Mangrove Sediments Research Articles

Anthropogenic activities affect the diverse autotrophic communities of coastal sediments

Coastal sediments are a critical domain for carbon sequestration and are profoundly impacted by human activities. Therefore, it is essential to understand the structure and components of benthic autotrophs that play a crucial role in carbon sequestration processes, as well as the influence of anthropogenic activities on their communities. This study utilized an urban estuary, an industrial sea bay, a maricultural sea region, and two mangrove coastlines within the coastal areas of Guangdong Province, China. The micro-benthos in these environments, including prokaryotes and eukaryotes, were identified through high-throughput sequencing of 16S rRNA and 18S rRNA genes. The findings show that the autotrophic composition was altered by the interactions of anthropogenic heavy metals (Cd and Zn) and micro-eukaryotes (protazoa, metazoa, and parasitic organisms). Industrial pollution reduced the abundance of both prokaryotic and eukaryotic autotrophs. Mangroves induced a substantial transformation in the sediment eukaryotic and prokaryotic composition, increasing the proportion of autotrophs, notably sulfur-oxidizing and iron-oxidizing bacteria and microalgae. This alteration suggests an increase in specific sulfur and iron cycling with simultaneous carbon sequestration within mangrove sediments. These results indicate that anthropogenic activities affect sediment carbon sequestration by altering autotrophic assemblages along coastlines, thereby inducing consequential shifts in overall elemental cycling processes.

Characterization of alkaline protease enzyme produced from marine yeast Candida orthopsilosis AKB-1 and its applications.

The present study has undertaken the isolation of marine yeasts from mangrove sediment samples and their ability to produce alkaline protease enzymes. A total of 14 yeast isolates were recovered on yeast-malt agar (YMA) and yeast extract peptone dextrose (YEPD) agar medium. After screening for proteolytic activity on skim milk agar, marine yeast isolate, AKB-1 exhibited a hydrolysis zone of 18mm. Optimal conditions for the enzyme production from yeast isolate AKB-1 were at 30°C, pH 8, fructose as carbon source, potassium nitrate as nitrogen source, and 25% saline concentration. Under the optimal conditions, the protease enzyme activity of the isolate AKB-1 was observed to be 978IU/mL. The structural and functional analysis was carried out through FTIR and HPLC analysis for the extracted protease enzyme. Furthermore, the enzyme produced was partially purified by solvent extraction using ethyl acetate and ammonium sulfate precipitation (3.4-fold) followed by dialysis (56.8-fold). The molecular weight of the purified enzyme was observed to be around 60kDa using SDS-PAGE. The extracted protein showed good antibacterial activity against six different clinical bacterial pathogens and the highest against Bacillus cereus (16 ± 0.5mm). The extracted protease enzyme was revealed to remove blood stains from cloth within 20min of application similar to the commercial detergent. The marine yeast isolate was further identified as Candida orthopsilosis AKB-1 (Accession number KY348766) through 18S rRNA sequencing, and a phylogenetic tree was generated.

Sargassum beaching on mangrove sediments shifts microbial and crab metabolisms and enhances blue carbon storage

AbstractBenthic metabolism and net carbon accumulation in mangroves sediments strongly depend on the quantity and quality of organic matter (OM) supplied, including material brought by coastal waters such as the macroalgae Sargassum spp. Mesocosms were used to assess the effect of eutrophication by Sargassum on mangrove sediments. The concentration of fatty acids (FAs), organic carbon and its carbon isotopic signature, and the sediments–air CO2 fluxes were used to follow the evolution of sedimentary OM in surface and subsurface sediments for 60 d. Sargassum beaching shifted microbial and crab metabolism, leading to a preferential degradation of the labile fraction of OM from both Sargassum (δ13C = −17.7‰ and high concentration of essential FAs) and mangrove leaves (δ13C: −28.9‰ and high concentrations of 18:2ω6 and 18:3ω3). Fatty acids composition of crabs hepatopancreas revealed they preferentially fed on Sargassum and these invertebrates also increased the particulate OM tidal export. In addition, microbial activity at the sediment surface was enhanced, as revealed by strong production of branched FAs and higher CO2 fluxes in mesocosms containing Sargassum. However, Sargassum beaching also increased the transfer and preservation of more refractory OM from mangrove leaves found in higher quantity in subsurface sediments (6–8 cm) after 60 d. Inputs of macroalgae induced a negative priming effect and enhanced the preservation of blue carbon in the sediments. This negative priming effect was enhanced by crab activities. These biotic interactions that include microbial communities apparently make mangrove efficient in storing carbon in a context of growing eutrophication of the tropical ocean.

