Marine Water Samples Research Articles

Biogenesis of Copper Oxide Nanoparticles using Marine Bacteria Pseudomonas aeruginosa: In vitro Antimicrobial and Photocatalytic Activities

The current study outlines an environmentally friendly procedure to synthesis the extracellular secondary metabolite-mediated copper oxide nanoparticles (CuONPs) using Bioinspired green chemistry method with Pseudomonas aeruginosa isolated from a marine water sample. The in vitro bio-reduction of Copper sulphate to CuONPs in the presence of secondary metabolites was confirmed using various analytical techniques, including UV-visible spectroscopy, FTIR spectroscopy, particle size analysis, scanning electron microscopy (SEM) and X-ray diffraction (XRD). In the UV-visible spectroscopy the synthesised nanoparticles was characterized with the maximum absorbance at 570 nm. SEM analysis showed the nanoparticles to be nearly cuboidal in shape with the size range of 108.0 nm to 252.2 nm at the 1,00,000x magnification. X-ray diffraction revealed particle sizes ranging from 4.19 nm to 26.95 nm with diffraction peaks at 38.05° and 31.67°, corresponding to lattice planes [6.56] and [100], indicating a polycrystalline wurtzite structure. The synthesized CuONPs exhibited significant antimicrobial activity against clinical pathogenic bacteria such as Escherichia coli, Bacillus cereus, Staphylococcus aureus and Proteus mirabilis, as well as fungicidal activity against phytopathogenic fungi including Alternaria solani, Rhizoctonia solani and Colletotrichum capsici. Additionally the photocatalytic activity of the Pseudomonas aeruginosa mediated CuONPs was estimated through the degradation of the triarylmethane dye-malachite Green.

Morphodynamics drive the transport and accumulation of anthropogenic microparticles in tropical coastal depositional systems in southeastern Brazil

A significant limitation in current coastal pollution research is that microplastics (<5 mm) comprise only a fraction of all anthropogenic microparticles (AMP, <5 mm) scale residues. Comprehensive AMP assessments, including those comprising semisynthetic, and modified natural compositions, are lacking. For instance, the accumulation of AMP in different coastal morphological features within a depositional system remains poorly known, fueling long-lasting debates about the distribution process of microparticles. Using a multi-proxy approach, we address mutual interactions between distinct surface morphologies (tidal flats, beaches, and foredunes) and transport and deposition dynamics of AMP. This issue was addressed by analyzing sediment and water samples collected at a marine protected area in the south coastal of São Paulo (Brazil). Here, we showed that AMP abundance in the tidal mudflat (18,500–20,500 particles/kg) was four times higher than in beach sands (4700–5900 particles/kg), while the lowest abundance was observed in foredune sands (4350 particles/kg). This can be attributed to the low-energy hydrodynamics of tidal flats associated with the cohesive behavior of muddy sediments, which consequently favor trapping and act as the main sink for AMP. Further, coastal processes (waves and currents) drive AMP onshore through sediment transport from the surfzone to the beach, from where the AMP becomes available for onshore eolian transport. Higher AMP abundance (85 particles/l) was observed in the marine water samples compared to the estuarine water samples (35 particles/l). Fibers <1 mm appeared as the predominant AMP in the sediment (99–100 %) and water (80–95 %) samples, primarily consisting of modified cellulose (73 %), dye signature only (16 %), and microplastics (11 %). Consequently, we argue that to fully comprehend the spatial distribution of AMP in coastal sediments and waters, it is crucial to analyze these microparticles from an integrated perspective, primarily considering the hydro-wind dynamics of different coastal morpho-sedimentary compartments combined with sediment grain size.

