Finding and characterizing new bacterial strains, including probiotic strains, is a crucial task in today’s world to expand the genetic data pool and identify new genes. In this study, we investigated the gut microbiota of one industrial species, Cyprinus carpio, and identified representatives of various microbial genera, including Citrobacter, Serratia, Bacillus, Enterococcus, and Kocuria. Notably, we discovered two strains of Hafnia with potentially probiotic properties. We conducted next-generation sequencing (NGS) of these strains, described their antibiotic resistance and antibacterial activity, and compared them with other representatives of the Hafnia genus. These strains, characterized by rapid growth, the presence of the ClpB heat shock protein gene, and genes associated with microplastic degradation, provide a promising basis for further research, including studies on their potential application in plastic biodegradation.

Metal ions can be eliminated from aqueous solutions using biosorbent, a substance made from plant biomass. This study investigated the potential use of Arundo donax stems as a cheap, natural biosorbent to remove cobalt ions (Co2+) from an aqueous solution. The biosorbent was characterized by the chemical composition analysis (cellulose, hemicellulose, and lignin), the point of zero charge (pHPZC), by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction analysis, and Fourier-transform infrared spectroscopy. According to the experimental data of kinetic studies, the equilibrium condition of Co2+ adsorption was attained 360 min after the biosorption started. The pseudo-first, pseudo-second, Elovich, and intra-particle diffusion models were used to model the kinetic experimental data. The best compliance was obtained with the pseudo-first order kinetic model, considering the highest value of the coefficient of determination R2 (0.996) and the lowest chi-square (?2) value (0.757). The findings of this study can be applied to the design of batch biosorption systems for the removal of Co2+ ions in real industrial systems.

In this study, the structure, morphology and composition of the synthesized magnetite/3D-printed wollastonite (3D_W/M) composite were characterized, and its adsorption performance with respect to As(V) and Cr(VI) were studied. Magnetite (MG) modified 3D printed wollastonite was obtained by two step procedure: modification of 3D_W with 3-aminoproylsilane (APTES) followed by controlled magnetite (MG) deposition to obtain 3D_W/M adsorbent. The structure/properties of 3D_W/M were confirmed by applying FTIR, XRD, TGD/DTA, and SEM analysis. The adsorption properties of hybrid adsorbents were carried out for As(V) and Cr(VI) removal - one relative to the initial pH value, the adsorbent mass, the temperature, and the adsorption time. Time-dependent adsorption study was best described by pseudo-second order equation, while Weber Morris analysis showed that intraparticle diffusion controled diffusional transport. Similar activation energy, 17.44 and 14.49 kJ?mol-1 for adsorption As(V) and Cr(VI) on 3D_W/M, respectively, indicated main contribution of physical adsorption. Determination of adsorption parameters was performed by applying different adsorption isotherm models, and the best fit was obtained using Freundlich model. The adsorption capacity of 24.16 and 29.6 mg g-1 for As(V) and Cr(VI) at 2?C, Co = 5.5 and 5.3 mg L-1, respectively, were obtained. Thermodynamic study indicated favourable process at a higher temperature. Preliminary fixed-bed column study and results fitting with Bohart-Adams, Yoon-Nelson, Thomas, and Modified dose-response model showed good agreement with results from the batch study.