Metal contamination in mangrove tissues, seeds, and associated sediments from the Vattanam mangrove forest of Palk Bay, southeastern India: An ecological risk assessment

In the present work, the concentrations of toxic heavy metals in mangrove sediments, mangrove leaves, and seeds collected from five stations in the Vattanam mangrove of Palk Bay, southeastern India, as well as the effects of the monsoon season on toxic heavy metals concentrations were determined. The concentrations were 17.5 μg/g for zinc (Zn), 9.11 μg/g for copper (Cu), and 6.03 μg/g for lead (Pb) in sediments; 10.71 μg/g (Zn) and 8.94 μg/g (Cu) in mangrove leaves; and 26.24 μg/g (Zn) and 17.01 μg/g (Cu) in mangrove seeds. At all sampling stations, the Cd concentration was below the limit of detection. These mangroves seem to have adapted successfully to their environment given their selective intake of only essential metals (Cu and Zn) and the restricted movement of non-essential metals (Cd and Pb). The concentrations of metals were below the maximum residual limits regulated by national and international standard limits.

A global assessment of mangrove soil organic carbon sources and implications for blue carbon credit.

Mangroves can retain both autochthonous and allochthonous marine and/or terrestrial organic carbon (OC) in sediments. Accurate quantification of these OC sources is essential for the proper allocation of blue C credits. Here, we conduct a global-scale analysis of sediments autochthonous and allochthonous OC contributions in estuarine and marine mangroves using stable isotopes. Globally, mangrove-derived autochthonous OC was the main contributor to estuarine and marine mangrove top-meter soil organic carbon (SOC) (49% and 62%, respectively). Less marine allochthonous OC (21%) was deposited than terrestrial allochthonous OC (30%) in estuarine mangrove sediments. Estuarine mangroves accumulated more SOC in sediments than marine mangroves (282 ± 8.1 Mg C ha-1 and 250 ± 5.0 Mg C ha-1, respectively), primarily due to the additional terrestrial OC inputs. Globally, marine mangroves held 67% of the total mangrove SOC, reaching 3025 ± 345 Tg C, while 1502 ± 154 Tg C was stored in estuarine mangrove sediments. The findings emphasize the substantial influence of coastal environmental settings on OC contributions, underlining the necessity of accurate OC source quantification for the effective allocation of blue carbon credits.

Isolation and Identification of Four Strains of Bacteria with Potential to Biodegrade Polyethylene and Polypropylene from Mangrove.

With the rapid growth of global plastic production, the degradation of microplastics (MPs) has received widespread attention, and the search for efficient biodegradation pathways has become a hot topic. The aim of this study was to screen mangrove sediment and surface water for bacteria capable of degrading polyethylene (PE) and polypropylene (PP) MPs. In this study, two strains of PE-degrading bacteria and two strains of PP-degrading candidate bacteria were obtained from mangrove, named Pseudomonas sp. strain GIA7, Bacillus cereus strain GIA17, Acinetobacter sp. strain GIB8, and Bacillus cereus strain GIB10. The results showed that the degradation rate of the bacteria increased gradually with the increase in degradation time for 60 days. Most of the MP-degrading bacteria had higher degradation rates in the presence of weak acid. The appropriate addition of Mg2+ and K+ was favorable to improve the degradation rate of MPs. Interestingly, high salt concentration inhibited the biodegradation of MPs. Results of scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier-transform infrared spectroscopy (FTIR) indicated the degradation and surface changes of PP and PE MPs caused by candidate bacteria, which may depend on the biodegradation-related enzymes laccase and lipase. Our results indicated that these four bacterial strains may contribute to the biodegradation of MPs in the mangrove environment.

