Diversity In Water Research Articles

Physicochemical parameters and plankton diversity in water from selected ponds within Makurdi Metropolis

Physicochemical parameters and plankton diversity in water from five (5) selected ponds was investigated. In the investigation, some physicochemical parameters of water, the composition and abundance of plankton were determined. Some of the parameters include temperature, electrical conductivity, pH, dissolved oxygen, nitrates and phosphate. The samples were collected and transported to the laboratory of the Department of Fisheries and Aquaculture, Joseph Sarwuan Tarka University Makurdi for analysis. The preserved plankton samples were observed using a digital Celestron compound microscope and digital Celestron cosmos dissecting microscope. A combination of keys and guides provided were used for identification of the plankton species. A total of 13 different plankton species, with a total abundance of 308 were observed. The most abundant species was Chlorella vulgaris with an abundance of 85 and was observed in all three pond types. This was followed by Scenedesmus acutus (45) which was observed only in the concrete and liner ponds. Paramecium was next and was observed only in the earthen and concrete ponds. The rest of the plankton species were observed in only one pond type. The physicochemical parameters for the selected earthen, concrete and liner ponds were also selected. The pH and dissolved oxygen were observed to be higher in the concrete pond and lowering the liner pond. The electrical conductivity and total dissolved solid were however lower in the concrete pond and higher in the earthen pond, both the temperature and turbidity were higher in the liner pond and lower in the earthen pond. The phosphate concentration was also higher in the linear pond and lower in the earthen pond, while the concentration of Nitrite was equal in both earthen and concrete pond with no amount observed in the liner pond.

PROFIL STRUKTUR KOMUNITAS LAMUN DI PERAIRAN PANTAI KELAPA INDAH DESA MAHU KECAMATAN SAPARUA TIMUR SEBAGAI SUMBER PEMBELAJARAN BIOLOGI

Background: Seagrass is a higher plant (Anthophyta) that lives and grows immersed in the marine environment; have vessels, have rhizomes, have roots, and reproduce generatively (seeds) and vegetatively. Seagrass is one of the natural resource ecosystem plants that lives in shallow waters and has many benefits for biota associated with the surrounding environment. Several studies related to seagrass ecosystems have been carried out in Maluku waters, but there are no records regarding the structural profile of seagrass communities on Saparua Island. Methods: This research is descriptive research. Descriptive research is used to reveal information about hydrological conditions, species composition, species diversity. This research was conducted in the waters of Kelapa Indah Beach, Mahu Village, Saparua District Results: The conditions of environmental physical and chemical factors with a temperature of 280C, salinity 31 ‰, pH 7.3, and Dissolved Oxygen 6 mg/L in the waters of Mahu village are sufficient to support the growth and spread of seagrass. Composition of the types of seagrass found in the coastal waters of Mahu village are 5 types and Conclusion: The level of seagrass diversity in Mahu village waters is classified as moderate.

Odonate diversity reflected by wetland quality in Gujarat, India

Odonate diversity reflected by wetland quality was carried out on three riverine wetlands (Fazalpur, Sankarda and Sindhrot) of Vadodara district in Central Gujarat during 2014-15. The value of Dissolve Oxygen (DO) and Biological Oxygen Demand (BOD) was highest and the values of Electrical Conductivity (EC), Chemical Oxygen Demand (COD) as well as total solids in the water were lowest at Fazalpur as compared to other sites. Sankarda Point was slightly more polluted than Fazalpur with a marshy habitat structure which is ideal habitat for Odonates. Odonates diversity was evaluated during September and October at eleven wetland sites around Anand and correlated with water quality parameters. Maximum species richness and species diversity index were recorded at Pariej tank which was the least polluted point. Minimum species richness was observed at Navagam Canal 2 (8 Species) and Canal 1 (10 species) all having huge loads of industrial effluents. The correlation coefficient between the water quality parameter and diversity index (Hʹ) showed that pH had a significant moderate positive correlation (P < 5.0, df. 9) and BOD3 had a significantly higher positive correlation (P < 1.0, df. 9). EC, Total Suspended Solids (TSS) and Total Solids (TS) had negative correlation with Odonate diversity. COD and Total Dissolved Solids (TDS) exhibited weak negative correlation with Odonate diversity.

