The environmental sustainability of microalgae as feed for aquaculture: a life cycle perspective.

The environmental sustainability of microalgae production for aquaculture purposes was analyzed using exergy analysis (EA) and life cycle assessment (LCA). A production process (pilot 2012, 240 m(2)) was assessed and compared with two upscaling scenarios (pilot 2013, 1320 m(2) and first production scale 2015, 2.5 ha). The EA at process level revealed that drying and cultivation had the lowest efficiencies. The LCA showed an improvement in resource efficiency after upscaling: 55.5 MJ(ex,CEENE)/MJ(ex) DW biomass was extracted from nature in 2012, which was reduced to 21.6 and 2.46 MJ(ex,CEENE)/MJ(ex) DW in the hypothetical 2013 and 2015 scenarios, respectively. Upscaling caused the carbon footprint to decline by factor 20 (0.09 kg CO2,eq/MJ(ex) DW in 2015). In the upscaling scenarios, microalgae production for aquaculture purposes appeared to be more sustainable in resource use than a reference fish feed (7.70 MJ(ex,CEENE) and 0.05 kg CO2,eq per MJ(ex) DW).

Cyclic AMP affinity purification and ESI-QTOF MS-MS identification of cytosolic glyceraldehyde 3-phosphate dehydrogenase and two nucleoside diphosphate kinase isoforms from tobacco BY-2 cells.

The soluble protein fraction of tobacco bright yellow 2 cells contained adenosine 3',5'-cyclic monophosphate (cAMP)-binding activity, detected with both a conventional binding assay and a surface plasmon resonance biosensor. A cAMP-agarose-based affinity purification procedure yielded three proteins which were identified by mass spectrometry as glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and two nucleoside diphosphate kinases (NDPKs). This is the first report describing an interaction between cAMP and these proteins in higher plants. Our findings are discussed in view of the reported role of the interaction of cAMP with GAPDH and NDPK in animals and yeast. In addition, we provide a rapid method to isolate both proteins from higher plants.

Indomethacin-induced G1/S phase arrest of the plant cell cycle.

In animal systems, indomethacin inhibits cAMP production via a prostaglandin-adenylyl cyclase pathway. To examine the possibility that a similar mechanism occurs in plants, the effect of indomethacin on the cell cycle of a tobacco bright yellow 2 (TBY-2) cell suspension was studied. Application of indomethacin during mitosis did not interfere with the M/G1 progression in synchronized BY-2 cells but it inhibited cAMP production at the beginning of the G1 phase and arrested the cell cycle progression at G1/S. These observations are discussed in relation to the putative involvement of cAMP biosynthesis in the cell cycle progression in TBY-2 cells.

Effect of indomethacin on cell cycle dependent cyclic AMP fluxes in tobacco BY-2 cells.

The evolution of adenosine 3',5'-cyclic monophosphate (cAMP) levels was investigated in synchronised tobacco BY-2 cells by virtue of a method based on immunoaffinity purification and analysis on electrospray tandem mass spectrometry. A transient peak in cAMP content was observed during the S and G1 phases of the cell cycle. Application of the prostaglandin inhibiting drug indomethacin at early S phase resulted in the loss of the cAMP peak in S phase and inhibited mitotic division. This inhibition of cAMP accumulation suggests the presence of a prostaglandin-dependent adenylyl cyclase activity, analogous to animal cyclases. A potential role for cAMP during the plant cell cycle is postulated.

Analysis of 3',5'-cAMP and adenylyl cyclase activity in higher plants using polyclonal chicken egg yolk antibodies.

Polyclonal antibodies were raised in chicken against an adenosine 3',5'-monophosphate-diphtheria toxoid antigen construct. The antibodies obtained show selectivity and high affinity toward 3',5'-cyclic nucleotides while exhibiting negligible affinity for 2',3'-cyclic nucleotides and other related adenine compounds. This paper reports on the development of an immunoaffinity purification procedure allowing both adenosine 3':5'-monophosphate (3',5'-cAMP) and adenylyl cyclase activity measurement in plant tissue samples. Basically, the technique consists of sequential purification of samples on solid-phase columns, the newly developed immunoaffinity columns, and quantitative analysis in ion-suppression HPLC coupled to photo diode array detection. The described method results in a drastic reduction of processing time compared to existing procedures and combines high yields (70-80%) and thorough purification, hence significantly increasing the sensitivity of quantification of 3',5'-cAMP content in higher plant material. Used in adenylyl cyclase activity measurement it also allows for a routine positive identification of the newly formed compound, 3',5'-cAMP, a feature generally lacking in existing adenylyl cyclase assays.