Natural and Anthropogenic Variation of Stand Structure and Aboveground Biomass in Niger Delta Mangrove Forests

Mangrove forests are important coastal wetlands because of the ecosystem services they provide especially their carbon potential. Mangrove forests productivity in the Niger Delta are poorly quantified and at risk of loss from oil pollution, deforestation, and invasive species. Here, we report the most extensive stem girth survey yet of mangrove plots for stand and canopy structure in the Niger Delta, across tidal and disturbance gradients. We established twenty-five geo-referenced 0.25-ha plots across two estuarine basins. We estimated aboveground biomass (AGB) from established allometric equations based on stem surveys. Leaf area index (LAI) was recorded using hemispherical photos. We estimated a mean AGB of 83.7 Mg ha–1 with an order of magnitude range, from 11 to 241 Mg ha–1. We found significantly higher plot biomass in close proximity to a protected site and tidal channels, and the lowest in the sites where urbanization and wood exploitation was actively taking place. The mean LAI was 1.45 and ranged fivefold from 0.46 to 2.41 and there was a significant positive correlation between AGB and LAI (R2 = 0.31). We divided the plots into two disturbance regimes and three nipa palm (Nypa fruticans) invasion levels. Lower stem diameter (5–15 cm) accounted for 70% of the total biomass in disturbed plots, while undisturbed regimes had a more even (∼25%) contribution of different diameter at breast height (DBH) size classes to AGB. Nipa palm invasion also showed a significant link to larger variations in LAI and the proportion of basal area removed from plots. We conclude that mangrove forest degradation and exploitation is removing larger stems (>15 cm DBH), preferentially from these mangroves forests and creates an avenue for nipa palm colonization. This research identifies opportunities to manage the utilization of mangrove resources and reduce any negative impact. Our data can be used with remote sensing to estimate biomass in the Niger Delta and the inclusion of soil, leaf properties and demographic rates can analyze mangrove-nipa competition in the region.

Preparation of activated carbon-based catalyst from nipa palm (Nypa fruticans) shell modified with KOH for biodiesel synthesis

An attempt to synthesize a low-cost carbon-based heterogeneous catalyst from biomass has been explored. The focus of this research was investigating the carbon-based catalyst from nipa palm shell modified with KOH in biodiesel synthesis. Dry nipa palm shell powder was carbonized at 300°C for 1 h to produce carbon. The carbon was then modified by impregnation with potassium hydroxide (KOH) solution. The carbon and modified carbon were analyzed by SEM-EDX. The modified carbon was applied as a heterogeneous catalyst in transesterification of palm oil and methanol. Transesterification was carried out at 60°C and stirred at 300 rpm. Reaction time and catalyst load was observed. Highest biodiesel yield of 95.5% was obtained at 2 h reaction time, 3% catalyst load, and methanol to oil ratio of 12:1. This preliminary study confirmed that KOH-modified carbon may act as a heterogeneous catalyst in biodiesel synthesis.

Antioxidants, inhibits the growth of foodborne pathogens and reduces nitric oxide activity in LPS-stimulated RAW 264.7 cells of nipa palm vinegar

Nipa palm vinegar (NPV) made from the sap of nipa palm (Nypa fruticans Wurmb.) has long been used as a local food seasoning and folk medicine. This study compared the bioactive compounds, antioxidant, in vitro anti-inflammatory and antimicrobial activities of three NPVs obtained from different plantations based on varied soil and water salinity levels, including fresh water NPV, brackish water NPV and saline water NPV. The analysis results revealed that total phenolic content of saline water NPV had statistically significantly lower than both fresh water and brackish water NPV (p < 0.0001). Furthermore percentage of acetic acid in brackish water NPV had statistically significantly lower than both fresh water and saline water. NPV (p = 0.002). Nevertheless, total flavonoid and pH, were not significantly different (p = 0.144 and 0.066, respectively). The antioxidant activities using three ABTS, DPPH and FRAP methods displayed similar patterns, in which saline water NPV showed the highest antioxidant activities, followed by brackish water and fresh water NPV, respectively. Antimicrobial activity was examined for seven enteropathogenic bacteria. The tested NPVs were found inhibitive against all test cultures with a minimum inhibitory concentration (MIC) of ≤ 7.8 µL/mL. The cytotoxicity of the NPV obtained from different plantations by MTT assay revealed low cytotoxicity. Anti-inflammatory activity was also carried out through the inhibition of nitric oxide production. The fresh water NPV exhibited the highest anti-inflammatory activity with IC50 17.59 ± 0.17 µL/mL, followed by saline and brackish water NPV with IC50 18.12 ± 0.49 and 28.29 ± 2.64 µL/mL, respectively. The findings indicated that NPV from different soil salinities could potentially be natural functional food and developed to antimicrobial and anti-inflammatory medicinal agents with safety.

Determination of Antioxidant Compounds, Proximate Compositions and Assessment of Free Radical Scavenging Activities of Nypa Fruticans Wurmb. Sap

Nipa palm sap (NPS) as source of medicine traditionally used to treat various diseases. This study identified good radical scavenging activity in NPS with the IC50 value of 33.36 μg/mL using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. NPS comprises of moisture (72.44%), ash (1.04%), protein (7.04%), carbohydrate (19.48%), fat (0%), and energy level (106 kcal). Glucose (0.3%) and fructose (1.8%) were detected using high-performance liquid chromatography. Maleic acid, cinnamic acid, chlorogenic acid, and kaempferol were the predominant compounds revealed by ultra-high-performance liquid chromatography. Overall, NPS has the potential antioxidants sources with significant health benefits and values for commercialisation.

