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Dr. G S Prasad
Diversity, molecular phylogeny, genomics and industrial applications of yeasts

Contact Address:

Dr. G S Prasad
Chief Scientist and Head, Microbial Type Culture Collection and Gene Bank (MTCC)
CSIR-Institute of Microbial Technology
Sector-39A, Chandigarh – 160036, India
Phone:    (Off)       :  091-172-66651165
               (Home)   :  091-172-6665507,  091-172-2697 550

Fax:                        :  091-172-2695215, 2690585
Email :

Write-up of research and development interests/focus, past and present goals:

1. Diversity, molecular phylogeny and genomics of yeasts : Our group is working on Diversity, molecular phylogeny of yeasts from different ecological niches of India. We examine the molecular phylogeny of yeasts using sequence analysis of D1/D2 variable domain of LSu rRNA gene and Internal Transcribed Spacer (ITS) region of ribosomal RNA gene cluster.   Diversity of yeasts from two high temperature regions of India (Coal bet region of Andhra Pradesh and Rajasthan) was examined by us. Our study showed that these regions have unique yeast species, and resulted in isolation of several interesting and new species. Some of the interesting new yeast speices described are Candida digboiensis from Digboi oil refinery, Assam (Prasad et al 2005, Int.J.Sys.Evol.Microbiol. 55:967-972); Cryptococcus rajasthanensis sp. nov., from Rajasthan (Saluja and Prasad, Int.J.Sys.Evol.Microbiol. 57:414-418);  Debaryomyces singareniensis from coal mine fileds, Andhra Pradesh (Saluja and Prasad, 2007, FEMS Yeast Research 7: 482-488); Candida ruelliae from flowers of Ruellia species from Rajasthan (Saluja and Prasad, 2008, FEMS Yeast Research. 8:660-666); Geotrichum silvicola from silk worm larvae, Assam (Pimenta et al. 2005, Int.J.Sys.Evol.Microbiol. 55 : 497-501); and Torulaspora indica sp.nov. from coal mine soils (Saluja et al. 2012, Antonie Van Leeuwenhoek. 101:733-42).  Studies are in progress to isolate yeasts from guts of beetles and other insects to examine their role in utilization/fermentation of xylose and other 5 carbon sugar. In collaboration with PGIMER, Chandigarh we have reported molecular methods for rapid identification human pathogenic fungus Apophysomyces elegans and related species (Chakrabarti et al., 2003. Journal of Clinical Microbiology 41:783–788). Reported unusual polymorphisms in the D1/D2 variable domain of LSU rDNA among mating strains of yeast species Clavispora lusitaniae (Lachance et al., 2003, FEMS Yeast Research 4: 253-258). We are sequencing of genomes of several novel Indian yeast species to gain insights of their industrial potential. Studies are in progress on production of xylitol, erythritol , sophorolipids and mannosylerythritol lipids (MEL) using the yeast species. We are also developing a microbial process for production of biopolymer pullulan.

2. Studies on enzymes involved in purine degradation pathway in yeast Kluyveromyces lactis: The study involves characterization of  four different enzymes of purine catabolismviz. adenine deaminase (ADE), guanine deaminase (GDA), purine nucleoside phosphorylase (PNP), and xanthine dioxygenase (XanA) of yeast Kluyveromyces lactis. Consumption of high purine content food and beverages increases the risk of developing hyperuricemia which is a leading cause of gout and is also a risk factor for several cardiovascular, renal and other metabolic disorder diseases. Enzymes of this pathway can be used to treat food and beverages to lower the purine content and enzymes like XanA and Uox are used as therapeutic agents against hyperuricemia.  We have characterized the enzymes of purine degradation pathway of Kluyveromyces lactis and demonstrated their application in beverages. We have cloned, over expressed and purified the adenine deaminase (ADE), Guanine deaminase (GDA), purine nucleoside phosphorylase (PNP), xanthine dioxygenase (XanA) and Uricase. These enzymes were characterized biochemically and were examined for their ability to lower the purine content of selected varieties of beer from Indian market.  Uricase and PNP crystal structures were solved and mutational studies were done and two mutants of uricase were found to have higher catalytic efficiency. We quantified the purine content in beer and demonstrated that these enzymes could lower the purine content in beer individually and in combination. Characterization and application of enzymes provide the evidence to develop a method for lowering the purine content in food and beverages. In future, it will be more appropriate to use host harbouring engineered version of enzymes to effectively lower purine content in food and beverages.

