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Biochemical Composition of Cyanobacterium Calothrix marchica and Perspectives its Using in Biotechnology

2020; Begell House; Volume: 22; Issue: 2 Linguagem: Inglês

10.1615/interjalgae.v22.i2.80

1940-4328

Alina Trofim, Valentina Bulimaga, M. B. Bulimaga,

Algal biology and biofuel production

In recent years, cyanobacteria have been found to be important sources of known bioactive substances, as well as newly discovered secondary metabolites. This research isolated and characterized one of the strains - Calothrix marchica Lemmermann CNMN-CB-18 - in pure culture. This strain grows in the soil of the Cogalnic River meadow, Cimislia, Moldova. The morphological characteristic of C. marchica revealed solitary blue-green trichomes. The vegetative cells are of different ranging, from square to rectangular with a width (4.0-7.0 μm) 2-4 times the length. Basal cells have a width of 4.5-6.0 μm. The terminal cell is round or slightly sharp. Each trichome contains a basic spherical or hemispherical basal heterocyst with a length of 2.0-5.5 μm and a width of 3.0-5.5 μm. The two step cultivation of C. marchica, with switching of the illumination from 1500 to 2500 lx on the 7th day, lead to a higher carbohydrate content (up to 40.5%) on BG11 medium; when compared to its growth in different lighting regimes (36.5-37.5%). The productivity of the strain showed similar tendencies: it reached values of up to 1.314 g/L for the two-step cultivation, whereas the 1500 and 2500 lx continuous illumination displayed lower values -0.714 and 0.87 g/L, respectively. The same trends were found with growth on Drew medium, however its poorer content of minerals lead to lower yields, as compared to BG11. The biochemical analysis of C. marchica grown on Drew medium demonstrates rich amounts of lipids - 33.7%, and carbohydrates - 32.9%, followed by proteins at 14.66%. Due to its ability to adjust to various growth conditions under controlled cultivation and accumulate high amounts of carbohydrates, this strain is a valuable source of bioactive substances for use in biotechnology in order to be applied in diverse fields such as: cosmetics, pharmaceuticals, agriculture, etc.