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Laboratory of Plant Substrates Bioconversion

Head of laboratory, Doctor, Professor V. Elisashvili

Contacts

Phone/fax: (995 32) 528129
E-mail: velisashvili@hotmail.com

Main Directions

  • Creation of the collection of industrially  important. basidiomycetes.
  • Investigation of wood-rotting fungi physiology and biochemistry.
  • Regulation of biosynthesis of  hydrolases (cellulases, xylanases) and oxidases (laccases and peroxidases).
  • Synthesis of polysaccharides, lectins and antioxidants by medicinal mushrooms.
  • Bioremediation of soils and waters polluted by industrial wastes and  industrial dyes decolourization.
  • Rlaboration of technologies of production  animal feed,  medicinal and edible mushrooms.

Research Activity

The collection of higher basidiomycetes (a unique collection of macromycetes in Georgia) has been created. It is a basis for screening of strains possessing important industrial properties  and the supplier of cultures for different institutions both in Georgia and in foreign countries. More than 100 basidiomycete strains have been checked for submerged and solid-state fermentation of wide range of agro-industrial plant wastes. In screening program very active and promising producers of laccase, Mn-peroxidase endoglucanase xylanase, ?-glucosidase , ?-xylosidase were selected.
Physiological regulation of Basidiomycetes cellulases and xylanases synthesis has been studied. Hydrolases synthesis in white rot fungi (Cerrena unicolor, Coriolus pubescens, Funalia trogii, Merulius tremellosus, Pleurotus salignus) is inducible, while brown rot fungi (Daedalea quercina, Fomitopsis pinicola, Pholiota aurivella) produce them constitutively. Although, the cellulase and xylanase synthesis of one brown rot fungus- Piptoporus betulinus is inducible in presence of cellobiose. Furthermore, the catabolite repression of cellulase and xylanase synthesis is widespread in all basidiomycetous fungi with the inducible enzyme synthesis.
The role of carbon source, microelements, aromatic compounds and dyes in regulation of laccase and Mn-peroxidase production was established. Thus, the use of cellobiose instead of avicel as a carbon source results in a 20-fold increase of C. unicolor laccase activity. Mannitol is the best carbon source for P. ostreatus and Phlebia radiata, whereas xylan ensures the highest laccase activity of C. pubescens. Laccase production is stimulated by xylidine in the case of C. pubescens and P. ostreatus, and by veratryl alcohol in the case C. unicolor.
Xylanases, cellulases, ?-glucosidases, laccases and Mn-peroxidase from C. unicolor, C. pubescens, Lentinus tigrinus and P. ostreatus were purified. Some physical-chemical and catalytic properties of these enzymes have been studied.     
Crude enzyme preparations of Pleurotus dryinus, Fomes fomentarius, Cerrena maxima, Funalia trogii decolorize such recalcitrant dyes as Amaranth, Remazol Brilliant Blue R, Indigo carmine, and Poly R-478.
Production of exo-polysaccharides is widespread among basidiomycetes belonging to various taxonomic and ecological groups. The yield of EPS depends on fungus peculiarities and could be regulated by cultivation conditions.
Lectin activity of submerged mycelia was investigated for the first time. Among all the fungi tested the highest hem agglutinating activity was revealed in Cerrena unicolor and Ganoderma ramnosissimum, G. applanatum mycelial biomass. G. ramnosissimum showed the highest specific activity specific hem agglutinating activity. Lectins from C. unicolor and Trametes versicolor were galactose specific whereas Ganoderma lucidum and G. ramnosissmum showed specificity for arabinose and GlcNAc, respectively.
Water extracts from Coprinus comatus, Agaricus nevoi, and Flammulina velutipes showed high (more than 85%) antioxidant activities (AA). When the ethanol extracts were tested, the highest AA was found in Agaricus nevoi, Omphalotus olearius, and Auricularia auricula-judae extracts (92.1%, 83.4%, and 80.2%, respectively). Anti-breast cancer effect of these extracts is now under investigation.
The activities of cellulases, xylanases, laccases, and Mn-peroxidases in colonization of various substrates by Pleurotus ostreatus (oyster mushroom) and Lentinus edodes (shiitake) and fruiting bodies development have been investigated.

