Two of the considerably versatile and promising biomaterials are chitin and chitosan. Chitin is known to be the most abundant natural amino mucopolysaccharide, produced annually almost as much as cellulose, and it is found in the structure of a wide number of intervertebrates ( crustaceans' exoskeleton, insects' cuticles) functioning as a structural component that provides strenght and protection to the organisms, and the cell walls of fungi, among others. On the other hand, chitosan only occurs naturally in some fungi (mucoraceae). The composition of chitin is based on β(14)-linked 2-acetamido-2-deoxy-β-D-glucose (N-acetylglucosamine

Chitin and chitosan have become of great interest not only as underutilized resources, but also as new functional materials of high potential in various fields. The methods of isolating chitosan from different sources: shrimp (Panaeus monodon), crab (Scylla olivicea and Scylla serrata), locust (Schistocerca gregaria), honeybee (Apis mellifera), beelte (Calosoma rugosa) and fish (Labeo rohita) were compared. The same steps of demineralization and deproteinization were followed for the chemical extraction of chitin, but the concentration of reagents, the temperatures and reaction times were varied, which resulted in chitosans with different degrees of deacetylation.

The Black Sea offers numerous harnessing possibilities for the medical and pharmaceutical, agricultural, food industry and cosmetic fields. Collagen extraction from the Black Sea fish is a research area of great interest. The purpose of this paper is to optimize the collagen quantitative analysis method based on hydroxyproline reagent through visible molecular absorption spectrometry. The adapted method was validated, achieving the following performance criteria: linearity, detection and quantification limits, accuracy/fidelity, stability/sturdiness, repeatability, and measurement uncertainty. The validated method was applied for the quantitative determination of collagen content in Grey Mullet fish and for the evaluation of collagen extraction output.

Knowledge of environmental pollution with an impact on health is essential for a sustainable environment and useful for people. The coastal areas of the world�s seas and oceans are polluted with different pollutants from technological sources and from other sources of socio-human activities. The pollutants studied are heavy metals Cd, Cu, Zn and Pb. In the paper are presented researches regarding the heavy metal concentrations determined in samples from marine water, sediments and algal mass, harvested from six stations from different areas of the Romanian Black Sea in two different years 2017 and 2018. The analyses were performed in the Chemistry Laboratories of the Faculty of Pharmacy, Ovidius University in Constanta, by a spectrophotometric method using Atomic Absorption Spectrometer ContrAA-700, Analytic Jena AG. For marine water in 2018 the following concentrations were obtained: Zn ] Pb ] Cu ] Cd and in 2017 the order was different: Zn ] Cu ] Pb ] Cd. For sediments in 2017 the order of concentrations is Cu ] Zn ] Pb ] Cd and in 2018 the highest values in the sediment are recorded by the next high values Cu ] Pb ] Zn ] Cd. Constant climate change and increased eutrophication in recent years have led to a massive increase in marine biomass in the Black Sea. For seaweed samples there are accumulations in the order of Zn ] Cu ] Pb ] Cd in both years. Bioaccumulation factors in water BCF water, were higher in algae for Zn and Cu. From the analysis of bioaccumulation factors, it can be noticed that seawater algae accumulate heavy metals from seawater and sediment (confirmed by BCF water ] 1 or BCF sed. ] 1). The accumulation of heavy metals in seaweed shows the existence of pollutants and marine pollution factors. Marine algae are the best biomarkers of pollution.

During the past years, it became obvious that the ecosystem presents a marine algae surpluses, which should be turned valuable in one way or another. The importance of the macrobenthic flora – algae and phanero-gammes – for the general productivity of the marine environment, especially in shallow waters, is becoming more and more obvious from the biological as well as from the economical point of view. The macrophytes also represent a particular life form. The benthic macroflora includes 33 species 4: 16 Chlorophyta, 10 Rhodophyta, 5 Phaeophyta, and 2 Phanerogama. The quantity of green algae (Chlorophyta) was higher in the Constanta – Eforie area, as red algae are predominant in the southern part of the littoral. Brown algae (Phaeophyta) were encountered in the Constanta city area (Punctaria) and in Vama-Veche (Cystoseira barbata). Yet, this fact indicates a slight amelioration of the marine ecosystem, after many years of eutrophication. The superior capitalisation of the marine biomass represents a highly important resource for the pharmaceutical industry, supplying raw material for the extraction of bioactive substances and various other substances, the purity of which is strongly connected to the state of the marine ecosystem.