Editorial

4 pages, 153 KiB

Open AccessEditorial

Diversity and Dynamics of Microbial Communities in Marine Ecosystems

by Yaodong He, Biswarup Sen and Guangyi Wang

Water 2024, 16(1), 31; https://0-doi-org.brum.beds.ac.uk/10.3390/w16010031 (registering DOI) - 21 Dec 2023

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The ecological and scientific significance of microbial communities in marine ecosystems is underscored by their diverse and dynamic nature [...] Full article

(This article belongs to the Special Issue Diversity and Dynamics of Microbial Communities in Marine Ecosystems)

Research

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12 pages, 2518 KiB

Open AccessArticle

Diversity and Community Composition of Labyrinthulomycetes Protists in the Coastal Zone of Hainan Island, South China Sea

by Jing Song, Xiuping Liu, Ningdong Xie, Jiaqian Li, Xianhua Liu, Biswarup Sen and Guangyi Wang

Water 2023, 15(4), 738; https://0-doi-org.brum.beds.ac.uk/10.3390/w15040738 - 13 Feb 2023

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Abstract

The study of heterotrophic protists in the ocean is still in its early stages, compared to other microorganisms such as bacteria, archaea, and photoautotrophic protists. Labyrinthulomycetes protists (LP) are a type of unicellular protists that are widely distributed in global waters and have [...] Read more.

The study of heterotrophic protists in the ocean is still in its early stages, compared to other microorganisms such as bacteria, archaea, and photoautotrophic protists. Labyrinthulomycetes protists (LP) are a type of unicellular protists that are widely distributed in global waters and have the potential to produce high-value products. In this study, the abundance, diversity, and community structure of LP in the coastal zone of Hainan Island in the South China Sea were investigated through quantitative PCR and high-throughput sequencing. The results showed that LP abundance varied by location and depth, with the highest levels (37.3 × 10³ copies/L) found in the middle layer offshore and the lowest (0.386 × 10³ copies/L) in the bottom layer offshore. The middle layer (chlorophyll maximum layer) had higher LP abundance both inshore and offshore than the surface and bottom layers. Interestingly, the highest LP richness and diversity was found in the inshore bottom. There was a significant difference in LP abundance between the offshore surface and bottom layers. The LP community was dominated by the genus Aplanochytrium, and four different ecotypes were identified. Additionally, the genus Aurantiochytrium had different cooperative and competitive strategies with bacteria in different habitats. This study sheds light on the abundance and community structure of LP in the coastal zone of Hainan Island, explores the potential interactions between LP and bacterial populations, and raises questions about the potential differentiation of LP ecotypes. Full article

(This article belongs to the Special Issue Diversity and Dynamics of Microbial Communities in Marine Ecosystems)

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16 pages, 2558 KiB

Open AccessArticle

Potential Contribution of Coastal Upwelling to Carbon Sink through Interaction between Cyanobacteria and Microbial Eukaryotes

by Xiuping Liu, Ningdong Xie, Jiaqian Li, Mohan Bai, Biswarup Sen and Guangyi Wang

Water 2022, 14(19), 3097; https://0-doi-org.brum.beds.ac.uk/10.3390/w14193097 - 01 Oct 2022

Cited by 1 | Viewed by 1510

Abstract

Upwelling, a common oceanographic event, can make great contributions, directly or indirectly, to deep ocean carbon sequestration. However, the extent of its contribution indirectly depends on the composition of microbial communities and the interactions between bacterioplankton and other microorganisms. This study provides insights [...] Read more.