Stand age-related effects of mangrove on archaeal methanogenesis in sediments: Community assembly and co-occurrence patterns

Mangrove sediment is a key source of methane emissions; however, archaea community structure dynamics and methanogenesis activities during long-term mangrove restoration remain unclear. In this study, microcosm incubations revealed a substantial reduction in microbial-mediated methane production potential from mangrove sediments with increasing stand age; methane production rates decreased from 0.42 ng g−1 d−1 in 6-year-old stands to 0.23 ng g−1 d−1 in 64-year-old stands. High-throughput sequencing revealed a reduction in community diversity because of specific microorganism colonization and species loss, notably a decline in the relative abundance of Bathyarchaeia in sediments of 64-year-old stands. In addition, mangrove sediments, especially those in older stands (20- and 64-year-old), had more complex and stable co-occurrence microbial networks than mudflats. Furthermore, archaea community assembly in older stands was dominated by stochastic processes wherein dispersal limitation was prominent, and that in younger stands (6- and 12-year-old) was driven by deterministic processes. The proportion of dispersal limitation of Bathyarchaeia and traditional methanogens in sediment decreased with an increase in stand age. Quantitative polymerase chain reaction analysis confirmed a decrease in Bathyarchaeia (from 3.50 to 0.54 copies g−1) and mcrA gene (from 3.83 to 0.25 copies g−1) abundance in mangrove sediments with an increase in stand age. These findings demonstrate the critical role of Bathyarchaeia in methanogenesis; the decline in microbial interactions and abundance, and the reduced proportion of dispersal limitation of Bathyarchaeia and traditional methanogens collectively contributed to the mitigation of microbial-mediated methane production potential in older mangrove stands.

Genome sequence of Sulfurimonas sp. C5, a potential chemolithoautotrophic, sulfur-oxidizing bacterium isolated from a mangrove sediment.

Sulfurimonas sp. strain C5 (MCCC 1A19556) is a strain with potential chemolithoautotrophic sulfur-oxidizing function, which is isolated from a mangrove sediment sample collected from Quanzhou Bay, Fujian Province, China. This report describes the genome sequence of strain C5, which possesses the gene sets for the sulfur-oxidizing pathway.

Tidal control on aerobic methane oxidation and mitigation of methane emissions from coastal mangrove sediments

Mangrove forests represent important sources of methane, partly thwarting their ecosystem function as an efficient atmospheric carbon dioxide sink. Many studies have focused on the spatial and temporal variability of methane emissions from mangrove ecosystems, yet little is known about the microbial and physical controls on the release of biogenic methane from tidally influenced mangrove sediments. Here, we show that aerobic methane oxidation is a key microbial process that effectively reduces methane emissions from mangrove sediments. We further demonstrate clear links between the tidal cycle and fluctuations in methane fluxes, with contrasting methane emission rates under different tidal amplitudes. Our data suggest that both the microbial methane oxidation activity and pressure-induced advective transport modulated methane fluxes in the mangrove sediments. Methane oxidation activity is limited by the availability of oxygen in the surface sediments, which in turn is controlled by tidal dynamics, further highlighting the interactive physico-biogeochemical controls on biological methane fluxes. Although we found some molecular evidence for anaerobic methanotrophs in the deeper sediments, anaerobic methane oxidation seems to play only a minor role in the mangrove sediments, with potential rates being two orders of magnitude lower than those of aerobic methane oxidation. Our findings confirmed the importance of surface sediments as biological barrier for methane. Specifically, when sediments were exposed to the air, methane consumption increased by ∼227%, and the methane flux was reduced by ∼62%, compared to inundated conditions. Our data demonstrate how tides can orchestrate the daily rhythm of methane consumption and production within mangrove sediments, thus explaining the temporal variability of methane emissions in the tidally influenced coastal mangrove systems.

Hydrodynamic Analysis of Sediment Deposition in Mangrove Wetlands of Zhanjiang Bay-Based on the Perspective of Sediment Grain Size

