Syzygium malaccense is native to Malaysia. It is sometimes called the malay apple, malay rose-apple, mountain rose-apple, mountain apple, water apple, or French cashew. The tree is very popular in many tropical and subtropical regions for its fruit and traditional medicine. The first complete chloroplast genome of Syzygium malaccense has been reported in this study. The complete chloroplast genome of Syzygium malaccense is 158,954 bp, composed of four regions: a large single-copy region with a size of 87,991 bp, a small single copy region with a size of 18,793 bp, and two inverted repeat regions with a size of 26,085 bp. The GC content is 36.97%. A total of 132 genes were annotated, including 84 encoding proteins, eight encoding rRNA genes, 37 encoding tRNA genes, and three encoding pseudo genes. Phylogenetic analysis showed that Syzygium aromaticum, Syzygium cumini, and Syzygium forrestii are closely related to Syzygium malaccense.
The nanoenvironment of nanobiocatalysts, such as local hydrophobicity, pH and charge density, plays a significant role in optimizing the enzymatic selectivity and specificity. In this study, Kluyveromyces lactis β-galactosidase (Gal) was assembled onto polystyrene nanofibers (PSNFs) to form PSNF-Gal nanobiocatalysts. We proposed that local hydrophobicity on the nanofiber surface could expel water molecules so that the transgalactosylation would be preferable over hydrolysis during the bioconversion of lactose, thus improve the galacto-oligosaccharides (GOS) yield. PSNFs were fabricated by electro-spinning and the operational parameters were optimized to obtain the nanofibers with uniform size and ordered alignment. The resulting nanofibers were functionalized for enzyme immobilization through a chemical oxidation method. The functionalized PSNF improved the enzyme adsorption capacity up to 3100mg/g nanofiber as well as enhanced the enzyme stability with 80% of its original activity. Importantly, the functionalized PSNF-Gal significantly improved the GOS yield and the production rate was up to 110g/l/h in comparison with 37g/l/h by free β-galactosidase. Our research findings demonstrate that the localized nanoenvironment of the PSNF-Gal nanobiocatalysts favour transgalactosylation over hydrolysis in lactose bioconversion.
Protein-based films are thin and flexible films derived from protein sources. They are
completely biodegradable and used in food engineering, packaging, drug recovery, and other
applications. In food packaging, gelatin is widely used due to properties such as low cost,
availability, functional attributes, mechanical (flexibility and tension) and optical (brightness
and opacity) strength, barrier against gas flow, and structural resistance to water and
microorganisms. Therefore, this paper reviews the characterisation of biodegradable
protein-based films from gelatin alternatives, mainly from fish and chicken skin, as food
packaging materials. The properties of film packaging derived from gelatin alternatives were
compared with films derived from mammalian gelatin. The findings showed that the blended
gelatin alternatives with polysaccharide improved physical properties such as water vapour
permeability, gas permeability, light transmission and transparency, thermal properties,
microstructure, colour, and heat sealability. Moreover, improvements in mechanical
properties such as tensile strength and elongation at break were also investigated. This review
also comes out with suggestions for future research on the compatibility between gelatin films
and food ingredients. This paper provides a comprehensive overview that promotes the
development of biodegradable blended films from gelatin alternatives for packaging
applications in the food industry and related fields.
The aim of the present work was to develop chicken skin gelatin films incorporated with
different concentrations of rice starch prepared by casting techniques. Six film-forming
solutions were prepared separately with different blend ratios of chicken skin gelatin to rice
starch: A (0/100), B (5/100), C (10/100), D (15/100), E (20/100), and F (25/100). The
rheological properties of the film-forming solutions (FFS) were determined using frequency
sweep. The mechanical and physical properties of the respective films were also evaluated.
With the increase in rice starch concentration, the storage (G’) modulus of FFS increased
dramatically with loss (G”) modulus as the oscillatory frequency rising to contribute to gel
behaviour (G’ > G”). As rice starch concentration increased, the chicken skin gelatin films
also demonstrated higher tensile strength, elongation at break, and water vapour permeability,
but reduced the solubility of gelatin films in water. Additionally, elevation in melting point
values indicated that the thermal stability of the composite films was enhanced with the
increment of rice starch concentration. Film F (with 25% rice starch) yielded the optimal film
formulation, as it had the highest tensile strength and a high elongation at break value. Thus,
film F shows the best potential as a film for food packaging.