A survey of water quality in areas of Albanian ports

This study report data on physical-chemical parameters and on concentrations of organic pollutants in marine water samples of Albanian ports. Nutrients, PH, temperature, conductivity, TSS, DO, BOD, COD, chlorines, sulfates, magnesium and calcium ions were the indicators used for evaluation of water quality. Also, organic pollutants (organochlorine pesticides, PCBs, PAH and benzene) were determined in seawater samples. Albania is facing by Ionian and Adriatic seas in a coastline of more than 300 km. Several ports are in function in Albanian coastline. Ship transport and many activities (automobile transport, mechanical activities, deposits, etc.) are the main factors of water pollution in port areas. Water samples from seven ports (the main Albanian ports) starting from Saranda port in the South to Shengjini port in the North, were analyzed in this study. Sampling was realized in May 2023. Based on physical-chemical indicators the water in the port of Saranda was the cleanest water, while Porto-Romano, Petrolifera and the fishing port in Zvernec was the most polluted one. Organic pollutants were detected in all water samples. Presence of the degradation products of pesticides may be related with previous uses of them. Presence of PCBs can be because of atmospheric deposition (volatile congeners), water currents and mechanical businesses (heavy congeners). PAHs and Benzene were detected on more than 70% of the analyzed samples. Intense ship and automobile transport in the port areas, mechanical businesses discharge and hydrocarbon processing i(Petrolifera and Porto-Romano) can be main factor for their presence. Water currents and new arrivals from the rivers can influence the levels and profile of pollutants. The found levels of organic pollutants in water samples of Albanian ports were higher than reported levels in previous studies for the Adriatic Sea (Albania coastline).

Unveiling primary production dynamics in the southern Bay of Bengal: Comparative analysis of in-situ measured data with multiple primary production models

In this study, marine water samples were collected at 18 sampling stations. The collected marine water samples were analysed using a well-calibrated UV spectrophotometer for chlorophyll-a estimation, and using a hyperspectral underwater radiometer, both buoy mode and profile mode in-situ data were collected. The study evaluated four different primary production models to study the dynamics of the southern Bay of Bengal. The simple Eppley model used in the study resulted in huge variations in the nearshore and frontal regions; the dark and light bottle methods showed enormous variations along all 18 sampling stations and underestimated the productivity of the southern Bay of Bengal. However, the VGPM model and its variants showed similar trends in near shore, frontal, and off-shore waters for all three transects, and the Kameda model closely matched the available literature for the primary production estimates of the southern Bay of Bengal. From the detailed analysis of the Kameda model, it is found that the average primary production for the Southern Bay of Bengal for the post monsoon season (February 2023) is estimated as 339.08 mgC/m2/d.

Interference-resistant gold nanoparticle assay for detecting Enterococcus in fresh and marine waters

Enterococci are common indicators of fecal contamination and are used to assess the quality of fresh and marine water, sand, soil, and sediment. However, samples collected from these environments contain various cells and other factors that can interfere with the assays used to detect enterococci. We developed a novel assay for the sensitive and specific detection of enterococci that is resistant to interference from other cells and environmental factors. Our interference-resistant assay used 30-nm gold nanoparticles (AuNPs), streptavidin, and a biotinylated Enterococcus antibody. Enterococci inhibited the interaction between streptavidin and biotin and led to the disaggregation of AuNPs. The absence of enterococci led to the aggregation of AuNPs, and this difference was easily detected by spectrophotometry. This interference-resistant AuNP assay was able to detect whole cells of Enterococcus in the range of 10 to 107 CFU/mL within 3 h, had high specificity for enterococci, and was unaffected by the presence of other intestinal bacteria, such as Escherichia coli. Our examination of fresh and marine water samples demonstrated no interference from other cells or environmental factors. The interference-resistant AuNP assay described here has the potential to be used as a rapid, simple, and effective method for monitoring enterococci in diverse environmental samples.