Probable Nipa Palm Wine-Associated Hepatitis A Outbreak after Attending a Funeral Ceremony in Sabah

Foodborne outbreaks of hepatitis A virus (HAV) are most commonly associated with fresh and frozen produce and with various types of shellfish. Alcoholic beverage-borne outbreaks of hepatitis A are extremely rare. Here, we report an outbreak of hepatitis A associated with the consumption of a traditional wine at a funeral ceremony in the Sabah state of Malaysian Borneo. Confirmed cases were determined by serum anti-HAV immunoglobulin M and/or for fecal HAV by reverse transcription polymerase chain reaction (RT-PCR). The amplicons of RT-PCR were subjected to nucleotide sequencing followed by phylogenetic analysis. We conducted a 1:2 case–control study to identify the possible exposure that led to the outbreak. Sixteen patients met the case definition, they were 18 to 58 years old and 90% of them were males. The case–control study showed that the consumption of nipa palm wine during the ceremony was significantly associated (P = 0.0017) with hepatitis A infection (odds ratio, 5.44; 95% CI, 1.80–16.43). Untreated river water was used to dilute the traditional wine, which was assumed to be the source of the infection. Phylogenetically, these viruses belonged to genotype IA and formed an independent cluster with strains from Taiwan, Japan, and the Philippines. This strain might be an emerging HAV in Asian countries. Environmental assessments were performed and environmental samples were negative for HAV. The incidence of hepatitis A in Sabah was also determined and it was 0.795/100,000 population. Strict monitoring of traditional wine production should be implemented by the local authority to prevent future outbreaks.

Pollination of Nypa fruticans (Wurmb.) in a South Florida botanic garden

When plants are removed from their native habitat, reproduction can be compromised if pollinators are absent, especially when plant-pollinator interactions are species-specific and the plant is self-incompatible. To avoid these pitfalls, botanic gardens often use hand pollination to ensure reproductive success of their living collections, an important aspect of ex-situ conservation. The nipa palm, Nypa fruticans, presents an interesting case study of pollination in a botanic garden and a plant’s ability to successfully reproduce outside its native range without assisted pollination. Nypa fruticans has been growing at Montgomery Botanical Center (MBC) in South Florida since 1984, but for years required hand pollination to produce viable fruit. A recent shift from hand pollination to unassisted pollination suggests that this palm has found an alternative to fertilize its flowers. We investigate possible pollinators and new opportunities for pollination outside the palm’s native range. Rather than the insects typically associated with N. fruticans pollination in its native range in Southeast Asia (i.e., flies and beetles), ants, specifically Paratrechina longicornis, were overwhelmingly the most abundant visitors to nipa palm inflorescences at MBC and likely represent an important pollinator or facilitator of pollination at the garden. Pollination research at botanic gardens complements in-situ field studies and provides important insights into the flexibility of pollination systems to achieve reproductive success outside a plant’s native range.

Reduced graphene oxide/cellulose microfiber hybrid from the Vietnamese Nipa palm tree: Synthesis, properties, and applications for preparation of poly(methyl methacrylate) composite

Cellulose microfibers were successfully fabricated from Vietnamese Nipa palm by mechanical and chemical treatments. The Nipa palm petioles were simply rolled, pressed, and separated. They were then pretreated with an alkaline solution and submitted to acid hydrolysis to remove the impurities (tCell). The microfibers were reinforced with reduced graphene oxide to form a hybrid that was reduced with hydrazine hydrate in the last stage (tCell-rGO). The structure and properties of tCell and tCell-rGO were evaluated by FTIR, XRD, DSC, TGA, SEM, BET, and the sheet resistance. It was observed that the treated cellulose microfibers exhibited a diameter of 10–20 μm and had good crystallinity in the structure. Both tCell and tCell-rGO exhibited low-density values of 1.52 kg/m3 and 0.58 kg/m3, respectively, and had good specific surface area values of 11.2 m2/g and 13.0 m2/g, respectively. These results supported the decrease in the density and the increase in the specific surface area of the tCell-rGO samples in comparison with the tCell. The existence of rGO sheets in the cellulose microfiber matrix resulted in changes in the structure, arrangement, and crystallization of pristine microfibers. The thermal property and electrical conductivity of the reinforced GO cellulose microfibers were significantly improved. rGO not only showed its role as a surface modification agent that helps the cellulose microfibers disperse better in the non-polar substrate, but also contributed to the increase of the heat-stable and mechanical properties of polymer. The thermal stability of tCell-rGO/PMMA composite was notably improved more than 40°C in maximum decomposition temperature by an emulsion polymerization technique. The material based on cellulose microfibers from the Vietnamese Nipa palm tree and reduced graphene oxide overcame some disadvantages such as the poor heat resistance, poor dispersion of the original fibers in the non-polar polymer and displayed great potential for environmentally friendly future applications.