Upwelling, a common oceanographic event, can make great contributions, directly or indirectly, to deep ocean carbon sequestration. However, the extent of its contribution indirectly depends on the composition of microbial communities and the interactions between bacterioplankton and other microorganisms. This study provides insights into the influence of upwelling on bacterioplankton at the whole community level and predicts their potential functional profiles. The α diversity of the bacterial community exhibited no significant differences between the upwelling area and non-upwelling area, while the community composition varied clearly in different habitats. Proteobacteria, Cyanobacteria, Bacteroidota, Firmicutes, and Actinobacteria were the five dominant phyla in all of the habitats. The proportions of members of Firmicutes were increased whereas Cyanobacteria were reduced in upwelling water. However, the percentage of Cyanobacteria was enhanced in the upwelling deep water. Functional genes that are involved in signal transductions, which belong to environmental information processing, were more active in upwelling surface water than in the other habitats. Closer and more complex relationships between bacterioplankton and microbial eukaryotes were found in the upwelling area, which altered with the variation of the external environmental conditions. Cyanobacteria showed a positive correlation with microbial eukaryotes in upwelling deep water. Combined with the high proportions of Cyanobacteria in upwelling deep water, this might be strong evidence that Cyanobacteria contribute to a deep ocean carbon sink. Overall, our study reveals the impacts of upwelling on the bacterial community composition, metabolic functions, and microbial interactions, which are significant to further understanding the carbon sink effects of upwelling. Full article

(This article belongs to the Special Issue Diversity and Dynamics of Microbial Communities in Marine Ecosystems)

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12 pages, 9480 KiB

Open AccessArticle

The Municipal Sewage Discharge May Impact the Dissemination of Antibiotic-Resistant Escherichia coli in an Urban Coastal Beach

by Jie Su, Jingfeng Fan, Hongxia Ming, Ge Guo, Yunhan Fu, Xiaohui Zhao, Sha Zhao, Quanrui Chen, Daoming Guan, Yuan Jin and Tingting Shi

Water 2022, 14(10), 1639; https://0-doi-org.brum.beds.ac.uk/10.3390/w14101639 - 20 May 2022

Cited by 6 | Viewed by 1700

Abstract

To determine the potential of the recreational marine environment as a dissemination vector of antibiotic-resistant microorganisms, the dissemination of antibiotic-resistant E. coli strains isolated from an urban coastal beach was studied. Sixty-nine and thirteen E. coli strains were isolated from the seawater and [...] Read more.

To determine the potential of the recreational marine environment as a dissemination vector of antibiotic-resistant microorganisms, the dissemination of antibiotic-resistant E. coli strains isolated from an urban coastal beach was studied. Sixty-nine and thirteen E. coli strains were isolated from the seawater and sand, respectively, in Fujiazhuang bathing beach, China. The average Antibacterial Resistance Index (ARI) value detected in the seawater is approximately three times that in beach sand. All the isolates from the sand were grouped into one cluster and only the isolates from the municipal sewage outlet were classified into three antibiogram clusters that were observed in the hetero-sites of the E. coli isolates. The E. coli strains with multiple antibiotic resistance (58% of total) were prevalent in the seawater, whereas the isolates from the sand were not detected with multiple antibiotic resistance. A significant association (p < 0.05) between all phenotypic and relative genotypic resistance profiles was observed in the isolates, except in the quinolones resistance genotype. The presence of a class 1 integron was significantly correlated with the resistance of E. coli to sulfonamides, streptomycin, and levofloxacin (p < 0.01). This study revealed that the municipal sewage discharge may impact the dissemination of antibiotic-resistant strains in the urban coastal beach, and that the class 1 integrons play an important role in mediating the resistance of E. coli to sulfonamide antibiotics. Full article

(This article belongs to the Special Issue Diversity and Dynamics of Microbial Communities in Marine Ecosystems)

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19 pages, 3661 KiB

Open AccessFeature PaperArticle

The Effects of a Typhoon on the Dynamic of Microbial Community Structure and Water Quality of the Marine Bathing Beach

by Hongxia Ming, Yantao Wang, Jie Su, Yunhan Fu, Jianrong Xu, Tingting Shi, Kaijia Ren, Yuan Jin and Jingfeng Fan

Water 2022, 14(10), 1631; https://0-doi-org.brum.beds.ac.uk/10.3390/w14101631 - 19 May 2022

Cited by 1 | Viewed by 1611

Abstract

Dalian Jinshitan beach was chosen to evaluate the impact of a typhoon on the bacterial community structure and water quality of a marine bathing beach. The concentration of enterococci was determined by the cultivation method. The bacterial community structure and abundance were analyzed [...] Read more.