Efficacy of chemical digestion methods to reveal undamaged microplastics from planktonic samples

Standardisation and validation of methods for microplastics research is essential. A major methodological challenge is the removal of planktonic organisms from marine water samples allowing for the identification of microplastics associated to planktonic communities. To improve the reproducibility and accuracy of digestion methods for the removal of planktonic biomass, we compared and modified existing chemical digestion methods. These digestion methods included an acidic digestion using nitric acid, alkaline digestions with potassium hydroxide (alkaline 1 digestion) and sodium hydroxide from drain cleaner (alkaline 2 digestion), an oxidative digestion using sodium dodecyl sulfate with hydrogen peroxide, and an enzymatic digestion using enzyme drain clean pellets. Chemical digestion of three densities of zooplankton communities (high, medium, and low) in the presence of five commonly found environmental microplastic pollutants (polyamide, polyethylene, polyethylene terephthalate, polypropylene, and polystyrene) were performed for each treatment. The chemical treatments were assessed for (i) their digestion efficiency of zooplankton communities by different biomass densities, and (ii) their impact on microplastic particles through the comparison of both chemical (Raman spectroscopy) and physical (length, width, and visual) changes, between the pre-treatment and post-treatment microplastic particles. The alkaline 1, alkaline 2 and oxidative methods demonstrated significantly better digestion efficiency (p < 0.05) than the modified enzymatic and acidic treatments. The acidic, alkaline 1, and alkaline 2, treatments caused the most damages to the microplastic particles. We suggest future studies to implement the oxidative digestion method with sodium dodecyl sulfate and hydrogen peroxide because of its high digestion efficiency, and low damage to microplastic particles. This method is similar to the wet peroxide oxidation digestion method used throughout the literature but can be implemented at a lower cost.

Advances and development in sampling techniques for marine water resources: a comprehensive review

Marine water resources (including seawater and pore-water) provide important information for understanding the marine environment, studying marine organisms, and developing marine resources. Obtaining high-quality marine water samples is significant to marine scientific research and monitoring of marine resources. Since the 20th century, marine water resources sampling technology has become the key research direction of marine equipment. In order to have a comprehensive understanding of marine water resource sampling technology, promote the development of marine water resource sampling technology, and obtain high-quality marine water samples, this paper summarizes the current development status of the sampling technology of marine water resources from the aspects of research and application. This paper first provides an overview of seawater and pore water sampling techniques. The two sampling technologies are categorized and discussed according to different sampling means, and the advantages of different sampling means are compared. We also found similarities between seawater and pore water sampling means. Then, a comprehensive analysis of existing technologies and equipment reveals the development trend of marine water resources sampling technology, for example, the need for high temporal and spatial accuracy in sampling, etc. Finally, it explores the challenges facing deep-sea water sampling technology regarding future research, development and equipment industrialization. These reviews not only help researchers better understand the current development of marine water sampling technologies but also provide an important reference for the future development of marine water sampling technology, which provides guidance and support for in-depth marine scientific research and effective use of marine resources.

Biocontrol of multidrug resistant pathogens isolated from fish farms using silver nanoparticles combined with hydrogen peroxide insight to its modulatory effect

This study was divided into two parts. The first part involved the isolation, and detection of the prevalence and antimicrobial resistance profile of Aeromonas hydrophila, Pseudomonas aeruginosa, and Vibrio species from Nile tilapia fish and marine aquatic water. One hundred freshly dead Nile tilapia fish were collected from freshwater aquaculture fish farms located in Al-Abbassah district, Sharkia Governorate, and 100 samples of marine aquatic water were collected from fish farms in Port Said. The second part of the study focused on determining the in vitro inhibitory effect of dual-combination of AgNPs-H2O2 on bacterial growth and its down regulatory effect on crucial virulence factors using RT-PCR. The highest levels of A. hydrophila and P. aeruginosa were detected in 43%, and 34% of Nile tilapia fish samples, respectively. Meanwhile, the highest level of Vibrio species was found in 37% of marine water samples. Additionally, most of the isolated A. hydrophila, P. aeruginosa and Vibrio species exhibited a multi-drug resistance profile. The MIC and MBC results indicated a bactericidal effect of AgNPs-H2O2. Furthermore, a transcriptional modulation effect of AgNPs-H2O2 on the virulence-associated genes resulted in a significant down-regulation of aerA, exoU, and trh genes in A. hydrophila, P. aeruginosa, and Vibrio spp., respectively. The findings of this study suggest the effectiveness of AgNPs-H2O2 against drug resistant pathogens related to aquaculture.