Comparative study on physico-chemical parameters of water, zooplankton and macrophytes diversity under the exposure of farm-made prebiotics in a semi- intensive aqua-farming system

The present study intended to investigate the variation of the physico-chemical status, zooplankton and macrophytes diversity of three semi-intensive ponds (each having 0.40 acre of water area) under Khano village of Galsi-II Block of Purba Bardhaman district, West Bengal, India. One was marked with control (C: fed only with locally available fish feed) and two others ponds (P1 and P2: fed with farm-made prebiotics plus locally available fish feed) were considered as treatment. The ‘farm-made prebiotics’ (made of fish-meal, ground-nut oil cake, bar-yeast, jaggery: fermented) was applied directly into the pond water fortnightly at the rate of 15 kg per acre fortnightly up to three months. The ponds were reared with Catla (Catla catla): Rahu (Labeo rohita): mrigal (Cirrhinus mrigala) at the ratio of 3:4:3. The water samples were drawn on day15, day30, day45, day60, day75 and day 90 at six corners of each pond. The average value was considered while computing the results of physico-chemical parameters, viz., transparency, temperature, pH, electrical conductivity (EC), carbon dioxide (CO2), dissolved oxygen (DO), total hardness (TH), total alkalinity (TA), phosphate (PO43-), chloride (Cl-), ammoniacal-nitrogen (NH4+-N), nitrate-nitrogen (NO3--N), sodium (Na+) and potassium (K+ ). The variations in the diversity of zooplankton and macrophytes in the study area were also measured. A marked difference in the case of physico-chemical parameters as well as the zooplankton and macrophytes diversity were observed under prebiotic exposure which may finally help in better growth of the fish species under prebiotic exposure. Finally, the fish farmers will be highly benefited from the application of such farm-made prebiotics.

A metagenomic comparison of clearwater, probiotic, and Rapid BFTTM on Pacific whiteleg shrimp, Litopenaeus vannamei cultures.

Biofloc technology improves water quality and promote the growth of beneficial bacteria community in shrimp culture. However, little is known about the bacteria community structure in both water and gut of cultured organisms. To address this, the current study characterised the metagenomes derived from water and shrimp intestine samples of novel Rapid BFTTM with probiotic and clearwater treatments using 16S V4 region and full length 16S sequencing. Bacteria diversity of water and intestine samples of Rapid BFTTM and probiotic treatments were similar. Based on the 16S V4 region, water samples of >20 μm biofloc had the highest abundance of amplicon sequence variant (ASV). However, based on full length 16S, no clear distinction in microbial diversity was observed between water samples and intestine samples. Proteobacteria was the most abundant taxon in all samples based on both 16S V4 and full length 16S sequences. Vibrio was among the highest genus based on 16S V4 region but only full length 16S was able to discern up to species level, with three Vibrios identified-V. harveyi, V. parahaemolyticus and V. vulnificus. Vibrio harveyi being the most abundant species in all treatments. Among water samples, biofloc water samples had the lowest abundance of all three Vibrios, with V. vulnificus was present only in bioflocs of <20 μm. Predicted functional profiles of treatments support the beneficial impacts of probiotic and biofloc inclusion into shrimp culture system. This study highlights the potential displacement of opportunistic pathogens by the usage of biofloc technology (Rapid BFTTM) in shrimp culture.

Oligotrophic waters of the Northwest Atlantic support taxonomically diverse diatom communities that are distinct from coastal waters.

Diatoms are important components of the marine food web and one of the most species-rich groups of phytoplankton. The diversity and composition of diatoms in eutrophic nearshore habitats have been well documented due to the outsized influence of diatoms on coastal ecosystem functioning. In contrast, patterns of both diatom diversity and community composition in offshore oligotrophic regions where diatom biomass is low have been poorly resolved. To compare the diatom diversity and community composition in oligotrophic and eutrophic waters, diatom communities were sampled along a 1,250 km transect from the oligotrophic Sargasso Sea to the coastal waters of the northeast US shelf. Diatom community composition was determined by amplifying and sequencing the 18S rDNA V4 region. Of the 301 amplicon sequence variants (ASVs) identified along the transect, the majority (70%) were sampled exclusively from oligotrophic waters of the Gulf Stream and Sargasso Sea and included the genera Bacteriastrum, Haslea, Hemiaulus, Pseudo-nitzschia, and Nitzschia. Diatom ASV richness did not vary along the transect, indicating that the oligotrophic Sargasso Sea and Gulf Stream are occupied by a diverse diatom community. Although ASV richness was similar between oligotrophic and coastal waters, diatom community composition in these regions differed significantly and was correlated with temperature and phosphate, two environmental variables known to influence diatom metabolism and geographic distribution. In sum, oligotrophic waters of the western North Atlantic harbor diverse diatom assemblages that are distinct from coastal regions, and these open ocean diatoms warrant additional study, as they may play critical roles in oligotrophic ecosystems.

