Non-targeted metabolomic profiling of filamentous cyanobacteria Aphanizomenon flos-aquae exposed to a concentrated culture filtrate of Microcystis aeruginosa

Various studies have observed that increased nutrient supply promotes the growth of bloom-forming cyanobacteria, but only a limited number of studies have investigated the influence of increased nutrient supply on bloom-forming cyanobacteria at the proteomic level. We investigated the cellular and proteomic responses of Microcystis aeruginosa to elevated nitrogen and phosphorus supply. Increased supply of both nutrients significantly promoted the growth of M. aeruginosa and the synthesis of chlorophyll a, protein, and microcystins. The release of microcystins and the synthesis of polysaccharides negatively correlated with the growth of M. aeruginosa under high nutrient levels. Overexpressed proteins related to photosynthesis, and amino acid synthesis, were responsible for the stimulatory effects of increased nutrient supply in M. aeruginosa. Increased nitrogen supply directly promoted cyanobacterial growth by inducing the overexpression of the cell division regulatory protein FtsZ. NtcA, that regulates gene transcription related to both nitrogen assimilation and microcystin synthesis, was overexpressed under the high nitrogen condition, which consequently induced overexpression of 2 microcystin synthetases (McyC and McyF) and promoted microcystin synthesis. Elevated nitrogen supply induced the overexpression of proteins involved in gas vesicle organization (GvpC and GvpW), which may increase the buoyancy of M. aeruginosa. Increased phosphorus level indirectly affected growth and the synthesis of cellular substances in M. aeruginosa through the mediation of differentially expressed proteins related to carbon and phosphorus metabolism. This study provides a comprehensive description of changes in the proteome of M. aeruginosa in response to an increased supply of 2 key nutrients.

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ВПЛИВ ДЖЕРЕЛ АЗОТНОГО ЖИВЛЕННЯ НА СИНТЕЗ КАРОТИНОЇДІВ ДЕЯКИМИ ШТАМАМИ БАЗИДІОМІЦЕТІВ

Biological Bulletin of Bogdan Chmelnitskiy Melitopol State Pedagogical University ◽

10.15421/20144_02 ◽

2014 ◽

Vol 4 (01) ◽

pp. 22

Author(s):

A. K. Veligodska ◽

O. V. Fedotov ◽

A. S. Petreeva

Keyword(s):

Culture Filtrate ◽

Nutrient Medium ◽

Culture Fluid ◽

Carotenoid Content ◽

Nitrogen Compounds ◽

Total Carotenoid ◽

Carotenoid Accumulation ◽

Total Carotenoid Content ◽

Peptone Medium ◽

Acetone Extracts

The influence of certain nitrogen compounds - components of glucose-peptone medium (GPM) on the accumulation of carotenoids by some strains was investigated by surface cultivating basidiomycetes. The total carotenoid content was set in acetone extracts of mycological material spectrophotometrically and calculated using the Vetshteyn formula. As the nitrogen-containing components used GPM with 9 compounds, such as peptone, DL-valine, L-asparagine, DL-serine, DL-tyrosine, L-proline, L-alanine, urea, NaNO3. The effect on the accumulation of specific compounds both in the mycelium and in the culture fluid of carotenoids by culturing certain strains of Basidiomycetes was identified. Adding to standard glucose-peptone medium peptone at 5 g/l causes an increase of carotenoid accumulation by strain L. sulphureus Ls-08, and in a concentration of 4 g/l by strains of F. hepatica Fh-18 and F. fomentarius Ff-1201. In order to increase the accumulation of carotenoids in the mycelium we suggested to make a standard glucose-peptone medium with proline or valine for cultivating of L. sulphureus Ls- 08 strain; alanine for F. fomentarius Ff-1201 strain; proline, asparagine and serine - for strain Fh-18 of F. hepatica. The results can be implemented in further optimization of the composition of the nutrient medium for culturing strains of Basidiomycetes wich producing carotenoids. Keywords: nitrogen-containing substances, Basidiomycetes, mycelium, culture filtrate, carotenoids

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