Technology development

One of the main objectives of the laboratory is the development of efficient biotechnological processes to be applied in the industries, thus improving their technological level and minimizing their cost and environmental impact.
We have developed:
Two low cost technologies of laccase and Mn-peroxidase production in laboratory scale fermentor with one of the highest yield in the world;
Highly competitive and inexpensive technology of lignocellulolytic enzyme production in submerged and solid-state fermentation of plant raw materials;
Technologies of extracellular polysaccharides (with immunomodulating activity) production in laboratory fermentor;
Oyster mushroom and shiitake production technologies on different lignocellulosic wastes;
Bioconversion of agro-industrial wastes to obtain animal feed enriched with protein and hydrolytic enzymes;
Textile dyes decolourization.

Members:

  1. Elisashvili Vladimer - Doctor, professor, head of laboratory
  2. Kachlishvili Eva – PhD, senior scientist
  3. Tsiklauri Nino – PhD, scientist
  4. Metreveli Eka – PhD, scientist
  5. Khardziani Tamar – PhD, lab assistant

Elisashvili Vladimer

1944 – Born
1973 - St Petersburg (Leningrad) State University
1974 - Candidate of Biological Sciences
1993 - Doctor of Biological Sciences
1989 - Head of Laboratory
2001–2003 – Invited professor to Haifa University.
Member of editorial of New – York scientific Academy and  International scientific journal (“International Journal of Medicinal Mushrooms” (Begell Publ. House, NY, USA).

Selected Publications

  1. Wasser S.P., Elisashvili V.I., Tan K.-K. Effect of carbon and nitrogen sources in the medium on Tremella mesenterica Retz.:Fr. (Heterobasidiomycetes) growth and polysaccharide production. International Journal of Medicinal Mushrooms, 2003, 5, 49-56.
  2. Elisashvili V., Chichua D., Kachlishvili E., Tsiklauri N., Kharziani T. Lignocellulolytic enzymes activity during growth and fruiting of the edible and medicinal mushroom Pleurotus ostreatus (Jack.: Fr.) Kumm. (Agaricomycetideae). International Journal of Medicinal Mushrooms, 2003, 5, 193-198.
  3. Mikiashvili N., Wasser S.P., Nevo E., Elisashvili V. Lignocellulolytic enzyme activities of medicinally important basidiomycetes from different ecological niches. International Journal of Medicinal Mushrooms, 2004, 6, 63–71.
  4. Elisashvili V., Wasser S., Tan K.-K., Chichua D., and Kachlishvili E. Extracellular Polysaccharide Production by Culinary–Medicinal Shiitake Mushroom Lentinus edodes (Berk.) Singer and Pleurotus (Fr.) P. Karst. Species Depending on Carbon and Nitrogen Source. International Journal of Medicinal Mushrooms, 2004, 6, 165–172.
  5. Mikiashvili N., Elisashvili V., Wasser S., Nevo E. Carbon and nitrogen sources influence the ligninolytic enzyme activity of Trametes versicolor. Biotechnology Letters. 2005, 27, 955-959.
  6. Elisashvili V., Penninckx M., Kachlishvili E., Asatiani M., Kvesitadze G. Use of Pleurotus dryinus for lignocellulolytic enzymes production in submerged fermentation of mandarin peels and tree leaves. Enzyme and Microbial Technology, 2006, 38, 998-1004.
  7. Songulashvili G., Penninckx M., Wasser S., Metreveli E., Aladashvili N., Asatiani M., Hadar Y., Elisashvili V. Bioconversion of plant raw materials in value-added products by Lentinus edodes and Pleurotus spp. International Journal of Medicinal Mushrooms, 2005, 7, 467-468.
  8. Mikiashvili N.A., Elisashvili V.I., Wasser S.P., Nevo E. Comparative study of lectin activity of higher basidiomycetes. International Journal of Medicinal Mushrooms, 2006, 8, 31-38.
  9. Kachlishvili E., Penninckx M.J., Tsiklauri N., Elisashvili V. Effect of nitrogen source on lignocellulolytic enzyme production by white-rot basidiomycetes under solid-state cultivation. World Journal of Microbiology and Biotechnology, 2006, 22, 391-397.
  10. Songulashvili G., Elisashvili V., Wasser S., Nevo E., Hadar Y. Laccase and manganese peroxidases activities of Phellinus robustus and Ganoderma adspersum grown on food industry wastes in submerged fermentation. Biotechnology Letters, 28, 1425-1429.
  11. Mikiashvili N., Wasser S., Nevo E., Elisashvili V. Effect of carbon and nitrogen sources on Pleurotus ostreatus ligninolytic enzyme activity. World Journal of Microbiology and Biotechnology, 2006, 22, 999-1002.
  12. Songulashvili G., Elisashvili V., Wasser S.P., Nevo E., Hadar Y. Basidiomycetes laccase and manganese peroxidase activity in submerged fermentation of food industry wastes. Enzyme and Microbial Technology, 2007, 41, 57-61.
  13. Cabana H., Jiwan J.L., Rosenberg R., Elisashvili V., Penninckx M., Agathos S.N., Jones J.P. Elimination of endocrine disrupting chemicals nonylphenol and bisphenol A and personal care product ingredient triclosan using enzyme preparation from the white rot fungus Coriolopsis polyzona. Chemosphere, 2007, 67, 770-778.
  14. Elisashvili V., Penninckx M., Kachlishvili E., Tsiklauri N., Metreveli E., Khardziani T., Kvesitadze G. Lentinus edodes and Pleurotus species lignocellulolytic enzymes activity in submerged and solid-state fermentation of lignocellulosic wastes of different composition. Bioresource Technology (Available online 12 March 2007).
  15. Elisashvili V., Penninckx M., Kachlishvili E., Tsiklauri N., Metreveli E., Khardziani T., Kvesitadze G. Lentinus edodes and Pleurotus species lignocellulolytic enzymes activity in submerged and solid-state fermentation of lignocellulosic wastes of different composition. Bioresource Technology, 2007 (accepted for publication).