Grain size is an important parameter reflecting the characteristics of sedimentary dynamics, and mangrove wetland sediments record abundant sedimentary environmental information during transportation and deposition. To investigate the vertical characteristics of sediment grain size and sedimentary dynamic processes in the mangrove wetlands of Zhanjiang Bay, this study analyzed the grain size parameters, frequency distribution curves, and hydrodynamic characteristics of sediment cores collected from the mangrove wetlands in Nansan Island (A), the south of Techeng Island (B), Guanhai Promenade (C), Dongtoushan Island (D), Huguang Town (E), and the west of Donghai Island (F). The objective was to reveal the evolution of sedimentary dynamics in Zhanjiang Bay over the past century. The results showed that: (1) There were significant differences in the grain size characteristics among the sediment cores. Cores A and B had poor sorting and flat kurtosis, with sediment types of silty sand. Core C had a sinuous mean grain size and kurtosis curve, poor sorting, positive skewness, and a sediment type of silty sand. Core D had negative skewness, poor sorting, and moderate kurtosis, with a sediment type of sandy silt. Cores E and F had negative skewness, poor sorting, and large variations in kurtosis, with sediment types of sandy silt; (2) The grain size frequency distribution curves at depths of 25 cm, 50 cm, 75 cm, and 100 cm in each sediment core exhibited bimodal and unimodal characteristics, indicating the involvement of multiple sedimentary media in the depositional process. Cores A, B, C, and D had grain sizes concentrated on the sandy particle end, indicating strong sedimentary dynamics. Cores E and F had prominent silt-sized grains, indicating weaker sedimentary dynamics; (3) The grain size characteristics of the sediments were related to their terrestrial or island origins and the sediment supply from runoff. The depositional processes were deeply influenced by tidal dynamics, mangrove distribution, and human activities. The accelerated deposition rate in Zhanjiang Bay in recent years may affect navigation channels, and thus, attention should be paid to the ecological environment of wetlands within the bay.

The Oldest Holocene Caribbean Mangroves and Postglacial Sea Level Rise: Biogeographical Implications

This commentary underscores the importance of the recent discovery of the oldest in situ Holocene mangrove sediments found to date in the Caribbean region. It also emphasizes the implications of this finding for understanding postglacial sea level rise and the subsequent recolonization of current Caribbean coasts by mangrove communities. These communities likely survived the last glaciation in small microrefugia located beyond the present continental shelf, from where they expanded to form the present-day mangrove biogeographical patterns.

Carbon stocks in mangrove ecosystems of Sri Lanka: Average contributions and determinants of sequestration potential

Mangroves are crucial in carbon sequestration despite covering only a small percentage of the Earth's surface. Latitudinal gradient primarily determines the distribution of climatic zones of distinct sunlight, temperature, and precipitation patterns, which influence the community structure of the mangrove ecosystem. The tropical climate of Sri Lanka contributes to the island's lush mangrove forests. The present study estimated that the average island's carbon sequestration capacity of Sri Lankan mangrove ecosystems is 524.25 t/ha representing a substantial volume of carbon storage that contributes to offset greenhouse effect due to increasing atmospheric CO2. Our results substantiated that rainfall positively influences total carbon sequestration capacity of mangrove ecosystems.It was also revealed that a positive relationship exists between vegetation structural complexity and sediment organic carbon, highlighting the influence of vegetation structure, that is primarily dependent on climatic conditions, on production of organic matter and sediment carbon sequestration. Globally, the carbon sink function of mangrove ecosystems is reported to be highest in the tropical areas and it declines towards sub-tropical higher latitudes while those in the southern hemisphere perform better carbon sinks than those in the northern hemisphere.The vertical distribution of total organic matter content in mangrove sediments was revealed to be in a descending order, manifesting the weak tidal removal of surface organic matter under the microtidal conditions in Sri Lankan marine waters, thus qualifying mangrove ecosystems in microtidal coasts as effective carbon sinks.

Carbon Sequestration Assesment of Mangrove Ecosystem in Karang Anyar Village, Tanggamus Regency

Mangroves is a ecosystem can absorb carbon more efective than teresterial vegetataion. The goal of this research is to analyze effectively carbon absorption in the mangrove aea in the Karang Anyar Village. The research was conducted in Karang Anyar Village. Survey and tree sampling were carried out from Juni to August 2024. Biomass measurements provided information on carbon sequestrtaion. Data obtained was analyzed using allometric equation. Results showed that mean carbon sequestration of the mangrove biomass in Karang Anyar Village was 40,45-69,24 kg C/m2. Carbon sink in mangrove sediment was 402,15-907,95 kg C/m2. This research showed that mangrove ecosystem in Karang Anyar Village held sufficiently high carbon stock. Nevertheless, the future study needs to be directed to carbon stock comparison with other locations in Lampung.

Metagenome Analysis of the Bacterial Communities of mangrove sediments from Neil Island of Andamans

Metagenome Analysis of the Bacterial Communities of mangrove sediments from Neil Island of Andamans

Occurrence, Source Apportionment, and Risk Assessment of Antibiotics in Mangrove Sediments from the Lianzhou Bay, China.

