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Near-UV radiation promotes growth of Chlorella.
- Source :
-
Environmental sciences : an international journal of environmental physiology and toxicology [Environ Sci] 2004; Vol. 11 (4), pp. 189-98. - Publication Year :
- 2004
-
Abstract
- The wavelength of natural sunlight reaching the Earth's surface was detected to be above 300 nm using a multichannel spectrodetector and the ratio of UV to photosynthetically active radiation (PAR) of sunlight in Japan (137 degrees E/35 degrees 11' N, altitude; 50 m) in early summer was estimated to be 0.07:1 (i.e., 7%). On the basis of this UV/PAR ratio, Chlorella ellipsoidea (IAM-27) cells were cultured in flasks under various conditions of UV irradiation in growth chambers. The growth (cell division) of these cells without near-UV radiation was inferior to that with near-UV radiation. Growth at a UV/PAR ratio of 7% (natural conditions), determined tentatively using our detector in the present study, was maximal similar to those at 14% and 28%; whereas that at 0.7% was somewhat less and that at 70% was considerably less. Growth was linked with the activities of stress enzymes. NAD(P)H-dependent oxidase [NAD(P)-DH] and xanthine oxidase (XOD), extracted from Chlorella exposed to near-UV radiation demonstrated lower activities than those from Chlorella not exposed to near-UV radiation. On the other hand, superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APOD) extracted from Chlorella exposed to near-UV radiation have higher activities than those from unexposed Chlorella. Near-UV radiation clearly acted as an important factor for growth (cell division), at least at UV/PAR ratios of up to 0.28:1.
Details
- Language :
- English
- ISSN :
- 0915-955X
- Volume :
- 11
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Environmental sciences : an international journal of environmental physiology and toxicology
- Publication Type :
- Academic Journal
- Accession number :
- 15746895