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Water pollution harms the human and marine environment. An optimal water quality is a global target for the well-being of all living organisms including human. Based on this concept, this study focused on the synthesis of magnetite nanoparticles using the wet chemical reduction technique and their incorporation with the preparation of magnetic chitosan hydrogel (CS-HG) nanocomposite. Fourier transform infrared spectroscopy (FT-IR), zeta potential, x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) were used as the main characterization tools. The magnetic CS-HG was applied to different types of multi-pollutant water to test its efficiency in removing different pollutants. Magnetic hydrogel showed high efficiencies (99.17, 98.27, 95.17, 93.9 and 49.59%) toward removing iron, phosphates, nitrite, nitrate and ammonia/ammonium, respectively. This study also investigated the effectiveness of a chemical treatment process by magnetic CS-HG in reducing bacterial populations in a water sample. The initial bacterial count of total coliforms (TC) ranged from 600,000 to 5,500,000CFU/ mL, significantly decreasing to 4,000 to 60,000CFU/ mL after treatment. Similarly, Pseudomonas counts were reduced from 25,000 to 50 to 75CFU/ mL. Notably, Aeromonas sp. and Vibrio sp. were not detected in the samples before or after treatment. Further analysis revealed that some previously identified Pseudomonas isolates belong to different bacterial genera, including Neobacillus novalis, Psychrobacillus lasiicapitis, Acinetobacter schindleri, and Bacillus paramycoides. Thus, magnetic CSHG could be applied to clean up different kinds of water. [ABSTRACT FROM AUTHOR]

Coral disease is one of the major threats to coral assemblages globally and can significantly influence the coral microbiome as a result of climatic and anthropogenic stressors. Coral disease surveys were conducted at three patch reefs in the northern Red Sea of Hurghada coast. Surveys occurred during a heatwave event in August 2021, when the average surface water temperature reached about 29 °C. This study compared the differences in bacterial communities associated with healthy and diseased coral tissues of nine reefbuilding coral genera collected from the surveyed reefs. The five most common coral diseases identified were black band disease (BBD), white syndrome (WS), growth anomalies (GA), pink line syndrome (PLS), and skeletal eroding band (SEB). In general, the microbial abundance in infected parts of corals was higher than that in healthy parts. Bacteria associated with the black band disease on Platygyra lamellina showed that the number of total bacteria found in the tissue were higher than that in the mucus of the corals. Furthermore, the cultural Vibrio populations (TCBS) of tissue samples were higher than that in mucus samples, and the Vibrio population of the infected coral tissue and mucus was greater than the healthy tissue and mucus. Bacterial 16S rRNA gene clone libraries derived from 12 cultivable isolates of coral mucus and tissue revealed a distinct partitioning of bacterial genera into healthy and diseased samples. Species identified from the healthy samples were dominated by Paracoccus yeei, Staphylococcus aureus, and Acinetobacter sp., while bacteria associated with BBD-affected coral samples were Acinetobacter sp., Desulfovibrio sp., Bacillus farraginis, Vibrio hepatarius, Vibrio brasiliensis, Arcobacter sp., and Micromonospora sp. The present study provides a baseline assessment of coral disease incidence and associated microbial communities in a northern Red Sea region, which is expected to rise as a consequence of increased frequency and severity of climatic and non-climatic stressors. [ABSTRACT FROM AUTHOR]

The rapid population and industrial development worldwide have increased chemical pollutants reaching the marine environment. In the present study, marine fungi were isolated from two collected petroleum sites at the Gulf of Suez, Red Sea, Egypt, during spring (2021). Fungal isolates were purified and screened for their ability to bio-remediate phenol and ortho-cresol bioremediation. Out of twenty two, eight marine fungal isolates represented their potency for the bioremediation of these phenolic compounds. These selected fungi were identified morphologically and numbered according to the AUMC center as Aspergillus flavus 15524, Aspergillus terreus 15525, Aspergillus flavus 15526 and Aspergillus terreus 15527 for phenol bioremediation, and Fusarium oxysporum 15528, Fusarium oxysporum 15529, Aspergillus terreus 15530 and Aspergillus terreus 15531 for o-cresol bioremediation. The two most potent marine fungal isolates able to degrade phenols with high efficiency are strains number 15527 and 1553 which were identified by DNA sequence as A. terreus MHG30 (ON649683) and MHG60 (ON649704), respectively. The optimum condition for phenol degradation by A. terreusMHG30 were 1000 mg/l phenol, pH-8 at 34°C, and contact time 168 hrs., while A. terreus MHG60 showed optimum condition using 250 mg/l ocresol, pH 6 at 31 C0 after 168 hrs. Maximum degradation rates were recorded at 88.34 and 98.1 % for ON649683 and ON649704 strains, respectively. Both strains, ON649683 and ON649704 were acquired with 61 and 64 inhibitory % for oxidase with 81 and 78 % for peroxidase enzymes, respectively. The Km/Vmax of both isolates was achieved at 0.18, 0.19, 0.03, and 0.29 for the studied enzymes. In addition, the active compounds of GC-Mass (Hexadecanoic acid, methyl ester, and 6, 9, 12-octadecatrienoic acid) are used to determine the unique eco-friendly compounds that result from the bioremediation procedure for phenol and o-cresol. [ABSTRACT FROM AUTHOR]

Possible inexpensive adsorbent sources are urgently required to remove metals and pollutants from aquaculture effluents. Thus, this study evaluated the intensive bacterial production and metal removal (Mn, Co, Ni, Cu, Zn, Pb and Cd) from marine water, which will be used for the culture of aquatic animals using biofloc technology (BFT). In the presence of sugarcane bagasse (T1) and rice-bran (T2) as organic carbon sources, marine polluted water was treated for 6 weeks. As expected, the bacterial numbers increased throughout the experimental period, which helped in breaking down the carbon source and metal removal. Overall, the percentages of heavy metal removal from water samples with different biofloc, and the sequence of adsorption of heavy metals from polluted marine water were Pb > Cu > Ni > Cd > Mn > Co > Zn for T1. Meanwhile, a slight difference was detected in the sequences of T2 as: Pb > Ni > Cu > Cd > Mn > Zn > Co. Furthermore, the relationships among different carbon sources, heavy metals and microbes were also analyzed using the principal component analysis (PCA) and correlation matrix. However, the bacterial and metal profiles have variability by 97.20% at the end of the experiment. The results of this study indicate that the heavy metals concentrations are affected by the bacteria and carbon sources directly via changes in their concentration which provides the opportunity to mitigate the impact of polluted water on the environment so far and provide the opportunity to use water free of heavy metals in aquaculture practices. [ABSTRACT FROM AUTHOR]