Diatom Assemblages from the Daginsky Mud Volcano Sediments (Eastern Sakhalin) and Their Implication

Diatom assemblages in mud volcanoes are quite rare and are poorly studied. The finding of a rich diatom flora in the sediments of the Daginsky Mud Volcano (DMV), located in the tidal zone of the Nyisky Bay of the Sea of Okhotsk, is of interest to study the conditions for the formation of host sediments in the zone of influence of various extreme factors, such as outflows of gases and water–mud mass, thermal springs, and tides. For this purpose, the taxonomical composition of diatom assemblages and concentration of diatoms in DMV sediments were studied. A comparison was made with the diatoms of geothermal springs of the Russian Far East associated with volcanic activity, and the stratigraphic occurrence of the found extinct diatoms was analyzed, which is important for determining their source and the age of the mud volcano roots. Diatom assemblages from DMV sediments are mainly characterized by the predominance of Metascolioneis tumida, Paralia sulcata, Odontella aurita, Pinnunavis yarrensis, Petroneis marina, Cocconeis scutellum, and Navicula digitoradiata. They consist of diatoms of different biotopes and extinct species. The diversity and abundance of brackish water and marine species indicates the predominant influence of sea waters on the formation of DMV sediments. The diverse freshwater species were mainly introduced into sediments with river runoff, but it is likely that some of these, such as the cosmopolitan alkaliphilic species, are inhabitants of geothermal springs. The presence of extinct species from the underlying Neogene sediments from where they were carried with gas–water–mud masses is the most typical for diatom assemblages of the DMV.

Bacterial diversity in water from Xifeng Hot Spring in China.

The Xifeng Hot Spring is one of the eight largest hot springs in China, which is rich in radon gas and sulphur in karst scenery. Little is known about the microbiota structure in the spring. The water was collected from three sites containing the outlet of spring water discharge site (OWD), spring pool for tourist (SPT) and sewage effluent pool (SEP) in the Xifeng Hot Spring and further analyzed by culture-independent technique and culture-dependent method. A total of 57 phyla were identified from the water samples. The dominate phyla at OWD was Bacteroidetes (46.93%), while it was Proteobacteria in both sites of SEP and SPT with relative richness of 61.9% and 94.9%, respectively. Two bacteria, Deinococcus and Hymenobacter, that confirmed to be radiation-resistant, seven sulphur bacteria and three thermophilic bacteria were detected fromXifeng Hot Spring. Furthermore, it was found that genus Flavobacterium was susceptible to environmental change with abundance of 11 ~ 2825 times higher in OWD than the other two groups. Compared bacteria from the OWD group with that from 14 hot springs in six countries, total 94 unique genera bacteria were found out from the Xifeng Hot Spring including four thiometabolism-related bacteria (Propionispira, Desulforegula, Desulfobacter and Desulfococcus) and the thermophilic bacterium (Symbiobacterium). Using microbial culturing and isolation technology, sixteen strains were isolated from the water samples of three sites. The diversity of microbiota was abundant and variable along with the niche changed in conditions and surroundings. It indicated that numbers of valuable bacteria resources could be explored from the special surroundings of Xifeng Hot Spring.