Dalian Jinshitan beach was chosen to evaluate the impact of a typhoon on the bacterial community structure and water quality of a marine bathing beach. The concentration of enterococci was determined by the cultivation method. The bacterial community structure and abundance were analyzed using the 16S rDNA next-generation sequencing and qPCR methods. Results showed that the abundance of cultivable enterococci both in alongshore and offshore seawater increased, while it decreased in dry, wet and submerged sand. The water quality deteriorated immediately after the typhoon, and nearly recovered one month after the typhoon. The typhoon event also decreased the bacterial abundance and changed the bacterial community of the beach. Sphingomonadaceae and Rhodobacteraceae significantly increased in seawater and decreased in dry sand immediately after the typhoon. Human and other fecal taxa increased in water and sand. One month after the typhoon, the diversity and many dominant bacterial taxa nearly recovered in seawater and wet sand. Our work shows that the typhoon changed the bacterial dynamics, deteriorated the water quality and proved the transportation of bacterial taxa and input of fecal pollution between water and beach sand or land. Apart from the impact of the typhoon, the geographical location was another important factor in the changed bacterial community. Full article

(This article belongs to the Special Issue Diversity and Dynamics of Microbial Communities in Marine Ecosystems)

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15 pages, 4250 KiB

Open AccessArticle

Daily Samples Revealing Shift in Phytoplankton Community and Its Environmental Drivers during Summer in Qinhuangdao Coastal Area, China

by Yike He, Zuoyi Chen, Xin Feng, Guangyi Wang, Gang Wang and Jiabo Zhang

Water 2022, 14(10), 1625; https://0-doi-org.brum.beds.ac.uk/10.3390/w14101625 - 18 May 2022

Cited by 5 | Viewed by 1429

Abstract

Rapid urbanization and economic development in coastal regions have significantly increased coastal nutrient pollution and remarkably changed the phytoplankton community and developed some species into bloom, resulting in large economic losses and serious threats to public health. Therefore, it is indispensable to reveal [...] Read more.

Rapid urbanization and economic development in coastal regions have significantly increased coastal nutrient pollution and remarkably changed the phytoplankton community and developed some species into bloom, resulting in large economic losses and serious threats to public health. Therefore, it is indispensable to reveal the shift in the phytoplankton community and phytoplankton abundance, and phytoplankton’s environmental drivers. However, previous studies could not present the details of the environmental drivers of phytoplankton due to samples being collected with low temporal resolution. Here, high-temporal-resolution (daily) samples were collected to investigate the influence of environmental factors on phytoplankton in Qinhuangdao for 44 days. Phytoplankton communities showed a rapid succession, with predominant genera changing in the order Skeletonema–Chaetoceros–Skeletonema–Thalassiosira. Similarly, Thalassiosira pacifica, Skeletonema costatum, Chaetoceros tortissimus, and Chattonella marina were identified as the dominant species and were abundant in 0–1.27 × 10⁷ cells·L⁻¹, 0–9.34 × 10⁶ cells·L⁻¹, 0–6.49 × 10⁶ cells·L⁻¹, and 0–3.64 × 10⁶ cells·L⁻¹, respectively. Moreover, inflows facilitate the rapid succession of the phytoplankton community. Dissolved inorganic phosphorus (DIP) was found to remarkably influence the succession of phytoplankton communities and the bloom of the top three dominant species, i.e., Thalassiosira pacifica, Skeletonema costatum, and Chaetoceros tortissimus. Overall, our results provide high-temporal-resolution observations of phytoplankton community succession and reveal its environmental drivers. This contributes to our current understanding of the occurrence of algae blooms and supports the development of management strategies to control algae bloom in coastal waters. Full article

(This article belongs to the Special Issue Diversity and Dynamics of Microbial Communities in Marine Ecosystems)

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13 pages, 2114 KiB

Open AccessFeature PaperArticle

Riverine Inputs Impact the Diversity and Population Structure of Heterotrophic Fungus-like Protists and Bacterioplankton in the Coastal Waters of the South China Sea

by Suisui Wang, Kalyani Sen, Yaodong He, Mohan Bai and Guangyi Wang

Water 2022, 14(10), 1580; https://0-doi-org.brum.beds.ac.uk/10.3390/w14101580 - 15 May 2022

Cited by 2 | Viewed by 2070

Abstract

Labyrinthulomycetes protists (LP) play an important role in ocean carbon cycling with an ubiquitous presence in marine ecosystems. As one of the most important environmental factors, salinity is known to regulate their diverse metabolic activities. However, impacts of salinity gradient on their distribution [...] Read more.

