Michele Greque de Morais1, Carolina Reichert1, Francieli Dalcanton1, Andrei José Durante1, Luís Fernando Marins2, Jorge Alberto Vieira Costa1
1Laboratory of Biochemical Engineering, Department of Chemistry, Federal University Foundation of Rio Grande, P. O. Box 474, 96201-900, Rio Grande, RS, Brazil
2Department of Physiological Sciences, Federal University Foundation of Rio Grande, P. O. Box 474, 96201-900, Rio Grande, RS, Brazil
Tóm tắt
A filamentous microorganism, morphologically similar to the cyanobacterium Arthrospira, was isolated from Mangueira Lagoon in Brazil, from which Arthrospira has not previously been isolated. Random amplified polymorphic DNA (RAPD) comparison with the standard Arthrospira platensis strains LEB 52 and Paracas indicated that the organism isolated was an Arthrospira isolate, which we denominated strain LEB 18. The RAPD analysis showed conserved sequences which indicated that the three strains belonged to the same genus, and were all Arthrospira species, but there were sufficient differences between them suggesting that they were separate strains. The strain LEB 18 was cultivated in undiluted Zarrouk medium and in 60% and 20% (v/v) Zarrouk medium diluted with sterilized Mangueira Lagoon water (MLW) using illuminance rates of 32.5, 45.5 and 58.5 μmol m−2 s−1 according to a complete 32 factorial design with a triplicate central point. The strains LEB 52 and Paracas were cultived in the conditions central point. Our new isolate produced the highest specific growth rate (μmax = 0.22 d−1) in 60% Zarrouk medium diluted with MLW and illuminated with 58.5 μmol m−2 s−1 and the highest protein content (86.0% w/w).
