Original paper
Ecophysiological characters and biochemical composition of Stichococcus bacillaris NAEGELI strains from low pH environments
Pollio, Antonino; Aliotta, Giovanni; Pinto, Gabriele; Paterno, Massimo; Bevilacqua, Agar
Algological Studies/Archiv für Hydrobiologie, Supplement Volumes No. 84 (1997), p. 129 - 143
42 references
published: Apr 23, 1997
DOI: 10.1127/algol_stud/84/1997/129
ArtNo. ESP142011800009, Price: 29.00 €
Abstract
The ecophysiological characters of 14 strains of Stichococcus bacillaris isolated from low pH environment of Italy at pH ≦ 3.0 were studied under different physiological conditions and compared with those found in a strain coming from a neutral environment. On the basis of the results obtained the strain 155, isolated from a sulphur spring, was selected for the determination of its biochemical composition under different growth conditions. Growth of strain 155 as function of pH occurred in the range of pH 2-12, the lower limit being quite similar to that of the soil from which it was isolated. At low pH values (2.0-3.5) morphological differences were also apparent. The strain showed to be only moderately halotolerant; the highest NaCl concentration supporting growth was 4.0%. The biochemical composition of this strain was determined during the exponential and the stationary phase of growth and under nitrogen-sufficient or deficient conditions. The protein content ranged from 10-42% of dry weight and total lipid varied from 19.8-55% of dry weight. Both protein and lipid contents were scarcely influenced by the phase of growth, whilst were largely dependent on the nitrogen concentration in the medium. Aminoacid profiles showed only minor variation in the different conditions considered. The major aminoacids found were: aspartate, glutamate, leucine, alanine and valine. The strain 155 of S. bacillaris synthesized as major fatty acids, 16:0, 18:1, 18:2 and 18:3 (α-linoleate), but also small amounts of ϒ-linoleate, 20:4 and 20:5 were detected. Nitrogen deficiency induced accumulation of 18:1 and 18:2 fatty acids.
Keywords
Acid-tolerant algae • Stichococcus bacillaris • protein • aminoacid • lipid • fatty acid