Influence of salinity on hair formation and phosphatase activities of the blue-green alga (Cyanobacterium)Calothrix viguieriD253

Abstract

A strain of Calothrix viguieri, isolated originally from the surface of a mangrove root, showed marked morphological and physiological responses to the salinity of the medium. When grown to P limitation in a freshwater medium, each trichome ended in a long hair and the culture showed marked cell-bound phosphomonoesterase and phosphodiesterase activities. When grown with various P sources (inorganic and organic) to P limitation in medium including 5'6g 1-~ NaCI, hairs were absent, phosphomonoesterase activity was much lower and phosphodiesterase activity absent. With five of the seven organic P sources tested, the yield was also lower in saline medium. Reduction of NaCI concentration led to development of hairs over a 24 h period, whereas increase in NaC1 led to the hairs being shed. Neither mannitol nor sorbitol led to similar effects to those brought about by NaC1. Use of an azo-dye staining technique (napthol AS-MX phosphate as P source and Fast Blue RR diazonium salt as coupling agent) showed that cell-bound phosphomonoesterase activity of cultures with hairs was localized on the hairs, with a sharp transition between the part of the trichome showing activity and that not doing so. In comparison with the

Alkaline phosphatase activities and the relationship to inorganic phosphate in the Pomeranian Bight (southern Baltic Sea)

“…This mechanism seems to be efficient because son et al 1988), bacteria (Hassan & Pratt 1977, Chrdst parallel investigations have shown that phytoplankton & Overbeck 1990, Ammerman 1991), and algal culdoes not show any decrease in specific production (Jost tures (Kuenzler & Perras 1965, Cembella et al 1984, & Pollehne 1998. When phosphate concentrations are Mahasneh et al 1990, Hernandez et al 1993). Paasche at the detection limit in summer and hydrolysis rates & Erga (1988) and Chr6st (1991) found that these relaare about 10 to 30% h-', the organic phosphorous pool will be converted within 3 to 10 h. Under hydrochemical conditions in autumn, an organic phosphorous content of about 0.9 pM, and median hydrolysis rates of about 1 % h-', the phosphorous turnover needs about 100 h. A threshold of 1 pM phosphate could be defined for the regulatory function of phosphate on APA.…”

Effect of salinity on growth, pigmentation, N2 fixation and alkaline phosphatase activity of cultured Trichodesmium sp.

“…However, it is unclear whether the changes in APA with salinity are due to the influence of salinity itself or to the influence of particular ions. For example, Mahasneh et al (1990) ) on the regulation of phosphate uptake in Trichodesmium.…”

Phosphatase Activity of Non-Hair Forming Cyanobacterium Rivularia and Its Role in Phosphorus Dynamics in Deepwater Rice-Fields

“…Dark conditions were also tested and were obtained by wrapping the bottle twice with aluminum foil. Practical details were given in [13,19]. Substrate was added to the bottles and bottles were tightly capped and run for 30 min.…”