In recent years, the widespread application of antibiotics has raised global concerns, posing a severe threat to ecological health. In this study, the occurrence, source, and ecological risks of 39 antibiotics belonging to 5 classes in mangrove sediments from Lianzhou Bay, China, were assessed. The total concentrations of the antibiotics (∑39 antibiotics) ranged from 65.45 to 202.24 ng/g dry weight (dw), with an average of 142.73 ± 36.76 ng/g dw. The concentrations of these five classes of antibiotics were as follows: Sulfonamides (SAs) > Tetracyclines (TCs) > Fluoroquinolones (QUs) > Penicillin (PCs) > Macrolides (MLs). The spatial distribution of antibiotics varied as high tidal zone > middle tidal zone > low tidal zone. The total organic carbon (TOC), pH, nitrate (NO3--N), and nitrite (NO2--N) of the sediment significantly influenced the distribution of antibiotics (p < 0.05). A source analysis identified untreated sewage from aquaculture as the primary source of antibiotics in the local mangrove. A risk assessment revealed that ciprofloxacin, norfloxacin, ofloxacin of QUs, and tetracycline of TCs exhibited medium risks to algae in certain sampling sites, while other antibiotics exhibited low or no risks to all organisms. Nevertheless, the total risk of all the detected antibiotics to algae was medium in 95% of the sites. The overall ecological risk level of antibiotics in the middle tidal zone was slightly lower than in the high tidal zone and the lowest in the low tidal zone. In summary, the experimental results provided insights into the fate and transport behaviors of antibiotics in mangrove sediments from Lianzhou Bay.

Cadmium contamination in sediments from a mangrove wetland: Insights from lead isotopes

Cadmium (Cd) pollution has gained significant attention in mangrove sediments due to its high toxicity and mobility. However, the sources of Cd and the factors influencing its accumulation in these sediments have remained elusive. In this study, we utilized lead (Pb) isotopic signatures for the first time to assess Cd contamination in mangrove sediments from the northern region of the Beibu Gulf. A strong correlation was observed between Cd and Pb concentrations in the mangrove sediments, suggesting a shared source that can be estimated using Pb isotopic signatures. By employing a Bayesian mixing model, we determined that 70.1 ± 8.2 % of Cd originated from natural sources, while 12.9 ± 4.9 %, 9.8 ± 3.7 %, and 7.1 ± 3.4 % were attributed to agricultural activities, non-ferrous metal smelting, and coal combustion, respectively. Our study clearly suggests that natural Cd could also dominate the high Cd content. Agricultural activities were the most important anthropogenic Cd sources, and the increased anthropogenic Cd accumulation in mangrove sediment was related to organic matter. This study introduces a novel approach for assessing Cd contamination in mangrove sediment, providing useful insights into Cd pollution in coastal wetlands.

Impact of geochemistry and microbes on the methylmercury production in mangrove sediments

Unraveling the geochemical and microbial controls on methylmercury (MeHg) dynamics in mangrove sediments is important, as MeHg can potentially pose risks to marine biota and people that rely on these ecosystems. While the important role of sulfate-reducing bacteria in MeHg formation has been examined in this ecologically important habitat, the contribution of non-Hg methylating communities on MeHg production remains particularly unclear. Here, we collected sediment samples from 13 mangrove forests in south China and examined the geochemical parameters and microbial communities related to the Hg methylation. MeHg concentrations were significantly correlated to the OM-related parameters such as organic carbon content, total nitrogen, and dissolved organic carbon concentrations, suggesting the importance of OM in the MeHg production. Sulfate-reducing bacteria were the major Hg-methylators in mangrove sediments. Desulfobacteraceae and Desulfobulbaceae dominated the Hg-methylating microbes. Classification random forest analysis detected strong co-occurrence between Hg methylators and putative non-Hg methylators, thus suggesting that both types of microorganisms contribute to the MeHg dynamics in the sediments. Our study provides an overview of MeHg contamination in south China and advances our understanding of Hg methylation in mangrove ecosystems.

Precision and bias of carbon storage estimations in wetland and mangrove sediments.

