title: Fungal Diversity and Cellulytic Activity in the Historic Huts, Ross Island, Antarctica

authors: Duncan, Shona Margaret

subjects: Fungal Biodiversity

abstract: The goal of this study was to undertake a microbial investigation of the Historic Huts areas on Ross Island, to gain knowledge of the fungal biodiversity and biochemical framework, focusing on the wood degrading potential of these fungi at both psychrophilic (cold) and mesophilic (moderate) temperatures. Eight hundred and forty nine samples were collected from three Heroic Era Historic Huts of Antarctica, from a variety of substrates but predominantly structural wood. The huts, Discovery Hut at Hut Point, Terra Nova Hut at Cape Evans and Nimrod Hut at Cape Royds, are located on Ross Island and were all assembled in the early 20th century by the Heroic Era explorers to house the expeditions, stores and animals. These wooden huts were abandoned when the expeditions left. The introduction of wood and other organic material to a pristine environment along with the creation of a microclimate within the harsh Antarctica environment created interesting sites for studying fungal diversity, wood decay and fungal cellulase enzymes in an extreme environment. Each hut can be classified as offering different conditions and circumstances for fungal propagules. Of the three huts, Terra Nova Hut is the only hut where there are visible fungal blooms within the hut and it, with Discovery Hut, had the greatest number of samples that contained fungi compared to Nimrod Hut which had the least. Discovery Hut, at less than 500 metres from the United States McMurdo Station, is the most visited by scientist and base staff and has been the most demonstrably affected by human impact of the three huts due to its closeness to the research stations on Ross Island To ensure a full understanding of the fungal diversity of the Historic Hut sites, a variety of sampling techniques were used along with a variety of culture media. Two thousand and seventy six isolates consisting of 1177 filamentous fungi and 899 single celled microorganisms (yeast and bacteria) were isolated; all these cultures were frozen and now form the University of Waikato Antarctic Culture Collection. Five genera dominated the fungal isolates that were identified and these were Cladosporium, Geomyces, Cadophora, Penicillium and Thelebolus. The fungal diversity of these Historic Huts' communities is low but the members present are metabolically active, consistent with other microbial communities in the Antarctic. The Historic Huts and surroundings contain a diverse array of provision in the way of wood and supplies, which provide nutrient sources for fungal growth. Endemic organisms present in the soil could have been enriched by using the introduced nutrient sources as primary and/or second metabolic substrates. In addition, fungi could have been introduced with the wooden huts and supplies when they were brought to Antarctica by the Heroic Era explorers, or introduced in the subsequent years with visitors and conservation work conducted at the sites. These introduced organisms, though, would have had to adapt to the change in climate and conditions posed by the Antarctic in order to survive and be subsequently isolated in this study. A screen for carboxymethylcellulase (CMCase) activity was done on a selection of the fungal isolates as the first step to understand the cellulytic potential of the Antarctica fungal community inhabiting the huts. One hundred and six fungal isolates from a total of 404, that were screened were deemed to be CMCase positive, 27 fungal isolates were chosen for further study including quantifying the activity of extracellular endo-1,4-β-glucanase at psychrophilic and mesophilic incubation temperatures. All but one isolate could produce endo-1,4-β-glucanase activity at 4 C and many produced more endo-1,4-β-glucanase activity at 4 C than at 15 C. Cadophora malorum 182, Cadophora malorum 242, Penicillium roquefortii 405, Penicillium roquefortii 408, Geomyces sp. 711, Geomyces sp. 824 and Cladosporium oxysporium 805 were selected for in-depth study of growth characteristics including growth temperature preferences, growth on a variety of cellulose substrates, water activity, and carbon sources, the latter done by using a commercially available microtitre plate containing 95 carbon sources. All seven of the fungal isolates were classified as psychrotolerant and produced, when cultured at either 4 C or at 15 C, cellulase, protease, amylase, xylanase, and pectinase and mannanase enzyme activities. The range of water activity that the Antarctic Penicillium roquefortii isolates could grow at was distinctive when compared with food Penicillium roquefortii isolates. The utilisation of different carbon sources showed that like many studies of Antarctica organism they have a diverse range of enzymatic activity, but interestingly the activity does not differ greatly with incubation temperature with most carbon sources being used or not used at both incubation temperatures tested. Although it took longer for the fungi
to grow at the psychrophilic temperatures, the range of carbon sources they utilised was not reduced. The protein composition of the extracellular supernatants was visualised using various electrophoretic and staining techniques. The cellulase activity of the protein bands was visualised by cellulose-containing zymograms, which illustrated that the cellulase complex in all fungi tested was multi-enzyme and differed between species, isolates and temperatures of culturing. The cellulase activity of Cadophora malorum 182 was enriched by purification techniques including ion exchange chromatography and native preparative electrophoresis. The protein complex was not purified to homogeneity, but enriched for a mixture of proteins and the mixture was described as having the following properties; a temperature range of β-1,4-glucan cellobiohydrolase activity from 20 C to 80 C with the optimum activity seen at 60 C, β-1,4-glucan cellobiohydrolase activity that is stable at 4, 25 and 40 C for at least 24 hrs, lost at 50  C and 80 C within 24 hrs and 2 minutes respectively. Along with β-1,4-glucan cellobiohydrolase activity, the protein mixture contained Avicelase, CMCase, xylanase and mannanase activity. The thesis research showed that there was limited fungal diversity in the Historic Huts and artefacts (a total of five dominant genera were identified) but the fungi are actively growing and producing viable spores in the cold of Antarctica and producing the necessary enzymes for degradation of wood. Although the metabolism and growth rate is slower at psychrophilic temperatures, the fungal isolates studied as part of this thesis research could still function enzymatically at cold temperatures and this includes the degradation of wood as evidenced by in vitro wood decay studies examined by scanning electron microscopy where two isolates of one species demonstrated the ability to degrade wood. The cellulase complex of the investigated fungal isolate was multi-enzymed and although the components were not purified to homogeneity, an enriched mixture of proteins had enzyme activity and stability in a broad temperature range, and activity to a variety of cellulosic substrates.
This thesis research adds to the knowledge of the fungal biodiversity in the Antarctic and increases the understanding of the biochemical framework, participating in relation to wood decay potential of these Antarctic fungal isolates.

text: Fungal Diversity and Cellulytic Activity in the Historic Huts, Ross Island, Antarctica The goal of this study was to undertake a microbial investigation of the Historic Huts areas on Ross Island, to gain knowledge of the fungal biodiversity and biochemical framework, focusing on the wood degrading potential of these fungi at both psychrophilic (cold) and mesophilic (moderate) temperatures. Eight hundred and forty nine samples were collected from three Heroic Era Historic Huts of Antarctica, from a variety of substrates but predominantly structural wood. The huts, Discovery Hut at Hut Point, Terra Nova Hut at Cape Evans and Nimrod Hut at Cape Royds, are located on Ross Island and were all assembled in the early 20th century by the Heroic Era explorers to house the expeditions, stores and animals. These wooden huts were abandoned when the expeditions left. The introduction of wood and other organic material to a pristine environment along with the creation of a microclimate within the harsh Antarctica environment created interesting sites for studying fungal diversity, wood decay and fungal cellulase enzymes in an extreme environment. Each hut can be classified as offering different conditions and circumstances for fungal propagules. Of the three huts, Terra Nova Hut is the only hut where there are visible fungal blooms within the hut and it, with Discovery Hut, had the greatest number of samples that contained fungi compared to Nimrod Hut which had the least. Discovery Hut, at less than 500 metres from the United States McMurdo Station, is the most visited by scientist and base staff and has been the most demonstrably affected by human impact of the three huts due to its closeness to the research stations on Ross Island To ensure a full understanding of the fungal diversity of the Historic Hut sites, a variety of sampling techniques were used along with a variety of culture media. Two thousand and seventy six isolates consisting of 1177 filamentous fungi and 899 single celled microorganisms (yeast and bacteria) were isolated; all these cultures were frozen and now form the University of Waikato Antarctic Culture Collection. Five genera dominated the fungal isolates that were identified and these were Cladosporium, Geomyces, Cadophora, Penicillium and Thelebolus. The fungal diversity of these Historic Huts' communities is low but the members present are metabolically active, consistent with other microbial communities in the Antarctic. The Historic Huts and surroundings contain a diverse array of provision in the way of wood and supplies, which provide nutrient sources for fungal growth. Endemic organisms present in the soil could have been enriched by using the introduced nutrient sources as primary and/or second metabolic substrates. In addition, fungi could have been introduced with the wooden huts and supplies when they were brought to Antarctica by the Heroic Era explorers, or introduced in the subsequent years with visitors and conservation work conducted at the sites. These introduced organisms, though, would have had to adapt to the change in climate and conditions posed by the Antarctic in order to survive and be subsequently isolated in this study. A screen for carboxymethylcellulase (CMCase) activity was done on a selection of the fungal isolates as the first step to understand the cellulytic potential of the Antarctica fungal community inhabiting the huts. One hundred and six fungal isolates from a total of 404, that were screened were deemed to be CMCase positive, 27 fungal isolates were chosen for further study including quantifying the activity of extracellular endo-1,4-β-glucanase at psychrophilic and mesophilic incubation temperatures. All but one isolate could produce endo-1,4-β-glucanase activity at 4 C and many produced more endo-1,4-β-glucanase activity at 4 C than at 15 C. Cadophora malorum 182, Cadophora malorum 242, Penicillium roquefortii 405, Penicillium roquefortii 408, Geomyces sp. 711, Geomyces sp. 824 and Cladosporium oxysporium 805 were selected for in-depth study of growth characteristics including growth temperature preferences, growth on a variety of cellulose substrates, water activity, and carbon sources, the latter done by using a commercially available microtitre plate containing 95 carbon sources. All seven of the fungal isolates were classified as psychrotolerant and produced, when cultured at either 4 C or at 15 C, cellulase, protease, amylase, xylanase, and pectinase and mannanase enzyme activities. The range of water activity that the Antarctic Penicillium roquefortii isolates could grow at was distinctive when compared with food Penicillium roquefortii isolates. The utilisation of different carbon sources showed that like many studies of Antarctica organism they have a diverse range of enzymatic activity, but interestingly the activity does not differ greatly with incubation temperature with most carbon sources being used or not used at both incubation temperatures tested. Although it took longer for the fungi
to grow at the psychrophilic temperatures, the range of carbon sources they utilised was not reduced. The protein composition of the extracellular supernatants was visualised using various electrophoretic and staining techniques. The cellulase activity of the protein bands was visualised by cellulose-containing zymograms, which illustrated that the cellulase complex in all fungi tested was multi-enzyme and differed between species, isolates and temperatures of culturing. The cellulase activity of Cadophora malorum 182 was enriched by purification techniques including ion exchange chromatography and native preparative electrophoresis. The protein complex was not purified to homogeneity, but enriched for a mixture of proteins and the mixture was described as having the following properties; a temperature range of β-1,4-glucan cellobiohydrolase activity from 20 C to 80 C with the optimum activity seen at 60 C, β-1,4-glucan cellobiohydrolase activity that is stable at 4, 25 and 40 C for at least 24 hrs, lost at 50  C and 80 C within 24 hrs and 2 minutes respectively. Along with β-1,4-glucan cellobiohydrolase activity, the protein mixture contained Avicelase, CMCase, xylanase and mannanase activity. The thesis research showed that there was limited fungal diversity in the Historic Huts and artefacts (a total of five dominant genera were identified) but the fungi are actively growing and producing viable spores in the cold of Antarctica and producing the necessary enzymes for degradation of wood. Although the metabolism and growth rate is slower at psychrophilic temperatures, the fungal isolates studied as part of this thesis research could still function enzymatically at cold temperatures and this includes the degradation of wood as evidenced by in vitro wood decay studies examined by scanning electron microscopy where two isolates of one species demonstrated the ability to degrade wood. The cellulase complex of the investigated fungal isolate was multi-enzymed and although the components were not purified to homogeneity, an enriched mixture of proteins had enzyme activity and stability in a broad temperature range, and activity to a variety of cellulosic substrates.
This thesis research adds to the knowledge of the fungal biodiversity in the Antarctic and increases the understanding of the biochemical framework, participating in relation to wood decay potential of these Antarctic fungal isolates.

year: 2007

title: Applying graphic design terms to image tagging

authors: Laing, Simon John

subjects: computer science

abstract: This paper describes key findings from research into the application of graphic design terms to the task of tagging images for later retrieval. The research was motivated by the needs of creative industries in interacting with large image collections, with particular emphasis given to the need for retrieval of imagery using loosely defined visual properties rather than exact match queries based on image subject or similarity. A set of terms chosen from design literature are presented and discussed together with experimental results from testing carried out on students and practitioners of graphic design. Ultimately the tested terms are found to be relatively well understood, though they do not appear to support a high degree of precision.

text: Applying graphic design terms to image tagging This paper describes key findings from research into the application of graphic design terms to the task of tagging images for later retrieval. The research was motivated by the needs of creative industries in interacting with large image collections, with particular emphasis given to the need for retrieval of imagery using loosely defined visual properties rather than exact match queries based on image subject or similarity. A set of terms chosen from design literature are presented and discussed together with experimental results from testing carried out on students and practitioners of graphic design. Ultimately the tested terms are found to be relatively well understood, though they do not appear to support a high degree of precision.

year: 2008

title: A Communitarian Approach to Accountability for the Common Good: A Case Study of Community Participation in Planning and Policy Making for Lake Taupo

authors: Arunachalam, Murugesh

subjects: accountability

abstract: This thesis seeks to gain a theoretical and empirical understanding of the meaning of a communitarian approach to accountability for the common good (CAACG). The hermeneutic analysis adopted in this study starts by explaining the researcher's pre-understandings which includes contemporary ideas on accountability, communitarianism and sustainability. A theoretical communitarian model was designed by synthesising these ideas. Using the theoretical model the researcher attempted to advance the meaning of CAACG in multiple contexts which include: the global context on sustainability; the New Zealand context on local governance; and more specifically in the context of planning and policy making for the sustainable development of the Taupo District. The use of such multiple contexts is crucial for this study. This is because communitarian ideology in New Zealand has historical roots in Local Government which, in recent years has been influenced by the global discourse on sustainable development. The adoption of multiple contexts is aimed at providing a holistic and historical understanding of planning and policy making processes in the Taupo District and the manifestation of CAACG in the processes.

In this interpretive study the term  text  is defined as the empirical data which consists of public documents, website material, minutes of community meetings, field notes and transcriptions of interviews. The empirical data is about processes and outcomes of collaboration between the community groups, public authorities and private entities in formulating strategies and policies for sustainable development of the Taupo District. Interpretation of the empirical data involved understanding the  text  from the vantage point of the pre-understandings of the interpreter. The interpretation of the  text  is is aimed at explaining the manifestation of CAACG in the Taupo District. The methodological orientations of the thesis are predominantly consistent with the hermeneutic tradition of Gadamer (1975). However, although the interpreter started with the intention of strictly confining to the subjectivist approach of Gadamer (1975), at times the hermeneutic methodology adopted by the researcher encroached into the methodological orientations of objectivist hermeneutics. The use of objectivist hermeneutic was inevitable as it was necessary to understand the authorial intention in the text before the interpreter understands the text from the perspective of his pre-understandings. Hence, the researcher rejects the assumption of objective-subjective dichotomy and subscribes more to the philosophical arguments advanced by contemporary scholars (such as Boland Jr, 1989 and Ricoeur, 1981) who find both the subjective and objective philosophies as necessary for interpreting texts. 