Pichia kurtzmaniana f.a. sp. nov., with the transfer of eight Candida species to Pichia.

Three yeast strains belonging to the ascomycetous yeast genus Pichia were isolated from two soil samples from Yunnan and Guizhou provinces and a marine water sample from Liaoning province, PR China. Phylogenetic analyses based on the sequences of the D1/D2 domains of the large subunit(LSU) rRNA gene and the internal transcribed spacer (ITS) region indicate that these three strains, together with 12 additional strains isolated from various substrates collected in different regions or countries of the world, represent a novel species of the genus Pichia, for which the name Pichia kurtzmaniana sp. nov. (holotype: strain CGMCC 2.7213) is proposed. The novel species differs from its close relatives Candida californica by eight (1.5 %) and 26 (11.1 %) mismatches in the D1/D2 domains and the ITS region, respectively; and from Pichia chibodasensis by 11 (2.1 %) and 20 (8.7 %) mismatches in the D1/D2 domains and the ITS region, respectively. In addition, eight Candida species which belong to the Pichia clade are transferred to the genus Pichia, resulting in the proposal of the following new combinations: Pichia cabralensis comb. nov., Pichia californica comb. nov., Pichia ethanolica comb. nov., Pichia inconspicua comb. nov., Pichia phayaonensis comb. nov., Pichia pseudolambica comb. nov., Pichia rugopelliculosa comb. nov., and Pichia thaimueangensis comb. nov.

Drop it all: extraction-free detection of targeted marine species through optimized direct droplet digital PCR.

Molecular biomonitoring programs increasingly use environmental DNA (eDNA) for detecting targeted species such as marine non-indigenous species (NIS) or endangered species. However, the current molecular detection workflow is cumbersome and time-demanding, and thereby can hinder management efforts and restrict the "opportunity window" for rapid management responses. Here, we describe a direct droplet digital PCR (direct-ddPCR) approach to detect species-specific free-floating extra-cellular eDNA (free-eDNA) signals, i.e., detection of species-specific eDNA without the need for filtration or DNA extraction, with seawater samples. This first proof-of-concept aquarium study was conducted with three distinct marine species: the Mediterranean fanworm Sabella spallanzanii, the ascidian clubbed tunicate Styela clava, and the brown bryozoan Bugula neritina to evaluate the detectability of free-eDNA in seawater. The detectability of targeted free-eDNA was assessed by directly analysing aquarium marine water samples using an optimized species-specific ddPCR assay. The results demonstrated the consistent detection of S. spallanzanii and B. neritina free-eDNA when these organisms were present in high abundance. Once organisms were removed, the free-eDNA signal exponentially declined, noting that free-eDNA persisted between 24-72 h. Results indicate that organism biomass, specimen characteristics (e.g., stress and viability), and species-specific biological differences may influence free-eDNA detectability. This study represents the first step in assessing the feasibility of direct-ddPCR technology for the detection of marine species. Our results provide information that could aid in the development of new technology, such as a field development of ddPCR systems, which could allow for automated continuous monitoring of targeted marine species, enabling point-of-need detection and rapid management responses.

Development of Biological Coating from Novel Halophilic Exopolysaccharide Exerting Shelf-Life-Prolonging and Biocontrol Actions for Post-Harvest Applications.

