The solubility of plant protein isolates is a key determinant of their potential application. Two protein isolates (PI) from ethanol-treated industrial rapeseed meal, PI_10.5–2.5 and PI_2.5–8.5, were prepared by sequential isoelectric precipitation of alkali-extracted proteins (pH 12) starting from pH 10.5 to 2.5 or from pH 2.5 to 8.5, respectively. Biochemical analyses revealed that PI_2.5–8.5 contained a higher amount of crude protein (72.84%) than PI_10.5–2.5 (68.67%). In the same protein isolate, the level of total phenols (0.71%) was almost two-fold higher than that in PI_10.5–2.5 (0.42%). No glucosinolates were established in both protein isolates. SDS-PAGE analysis demonstrated that PI_10.5–2.5 contained 10 to 15 kDa protein fractions in a relatively higher amount, while PI_2.5–8.5 was enriched in 18 to 29 kDa protein fractions. PI_10.5–2.5 exhibited high solubility, varying from 41.74% at pH 4.5 to 65.13% at pH 6.5, while PI_2.5–8.5 was almost two-fold less soluble under the same conditions. Up to pH 5.5, the addition of NaCl at 0.03 and 0.25 M diminished the solubility of PI_2.5–8.5, while the solubility of PI_10.5–2.5 was increased. The supplementation of PI_10.5–2.5 with 0.25 M NaCl enhanced the protein solubility to 56.11% at pH 4.5 and 94.26% at pH 6.5. The addition of 0.03 M NaCl also increased the solubility of this protein isolate but to a lower extent. Overall, the approach for sequential precipitation of proteins influenced the biochemical characteristics, protein fractional profile and solubility of prepared protein isolates.

Resting stages are common for the life cycle of some phytoplankton species, including blooming and potentially toxic species. The “seed bank” accumulated in the sediments can initiate blooms in the water column and could be an early warning signal of harmful algal blooms (HABs). In order to identify the phytoplankton cyst assemblages, thirteen surface sediment samples were collected from different sites in the Black Sea. The diversity of the resting stages was assessed using high-throughput sequencing metabarcoding (V7-9 hypervariable region of the 18S rDNA). One hundred and eighty microalgal species were identified with high level of similarity to the reference sequences. Dinoflagellates were dominated by Biecheleria, Gymnodinium and Karlodinium. Within diatoms, Skeletonema, Chaetoceros and Thalassiosira were the most abundant genera. Sixteen of the detected operational taxonomic units (OTUs) were assigned to harmful microalgae (12 dinoflagellates species, 1 diatom, 1 haptophyte and 2 raphidophytes). No pattern of microalgal sequences depth distribution was discriminated. The results show that DNA metabarcoding has a great potential for assessment of the phytoplankton diversity in environmental sediments.

A revised checklist of the fish fauna of the Black Sea is reported. This paper is the first attempt to present an actual Check List of the fishes in the Black Sea according to the data available in the Black Sea countries, as well as their current conservation status, enlisted in IUCN. The total number of the Black Sea fish species is 189. Concerning the conservation status only two species (1.06 %) are extinct (Acipenser nudiventris and A. sturio), 3.70 % are critically endangered, 16.40 % are vulnerable, 1.06% are endangered, for 10.58 % there is a lack of data, 26.46% has been classified in the category “Least concern”, 2.65 % are “Near threatened” and 38. 10% are “Not evaluated”.