The hermeneutic analysis undertaken in this study suggests that the meaning of CAACG appears in the context of communal processes (including planning and policy making processes) and the strategies and policies formulated by the Taupo community. The meaning of CAACG may not be obvious to any reader of the  text . It arises from the interpretation of the  text  from the perspective of the interpreter's pre-understandings on a communitarian approach to accountability. The interpretation suggests the existence of a community of interests, community values and concerns, and communal processes in the Taupo District.  Community values and concerns are associated with Lake Taupo. The primary concern of the community is the pollution of Lake Taupo caused by animal farming in the land surrounding the lake and the impact the pollution has on the environmental, economic and cultural values of the community. The communal processes involved collaboration between the community and public authorities in planning and policy making for the protection of Lake Taupo. The interpretation also indicates the manifestation of several dimensions of accountability in the communal processes; joint accountability or 360 degree accountability in the Taupo District; and the holistic meaning of environmental and social accounting.

In the Taupo District the operation of the CAACG can be affected by several factors. Symmetry of power can be affected in terms of the preferential treatment given to the indigenous community and its segregation from the rest of the community. The strong influence of local authorities in the planning and decision making processes makes the community appear helpless without the local authorities. Communitarian processes intended to empower the community may actually strengthen the position of local authorities. Power has actually shifted from Central Government to local authorities and may not necessarily have shifted to communities. However, the endeavours to engage the community in the Taupo District can be seen as attempts to build the capacity of the community to participate in the processes and time will tell how effective the CAACG will prove to be.

This thesis is the pioneer in advancing the theorization of the CAACG and has added a substantial contribution to accountability literature. It suggests a new way of looking at environmental and social accounting in which the emphasis is on community involvement through reporting and deliberation (dialectical dimension of accountability) on the impacts of human activities on the natural environment. The CAACG is premised on the centrality of community and the assumption of a 360 degree accountability in which everyone in the community has mutual responsibility to protect the common good and can be subject to critical enquiry for the adverse impacts of their activities on the common good. The CAACG does not accord private corporations the privilege status of  reporting entities  but considers environmental and social accounting as the agenda of the community. 

The concept of CAACG is not utopian as it may sound to some readers of this thesis. There are ample evidence of communities throughout the world demanding a voice in statutory planning and decision making for sustainable development. The increasing focus on environmental sustainability and community participation in the planning and decision making processes arises from greater awareness of the detrimental impacts of environmental pollution and the realisation that the decision on the common good cannot be left to free market forces and private corporations. The natural environment belongs to a community of interests which wants to participate in joint responsibility and collective planning and decision making. No individual or group has the right to make decisions about the natural environment without consulting the community.

text: A Communitarian Approach to Accountability for the Common Good: A Case Study of Community Participation in Planning and Policy Making for Lake Taupo This thesis seeks to gain a theoretical and empirical understanding of the meaning of a communitarian approach to accountability for the common good (CAACG). The hermeneutic analysis adopted in this study starts by explaining the researcher's pre-understandings which includes contemporary ideas on accountability, communitarianism and sustainability. A theoretical communitarian model was designed by synthesising these ideas. Using the theoretical model the researcher attempted to advance the meaning of CAACG in multiple contexts which include: the global context on sustainability; the New Zealand context on local governance; and more specifically in the context of planning and policy making for the sustainable development of the Taupo District. The use of such multiple contexts is crucial for this study. This is because communitarian ideology in New Zealand has historical roots in Local Government which, in recent years has been influenced by the global discourse on sustainable development. The adoption of multiple contexts is aimed at providing a holistic and historical understanding of planning and policy making processes in the Taupo District and the manifestation of CAACG in the processes.