Diversity and assembly of planktonic protist communities in the Jeju Strait, Korea

This study examined planktonic protists—microbial eukaryotes with cell sizes between 2 and 200 µm—to understand their diversity, assembly processes, and co-existence patterns in surface waters of the Jeju Strait (JS), Korea. Using small organelle-enriched metagenomics, the study identified 252 operational taxonomic units (OTUs) across three distinct oceanographic regions of the JS during multiple seasons. Interestingly, there were no significant variations in the diversity or phylogenetic structures of these planktonic protist communities (PPCs), indicating a uniform distribution of PPCs across the strait. However, a higher clustering of their phylogenetic structure was observed in November, implying that seasonal environmental factors influenced their assembly. The study also discovered that seasonal shifts had a major impact on the composition of these communities. For example, Myzozoa was more prevalent in March, while Ochrophyta dominated in November. Protist size also varied seasonally, with larger protists increasing from June to November and then decreasing by March. Neutral community model analysis provided insights into the role of stochastic processes in shaping community assembly. The majority of OTUs fell into the neutral category, while a smaller proportion displayed non-neutral patterns. For instance, certain species like Pseudo-nitzschia and Chaetoceros were frequently found but had lower abundance, while other species like Alexandrium and Protoceratium were less frequent but more abundant. The feeding patterns, or trophic modes, of these protists also showed variations. Additionally, the study unveiled a complex network of species interactions within the strait, including positive mutualistic relationships and negative competitive interactions. The intricate interaction network consisted of 61 distinct modules, suggesting the presence of specialized subgroups within the PPCs that fulfill unique ecological roles. These subgroups contribute significantly to the overall stability and resilience of the ecosystem.

Short-term effect of reclaimed wastewater quality gradient on soil microbiome during irrigation

To investigate the effect of wastewater (WW) treatment on soil bacterial communities, water of different quality was used to irrigate eight lettuces per tank: raw municipal wastewater (RWW), WW treated with an aerated constructed wetland (CWW) and WW treated with a membrane bioreactor (MBW), and tap water (TW). The physicochemical and microbiological characteristics (quality indicators) of these water types were characterized, and the water and soil bacterial communities were monitored by quantitative PCR (qPCR) and 16S rRNA gene sequencing. Despite marked differences in microbial load and diversity of waters, soil communities remained remarkably stable after irrigation. Microbial biomass was increased only in soils irrigated with RWW. At the end of the irrigation period (day 84), soil and water shared a large fraction of their bacterial communities, from 43 % to 70 %, depending on the water quality, indicating a transfer of bacterial communities from water to soil. Overall, the relative abundance of Proteobacteria and Acidobacteria was increased and that of Actinobacteria was decreased in soils irrigated with MBW, CWW and even more with RWW. Multivariate ordination clearly separated soils in three groups: soils irrigated with the cleanest water (TW), with treated WW (MBW and CWW), and with untreated WW (RWW). Nitrifying, denitrifying, and nitrogen-fixing bacteria were quantified by qPCR targeting amoA, narG, and nifH, respectively. Nitrifying bacteria were the most affected by the water quality, as indicated by amoA copy number increase in RWW-irrigated soil and decrease in CWW-irrigated soil. Overall, the abundance of all three genes was positively influenced by RWW treatment. In conclusion, the 84 days of irrigation influenced the soil microbial communities, and the impact depended on the quality of the used water.

Microplastic abundance, distribution, and diversity in water and sediments along a subtropical river system.

Microplastic pollution in aquatic environments has been a ubiquitous concern in recent years, owing to their rapid production combined with poor waste management practices. However, information on freshwater microplastics in the Global South is still scarce, despite growing research on freshwater microplastics in recent years, particularly within the Global North. To help address this knowledge gap, we studied water and sediment microplastic dynamics along a subtropical river system, i.e. Crocodile River around the Nelspruit City area (South Africa), across three different seasons (i.e. cool-dry, hot-dry, hot-wet) using a combination of diversity indices and multivariate analyses. Microplastics were more abundant during the cool-dry season in the surface water samples (mean 1058 particles m-3) and high during the hot-dry season (mean 568 particles kg-1 dwt) in the sediment samples. The hot-wet season had a low particle density in both surface water (mean 625 particles m-3) and sediments (mean 86 particles kg-1 dwt) samples. Microplastic shapes were dominated by fibres and fragments, with the colour scheme dominated by transparent, blue, and black. The abundance of microplastics was positively correlated with pH and resistivity, and negatively with river flow. Wastewater was attributed as a primary source of microplastics, particularly because of the observed dominant fibre microplastics, usually released during laundry. Our results suggest that Crocodile River and its tributaries are temporary sinks of microplastics during periods of low rainfall. Implications of this pollution are far-reaching, including effects on residents who are dependent on the Crocodile River as a source of drinking water and aquatic biota which may be exposed to these pollutants.

