THE EFFECT OF SULFIDE ON THE BLUEGREEN ALGAE OF HOT SPRINGS. I. NEW ZEALAND AND ICELAND 1

• Published in: Journal of Phycology
• Main Author: Castenholz, Richard W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1976
• Subjects: New Zealand; Iceland
• Online Access: http://dx.doi.org/10.1111/j.1529-8817.1976.tb02826.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1529-8817.1976.tb02826.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1529-8817.1976.tb02826.x

SUMMARY The concentration of soluble sulfide (H 2 S, HS − , S = ) 2 in hot springs of New Zealand and Iceland has a “species‐determining” effect which appears to override the effect of all other chemical factors excepting hydrogen ion concentration. The cosmopolitan high‐temperature form (HTF) of Mastigocladus laminosus (Ag.) Cohn appears to be sensitive to concentrations of S = over 0.15 mg·l −1 in New Zealand and 0.25 mg·l −1 in Iceland. It was absent in thermal streams where S = level was high enough to exceed this concentration at a point below its optimal temperature range (i.e., below ca. 50 C). In low or non‐S = springs in these regions this alga formed mats to an upper temperature limit of 63–64 C. In contrast, one bluegreen alga (Oscillatoria amphigranulata van Goor) occurred abundantly only in moderate to high S = springs of New Zealand; this was a species with an upper temperature limit of about 57 C. Field 14 C‐HCO 3 − incorporation experiments with various levels of added S = confirmed the sensitivity of HTF Mastigocladus and the great tolerance of O. amphigranulata. In the latter, the photosynthetic incorporation of 14 C‐HCO 3 − was sustained or enhanced by the additions of S = in the presence of 5 × 10 −5 m DCMU, an inhibitor of photoelectron transport on the reducing side of photosystem II. It is possible, but not proven, that S = may act as a photoreductant in this species.