Limits...
Portrait of a Geothermal Spring, Hunter's Hot Springs, Oregon.

Castenholz RW - Life (Basel) (2015)

Bottom Line: All of these demarcations are easily visible in the field.In addition, there is a biosulfide production in some sections of the springs that have a large impact on the microbiology.Most of the temperature and chemical limits have been explained by field and laboratory experiments.

View Article: PubMed Central - PubMed

Affiliation: Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, USA. rcasten@uoregon.edu.

ABSTRACT
Although alkaline Hunter's Hot Springs in southeastern Oregon has been studied extensively for over 40 years, most of these studies and the subsequent publications were before the advent of molecular methods. However, there are many field observations and laboratory experiments that reveal the major aspects of the phototrophic species composition within various physical and chemical gradients of these springs. Relatively constant temperature boundaries demark the upper boundary of the unicellular cyanobacterium, Synechococcus at 73-74 °C (the world-wide upper limit for photosynthesis), and 68-70 °C the upper limit for Chloroflexus. The upper limit for the cover of the filamentous cyanobacterium, Geitlerinema (Oscillatoria) is at 54-55 °C, and the in situ lower limit at 47-48 °C for all three of these phototrophs due to the upper temperature limit for the grazing ostracod, Thermopsis. The in situ upper limit for the cyanobacteria Pleurocapsa and Calothrix is at ~47-48 °C, which are more grazer-resistant and grazer dependent. All of these demarcations are easily visible in the field. In addition, there is a biosulfide production in some sections of the springs that have a large impact on the microbiology. Most of the temperature and chemical limits have been explained by field and laboratory experiments.

No MeSH data available.


Related in: MedlinePlus

Cartoon summary of phototroph and ostracod distributions in Hunter’s streams. Upper portion with visible field distributions. Lower line below indicates Chloroflexus undermat distribution (47–68 °C) and ostracod, Pleurocapsa, Calothrix distributiions below 47 °C. The lower horizontal bars indicate ranges in culture of 4 Synechococcus thermotypes [3] and those of Chloroflexus, Oscillatoria (=Geitlerinema), Pleurocapsa, Calothrix, and Potamocypris (former name of the ostracod, Thermopsis thermophile). The range between arrows indicates the approximate optimal range for growth in culture.
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life-05-00332-f018: Cartoon summary of phototroph and ostracod distributions in Hunter’s streams. Upper portion with visible field distributions. Lower line below indicates Chloroflexus undermat distribution (47–68 °C) and ostracod, Pleurocapsa, Calothrix distributiions below 47 °C. The lower horizontal bars indicate ranges in culture of 4 Synechococcus thermotypes [3] and those of Chloroflexus, Oscillatoria (=Geitlerinema), Pleurocapsa, Calothrix, and Potamocypris (former name of the ostracod, Thermopsis thermophile). The range between arrows indicates the approximate optimal range for growth in culture.

Mentions: The positioning of all phototrophic microorganisms and the herbivorous ostracod in the thermal gradient of Hunter’s Hot Springs is shown in a composite cartoon (Figure 18). It has been shown that in some cases the upper limit of some species is determined by temperature (e.g., Synechococcus high temperature type, Geitlerinema, ostracods, Thermochromatium, and probably Beggiatoa. But the lower limit of the massive distribution of Synechococcus is limited by Geitlerinema, and that of Geitlerinema and Synechococcus/Chloroflexus by the ostracods. Although it is known that Pleurocapsa and Calothrix are capable of growth at higher than the field distributions [26] the impact of ostracod grazing determines the actual distribution. All of the organisms present in Hunter’s Hot Springs tapered out because of suboptimal temperatures at ambient or <30 °C, and other phototrophs were only occasionally present (e.g., phycoerythrin-containing Nostoc, and filamentous green algae).


Portrait of a Geothermal Spring, Hunter's Hot Springs, Oregon.

Castenholz RW - Life (Basel) (2015)

Cartoon summary of phototroph and ostracod distributions in Hunter’s streams. Upper portion with visible field distributions. Lower line below indicates Chloroflexus undermat distribution (47–68 °C) and ostracod, Pleurocapsa, Calothrix distributiions below 47 °C. The lower horizontal bars indicate ranges in culture of 4 Synechococcus thermotypes [3] and those of Chloroflexus, Oscillatoria (=Geitlerinema), Pleurocapsa, Calothrix, and Potamocypris (former name of the ostracod, Thermopsis thermophile). The range between arrows indicates the approximate optimal range for growth in culture.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390855&req=5

life-05-00332-f018: Cartoon summary of phototroph and ostracod distributions in Hunter’s streams. Upper portion with visible field distributions. Lower line below indicates Chloroflexus undermat distribution (47–68 °C) and ostracod, Pleurocapsa, Calothrix distributiions below 47 °C. The lower horizontal bars indicate ranges in culture of 4 Synechococcus thermotypes [3] and those of Chloroflexus, Oscillatoria (=Geitlerinema), Pleurocapsa, Calothrix, and Potamocypris (former name of the ostracod, Thermopsis thermophile). The range between arrows indicates the approximate optimal range for growth in culture.
Mentions: The positioning of all phototrophic microorganisms and the herbivorous ostracod in the thermal gradient of Hunter’s Hot Springs is shown in a composite cartoon (Figure 18). It has been shown that in some cases the upper limit of some species is determined by temperature (e.g., Synechococcus high temperature type, Geitlerinema, ostracods, Thermochromatium, and probably Beggiatoa. But the lower limit of the massive distribution of Synechococcus is limited by Geitlerinema, and that of Geitlerinema and Synechococcus/Chloroflexus by the ostracods. Although it is known that Pleurocapsa and Calothrix are capable of growth at higher than the field distributions [26] the impact of ostracod grazing determines the actual distribution. All of the organisms present in Hunter’s Hot Springs tapered out because of suboptimal temperatures at ambient or <30 °C, and other phototrophs were only occasionally present (e.g., phycoerythrin-containing Nostoc, and filamentous green algae).

Bottom Line: All of these demarcations are easily visible in the field.In addition, there is a biosulfide production in some sections of the springs that have a large impact on the microbiology.Most of the temperature and chemical limits have been explained by field and laboratory experiments.

View Article: PubMed Central - PubMed

Affiliation: Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403, USA. rcasten@uoregon.edu.

ABSTRACT
Although alkaline Hunter's Hot Springs in southeastern Oregon has been studied extensively for over 40 years, most of these studies and the subsequent publications were before the advent of molecular methods. However, there are many field observations and laboratory experiments that reveal the major aspects of the phototrophic species composition within various physical and chemical gradients of these springs. Relatively constant temperature boundaries demark the upper boundary of the unicellular cyanobacterium, Synechococcus at 73-74 °C (the world-wide upper limit for photosynthesis), and 68-70 °C the upper limit for Chloroflexus. The upper limit for the cover of the filamentous cyanobacterium, Geitlerinema (Oscillatoria) is at 54-55 °C, and the in situ lower limit at 47-48 °C for all three of these phototrophs due to the upper temperature limit for the grazing ostracod, Thermopsis. The in situ upper limit for the cyanobacteria Pleurocapsa and Calothrix is at ~47-48 °C, which are more grazer-resistant and grazer dependent. All of these demarcations are easily visible in the field. In addition, there is a biosulfide production in some sections of the springs that have a large impact on the microbiology. Most of the temperature and chemical limits have been explained by field and laboratory experiments.

No MeSH data available.


Related in: MedlinePlus