Two new species of Cymbasoma (Multicrustacea: Copepoda: Monstrilloida: Monstrillidae) from the North Atlantic

ABSTRACT Monstrilloid copepods are protelean endoparasites of benthic invertebrates. Their adult free-living stage is chiefly found in the plankton of shallow coastal systems, estuaries and coral reefs; there are no previous records of monstrilloids from deeper marine habitats including epipelagic or mesopelagic waters. Two new species of the monstrilloid copepod genus Cymbasoma Thompson, 1888 are described based on adult females incidentally captured by an epibenthic sledge operated at a depth range of 118–302 m off north-west Iceland and the Norway Channel. Cymbasoma norvegicum sp. nov. is distinguished by a combination of characters including a long, constricted anal somite, bilobed fifth legs with long inner lobe, antennules with fused segments, and first antennule segment unarmed. Cymbasoma pedroi sp. nov. has a pair of rounded posterolateral protuberances on the genital somite, fused fifth legs lobes, and an anteriorly produced, ornamented forehead. Both species are considered new members of the Cymbasoma rigidum species group, widely distributed in different geographic areas but not previously known from epi-mesopelagic depths. The finding of these new species represents the first discovery of monstrilloids at epi-mesopelagic depths in the Pacific Ocean and it significantly adds to our knowledge of this copepod order, thus highlighting their potentially high yet unstudied diversity in deeper waters. http://www.zoobank.org/urn:lsid:zoobank.org:pub:C05EEC28-9936-41CB-BC9E-D990AE53B3B1

Mutual Effects of Temperature and Microorganisms on the Chemical Characteristics of Coal Mine Drainage

Coal mining activities produce coal mine drainage which becomes a potential pollutant of regional groundwater. The temperature and microbial community in aquifers and rock formations change with coal mining depth increases. While the influence mechanisms of temperature and microorganisms on the hydrochemical characteristics of mine water are poorly understood. This study investigated a typical minefield in north China and performed the water–rock (coal) incubation experiments to explore the effect of temperature and microorganisms on the chemical characteristics of mine water. Hydrochemistry type of coal mine water in the goafs and main water-filled aquifers of Xinjulong coal mine was the SO4–Na type. Proteobacteria and Firmicutes were the main bacterial phyla in the coal mine water. The increasing closure time of goafs decreased SO4 2− concentration and increased the microbial diversity in mine water. The 28-day incubation experiments found Na+ and SO4 2− slightly increased by 5.13 and 6.67%, respectively, and HCO3 − decreased by 14.33% when the temperature rose by 10 °C. The Shannon index of the bacterial community in water–coal system increased by 6.7% and the relative abundance of Hydrogenophaga decreased by 22.7%, while that of Thiobacillus increased by 31.56%. The microbial activities decreased Na+ and SO4 2− by 2.31 and 4.95%, respectively, but increased HCO3 − by 7.59%. The functional prediction showed the microorganisms undergone sulfur conversion reactions and affected the dissolution of ions in mine water. The results were crucial for understanding the mutual effects of temperature and microorganisms on the hydrochemical characteristics of coal mine water.

Bacterial community structure of water, sediment and microplastics in Poyang Lake wetland.

As a new type of pollutant, microplastics accumulate continuously in the environment. The environmental problems caused by microplastics have attracted wide attention. In this study, we collected water, sediment and four types of microplastics (film, foam, fiber and fragment) from wetland in East Lake area of Poyang Lake. We used high-throughput sequencing technology to analyze the bacterial diversity and community structure of water, sediment, and microplastics surface. The results showed that the bacterial richness and diversity of water and sediment were significantly higher than that on microplastics, and the bacterial richness of foaming microplastics was significantly lower than that of the other three types of microplastics. There were significant differences of bacterial communities between water, sediment, and microplastics. There were significant differences cross different types of microplastics. Proteobacteria, Bacteroidetes, and Actinobacteria were the main bacterial communities of water, sediment, and microplastics. The relative abundance of Bacteroidetes and Actinobacteria in water was higher than that in sediments and microplastics, while the relative abundance of Bacteroidetes and Actinobacteria in foaming microplastics was higher than that in other three types. At the genus level, the dominant ones included Massilia, Flavobacteria, and Pseudomonas. The relative abundance of Massilia and Pseudomonas in water and sediments was lower than that on microplastics, and the relative abundance of Flavobacteria was not different among water, sediment and microplastics. The relative abundance of Massilia in microplastics followed an order of fragment>fiber>film>foam, and that of Pseudomonas was film>fiber>foam>fragment. The results of metabolic pathway prediction analysis showed that except for foaming microplastics, the bacterial metabolic pathways on the surface of the other three types of microplastics were significantly different from those in water and sediment. The cellular processes, organismal systems, environmental information processing, and human diseases in bacterial metabolic pathways on microplastics surface were significantly higher than those in water and sediment. Our results suggested that microbial community structure on the surface of microplastics was significantly different from that in water and sediment, and that the morphology type of microplastics affected microbial community structure on the surface.

