Technical Sessions-Abstracts-Oral session 5-OS-51-OS-54

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

ORAL SESSION 5

OS – 51

Biodegradation of Pentachlorophenol by white rot fungi isolated from forests of Western Ghats of Karnataka India.

Ch. Ramesh and Manohar G. Pattar*
Mycology Laboratory Department of Botany, Karnatak University, Dharwad 580 003 (Karnataka).
*E-mail: pgmanohar@gmail.com

Pentachlorophenol (PCP) is a major organic compound used in the wood preservation. White rot fungal strains screened from local sources such as wood trunks and twigs of higher plants. Five selected isolates of White Rot Fungi (WRF) Viz: Laetiporus cincinnatus, Trametes versicolor, Fomes fomentarius, Ganoderma aplanutun and Pleurotus ostreatus isolated from Sambrani and Dandeli forests of Western Ghats of Karnataka. The isolates were evaluated for the in-vitro biodegradation of PCP. The presence of extracellular laccase shows that these isolates are capable of degrading variety of xenobiotics including biodegradation of PCP. The maximum laccase activity (0.14 ± 003U) of F. fomentarius, P. ostreatus followed by T. versicolor study has shown significant efficiency on biodegradation of PCP which was quantitatively estimated and analyzed by High Performance Liquid Chromatography (HPLC). The static culture studies have been shown among all the isolates F. fomentarius (100%) and P. ostreatus (99.40±1.29%) degraded the PCP over 30 days of incubation.

OS – 52
L-asparaginase from fungi

T. S. Murali, Geetha Suvarna, P. M. Gopinath and K. Satyamoorthy
Division of Biotechnology, Manipal Life Sciences Centre, Manipal University,
Manipal 576 104 Karnataka.

Asparaginase (L-asparagine amido hydrolase, E.C. 3.5.1.1) is an anti-neoplastic agent and used in combination with other chemo-therapeutic agents in the treatment of acute leukemia. L-asparaginase (molecular weight-139,000) belongs to an amidase group that produces aspartic acid and ammonia by asparagine hydrolysis. L-asparaginase is produced by many bacteria, plants and animals such as E. coli, Erwinia sp., Candida utilis. Microbial asparaginases are being investigated for their therapeutic potential in treating acute lymphoblastic leukemia, and carcinomas. However, the bacterial enzyme causes few side effects such as liver damage, respiratory distress and hence there is a need for eukaryotic source of this enzyme. Though, fungi such as Aspergillus and Fusarium are known to produce asparaginase, very few studies have been carried out with regard to endophytic fungi. Endophytic fungi elicit several metabolites of medicinal importance and hence we screened endophytes isolated from medicinal plants such as Catharanthus roseus, Coleus sp. for their L-asparaginase production. The results were compared with L-asparaginase produced by filamentous fungi isolated from soil and water environments. Both qualitative and quantitative analyses of the enzyme were carried out. The results will be discussed in detail.

OS – 53

Marine derived fungi and their potential in metal bioremediation

Sarita Nazareth
Department of Microbiology, Goa University, Goa 403 206.

Marine-derived fungi comprise the obligate marine fungi and facultative species that are found in terrestrial ecosystems as well. These marine fungi have been discovered in different marine habitats exposed to various conditions, some of which may be extreme environments and the microorganisms adapted to withstand these harsh conditions. Pollution of our aquatic ecosystems by the influx of heavy metals has become a matter of concern over the last few decades. This toxic metal waste cannot be degraded by biological and chemical processes, nor can they be decomposed by in situ biological means and thus persist indefinitely in the environment, affecting organisms at the biochemical and cellular level: enzymes, nucleic acids, transport systems for essential nutrients and ions, displacement of essential ions from cellular sites, and disruption of cell and organ membrane integrity, eventually affecting community and population dynamics, thus causing severe damage to aquatic life, accumulating through the food chain and posing a grave threat to life. These deleterious effects and the emergence of more severe environmental protection laws have encouraged studies about removal and / or recovery of heavy metals from aqueous solutions. This can be achieved using biosorption or bioaccumulation which provides an attractive cost-effective, environment-friendly alternative to the physico-chemical method.The complex structure of microorganisms affords different means for metals to be taken up by the microbial cell, including ionic interactions and a passive sorption, not requiring live cells, or an energy-dependent, active uptake by live cells The fungi that predominate the estuarine waters, Goa, are observed to belong mainly to the genera of Aspergillus and Penicillium, with a few others of Cladosporium, Alternaria, Fusarium. Studies have shown that the fungi tolerate fairly high concentrations of heavy metals and react by developing a thickened cell wall perhaps due to increased chitin deposition, or a slow, dense mycelial aggregation as a means of protection and survival; they may also show morphological abnormalities such as swollen apical tips, or a constricted growth or an increase / decrease / absence / de novo synthesis of pigment production.


OS – 54

Onychomycosis - a potential threat to gardeners

Shaveta Jandial* and Geeta Sumbali
Department of Botany,
University of Jammu, Jammu 180 006
*E-mail: shavetajandial@yahoo.com

Onychomycosis means infection of nails caused by dermatophytes, yeasts and non-dermatophytic filamentous fungi. Previously researchers believed dermatophytes to be most commonly responsible for onychomycosis. But the spectrum of moulds capable of inducing onychomycosis is larger than commonly assumed, as many non-dermatophytic fungi such as Aspergillus spp., Fusarium spp., Onchocola spp., Scopulariopsis spp. etc have been recovered from nails. Farmers and gardeners are generally thought to be at higher risk of geophilic dermatomycoses because of their occupational contact with soil. Keeping this in view, a survey was undertaken to assess the pathogenic potential of dermatophytic/non-dermatophytic moulds from the toe and finger nails of 14 gardeners working in the botanical garden of University of Jammu. Visual observations showed that finger nails of only one gardener were affected. Frequent isolations from the nail clippings done on SDA (Sabouraud’s dextrose agar medium) yielded Fusarium equisetii as the causal agent. This is a new addition to the already existing list of non-dermatophytic agents of onychomycosis.
Myco-keratinophiles recovered from the soils of botanical garden of Jammu University also showed a preference for efficiently colonizing and utilizing nail keratin, thus predicting their pathogenic potential for onychomycosis.