The literature presents the preserving effect of biological coatings developed from various microbial sources. However, the presented work exhibits its uniqueness in the utilization of halophilic exopolysaccharides as food coating material. Moreover, such extremophilic exopolysaccharides are more stable and economical production is possible. Consequently, the aim of the presented research was to develop a coating material from marine exopolysaccharide (EPS). The significant EPS producers having antagonistic attributes against selected phytopathogens were screened from different marine water and soil samples. TSIS01 isolate revealed the maximum antagonism well and EPS production was selected further and characterized as Bacillus tequilensis MS01 by 16S rRNA analysis. EPS production was optimized and deproteinized EPS was assessed for biophysical properties. High performance thin layer chromatography (HPTLC) analysis revealed that EPS was a heteropolymer of glucose, galactose, mannose, and glucuronic acid. Fourier transform infrared spectroscopy, X-ray diffraction, and UV-visible spectra validated the presence of determined sugars. It showed high stability at a wide range of temperatures, pH and incubation time, ≈1.63 × 106 Da molecular weight, intermediate solubility index (48.2 ± 3.12%), low water holding capacity (12.4 ± 1.93%), and pseudoplastic rheologic shear-thinning comparable to xanthan gum. It revealed antimicrobial potential against human pathogens and antioxidants as well as anti-inflammatory potential. The biocontrol assay of EPS against phytopathogens revealed the highest activity against Alternaria solani. The EPS-coated and control tomato fruits were treated with A. solani suspension to check the % disease incidence, which revealed a significant (p < 0.001) decline compared to uncoated controls. Moreover, it revealed shelf-life prolonging action on tomatoes comparable to xanthan gum and higher than chitosan. Consequently, the presented marine EPS was elucidated as a potent coating material to mitigate post-harvest losses.

Isolation and characterization of Candida tropicalis B: a promising yeast strain for biodegradation of petroleum oil in marine environments

The increasing interest in environmental protection laws has compelled companies to regulate the disposal of waste organic materials. Despite efforts to explore alternative energy sources, the world remains heavily dependent on crude petroleum oil and its derivatives. The expansion of the petroleum industry has significant implications for human and environmental well-being. Bioremediation, employing living microorganisms, presents a promising approach to mitigate the harmful effects of organic hydrocarbons derived from petroleum. This study aimed to isolate and purify local yeast strains from oil-contaminated marine water samples capable of aerobically degrading crude petroleum oils and utilizing them as sole carbon and energy sources. One yeast strain (isolate B) identified as Candida tropicalis demonstrated high potential for biodegrading petroleum oil in seawater. Physiological characterization revealed the strain’s ability to thrive across a wide pH range (4–11) with optimal growth at pH 4, as well as tolerate salt concentrations ranging from 1 to 12%. The presence of glucose and yeast extract in the growth medium significantly enhanced the strain's biomass formation and biodegradation capacity. Scanning electron microscopy indicated that the yeast cell diameter varied based on the medium composition, further emphasizing the importance of organic nitrogenous sources for initial growth. Furthermore, the yeast strain exhibited remarkable capabilities in degrading various aliphatic and aromatic hydrocarbons, with a notable preference for naphthalene and phenol at 500 and 1000 mg/l, naphthalene removal reached 97.4% and 98.6%, and phenol removal reached 79.48% and 52.79%, respectively. Optimization experiments using multi-factorial sequential designs highlighted the influential role of oil concentration on the bioremediation efficiency of Candida tropicalis strain B. Moreover, immobilized yeast cells on thin wood chips demonstrated enhanced crude oil degradation compared to thick wood chips, likely due to increased surface area for cell attachment. These findings contribute to our understanding of the potential of Candida tropicalis for petroleum oil bioremediation in marine environments, paving the way for sustainable approaches to address oil pollution.

Isolation and characterization of polyhydroxyalkanoate producing halotolerant Bacillus subtilis SG1 using marine water samples collected from Calicut coast, Kerala

Isolation and characterization of polyhydroxyalkanoate producing halotolerant Bacillus subtilis SG1 using marine water samples collected from Calicut coast, Kerala

A Near-Real-Time Achromopeptidase-Based Enzyme Assay for Biomonitoring of Zinc Pollution in Kuah's Jetty in Langkawi