A Rural-urban Comparison of Living Conditions in Households with and without Disabilities in Uganda

This manuscript is developed from research conducted in 2018–2019 on “Living Conditions among Persons with Disabilities in Uganda.” The paper compares living conditions among households with and without disabilities by rural-urban locations on these indicators: asset possession, dietary diversity, information access, sources and type of water, energy and housing standard and infrastructure. These are believed to be the basic necessities for a family and vital for determining a family’s welfare; however, existing literature suggests that they have not received much research focus. The household is the focus because most of the Uganda government’s poverty reduction interventions target it. This quantitative study sampled 10,710 and 5,333 rural-urban households with and without disabilities, respectively, randomly selected from 12 subregions of Uganda. The study applied the social model of disability, the human rights-based model and the citizenship theory because they are most relevant in this context. The social model helps to identify the social dimension of disability, which demands changes in society that are inclusive of persons with disabilities. The implementation of the principles of the human rights and the citizenship model and theory, respectively, helps to unlock the opportunities of persons with disabilities and their full potential to enable individuals with disabilities to have control over their environment. The study finds that there are glaring gaps between households with and without disabilities by rural-urban locations along the above-mentioned indicators, to the disadvantage of households with disabled members. Therefore, social workers and developers should advocate and lobby stakeholders for social change and interventions that tap the opportunities and full potential of persons with disabilities.

Hydrobiome of Thermal Waters: Potential Use in Dermocosmetics

Over the course of the last 20 years, numerous studies have identified the benefits of thermal waters on different skin conditions. Consequently, several investigations have been carried out on their effects on the skin, which are linked to their chemical composition, and, recently, scientists have turned their attention to the role of the thermal spring’s microbiota, named “hydrobiome”, regarding these therapeutic effects. At the same time, the development of cosmetics based on pre, pro, and postbiotics has reached great relevance and research is increasing every day. This review gathers information on the biological diversity of thermal spring waters and their potential use in obtaining biological compounds, metabolites, or bacterial extracts for use in dermocosmetics as active ingredients. These bioactive compounds are able to improve dermatological diseases such as atopic dermatitis or rosacea and ameliorate pruritus and xerosis; moreover, they can increase protection against UV exposure, strengthen barrier function, maintain good homeostasis of skin defenses, repair damaged skin, promote wound healing, improve skin condition, reduce uneven skin pigmentation, and prevent skin aging. From a future perspective, fruitful cooperation among researchers, hydrologists, thermal spa centers, and cosmetic industries will drive this sector toward a better understanding of the role of the hydrobiome of thermal spring waters on healthy skin and dermatological diseases and consider the inclusion of derivatives of this hydrobiome (in the form of fermenters, lysates, extracts, etc.) in dermocosmetic formulations. Therefore, and being aware of the potential of the hydrobiome in dermatological and skin care applications, the future prospects for the use of bioactive substances derived from it in dermocosmetic formulations are promising.

Physicochemical Characterization and Microbial Diversity of Calcareous Water in Huanglong Ravine, China—A World’s Heritage Site

Physicochemical Characterization and Microbial Diversity of Calcareous Water in Huanglong Ravine, China—A World’s Heritage Site

Effects of antibiotics (enrofloxacin) on microbial community of water and sediment in an aquatic ecological model.

