed an expression system based on filamentous fungi for expression of heterologous proteins. Expression cassette containing a highly efficient cellobiohydrolase promoter, secretion and termination signal from T reesei, and with adapters for stable chromosome integration in the host was developed and expression of green fluorescence protein and human interferon beta (HuIFNβ) was demonstrated in the filamentous fungus Aspergillus unguis. The expression system is being further developed with better host range and a more efficient and unique promoters and control systems secreted expression of eukaryotic proteins.

Res2

Xenobiotic degradation by bacteria: Mechanisms and implications in resistance to antimicrobials

Pesticides are xenobiotics deliberately introduced into the environment and their degradation by microorganisms are immensely important, since as potent toxins affecting even non-target organisms, they have serious consequences on the ecosystem. Bacteria being the primary degraders of xenobiotics in nature play a very important role in the decontamination /removal of pesticides from soil and aquatic bodies. We have been investigating the effect of chlorpyrifos (CP), an organophosphate pesticide on two model bacteria - Escherichia coli and a soil isolate -Pseudomonas nitroreducens AR-3; the former not a degrader of the compound but which can tolerate high concentrations of CP, and the latter, one of the fastest reported (97% CP degradation in 8h) degrader of CP. Further investigation into the cellular and molecular mechanisms involved in tolerance and degradation revealed the efflux mediated tolerance of CP in E. coli, facilitated by the complex coordinated network of transporters and stress responsive pathways. The responses to pesticide also enabled resistance to antibacterial metals and antimicrobials like antibiotics, possibly due to the development of cross resistance, caused by the similarity in resistance mechanisms. On the other hand, degradation of CP in P. nitroreducens involved the down-regulation of transporters and stress responsive proteins with enhanced expression of proteins involved in carbohydrate and energy metabolisms and electron transport, essentially for utilization of the pesticide. The mechanisms responsible for degradation and tolerance are different in bacteria and the studies indicate that the responses to xenobiotic exposure in tolerant bacteria may culminate in multidrug resistance, which is an alarming finding. We are now investigating further implications of this finding, and towards understanding if the xenobiotic resistance mechanisms offer transferable resistance to antimicrobials in bacteria, which if true would have tremendous implications to the way we see development of multidrug resistance in bacteria.

Res CP
Honors and Awards
  • Member, Kerala State Biotechnology Commission (Current)
  • Member of the expert committee for monitoring and controlling the activities of SCRIPT (State-Centre Resource Institute for Partnership in Technology), an institute established in the Kerala State Council for Science, Technology and Environment with the mandate of fostering partnership between investors and technologists in order to overcome barriers in technology adaptation (Current)
  • SB Chincholkar Memorial Award for outstanding contributions in the area of Microbial and Enzyme Technology from Biotech Research Society, India (BRSI) (2015)
  • Member, Board of Studies, Mahatma Gandhi University, Kottayam, India (2020-Current)
  • Member, Board of Studies, Cochin University of Science and Technology, Kochi, India (2020-Current)
  • Listed in the Stanford University List of Top 2% Scientists of the World (2020)