Enzyme-based assay in near-real-time biomonitoring provides high sensitivity to bioavailable contaminants, leading to quick results that support prompt action. It is essential to use this method to reduce pollution in drinking, agriculture and marine waters and protect the health of both humans and animals. This work applies a previously discovered enzyme test in biomonitoring to identify contaminants, particularly zinc, in marine water samples from the Langkawi Island, an island that harbors the UNESCO's Geoforest Park status. We used the achromopeptidase dye binding assay, specifically designed for detecting mercury zinc at levels below one part per million, to identify trace amounts of these metal successfully. The test demonstrated a sensitive, quick, and cost-efficient monitoring method with little inhibition (&lt;10%) during a 6-hour field trial for three consecutive days, suggesting low pollution levels and confirmed by instrumental analysis. This method allows for the prompt identification of environmental pollutants, which helps take appropriate actions and safeguard ecotourism locations by offering data-driven information for policy development. Enzyme tests are simple and visually appealing, making them effective instructional tools that help raise environmental awareness and support conservation initiatives. Our research highlights the need to use enzyme tests for broad environmental evaluation, harmonizing local monitoring methods with global standards, and promoting international cooperation in environmental conservation. This work enhances our comprehension of ecological well-being in marine and brackish waterways and underscores the significance of ongoing monitoring to protect natural environments.

Isolation and Identification of Culturable Bacteria from South China Seawater and Preliminary Screening of Marine Biocontrol Bacteria.

Marine microorganisms have evolved special metabolic pathways to produce numerous bioactive substances with novel structures and unique functions. This study analyzed the diversity of culturable bacteria in marine water samples from the South China Sea and screened the isolated bacteria with pathogenic fungi. A total of 200 culturable strains of 72 different bacteria were obtained from 56 water samples from the South China Sea. They belonged to three phyla and four classes, namely Gammaproteobacteria, Alphaproteobacteria, Bacilli and Actinomycetia. Bacilli was the dominant class, comprising up to 59.72%, followed by Gammaproteobacteria (20.83%). Bacillus, Pseudomonas, Paenibacillus and Rhizobium were the most dominant genera. Among these strains, HY-88 and HY-91 encoding BamC, FenB and PKSI genes were selected and identified as Bacillus subtilis. The respective inhibition rates of the HY-88 caused by plate confrontation against Magnaporthe grisea, Fusarium oxysporum, Botrytis cinerea, anthrax and Botrytis cinerea were 90.91%, 54.29%, 52.17% and 51.72%, in comparison with HY-91 86.36%, 48.57%, 47.83% and 34.48%. In addition, the supernatant of HY-88 showed a lesion inhibition rate of 74.5%, which was significantly higher than HY-91 (60.55%). In addition, HY-88 and HY-91 showed strong antifungal activity to Colletotrichum viniferum on detached Shine Muscat grapes. Tolerance tests showed that the HY-88 and HY-91 grew at 10-40 °C, 7-10% NaCl and pH 3-11. HY-88 and HY-91 could inhibit various fungal plant diseases, which lays a foundation for the development of new biopesticides.

Detecting small microplastics down to 1.3 μm using large area ATR-FTIR

Large area attenuated total reflectance-Fourier transform infrared spectroscopy (LAATR-FTIR) is introduced as a novel technique for detecting small microplastics (MPs) down to 1.3 μm. Two different LAATR units, one with a zinc selenide (ZnSe) and one with a germanium (Ge) crystal, were used to detect reference MPs < 20 μm, and MPs in marine water samples, and compared with μ-FTIR in transmission mode. The LAATR units performed well in identifying small MPs down to 1.3 μm. However, they were poorly suited for large MPs as uneven particle thickness resulted in uneven contact between crystal and particle, misinterpreting large MPs as many small MPs. However, for more homogeneous matrices, the technique was promising. Further assessment indicated that there was little difference in spectra quality between transmission mode and LAATR mode. All in all, while LAATR units struggle to substitute transmission mode, it provides additional information and valuable information on small MPs.

Vishniacozyma pseudocarnescens sp. nov., a new anamorphic tremellomycetous yeast species.