3. Novel uricases and thier applications: Enzymes, due to their specific substrate activity and unparalleled reaction efficiency, are promising therapeutic agents. Moreover, there are certain shortcomings of enzymes such as slow enzymatic activity under physiological conditions, inherent immunogenicity, and short circulation life, which in one way or another hampers there use in world of therapeutics. Uricase is one of such enzymes which can be used as therapeutic. Therefore, uricase from various sources including microbial and higher organisms, has been exploited for its use as drug for human use.  We have cloned and expressed uricase of yeasts in both eukaryotic and prokaryotic expression systems. We have also performed mutational studies on uricase cloned in E.coli and we have found two mutants with higher catalytic efficiency than that of wild type uricase (Prasad, G.S. and Ravikumar, Y. Novel uricases and their applications.WO2014170916-A2). Studies are under progress for optimizing its properties like stability, activity, yield and antigenicity to make it a suitable candidate for therapeutics. 

Ongoing Research Projects :

• Expansion and modernization of Microbial Type Culture Collection and Gene Bank (MTCC) 12th plan project. (Council of Scientific and Industrial Research and Department of Biotechnology)

• Elucidation of purine degradation pathway in yeast Kluyveromyces actis. (Council of Scientific and Industrial Research)

• Novel uricase mutants and their application (Council of Scientific and Industrial Research)

• Diversity of fungi (Filamentous molds and yeasts) associated with some traditionally prepared mixed starter cultures of North east India and study of their biotechnological potential” (Department of Biotechnology, Twining Program for North Eastern Region)

• Epidemiology, pathogenomics, and system biology of A. flavus infections in India - an integrative approach" (Department of Biotechnology) (In collaboration with PGIMER, Chandigarh)

• Zygomycetes and mucormycosis : Epidemiology, taxonomy and molecular biology” (Department of Biotechnology) (In collaboration with PGIMER, Chandigarh)

Significant recognition: Awards, fellowships, international funding of distinction, technologies transferred/licensed etc.:

National :
  • Member "Technical Committee for the revision of - NABL-102" Document (Guidelines for Biological Testing Laboratories), National Accreditation Board for Testing and Calibration Laboratories (NABL), Department of Science and Technology (DST)
  • Member “Core Expert Group (CEG) on Designated Repositories” National   Biodiversity Authority, Govt. of India
  • Member "Niche Area Committee on "Value-added Biomas & Products from Natural Resources" for vision 2025 - Department of Biotechnology, Govt. of India
  • Representative of Director, CSIR-IMTECH in “Expert Committee on Access and Benefit Sharing”, National Biodiversity Authority, Govt. of India.
  • Representative of Director, CSIR-IMTECH in “Expert Committee on Agro Biodiversity”, National Biodiversity Authority, Govt. of India.
  • Selected for V. Agnihotrudu Memorial Lecture by Mycological Society of India 2016.
International :
  • Visiting Scientist, RIKEN (The Institute of Physical and Chemical Research), Wako-shi, Japan
  • Visiting Scientist, Institute of Plant Genetics and Crop Plants Research,  (IPK), Gatersleben, Germany
  • Awarded INSA-DFG fellowship (2007)
  • Awarded JSPS Fellowship (1999) by RIKEN, Japan
  • Member, International Technical Expert Workshop of Food and Agricultural Organization (FAO) workshops on ‘‘Access and Benefit-Sharing (ABS) of Genetic Resources for Food and Agriculture”’ held in Brussels, Belgium January 2009.
  • Member, International Technical Expert Workshop of Food and Agricultural Organization (FAO) workshops on ‘‘Access and Benefit-Sharing (ABS) of Genetic Resources for Food and Agriculture”’ held in Brussels, Belgium March 2011.
  • Member Executive Committee, World Federation of Culture Collections (WFCC)
  • Country representative, Asian Consortium for the Conservation and Sustatainable Utilization of Microbial Resources (ACM)
  • Awarded Indo-German Project "Production of purine degrading enzymes in Arxula adeninivorans and their possible use for production of foods with reduced purine content". (Department of Biotechnology and BMBF Germany)
Technologies transferred/ under development :
(a) Flocculating yeast technology for ethanol production: Part of the team that developed the Floccculating yeast strains useful for industrial production of ethanol. This technology has been transferred to M/S Dhampur Sugar Mills and is being used in their facility.
(b) Technology for biopolymer pullulan production and up-scaling: In collaboration with one of my colleague in CSIR-IMTECH we have developed a technology for production of biopolymer Pullulan. This has been used as a food ingredient for over 20 years in Japan, and has Generally Regarded As Safe (GRAS) status in the USA and Japan for a much wider range of applications. Pullulan can be formed into capsules for use with pharmaceutical and nutraceutical products. Its non-animal origin ensures there are no safety concerns with the consumers and it is suitability for all the consumers groups.
(c) Novel uricases and thier applications : Uric acid is formed during purine catabolism. Uricase which converts uric acid into allantoin, is not functional in humans. Excess of uric acid in body leads to hyperuricemia, which later on results into more severe form of disease, gout. Uricase is used as a therapeutic for the treatment of gout and hyperuricemia. We have a novel uricase and its two mutants with higher catalytic efficiency. Our plan is to provide an enzyme which is a suitable and competing candidate as a therapeutic and/or diagnostic molecule.
Industry sponsored projects completed:
• Molecular Characterization of isolates of Coniothyrium minitans. (T.Stanes & Company, Coimbatore).
• Molecular characterization of Chaetomium globosusm cultrues ((T.Stanes & Company, Coimbatore).
• Identification of of biocontrol agents ((T.Stanes & Company, Coimbatore)
• Molecular Characterization of microbial cultures : (Fresenius Kabi Oncology Limited, Baddi) 
• Confirmation and characterization of Saccharomyces boulardii strains (B.V. Inc. Belgium)
• Molecular characterization of Saccharomyces boulardii strain (Unique Biotech, Hyderabad, India)
• Novel skin care molecules (Pocter and Gamble (India). 
Successful management and modernization of MTCC National Facility: Heading the Microbial Type Culture Collection and Gene Bank (MTCC) since 2010 and transformed the functioning of the division. MTCC is now serving more than 12,500 researchers from all over the country. During the last 5 years it has supplied more than 35,000 microbial cultures to researchers and characterized more than 3000 microbial cultures. MTCC scientists have described about 100 novel microbial taxa from the country. MTCC is now comparable with any of the best microbial culture collections in the World in terms of facilities and expertize.  Coordinating the 12th plan project “Expansion and modernization of Microbial Type Culture Collection and Gene Bank (MTCC)”.  As part of this a separate building for the MTCC National Facility has been built. A new website with user friendly features, and e-commerce facility using SBIepay gateway  has been launched. MTCC services are certified under Quality Management System of ISO 9001:2008.

Selected list of Publications and Patents:

Selected Publications

1.  Chakrabarti,A., A. Ghosh, G. S. Prasad, J. K. David, S. Gupta, A. Das,V. Sakhuja, N. K. Panda, S. K. Singh, S. Das, and T. Chakrabarti (2003). Apophysomyces elegans: an Emerging Zygomycete in India. Journal of Clinical Microbiology 41:783–788.

2.   Lachance, M.A., H.M.Daniel, W.Meyer, G.S.Prasad, S.P.Gautam and K.Boundy-Mills (2003). The D1/D2 domain of the large-subunit rDNA of the yeast species Clavispora lusitaniae is unusually polymorphic. FEMS Yeast Research 4: 253-258

3.   Rani, S. Swarupa, I. K. Kunwar, G. S. Prasad and C. Manoharachary. (2004). Glomus hyderabadensis, a new species: its taxonomy and phylogenetic comparison with related species. Mycotaxon 89: 245-253. 2004.

4.   Pimenta,R.S.,  P. D. D. Alves, A. Correa Jr, M.-A. Lachance, G. S. Prasad, R. Ram, B. R. R. P. Sinha and C. A. Rosa. 2005. Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus Galactomyces. International Journal of Systematic and Evolutionary Microbiology. 55 : 497-501.

5.  Prasad, G.S., S,Mayilraj, Nitu Sood, Vijeta Singh, Banwari Lal. 2005.Candida digboiensis sp.nov. a novel anamorphic yeast species from acidic tar sludge contaminated oil field.  International Journal of Systematic and Evolutionary Microbiology. 55:967-972.

6.  Mayilraj, S., Prasad GS, K.Suresh, S.Shivaji, H.S.Saini, T.Charkrabarti.2005. Planococcus stackebrandtii sp. nov., isolated from a cold desert of the Himalayas, India. International Journal of Systematic and Evolutionary Microbiology. 55 : 91-94

7.   Saha P, Krishnamurthi S, Mayilraj S, Prasad GS, Bora TC, Chakrabarti T. 2005. Aquimonas voraii gen. nov., sp. nov., a novel gammaproteobacterium isolated from a warm spring of Assam, India. International Journal of Systematic and Evolutionary Microbiology 55:1491-1495.