Patents of USSR

Elisashvili V.I., Loytsanskaya M.S., Tkachenko A.A. Method for the production of levansucrase. USSR author's certificate ¹ 775124, 1980.
Elisashvili V.I., Loytsanskaya M.S. Method for the production of high molecular levan. USSR author's certificate ¹ 859375, 1981.

International patent

Elisashvili V., Rebhun M. Wood-rotting basidiomycetes for production of ligninolytic enzymes. WO 2006/114787 A3; Publication date: 02/11/2006.

Grants of the Georgian Academy of Sciences

  1. 1997–1999 – 14.5  Working out scientific ground for the realization of mycelial fungi biosynthetic potential to obtain enzyme preparations.
  2. 2000–2001 – 14.9. Characterization and practical uses of lignocellulolytic activities of wood-rotting basidiomycetes isolated from different ecological niches of Georgia.
  3. 2002–2003 – 14.10.02. Biosynthesis of enzymes and polysaccharides of wood-rotting basidiomycetes isolated from different ecological niches of Georgia.

International Grants

  1. 2003-2005 STCU G-101. Creation of collection of extremophilic mycelial fungi isolated from all ecological niches of the Caucasus and elaboration of the technologies based on their degradational, oxidizing and synthesizing potential (www.stcu.int).
  2. 2003-2004 Development of strategies of environment pollution prevention by bioconversion (validation) of municipal and agro-industrial wastes into value-added products (grant from Brussels government in the frame of “Research in Brussels”).
  3. 2006-2009 STCU 3740.  Development of technologies of basidiomycetes ligninolytic enzymes production, dyes decolourization, and TNT-polluted soil bioremediation (www.stcu.int).

National Grant

2006-2009 06-75-6-250 Basidiomycetes as the biological factories for bioconversion of agro-industrial wastes into value-added products (enzymes, polysaccharides, lectins, etc.).

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