In order to explore the impact of antibiotics (enrofloxacin) on microbial community in aquatic environment, an indoor aquatic ecological model was built, and different concentrations of enrofloxacin (0.05, 0.5, 5, and 50 mg/L) were added in the aquatic ecological model. In addition, the water and sediment samples were collected on the 0, 7, 30, and 60 days, and the changes in microbial community were studied through 16S rDNA high-throughput sequencing. The results showed that when the concentration of enrofloxacin was 50 mg/L, the relative abundance of Actinomycetes was increased. In the water, the bacterial richness and diversity communities first decreased and then gradually recovered with the passage of time; On the 7th day, the diversity and richness index of species in the treatment groups with enrofloxacin at 5 and 50 mg/L decreased to the lowest; On the 30th day, the diversity and richness index of species began to rise; On the 60th day, the diversity index and richness index of water species began to increase, while the diversity index and richness index of sediment species decreased. In conclusion, the addition of enrofloxacin negatively affected the microbial community structure in an indoor aquatic ecological model, 50 mg/L enrofloxacin could increase the relative abundance of Actinomycetes, and decrease the diversity and richness index of water and sediment.

Seasonal and spatial dynamics of phylogenetic structure of fish communities in coastal waters

Understanding community assembly has long attracted the attention of ecologists. There are a lot of studies on how community assembly mechanisms work through phylogenetic analysis. Nevertheless, phylogenetic structures have generally been assumed to be stable over time in most studies, and little attention has been paid to seasonal shifts in phylogenetic structure, which is important to mobile animals. In this study, phylogenetic distance was measured as the mean pairwise distance (MPD) and as mean nearest taxon distance (MNTD). The phylogenetic structures of fish communities in different regions, subregions and at sampling stations were examined using the standardized effect sizes of MPD and MNTD (SES.MPD and SES.MNTD) under null model independent swap over four seasons in the coastal waters of Shandong Province, China. Generalized additive model (GAM) was used to detect which environmental factors have an important impact on phylogenetic structure indices at each sampling station. The fish communities were phylogenetically clustered in most seasons in the whole survey waters, indicating environmental filtering tended to shape the whole fish assemblage. Two phylogenetic indices indicated that the phylogenetic structure (phylogenetic over-dispersion or phylogenetic clustering) was inconsistent on the different regions and subregions. For fish assemblages at each sampling station, the phylogenetic structure of fish communities presented patchy distribution patterns in different seasons. GAM analysis showed that phylogenetic structure responded differently to different environmental factors over four seasons, and the change in phylogenetic structure indices was significantly associated with environmental factors, especially in autumn and winter. SES.MPD can better respond to environmental changes than SES.MNTD. Spatial factors (longitude and latitude) were important factors influencing fish community assembly, indicating that fish communities at offshore stations with low latitude exhibit a relatively high degree of phylogenetic overdispersion. It was difficult to draw consistent conclusions about seasonal changes in phylogenetic structure of fish communities on different temporal and spatial scales. It is possible that seasonal variations and spatial scales in assembly mechanisms contribute to maintaining marine fish diversity in temperate waters, resulting in different phylogenetic structures in fish community.

Analysis of diversity and antibiotic susceptibility profile of bacterial strains isolated from freshwater canal of Lahore, Pakistan

The key objective of current study was to analyse the bacterial diversity of canal water of Lahore, Pakistan. Members of Enterobacteriaceae were targeted that may pose serious health issues to human health. Total 50 bacterial strains were isolated by using Eosin Methylene Blue agar and MacConkey agar. The 16S rRNA gene sequencing of 30 strains confirmed the final taxonomic status of bacterial strains. The results manifested that strains belong to genera of Enterobacter, Escherichia, Klebsiella, Pseudomonas, Acinetobacter, Aeromonas and Vogesella. Antibiotic susceptibility profile of isolates was evaluated against 13 different antibiotics. E. coli SCE-1 showed highest resistant against majority of the antibiotics. Whereas all strains were sensitive to Amikacin (30 µg). Aeromonas hydrophila SD-6 exhibited highest sensitivity against all antibiotics except ampicillin (10 µg) and amoxicillin (25 µg). None of the bacterial strain was completely resistant or susceptible to all antibiotics. Except E. coli all strains were sensitive to Amikacin (30 µg), Gentamycin (30 µg) and Norfloxacin (10 µg). Most of the strains showed intermediate and resistant antibiotic profile towards Nitrofurantoin (300 µg). Latex agglutination test was performed for the screening of E. coli O157 that showed negative results for this serotype. The detection of potential human pathogens like E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and A. hydrphila in canal water indicates that it is not suitable for domestic purposes, recreational activities, and irrigation