8.  Singla AK, Mayilraj S, Kudo T, Krishnamurthi S, Prasad GS, Vohra RM. 2005. Actinoalloteichus spitiensis sp. nov., a novel actinobacterium isolated from a cold desert of the Indian Himalayas. International Journal of Systematic and Evolutionary Microbiology.  55:2561-2564. 

9.   Puja Saluja and G.S.Prasad. 2007. Cryptococcus rajasthanensis sp. nov., an anamorphic yeast species related to Cryptococcus laurentii, isolated from Rajasthan, India. International Journal of Systematic and Evolutionary Microbiology 57: 414-418.

10. Puja Saluja and G.S.Prasad. 2007.  Debaryomyces singareniensis sp. nov., a novel yeast species isolated from a coal-mine soil in India. FEMS Yeast Research 7: 482-488

11. Saluja P, Prasad GS. 2008.Candida ruelliae sp. nov., a novel yeast species isolated from flowers of Ruellia sp. (Acanthaceae). FEMS Yeast Research. 8:660-666.

12. Daniel, H.M. and Prasad, G.S. 2010. The role of culture collections as interface between providers and users: the example of yeasts. Research in Microbiology 161:488-496

13. Choudhury, AR., Puja Saluja, G.S. Prasad (2011).Pullulan production by an osmotolerant   Aureobasidium pullulans RBF-4A3 isolated from flowers of Caesulia axillaris. Carbohydrate Polymers 83 : 1547–1552

14. Suzuki, M., Prasad, G.S. and Kurtzman, C.P. (2011). Debaryomyces Lodder & Kreger-van Rij (1952), In : The Yeasts, a Taxonomic Study, Edited by Kurtzman,C.P., Fell, J.W. and Boekhout,T. Elsevier Publishers

15. Roy Choudhury A, Sharma N, Prasad GS. (2012). De-oiled jatropha seed cake is a useful nutrient for pullulan production. Microbial Cell Factories. 11: 39. 

16. Saluja P, Yelchuri RK, Sohal SK, Bhagat G, Paramjit, Prasad GS. (2012). Torulaspora indica a novel yeast species isolated from coal mine soils. Antonie Van Leeuwenhoek. 101:733-42

17. Roy Choudhury, A, M.S. Bhattacharyyaa, G.S. Prasad (2012). Application of response surface methodology to understand the interaction of media components during pullulan production by  Aureobasidium pullulans RBF-4A3. Biocatalysis and Agricultural Biotechnology, 1:232–237

18. Sharma N, Prasad GS, Choudhury AR. (2013). Utilization of corn steep liquor for biosynthesis of pullulan, an important exopolysaccharide. Carbohydrate Polymers 93 : 95-101. 

19. Choudhury, AR., Bhattacharjee, P. and Prasad, GS. (2013). Development of Suitable Solvent System for Downstream Processing of Biopolymer Pullulan Using Response Surface Methodology. PLOS ONE  8:10: e77071   Published: OCT 15 2013

20. Khatri I, Akhtar A, Kaur K, Tomar R, Prasad GS, Ramya TN, Subramanian S. (2013). Gleaning evolutionary insights from the genome sequence of a probiotic yeast Saccharomyces boulardii. Gut Pathogens. 22;5(1):30. doi: 10.1186/1757-4749-5-30.

21. Singh P, Singh SM, Tsuji M, Prasad GS, Hoshino T (2014). Rhodotorula svalbardensis sp. nov., a novel yeast species isolated from cryoconite holes of Ny-Ålesund, Arctic. Cryobiology. 68:122-128.

22. Mehta A, Prasad GS, Choudhury AR (2014). Cost effective production of pullulan from agri-industrial residues using response surface methodology. International Journal of Biological Macromolecules 64:252-256.