Three strains belonging to the basidiomycetous yeast genus Vishniacozyma were isolated from marine water samples collected from intertidal zones in Liaoning province, northeast China. Phylogenetic analyses based on the sequences of the small subunit (SSU) ribosomal DNA (rDNA), the D1/D2 domain of the large subunit (LSU) ribosomal DNA (rDNA), the internal transcribed spacer region (ITS), the two subunits of DNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1), and the mitochondrial gene cytochrome b (CYTB) showed that these strains together with 20 strains from various geographic and ecological origins from other regions of the world represent a novel species in the genus Vishniacozyma. We propose the name Vishniacozyma pseudocarnescens sp. nov. (holotype CGMCC 2.6457) for the new species, which differs phenotypically from its close relatives V. carnescens, V. tephrensis, and V. victoriae by its ability to grow at 30 °C and on 50 % (w/v) glucose-yeast extract agar.

Tracing the footprints of SARS-CoV-2 in oceanic waters

The detection of SARS-CoV-2 in water environments has predominantly focused on wastewater, neglecting its presence in oceanic waters. This study aimed to fill this knowledge gap by investigating the occurrence of SARS-CoV-2 in remote sea and oceanic waters, at large distances from the coastline. Forty-three 500-liter samples were collected between May 2022 and January 2023 from the Atlantic Ocean, the Mediterranean Sea, the Arctic region, the Persian Gulf and the Red Sea. Using molecular detection methods including real-time RT-qPCR and nested PCR followed by sequencing, we successfully detected SARS-CoV-2 RNA in 7 of the 43 marine water samples (16.3 %), and specifically in samples taken from the Atlantic Ocean and the Mediterranean Sea. The estimated concentrations of SARS-CoV-2 genome copies in the positive samples ranged from 6 to 470 per 100 l. The presence of mutations characteristic of the Omicron variant was identified in these samples by amplicon sequencing. These findings provide evidence of the unforeseen presence of SARS-CoV-2 in marine waters even at distances of miles from the coastline and in open ocean waters. It is important to consider that these findings only display the occurrence of SARS-CoV-2 RNA, and further investigations are required to assess if infectious virus can be present in the marine environment.

Determination of Bisphenol A (BPA) in the Port of Gdynia Waters Using Gas Chromatography Coupled with Mass Spectrometry (GC-MS)

This paper presents a procedure for the determination of bisphenol A (BPA) in seawater. Gas chromatography coupled with mass spectrometry (GC-MS) was used as the analytical method, preceded by analyte isolation via solid-phase extraction (SPE). Initially, the best conditions for extraction, derivatization, and GC-MS analysis were established. The need for derivatization in the determination of BPA was investigated, and for this reason, two methods of sample preparation were compared: with and without the derivatization step. The parameters of the two methods of sample preparation were compared with each other, and a more efficient method was chosen for the analysis of marine water samples. Afterwards, the validation process was carried out and the following parameters were determined: limit of detection (LOD), limit of quantification (LOQ), linearity, precision, reproducibility, and repeatability. Finally, the results of the determination of bisphenol A in water samples collected from five harbor basins of the Port of Gdynia using an unmanned mobile research unit, HydroDron-1, were presented. The identified concentrations ranged from 0.01 µg/L to 0.03 µg/L, depending on the investigated area.

Characterization of Anammox Bacteria from Marine Water and Sediment Samples

Anammox activity of water and sediment taken from marine ecosistem around Semarang were investigated in anammox media agar and batch reactor. Effect of increasing salinities (3% to 5%, 7% and 9%) and decreasing salinities (3% to 2%, 1% and 0%) were investigated. Water and sediment taken from marine ecosistem around Semarang city showed a positive result. Increasing salinity up to 9% will have a positive influence on the activity of anammox bacteria. Whereas, the decrease in salinity will negatively affect anammox bacteria. The ratio of ammonium:nitrite for anammox process ranges from 0.89 to 1.22 and ammonium removal rate varies from 0.08 to 0.59 mg-N/liter hour.