Strobilanthes crispus and Clinacanthus nutans are popular herbal plants in the Southeast
Asian region. The present work was aimed at determining the antioxidant activities and the
associated components in the leaf extracts of both species using polar and non-polar solvents
namely water, methanol, ethyl acetate, and hexane. The total phenolic content (TPC) and total
flavonoid content (TFC) were higher in the leaf extracts of S. crispus as compared to C.
nutans. Among the solvents, methanol was the best solvent in extracting the antioxidant
components for S. crispus (TPC: 159.85 ± 0.89 mg GAE/g extract and TFC: 955.47 ± 2.66 mg
RE/g extract). However, for C. nutans, its methanolic extract yielded the highest TPC (36.39
± 0.17 mg GAE/g extract), whereas ethyl acetate yielded the highest TFC (229.61 ± 7.81 mg
RE/g extract). The high levels of both TPC and TFC contributed to the antioxidant activities
of S. crispus extract as reflected in the methanolic extract attaining the highest level of
antioxidant activities, measured by ferric reducing antioxidant power (FRAP) (6.84 ± 1.12
mmol Fe2+/g extract), DPPH radical scavenging (IC50: 203.60 ± 7.28 μg/mL), and Trolox
equivalent antioxidant capacity (TEAC) (1.01 ± 0.01 mmol TE/g extract) assays. This
contrasted with C. nutans which showed lower antioxidant activities owing to its lower TPC
and TFC. Correlation analysis revealed significant correlations (p < 0.05, r = 0.915 - 0.985)
between both TPC and TFC in S. crispus and antioxidant activities. However, only TPC of C.
nutans showed a significant correlation with FRAP values (r = 0.934). Further tentative
identification of the constituents in the extracts using HPLC-ESI-QToF-MS/MS revealed the
existence of 20 polyphenolic compounds in both S. crispus and C. nutans, which were likely
responsible for their antioxidant activities. In addition, 15 polyphenolic compounds classified
as chalcones, isoflavanoids, flavones, and flavonols have not been previously reported in both
species. The methanolic extracts of both species yielded a higher content of antioxidants, with
S. crispus offering a richer source of dietary antioxidants as compared to C. nutans. However,
further study is needed to identify their bioactivities in relation to their bioactive components.
The window of maximum susceptibility for the development of dental fluorosis for anterior
teeth is during the first two to three years of life. The primary source of fluoride intake for
infants at this age is mainly from the diet including infant formula. Thus, the present work
aimed to investigate the fluoride concentration in commercially available Malaysian infant
formulas that required reconstitution before consumption. A total of 29 infant formulas available in the Malaysian market were reconstituted with deionised water, fluoridated tap water,
and filtered tap water. The fluoride concentration of the infant formulas was analysed directly
using a fluoride ion selective electrode. The daily fluoride intake estimation from the infant
formulas was calculated using the median infant body weight and recommended volumes for
formula consumption from newborn to > 12 months of age. Results showed that the fluoride
concentration of the infant formulas when reconstituted with deionised water ranged between
0.009 to 0.197 mg/L that contributed to the estimated daily fluoride intake ranging from 0.005
to 0.100 mg (total intake per day) or 0.001 to 0.025 mg/kg (total intake per body weight/day).
The fluoride concentration in the selected infant formulas was low, but after reconstitution
with fluoridated tap water, the overall fluoride concentration in infant formulas sample significantly increased (p < 0.001). Nevertheless, the estimated daily fluoride intake from infant
formulas alone did not exceed the lowest-observed-adverse-effect level (LOAEL) of fluoride
at 0.10 mg/kg/day.
Frictional and nanomechanical properties of nanostructured polymer surfaces are important to their technological and biomedical applications. In this work, poly(ethylene terephthalate) (PET) surfaces with a periodic distribution of well-defined nanopillars were fabricated through an anodization/embossing process. The apparent surface energy of the nanopillared surfaces was evaluated using the Fowkes acid-base approach, and the surface morphology was characterized using scanning electron microscope (SEM) and atomic force microscope (AFM). The normal and lateral forces between a silica microparticle and these surfaces were quantified using colloidal probe atomic force microscopy (CP-AFM). The friction-load relationship followed Amonton's first law, and the friction coefficient appeared to scale linearly with the nanopillar height. Furthermore, all the nanopillared surfaces showed pronounced frictional instabilities compared to the smooth sliding friction loop on the flat control. Performing the stick-slip amplitude coefficient (SSAC) analysis, we found a correlation between the frictional instabilities and the nanopillars density, pull-off force and work of adhesion. We have summarised the dependence of the nanotribological properties on such nanopillared surfaces on five relevant parameters, i.e. pull-off force fp, Amontons' friction coefficient μ, RMS roughness Rq, stick-slip amplitude friction coefficient SSAC, and work of adhesion between the substrate and water Wadh in a radar chart. Whilst demonstrating the complexity of the frictional behaviour of nanopillared polymer surfaces, our results show that analyses of multiparametric nanotribological properties of nanostructured surfaces should go beyond classic Amontons' laws, with the SSAC more representative of the frictional properties compared to the friction coefficient.
The relationship between acute thermal tolerance and habitat temperature in ectotherm animals informs about their thermal adaptation and is used to assess thermal safety margins and sensitivity to climate warming. We studied this relationship in an equatorial freshwater snail (Clea nigricans), belonging to a predominantly marine gastropod lineage (Neogastropoda, