title: Thermotolerant purple nonsulfur bacteria from New Zealand geothermal areas

authors: Charlton, Peter John

abstract: Purple nonsulfur bacteria (PNSB) are a metabolically and nutritionally diverse group of photosynthetic organisms that have been isolated from many environments. Three thermotolerant or mildly thermophilic strains are known from thermal areas in the United States and Japan. Only mesophilic isolates have been obtained from Russian hot springs. 

Enrichment cultures selective for PNSB were set up on samples taken from a range of New Zealand geothermal areas. Photosynthetic purple bacteria could readily be isolated from Waimangu and Orakei Korako samples, but could not be isolated from Tokaanu mats. In total, 35 isolates belonging to the genera Rhodopseudomonas, Rhodoplanes, Blastochloris, Rubrivivax, Rhodomicrobium, Rhodospirillum and Phaeospirillum were obtained from 18 positive sample sites. The majority of isolates grew optimally around 40°C and had temperature maxima ranging from 43 to 47°C. Other isolates had lower optima and were thermotolerant. Many Rhodoplanes and Blastochloris isolates represented novel genospecies, though some could not be unambiguously distinguished by their phenotypic properties. The novel species Rhodoplanes venustus sp. nov., Rhodoplanes segnis sp. nov., and Phaeospirillum tepidarium sp. nov. are proposed. 

Molecular methods were used to specifically detect photosynthetic purple bacteria. A clone library of photosynthetic reaction centre pufL genes amplified from an Orakei Korako mat sample was constructed and screened. No clone sequences were identical to those of organisms isolated previously or in the current study. The clone library was dominated by sequences attributable to aerobic anoxygenic phototrophic bacteria. Four novel pufL sequences attributable to purple nonsulfur bacteria were obtained.

Rhodoplanes strains possessed the ability to use nicotinic acid as sole source of carbon and nitrogen, via a pathway that includes 6-hydroxynicotinate and glutarate as intermediates, as are in the Azorhizobium caulinodans pathway. Unlike other nicotinic-acid degrading organisms, growth of Rhodoplanes on nicotinate was not inhibited by addition of tungstate.

text: Thermotolerant purple nonsulfur bacteria from New Zealand geothermal areas Purple nonsulfur bacteria (PNSB) are a metabolically and nutritionally diverse group of photosynthetic organisms that have been isolated from many environments. Three thermotolerant or mildly thermophilic strains are known from thermal areas in the United States and Japan. Only mesophilic isolates have been obtained from Russian hot springs. 

Enrichment cultures selective for PNSB were set up on samples taken from a range of New Zealand geothermal areas. Photosynthetic purple bacteria could readily be isolated from Waimangu and Orakei Korako samples, but could not be isolated from Tokaanu mats. In total, 35 isolates belonging to the genera Rhodopseudomonas, Rhodoplanes, Blastochloris, Rubrivivax, Rhodomicrobium, Rhodospirillum and Phaeospirillum were obtained from 18 positive sample sites. The majority of isolates grew optimally around 40°C and had temperature maxima ranging from 43 to 47°C. Other isolates had lower optima and were thermotolerant. Many Rhodoplanes and Blastochloris isolates represented novel genospecies, though some could not be unambiguously distinguished by their phenotypic properties. The novel species Rhodoplanes venustus sp. nov., Rhodoplanes segnis sp. nov., and Phaeospirillum tepidarium sp. nov. are proposed. 

Molecular methods were used to specifically detect photosynthetic purple bacteria. A clone library of photosynthetic reaction centre pufL genes amplified from an Orakei Korako mat sample was constructed and screened. No clone sequences were identical to those of organisms isolated previously or in the current study. The clone library was dominated by sequences attributable to aerobic anoxygenic phototrophic bacteria. Four novel pufL sequences attributable to purple nonsulfur bacteria were obtained.

Rhodoplanes strains possessed the ability to use nicotinic acid as sole source of carbon and nitrogen, via a pathway that includes 6-hydroxynicotinate and glutarate as intermediates, as are in the Azorhizobium caulinodans pathway. Unlike other nicotinic-acid degrading organisms, growth of Rhodoplanes on nicotinate was not inhibited by addition of tungstate.

year: 2002

title: Palynology, vegetation and climate of the Waikato lowlands, North Island, New Zealand, since c. 18,000 years ago

authors: Newnham, Rewi M.

subjects: Waikato

abstract: The vegetational and climatic history of the Waikato lowlands during the last c. 18,000 years is inferred from the palynology of sediment cores from Lakes Rotomanuka, Rotokauri, and Okoroire. Intra- and inter-lake correlations were aided by multiple tephra layers interbedded with the lake sediments. The detailed chronological resolution given by these tephra sequences shows that late glacial-post glacial vegetational and climatic changes were nearly simultaneous throughout the Waikato lowlands.

text: Palynology, vegetation and climate of the Waikato lowlands, North Island, New Zealand, since c. 18,000 years ago The vegetational and climatic history of the Waikato lowlands during the last c. 18,000 years is inferred from the palynology of sediment cores from Lakes Rotomanuka, Rotokauri, and Okoroire. Intra- and inter-lake correlations were aided by multiple tephra layers interbedded with the lake sediments. The detailed chronological resolution given by these tephra sequences shows that late glacial-post glacial vegetational and climatic changes were nearly simultaneous throughout the Waikato lowlands.

year: 1989

title: Systemic racism and oppression in psychology: Voices from psychologists, academic staff, and students

authors: Waitoki, Waikaremoana

subjects: psychology

abstract: Psychology must reassess its training approach, as the current monocultural paradigm not only causes harm, but also fails to equip psychologists with the knowledge needed to provide culturally appropriate care for Māori, Pacific, Asian, and other minoritised groups. Findings from this report contribute to the growing evidence of the urgent need to address barriers preventing Māori, Pacific, Asian, and other minoritised groups from participating effectively in professional psychology programmes. This 
report calls for action for everyone in psychology to embrace the changes needed to improve the cultural safety of the discipline and hold ourselves accountable for supporting the development of Te Tiriti-aligned psychology.

text: Systemic racism and oppression in psychology: Voices from psychologists, academic staff, and students Psychology must reassess its training approach, as the current monocultural paradigm not only causes harm, but also fails to equip psychologists with the knowledge needed to provide culturally appropriate care for Māori, Pacific, Asian, and other minoritised groups. Findings from this report contribute to the growing evidence of the urgent need to address barriers preventing Māori, Pacific, Asian, and other minoritised groups from participating effectively in professional psychology programmes. This 
report calls for action for everyone in psychology to embrace the changes needed to improve the cultural safety of the discipline and hold ourselves accountable for supporting the development of Te Tiriti-aligned psychology.

year: 2024