title: Antarctic bacteria and enzyme temperature optima

authors: Hawkins, Sarah Kate

abstract: The temperature optimum of enzyme activity, as recently described by Daniel et al. (2001), is thought to play a central role in the adaptation of an enzyme to its environmental temperature. The aim of this research was to exploit this recent development in. determining temperature/activity relationships by correlating the environmental temperature of Antarctic bacteria with the properties of their enzymes. To avoid the problems associated with the comparison of taxonomically distant bacteria, enzymes were sourced from a single genus, Bacillus. 
Psychrotolerant bacteria were isolated from soils sampled at several sites (Dry Valleys, Bratina Island and Cape Crozier) in the Ross Sea region, Antarctica. At each sampling location, continuous 24 h temperature profiling of the top 2 cm of soil showed exposure to a wide temperature range (up to 20°C difference between maximum and minimum temperature) over the day. Initial characterisation revealed that 26 out of the 52 isolates obtained were Gram positive rods. Random amplified polymorphic DNA (RAPD) analysis of extracted genomic DNA and denaturing gradient gel electrophoresis (DOGE) of the 16S rRNA genes were performed on this subgroup. Five groups of closely related bacteria were identified, along with several unique isolates. 16S rDNA sequencing of eight of these isolates identified them as most likely representing the Bacillus, Planococcus, Arthrobacter, Pseudomonas, Carnobacterium and Psychrobacter genera. Isolates PRl and MV2 (identified as species of Bacillus) were found to have an approximate optimum growth temperature of 27°C and >30°C, respectively. 
A survey of extracellular proteases, esterases/lipases, glucosidases and galactosidases was initially performed on thermophilic Antarctic bacteria previously isolated from geothermal soils from Mount Erebus, Ross Island. The final choice of an intracellular enzyme, dihydrofolate reductase (DHFR), for temperature characterisation was preferable due to its ubiquitous expression and to allow comparison of the results with thermal properties of DHFRs from other sources.
An extrapolation of the temperature dependence of PRl DHFR activity back to zero time revealed a 'real' temperature optima of 44°C, where at higher temperatures in the profile, the enzyme showed a decrease in catalytic rate greater than could be accounted for by irreversible denaturation. A temperature optimum determination for thermophilic DHFR from B. stearothermophilus also displayed a clear peak of activity at 47°C at zero time. 
Data obtained for the psychrotolerant and thermophilic enzymes were insufficient to confirm the environmental significance of this intrinsic property. However, the idea that 'true' temperature optima reflects the environmental temperature was validated, being lower for the psychrotolerant enzyme compared to the thermophilic enzyme.

text: Antarctic bacteria and enzyme temperature optima The temperature optimum of enzyme activity, as recently described by Daniel et al. (2001), is thought to play a central role in the adaptation of an enzyme to its environmental temperature. The aim of this research was to exploit this recent development in. determining temperature/activity relationships by correlating the environmental temperature of Antarctic bacteria with the properties of their enzymes. To avoid the problems associated with the comparison of taxonomically distant bacteria, enzymes were sourced from a single genus, Bacillus. 
Psychrotolerant bacteria were isolated from soils sampled at several sites (Dry Valleys, Bratina Island and Cape Crozier) in the Ross Sea region, Antarctica. At each sampling location, continuous 24 h temperature profiling of the top 2 cm of soil showed exposure to a wide temperature range (up to 20°C difference between maximum and minimum temperature) over the day. Initial characterisation revealed that 26 out of the 52 isolates obtained were Gram positive rods. Random amplified polymorphic DNA (RAPD) analysis of extracted genomic DNA and denaturing gradient gel electrophoresis (DOGE) of the 16S rRNA genes were performed on this subgroup. Five groups of closely related bacteria were identified, along with several unique isolates. 16S rDNA sequencing of eight of these isolates identified them as most likely representing the Bacillus, Planococcus, Arthrobacter, Pseudomonas, Carnobacterium and Psychrobacter genera. Isolates PRl and MV2 (identified as species of Bacillus) were found to have an approximate optimum growth temperature of 27°C and >30°C, respectively. 
A survey of extracellular proteases, esterases/lipases, glucosidases and galactosidases was initially performed on thermophilic Antarctic bacteria previously isolated from geothermal soils from Mount Erebus, Ross Island. The final choice of an intracellular enzyme, dihydrofolate reductase (DHFR), for temperature characterisation was preferable due to its ubiquitous expression and to allow comparison of the results with thermal properties of DHFRs from other sources.
An extrapolation of the temperature dependence of PRl DHFR activity back to zero time revealed a 'real' temperature optima of 44°C, where at higher temperatures in the profile, the enzyme showed a decrease in catalytic rate greater than could be accounted for by irreversible denaturation. A temperature optimum determination for thermophilic DHFR from B. stearothermophilus also displayed a clear peak of activity at 47°C at zero time. 
Data obtained for the psychrotolerant and thermophilic enzymes were insufficient to confirm the environmental significance of this intrinsic property. However, the idea that 'true' temperature optima reflects the environmental temperature was validated, being lower for the psychrotolerant enzyme compared to the thermophilic enzyme.

year: 2003

title: Evaluation of environmental literacy of pre-service teachers in New Zealand

authors: Dada, Oluwaseun Deborah

subjects: Environmental education

abstract: Environmental education (EE) has been recognized as a vital tool that could help to alleviate the prevailing environmental and sustainability issues facing our world today. One of the goals of environmental education (EE) has been recognized as the development of environmental literacy (EL). The development of environmental literacy for pre-service teachers (PSTs) is critical if they are to be confident and competent to deliver EE in schools. This study sought to examine the preparedness of PSTs to teach EE in New Zealand primary schools, after completing a compulsory EE paper in their first year of a three-year teacher education programme, in a New Zealand public university. This research is relevant as EE in New Zealand primary schools is recommended to be taught through integration into the core learning areas. 

This study was conducted using a case study strategy within an interpretive paradigm to seek the meanings of the experiences of PSTs and their learning in the EE paper. Data was gathered from different cohorts of pre-service teachers and their lecturers using a mixed method approach that involved administration of questionnaires, focus group discussions, interviews, observations, and document analysis. The cohorts included Year 1 PSTs taking the paper at the time the research was conducted, Year 3 PSTs looking back on the paper they had previously taken two years ago, and beginning teachers who had recently completed the degree. Quantitative data were analyzed using descriptive and inferential statistics such as t-test, ANOVA, Pearson product moment correlation and path analysis. Statistical Package for the Social Sciences (SPSS) was used to run undertake these tests. The qualitative data were analyzed thematically using content analysis. 

Findings from this study showed that the EE paper has an immediate impact on PSTs’ EL, especially on their knowledge and concern for issues extensively discussed during the paper. The PSTs also believed that, amongst other experiences or papers taken at the University, the EE paper contributed the most to their EL. However, the EL developed seem to have waned two years after taking the EE paper as indicated by the findings from the Year 3 PST cohort. Upon graduation, at least six months into teaching, experiences of the beginning teachers indicate that school managements’ priorities played a major role in whether EE is implemented into their teaching or not. Other factors identified are issues with approaches for integrating EE into teaching, knowledge of EE, overcrowded curriculum and lack of time, teachers’ interests and a novel factor identified as ‘rituals’. 

This research highlights the vital role teacher education programmes play in developing EL of PSTs and their preparedness to teach EE in primary schools. It also contributes to an understanding of current issues associated with the challenges of teacher education programmes in achieving the goal of developing environmentally literate teachers. This research concludes that in order to successfully implement EE in New Zealand primary schools, there is the need for amendments to the current EE policies in New Zealand primary schools. Also, teacher education programmes need to modify their curriculum and pedagogical approaches to enhance the development of PSTs’ EL to ensure that teachers are well equipped and confident to teach EE before they begin their teaching career.

text: Evaluation of environmental literacy of pre-service teachers in New Zealand Environmental education (EE) has been recognized as a vital tool that could help to alleviate the prevailing environmental and sustainability issues facing our world today. One of the goals of environmental education (EE) has been recognized as the development of environmental literacy (EL). The development of environmental literacy for pre-service teachers (PSTs) is critical if they are to be confident and competent to deliver EE in schools. This study sought to examine the preparedness of PSTs to teach EE in New Zealand primary schools, after completing a compulsory EE paper in their first year of a three-year teacher education programme, in a New Zealand public university. This research is relevant as EE in New Zealand primary schools is recommended to be taught through integration into the core learning areas. 

This study was conducted using a case study strategy within an interpretive paradigm to seek the meanings of the experiences of PSTs and their learning in the EE paper. Data was gathered from different cohorts of pre-service teachers and their lecturers using a mixed method approach that involved administration of questionnaires, focus group discussions, interviews, observations, and document analysis. The cohorts included Year 1 PSTs taking the paper at the time the research was conducted, Year 3 PSTs looking back on the paper they had previously taken two years ago, and beginning teachers who had recently completed the degree. Quantitative data were analyzed using descriptive and inferential statistics such as t-test, ANOVA, Pearson product moment correlation and path analysis. Statistical Package for the Social Sciences (SPSS) was used to run undertake these tests. The qualitative data were analyzed thematically using content analysis. 

Findings from this study showed that the EE paper has an immediate impact on PSTs’ EL, especially on their knowledge and concern for issues extensively discussed during the paper. The PSTs also believed that, amongst other experiences or papers taken at the University, the EE paper contributed the most to their EL. However, the EL developed seem to have waned two years after taking the EE paper as indicated by the findings from the Year 3 PST cohort. Upon graduation, at least six months into teaching, experiences of the beginning teachers indicate that school managements’ priorities played a major role in whether EE is implemented into their teaching or not. Other factors identified are issues with approaches for integrating EE into teaching, knowledge of EE, overcrowded curriculum and lack of time, teachers’ interests and a novel factor identified as ‘rituals’. 

This research highlights the vital role teacher education programmes play in developing EL of PSTs and their preparedness to teach EE in primary schools. It also contributes to an understanding of current issues associated with the challenges of teacher education programmes in achieving the goal of developing environmentally literate teachers. This research concludes that in order to successfully implement EE in New Zealand primary schools, there is the need for amendments to the current EE policies in New Zealand primary schools. Also, teacher education programmes need to modify their curriculum and pedagogical approaches to enhance the development of PSTs’ EL to ensure that teachers are well equipped and confident to teach EE before they begin their teaching career.

year: 2018

title: Researcher-teacher collaboration in Māori-medium education: Aspects of learning for a teacher and researchers in Aotearoa New Zealand when teaching mathematics

authors: Hawera, Ngārewa

subjects: teacher

abstract: This paper describes aspects of learning for a teacher in a Māori-medium Year 7–8 classroom and two mathematics education researchers from a university when they collaborated on a project supporting children to develop their ideas about transformation geometry. Key principles of kaupapa Māori (Māori ideology) methodology such as ako (reciprocal learning), manākitanga (showing care, respect and kindness) and whanaungatanga (family-like relationships) were integral to the initiation and facilitation of the research. Data presented is qualitative and derived largely from wānanga ā-kanohi (face-to-face discussion) between the participants. Results revealed that the collaborative partnership was conducive to developing insights into the complexities of learning mathematics in an indigenous setting. Issues of collegiality, learning mathematics in a second language, teacher mathematical knowledge and appropriate contexts for learning mathematics are analysed and discussed.

text: Researcher-teacher collaboration in Māori-medium education: Aspects of learning for a teacher and researchers in Aotearoa New Zealand when teaching mathematics This paper describes aspects of learning for a teacher in a Māori-medium Year 7–8 classroom and two mathematics education researchers from a university when they collaborated on a project supporting children to develop their ideas about transformation geometry. Key principles of kaupapa Māori (Māori ideology) methodology such as ako (reciprocal learning), manākitanga (showing care, respect and kindness) and whanaungatanga (family-like relationships) were integral to the initiation and facilitation of the research. Data presented is qualitative and derived largely from wānanga ā-kanohi (face-to-face discussion) between the participants. Results revealed that the collaborative partnership was conducive to developing insights into the complexities of learning mathematics in an indigenous setting. Issues of collegiality, learning mathematics in a second language, teacher mathematical knowledge and appropriate contexts for learning mathematics are analysed and discussed.

year: 2014