Labyrinthulomycetes protists (LP) play an important role in ocean carbon cycling with an ubiquitous presence in marine ecosystems. As one of the most important environmental factors, salinity is known to regulate their diverse metabolic activities. However, impacts of salinity gradient on their distribution and ecological functions in natural habitats remain largely unknown. In this study, the dynamics of LP abundance and community structure were examined in the surface water of plume, offshore, and pelagic habitats in the South China Sea (SCS). The highest (5.59 × 10⁵ copies L⁻¹) and lowest (5.28 × 10⁴ copies L⁻¹) abundance of LP were found to occur in the waters of plume and pelagic habitats, respectively. Multiple dimensional scaling (MDS) analysis revealed a strong relationship between salinity and LP community variation (p < 0.05, rho = 0.67). Unexpectedly, relative low LP diversity was detected in the brackish water samples of the plume. Moreover, our results indicated the genus Aplanochytrium dominated LP communities in offshore and pelagic, while Aurantiochytrium and Ulkenia were common in the plume. Physiological and metabolic features of these genera suggested that LP ecological functions were also largely varied along this salinity gradient. Clearly, the salinity gradient likely regulates the diversity and functional partitioning of marine protistan micro-eukaryotes in the world’s oceans. Full article

(This article belongs to the Special Issue Diversity and Dynamics of Microbial Communities in Marine Ecosystems)

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16 pages, 3971 KiB

Open AccessArticle

Characterization of the Bacterial Community in the Ecosystem of Sea Cucumber (Apostichopus japonicus) Culture Ponds: Correlation and Specificity in Multiple Media

by Yeqing Zhou, Jingjing Zhang, Luo Wang, Hanchen Xu, Zhiping Lin, Yanxia Liu, Zhenlin Hao, Jun Ding and Yaqing Chang

Water 2022, 14(9), 1386; https://0-doi-org.brum.beds.ac.uk/10.3390/w14091386 - 25 Apr 2022

Cited by 1 | Viewed by 1560

Abstract

The bacterial community is an essential component of the aquaculture pond ecosystem, which not only improves and restores the aquaculture environment but also maintains a stable ecological equilibrium with the external environment. Here, Illumina 16S rRNA sequencing was conducted to characterize the bacterial [...] Read more.

The bacterial community is an essential component of the aquaculture pond ecosystem, which not only improves and restores the aquaculture environment but also maintains a stable ecological equilibrium with the external environment. Here, Illumina 16S rRNA sequencing was conducted to characterize the bacterial community in the ecosystem of sea cucumber Apostichopus japonicus culture ponds, as well as their correlation with overall community structures. The alpha-diversities of bacterial community among water, sediment, and the gut of A. japonicus were consistent across culture ponds from different areas. Specifically, the richness and diversity of bacterial communities were the highest in sediment, followed by the gut, and the lowest in water. The dominant bacterial community among multiple media was Proteobacteria, which occupies a large proportion of the bacterial community structure, followed by Bacteroidetes and Verrucomicrobia. Highly similar bacterial community structures were present in multiple media among different areas, which provides evidence for deterministic natural evolution. Meanwhile, there was a significant difference (p < 0.05) in the specific bacterial communities across the multiple media. The specific functions of the multiple media in the ecosystem are the main reason for the formation of different bacterial communities. This work demonstrates that bacterial communities are the result of natural evolution within the ecosystem during adaptation to the required environment. Full article

(This article belongs to the Special Issue Diversity and Dynamics of Microbial Communities in Marine Ecosystems)

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