23. Choudhury AR, Malhotra A, Bhattacharjee P, Prasad GS (2014). Facile and rapid thermo-regulated biomineralization of gold by pullulan and study of its thermodynamic parameters. Carbohydrate Polymers 106:154-159

24. Pooja Dixit,Ananya Mehta,Geeta Gahlawat, Prasad GS and Choudhury AR, (2015). Understanding the effect of interaction among aeration, agitation and impeller positions on mass transfer during pullulan fermentation by Aureobasidium pullulans. RSC Advances. 2015, 5, 38984

25. Prasanna Honnavar, Gandham S Prasad, Anup Ghosh, Sunil Dogra, Sanjeev Handa, and Shivaprakash Rudramurthy" (2016). Malassezia arunalokei sp. nov., a novel yeast species isolated from seborrhoeic dermatitis patients and healthy individuals from India". Journal of Clinical Microbiology 54:1826–1834.

26. Prasanna Honnavar ;  Arunaloke Chakrabarti; G S Prasad; Pankaj Singh; Sunil Dogra; Shivaprakash Mandya Rudramurthy. (2016). β-Endorphin enhances the phospholipase activity of the dandruff causing fungi Malassezia globosa and Malassezia restricta. Medical Mycology.Med Mycol (2016). doi: 10.1093/mmy/myw058,First published online: August 5, 2016

27. Mahor, Priyanka, Prasad GS, and Thakur KG.(2016). Functional and Structural Characterization of Purine Nucleoside Phosphorylase from Kluyveromyces lactis and Its Potential Applications in Reducing Purine Content in Food.PLoS One.11(10):e0164279. 

28. Indu Khatri, Rajul Tomar , K. Ganesan , G. S. Prasad & Srikrishna Subramanian (2017). Complete genome sequence and comparative genomics of the probiotic yeast Saccharomyces boulardii. Scientific Reports | 7: 371 | DOI:10.1038/s41598-017-00414-2




Patents granted abroad :

Mondal, A.K.; Prasad, G.S. and Chakrabarti, T.  Strains of yeast of Saccharomyces cerevisiae  and a process for the preparation on such strains of yeast (As Amended) (US Patent no. 5693526 dated 02/12/1997)
Mondal, A.K.; Prasad, G.S. and Chakrabarti, T.  Novel strains of yeast of genus- Saccharomyces species-cerevisiae and a process for the preparation of such strains of yeast ( Patent no. EP0798382 B1 dated 12/11/2003)

Patents granted in India:

Ganesan, K.; Prasad, G.S.; Sharma, V.M.; Ghosh, I.; Chopra, R. and Chakrabarti, T.     A process for the preparation of improved thermotolerant flocculent strains of saccharomyces (Indian Patent No.: 189737)

Patents filed in India/abroad :

Mondal, A.K.; Prasad, G.S. and Chakrabarti T.   A process for the preparation of improved strains of yeast saccharomyces cerevisiae (Patent application no. 0012DEL2003)
Mondal, A.K.; Prasad, G.S. and Chakrabarti, T. A process for the preparation of improved strains of yeast saccharomyces cerevisiae (Patent application no. 1718DEL1994)
Mondal, A.K.; Prasad, G.S. and Chakrabarti, T. Novel strains of yeast of genus- Saccharomyces species-cerevisiae and a process for the preparation of such strains of yeast    (Patent no. 96/2541 dated 27/08/1997) (South Africa)
Prasad, G.S. and Ravikumar, Y. Novel uricases and their applications.WO2014170916-A2  
Prasad, G.S. and Ravikumar, Y. Novel uricases and their applications.IN201301145-11 
Prasad, G.S. and Ravikumar,  Novel uricase mutants. EP 2986720 A2. Publication date:24 Feb 2016
Prasad, G.S. and Ravikumar, Y. Novel uricase muants. European Patent application 14734916.1 date of filing 17.04.2014 (Designated countries 38)

Present group members:

  • Mr. Paramjit (Technial Staff)
  • Mr. Rajul Tomar (SRF)
  • Ms. Durga Mahor (SRF)
  • Mr. Sachin Kumar (SRF)
  • Ms. Alka Kumari (JRF)
  • Ms. Varinder Kaur (PF)
  • Mr. Raju ((PF)
  • Mr. Surinder (PA)

Past group members:

  • Dr. Puja Saluja 
  • Dr. Y. Ravikumar
  • Dr. Kakoli Biswas
  • Dr. Charles Omoifo
  • Dr. Charles
  • Mr. Pukhraj Vishno
  • Mr. Sham Bhatnagar
  • Mr. Mohit Yadav
  • Ms. Satinder Kaur
  • Ms. Gethika Bhagat
  • Ms. Priyanka
  • Ms. Elsa
  • Ms. Rupinder Kaur Saini
  • Mr. Asutosh Kumar Tiwari
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