Peaty sediments in coastal wetlands play an important role in the sequestration of atmospheric carbon dioxide and its belowground storage. Sediment cores are used to quantify organic matter (OM) density, estimated by multiplying the bulk density of a core segment by its OM fraction. This method can be imprecise, as repeated samples often differ widely. Recent studies have shown that sediment bulk density and OM fraction are not independent but tightly related by a function called the ideal-mixing model. Thus, the bulk density of the sediment can be directly estimated from its OM fraction. Statistical theory and simulations demonstrate that the high variance in the product estimation of OM density is the result of error propagation in the product of two functionally related variables with independent errors. Estimating OM density in wetland sediments using the ideal-mixing model is more precise than the traditionally used product estimate, especially in highly organic sediments.

Methylotrophic substrates stimulated higher methane production than competitive substrates in mangrove sediments

Although mangrove forests can uptake atmospheric CO2 and store carbon as organic matter called “blue carbon”, it is also an important natural source of greenhouse gas methane. Methanogens are major contributors to methane and play important roles in the global carbon cycle. However, our understanding of the key microbes and metabolic pathways responsible for methanogenesis under specific substrates in mangrove sediments is still very limited. Here, we set an anaerobic incubation to evaluate the responses of methanogens in mangrove sediments from South China to the addition of diverse methanogenic substrates (H2/CO2, acetate, trimethylamine (TMA), and methanethiol (MT)) and further investigated the dynamics of the whole microbial community. Our results showed that diverse substrates stimulated methanogenic activities at different times. The stimulation of methanogenesis was more pronounced at early and late periods by the addition of methylotrophic substrates TMA and MT, respectively. The amplicon sequencing analysis showed that genus Methanococcoides was mainly responsible for TMA-utilized methanogenesis in mangrove sediment, while the multitrophic Methanococcus was most abundant in H2/CO2 and MT treatments. Apart from that, the bacteria enrichments of Syntrophotalea, Clostridium_sensu_stricto_12, Fusibacter in MT treatments might also be associated with the stimulation of methane production. In addition, the metagenomic analysis suggested that Methanosarcinaceae was also one of the key methanogens in MT treatments with different genomic information compared to that in TMA treatments. Finally, the total relative abundances of methanogenesis-related genes were also highest in TMA and MT treatments. These results will help advance our understanding of the contributions of different methanogenesis pathways and methanogens to methane emissions in mangrove sediments.

Novel Sustainable Bio-fertilizer Formulated with Mangrove-associated Bacteria Enhances Duckweed Growth and Protein Content

Duckweed is a future food and a source of affordable protein that has the potential to replace animal protein. This study aims to formulate a bio-fertilizer consisting of mangrove-associated bacteria to boost the growth and protein of duckweeds as a sustainable approach to increase plant-based protein yields. The culture-depending technique was performed by using Aleksandrow agar, Pikovskaya’s agar, and Jensen agar to screen potassium-solubilizing bacteria, phosphate-solubilizing bacteria and nitrogen-fixing bacteria, respectively, from mangrove soil sediments. Mangrove-associated bacteria that are close to &lt;i&gt;Acinetobacter radioresistens&lt;/i&gt;, &lt;i&gt;Brachybacterium paraconglomeratum&lt;/i&gt;, and &lt;i&gt;Enterobacter cloacae&lt;/i&gt;, which are known as nitrogen-fixing bacteria, &lt;i&gt;Klebsiella quasipneumoniae&lt;/i&gt;, &lt;i&gt;Bacillus tropicus&lt;/i&gt;, and &lt;i&gt;Paenibacillus pasadenensis&lt;/i&gt; known as potassium-solubilizing bacteria, and &lt;i&gt;Bacillus cereus&lt;/i&gt; and &lt;i&gt;Bacillus thuringiensis&lt;/i&gt; known as phosphate-solubilizing bacteria were identified through 16S rRNA gene sequencing. After that, three sets of bio-fertilizers were randomly formulated. Each set consisted of nitrogen-fixing bacteria, potassium- and phosphate-solubilizing bacteria, as well as commercial compost as a carrier. These formulated bio-fertilizers were evaluated for plant growth promotion and protein production on duckweed plants under temperatures between 26 and 30°C. The results showed that each set of our formulated bio-fertilizer can increase the nitrogen (N), phosphorus (P), and potassium (K), duckweed growth, and protein content when compared to the control group. It indicates that bio-fertilizers formulated with mangrove-associated bacteria and high NPK contents could enhance the growth of duckweed as well as its protein content, which could supply our future plant-based protein sustainably.