In this interpretive study the term  text  is defined as the empirical data which consists of public documents, website material, minutes of community meetings, field notes and transcriptions of interviews. The empirical data is about processes and outcomes of collaboration between the community groups, public authorities and private entities in formulating strategies and policies for sustainable development of the Taupo District. Interpretation of the empirical data involved understanding the  text  from the vantage point of the pre-understandings of the interpreter. The interpretation of the  text  is is aimed at explaining the manifestation of CAACG in the Taupo District. The methodological orientations of the thesis are predominantly consistent with the hermeneutic tradition of Gadamer (1975). However, although the interpreter started with the intention of strictly confining to the subjectivist approach of Gadamer (1975), at times the hermeneutic methodology adopted by the researcher encroached into the methodological orientations of objectivist hermeneutics. The use of objectivist hermeneutic was inevitable as it was necessary to understand the authorial intention in the text before the interpreter understands the text from the perspective of his pre-understandings. Hence, the researcher rejects the assumption of objective-subjective dichotomy and subscribes more to the philosophical arguments advanced by contemporary scholars (such as Boland Jr, 1989 and Ricoeur, 1981) who find both the subjective and objective philosophies as necessary for interpreting texts. 

The hermeneutic analysis undertaken in this study suggests that the meaning of CAACG appears in the context of communal processes (including planning and policy making processes) and the strategies and policies formulated by the Taupo community. The meaning of CAACG may not be obvious to any reader of the  text . It arises from the interpretation of the  text  from the perspective of the interpreter's pre-understandings on a communitarian approach to accountability. The interpretation suggests the existence of a community of interests, community values and concerns, and communal processes in the Taupo District.  Community values and concerns are associated with Lake Taupo. The primary concern of the community is the pollution of Lake Taupo caused by animal farming in the land surrounding the lake and the impact the pollution has on the environmental, economic and cultural values of the community. The communal processes involved collaboration between the community and public authorities in planning and policy making for the protection of Lake Taupo. The interpretation also indicates the manifestation of several dimensions of accountability in the communal processes; joint accountability or 360 degree accountability in the Taupo District; and the holistic meaning of environmental and social accounting.

In the Taupo District the operation of the CAACG can be affected by several factors. Symmetry of power can be affected in terms of the preferential treatment given to the indigenous community and its segregation from the rest of the community. The strong influence of local authorities in the planning and decision making processes makes the community appear helpless without the local authorities. Communitarian processes intended to empower the community may actually strengthen the position of local authorities. Power has actually shifted from Central Government to local authorities and may not necessarily have shifted to communities. However, the endeavours to engage the community in the Taupo District can be seen as attempts to build the capacity of the community to participate in the processes and time will tell how effective the CAACG will prove to be.

This thesis is the pioneer in advancing the theorization of the CAACG and has added a substantial contribution to accountability literature. It suggests a new way of looking at environmental and social accounting in which the emphasis is on community involvement through reporting and deliberation (dialectical dimension of accountability) on the impacts of human activities on the natural environment. The CAACG is premised on the centrality of community and the assumption of a 360 degree accountability in which everyone in the community has mutual responsibility to protect the common good and can be subject to critical enquiry for the adverse impacts of their activities on the common good. The CAACG does not accord private corporations the privilege status of  reporting entities  but considers environmental and social accounting as the agenda of the community. 

The concept of CAACG is not utopian as it may sound to some readers of this thesis. There are ample evidence of communities throughout the world demanding a voice in statutory planning and decision making for sustainable development. The increasing focus on environmental sustainability and community participation in the planning and decision making processes arises from greater awareness of the detrimental impacts of environmental pollution and the realisation that the decision on the common good cannot be left to free market forces and private corporations. The natural environment belongs to a community of interests which wants to participate in joint responsibility and collective planning and decision making. No individual or group has the right to make decisions about the natural environment without consulting the community.

year: 2010