Technical sessions-Abstracts-Oral Session 3-OS-31-OS-35

36th Ann. Meeting of MSI & Nat. Seminar on Fungal Biodiversity & Bioprospecting….. Goa, India Oct., 29-30, 2009

ORAL SESSION 3

OS – 31

Growth Response of Solanum nigrum L. to Arbuscular mycorrhizal fungi and Plant growth promoting microorganisms

K. V. Chethan Kumar, Sukesh* and Chandrashekar K.R*
Department of Microbiology, Post graduate study centre, MSRCASC, Bangalore.
*Department of Applied Botany, Mangalore University, Mangalagangothri, Mangalore.

Pot experiments were conducted to know the influence of inoculation with Arbuscular mycorrhizal fungi (AM fungi) and the Plant growth promoting microorganisms (PGPRMs). Efficacy of ten Arbuscular mycorrhizal fungi on Solanum nigrum (Medicinal Plant) was studied. Plants grown in the presence of AM fungi generally showed an increase in plant growth and biomass over those grown in the absence of AM fungal inoculation. It was observed that Glomus mosseae was the best AM symbiont to enhance the plant biomass. This best AM symbiont was selected to study the response of Solanum nigrum to the inoculation in combination with different PGPRMs (Trichoderma viridae, Aspergillus awamorii, Azotobacter chroococcum and Psuedomonas fluorescence). The plant height, number of leaves per plant, number of branches per plant, Plant dry and fresh matter, Plant P content and N content were significantly higher in plants inoculated in combination with Glomus mosseae and PGPRMs. A higher root colonization and phosphatase activity was also observed in the plants inoculated with Glomus mosseae alone and in combination. This study clearly brings out that inoculation with Glomus mosseae + PGPRMs not only improve the growth, biomass yield, P nutrition of Solanum nigrum, but also help in sustainable agricultural practices in the cultivation of Solanum nigrum.


OS – 32

Production, purification and characterization of an extracellular lipase from Aspergillus japonicus isolated from Ropalidia marginata paper nest

A. Jayaprakash* and P. Ebenezer
Centre for Advanced Studies in Botany, University of Madras, Guindy campus, Chennai 600 025.
*E-mail: aruljaypee@gmail.com

Lipases (EC 3.1.1.3) hydrolyze triglycerides to fatty acids and glycerol. They are widely distributed in nature. Although lipases have been found in many species of animals, plants, bacteria, yeast, and fungi, the enzymes from microorganisms are most interesting because of their potential applications in various industries such as food, dairy, pharmaceutical, detergents, textile,biodiesel, and cosmetic industries, and in synthesis of fine chemicals, agrochemicals, and new polymeric materials. Fungi are important enzyme producers since they produce enzymes extracellularly. The present investigation is aimed at the isolation of paper nest-inhabiting fungi of Ropalidia marginata and screening the same for extracellular lipase activity, identification of promising lipolytic fungal isolates and optimization of enzyme production of the isolates by response Surface Methodology (RSM). Further, purification and characterization of the extracellular lipase by Ion exchange and gel filtration chromatography.

OS – 33

Yeast Killer toxins elaborated by the anamorphic basidiomycetous yeast Cryptococcus neoformans towards various ascomycetous yeast genera

Peralam Yegneswaran Prakash, Taronish Dubash*, Sugandhi Rao**
Medical Mycology Laboratory, Department of Microbiology, Kasturba Medical College,
*Division of Biotechnology, Manipal Life Sciences Centre, Manipal University, Karnataka.
**Department of Microbiology and Immunology, Kasturba Medical College International Centre, Manipal University, Karnataka.

Yeast cells liberate lethal polypeptides toxins designated as killer proteins or killer toxins to which they themselves are immune. The killer yeasts produce toxins as either proteins or glycoproteins, and these toxins are fatal to other yeast strains. Not all yeasts strains are sensitive to killer toxins and yeasts are currently classified as killer strains, sensitive strains, unaffected strains and competitive yeast strains. In recent years several new killer yeast strains have been reported but not yet well classified. The activity of theses toxins is analogous to the activities of bacteriocins in bacterial strains. To isolate Cryptococcus neoformans from clinical and ecological sources and check for killer toxin elaborated by them and their interaction with the pathogenic and non-pathogenic ascomycetous yeast genera. The Killer yeast activity was estimated using the calorimetric measuring of cell growth using the Thiazole blue tetrazolium bromide (MTT) Assay where in the reduction takes place only when mitochondrial reductase enzymes are active and therefore conversion can be directly related to the number of viable cells. In addition the plate count agar (PCA) Assay using YEPG agar to determine the viable counts and Methylene Blue (MB) agar diffusion assay were performed. Data analyses were performed using SPSS 10.0 Software. Ecological isolates of Cryptococcus neoformans were found to elaborate the Killer phenotypes in comparison to the Clinical isolates (P<0.05). The Killer activity were documented against test strains of Pichia , Brettanomyces, Saccharomyces, Candida. The existence of killer phenotype in a relatively higher number in the ecological source may serve in the elimination of competitors, either literal killing or a severe reduction in the fitness of sensitive strains, through blocking one or a few specific vital biochemical reactions in their metabolic pathways or punching a hole in the cell membrane. Whatever actual form it takes, toxin production is a clear case of interference competition a type of ecological interaction differing from resource competition in that it involves a direct active suppression of the rival population by means other than just exhausting the common limiting resources.

OS – 34

Mycoparasitic Penicillium on Aspergillus niger causing pomegranate fruit rot

Rahul Sharma and S.K. Singh
National Facility for Culture Collection of Fungi, Agharkar Research Institute,
G.G. Agarkar Road, Pune 411004, MS.

Recently a Pomegranate fruit rot (post harvest) was encountered caused by a member of Aspergillus niger complex which currently comprises of nine species. During isolation of the fungus certain grayish conidial heads were seen in the centre of the fungal colonization, which on close observation with stereomicroscope appeared Penicillium like conidial apparatus which eventually was confirmed by microscopy and the two species were separated in pure form. Penicillium species are known to parasitize Aspergillus conidial heads (Horn & Peterson, 2008) but the phenomenon is quite uncommon. In our case, whether this association is strictly parasitic in nature is still a matter of speculation since no substantial Penicillium mycelium was seen growing inside Aspergillus niger hyphae. Molecular characterization was done to identify the two species involved and the present communication puts more light on this association between two most versatile mitosporic genera of Plectomycetes.

OS – 35

Fungal Endophytes: A Potential Source of Anticancer Compounds

S.K. Deshmukh*
Department of Natural Products, Piramal Life Sciences Limited, 1, Nirlon Complex, Off Western Express Highway, Near NSE Complex, Goregaon (East), Mumbai 400 063.
*E-mail: sunil.deshmukh@piramal.com

Endophytic fungi are microorganisms that colonize living, internal tissue of plants without causing any immediate, overt, negative effects or external symptoms. Recently, a great deal of interest has been generated by discovery of remarkable pharmacological agents from endophytic fungi and also recognized as potential source of bioactive secondary metabolites with a high level of structural diversity . These fungi are known to produce anticancer compound viz. Taxol, Vincristine, and Camptothecine which were originally obtained from the host plant. In the pre
sentation, the emphasis will be given to both endophytic fungi and their chemical diversity. Some emphasis will also be given to anticancer compounds produced by this group of fungi.The need of an extensive survey of this group of fungi from unexplored areas and exploitation of their ability to produce anticancer compounds, and culture collection of this group of fungi will also be highlighted.