prog detail - International Mycological Association

PS4-398-0143
Stachylina in India: occurrence and relationships with temperature and hydrogen-ion concentration of the
waters
J. K. Misra
Sri J. N. P. G. College, Lucknow, Uttar Pradesh, India
Bioinventoring of Harpellales (Trichomycetes) was undertaken to fill the lacuna in our knowledge of these fungi from
India.
Bloodworms (Chironomus sp, Chironomidae) were regularly collected for a year (Jan-Dec. 2004) from stagnant water
bodies in and around Lucknow by scooping the muddy water using iron strainer. Temperature and pH of the water
were recorded at the time of collection of bloodworms. The bloodworms were dissected in a drop of distilled water
under binocular stereomicroscope and peritrophic membranes were examined under phase contrast microscope in
water mount for the presence of the thalli of Stachylina on them.
Stachylina chironomidarum and St. grandispora were observed. St. chironomidarum was not common in occurrence
while St. grandispora was found throughout the year, of course, in varying percentages as shown in table below. St.
grandispora exhibited enough variations in the number and size of the trichospores.
Per cent occurrence of Stachylina grandispora in the Bloodworms collected in different months from stagnant water
bodies in and around Lucknow (Jan. 2004-Dec. 2004)
Month Water temperature PH Number of Bloodworms % occurrence of Stachylina
in Celcius. collected grandispora
January 19 8.00 09 45
February 23 8.00 10 59
March 29 9.00 08 55
April 30 9.10 13 36
May 32 9.00 09 34
June 32 9.20 13 45
July 27 9.00 12 46
August 29 9.00 04 38
September 29 8.00 07 35
October 26 8.00 09 70
November 18 8.00 07 29
December 11 8.00 06 23
The correlation coefficient (r) analysis of the present set of data is not significant but the relationships do exist.
PS4-399-0218
Fungal Ligninolytic Enzymes in the Forest Soil Environment: Occurrence, Distribution and Role in Soil
Organic Matter Transformation
P Baldrian, J Snajdr, V Valásková
Institute of Microbiology ASCR, Praha 4, Czech Republic
Ligninolytic oxidases and peroxidases of saprotrophic fungi are the enzymes responsible for the transformation of lignin
– the second most abundant biopolymer. In forest soil, ligninolytic enzymes contribute to the degradation of lignin in
decaying leaf litter and to the transformation of humic substances with a similar chemical structure. The aim of this
work was to quantify the activity of ligninolytic enzymes found in oak forest soil with respect to their spatial distribution
and temporal variability, to find its producers, litter decomposing fungi (LDF), and to identify the role of the enzymes
in the transformation of soil organic matter.
Enzyme activity was measured in environmental samples from oak (Quercus petraea) forest and linked with fungal
occurrence and biomass and the production of other extracellular enzymes. The species producing ligninolytic
enzymes were isolated from the studied soil and tested for their ability to perform degradation of freshly fallen leaves
and to transform humic substances isolated from the site.
Laccase and Mn-peroxidase (MnP) but not lignin peroxidase were found in the studied soil with laccase activity being
by far higher. Activity of both enzymes decreased with the soil depth and showed a patchy pattern of horizontal
distribution with “hotspots”. These were in case of laccase often associated with the occurrence of LDF fruit bodies.
During the growth of LDF isolates on oak leaves, laccase was again the major enzyme and it was produced mainly in
the initial phases of decay. Ligninolytic enzymes also contributed to the transformation of humic compounds. Their
production was usually induced by humic acids, but humic and fulvic acids also competitively inhibited laccase
activity.
Laccase and MnP play important roles in the turnover of carbon in the soil environment during the transformation of
lignin in the fresh biomass (fallen litter) and nutrients liberation from the recalcitrant humic material.
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