Physiological characteristics of fungi associated with antarctic environments
The permanent ice covers on the lakes of Antarctica's McMurdo Dry Valleys region harbor a diverse group of phototrophic and heterotrophic microorganisms that metabolize during the short summer months when solar radiation produces melt inclusions within the ice and provides energy to drive photo...
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Montana State University - Bozeman, College of Agriculture
2016
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ftmontanastateu:oai:scholarworks.montana.edu:1/9835 2023-05-15T13:54:59+02:00 Physiological characteristics of fungi associated with antarctic environments Kudalkar, Priyanka Sushil Chairperson, Graduate Committee: John C. Priscu McMurdo Dry Valleys (Antarctica) 2016 application/pdf https://scholarworks.montana.edu/xmlui/handle/1/9835 en eng Montana State University - Bozeman, College of Agriculture https://scholarworks.montana.edu/xmlui/handle/1/9835 Copyright 2016 by Priyanka Sushil Kudalkar Fungi Bioactive compounds Thesis 2016 ftmontanastateu 2022-06-06T07:26:24Z The permanent ice covers on the lakes of Antarctica's McMurdo Dry Valleys region harbor a diverse group of phototrophic and heterotrophic microorganisms that metabolize during the short summer months when solar radiation produces melt inclusions within the ice and provides energy to drive photosynthesis. Laboratory cultures of fungi were obtained from ice cores taken from Lakes Bonney (east lobe) and Chad, and sediments collected from Subglacial Lake Whillans (West Antarctica). Using molecular techniques, the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA) was sequenced to identify fungal types and to determine whether they may be unique to this region. Four axenic fungal cultures, Tetracladium ellipsoideum, Lecythophora hoffmannii, Mucor sp., and an unidentified Ascomycota were successfully isolated. These isolates are closely related to organisms that have been previously reported in Antarctica and other cold habitats. The isolates were tested for growth characteristics under various temperature and nutrient regimes. Temperature response experiments revealed that all the isolated fungi were psychrotolerant and growth rates were greatest at 25°C. Of major significance in evaluating the potential of Antarctic fungi as a bioresource is their ability to produce bioactive compounds. Two out of four isolated organisms exhibited antimicrobial activity against several plant pathogens. The metabolic potential and preferred substrate utilization was examined by exposing fungal isolates to a variety of substrates in a 96 well "Biolog" plate. A strong correlation was found among substrate utilization, isolates, temperature and the different carbon substrates. This experiment revealed that the isolated fungi have preferences for different labile carbon substrates at 4°C and 24°C which may imply different physiologies at different times of year in the lake ice-covers. Results from my studies will help understand the role of fungi in lake ice and subglacial lake sediment ecosystems, and the physiology of ... Thesis Antarc* Antarctic Antarctica McMurdo Dry Valleys West Antarctica Montana State University (MSU): ScholarWorks Antarctic Bonney ENVELOPE(162.417,162.417,-77.717,-77.717) McMurdo Dry Valleys West Antarctica Whillans ENVELOPE(-64.250,-64.250,-84.450,-84.450) |
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Montana State University (MSU): ScholarWorks |
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ftmontanastateu |
language |
English |
topic |
Fungi Bioactive compounds |
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Fungi Bioactive compounds Kudalkar, Priyanka Sushil Physiological characteristics of fungi associated with antarctic environments |
topic_facet |
Fungi Bioactive compounds |
description |
The permanent ice covers on the lakes of Antarctica's McMurdo Dry Valleys region harbor a diverse group of phototrophic and heterotrophic microorganisms that metabolize during the short summer months when solar radiation produces melt inclusions within the ice and provides energy to drive photosynthesis. Laboratory cultures of fungi were obtained from ice cores taken from Lakes Bonney (east lobe) and Chad, and sediments collected from Subglacial Lake Whillans (West Antarctica). Using molecular techniques, the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA) was sequenced to identify fungal types and to determine whether they may be unique to this region. Four axenic fungal cultures, Tetracladium ellipsoideum, Lecythophora hoffmannii, Mucor sp., and an unidentified Ascomycota were successfully isolated. These isolates are closely related to organisms that have been previously reported in Antarctica and other cold habitats. The isolates were tested for growth characteristics under various temperature and nutrient regimes. Temperature response experiments revealed that all the isolated fungi were psychrotolerant and growth rates were greatest at 25°C. Of major significance in evaluating the potential of Antarctic fungi as a bioresource is their ability to produce bioactive compounds. Two out of four isolated organisms exhibited antimicrobial activity against several plant pathogens. The metabolic potential and preferred substrate utilization was examined by exposing fungal isolates to a variety of substrates in a 96 well "Biolog" plate. A strong correlation was found among substrate utilization, isolates, temperature and the different carbon substrates. This experiment revealed that the isolated fungi have preferences for different labile carbon substrates at 4°C and 24°C which may imply different physiologies at different times of year in the lake ice-covers. Results from my studies will help understand the role of fungi in lake ice and subglacial lake sediment ecosystems, and the physiology of ... |
author2 |
Chairperson, Graduate Committee: John C. Priscu |
format |
Thesis |
author |
Kudalkar, Priyanka Sushil |
author_facet |
Kudalkar, Priyanka Sushil |
author_sort |
Kudalkar, Priyanka Sushil |
title |
Physiological characteristics of fungi associated with antarctic environments |
title_short |
Physiological characteristics of fungi associated with antarctic environments |
title_full |
Physiological characteristics of fungi associated with antarctic environments |
title_fullStr |
Physiological characteristics of fungi associated with antarctic environments |
title_full_unstemmed |
Physiological characteristics of fungi associated with antarctic environments |
title_sort |
physiological characteristics of fungi associated with antarctic environments |
publisher |
Montana State University - Bozeman, College of Agriculture |
publishDate |
2016 |
url |
https://scholarworks.montana.edu/xmlui/handle/1/9835 |
op_coverage |
McMurdo Dry Valleys (Antarctica) |
long_lat |
ENVELOPE(162.417,162.417,-77.717,-77.717) ENVELOPE(-64.250,-64.250,-84.450,-84.450) |
geographic |
Antarctic Bonney McMurdo Dry Valleys West Antarctica Whillans |
geographic_facet |
Antarctic Bonney McMurdo Dry Valleys West Antarctica Whillans |
genre |
Antarc* Antarctic Antarctica McMurdo Dry Valleys West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica McMurdo Dry Valleys West Antarctica |
op_relation |
https://scholarworks.montana.edu/xmlui/handle/1/9835 |
op_rights |
Copyright 2016 by Priyanka Sushil Kudalkar |
_version_ |
1766261196779945984 |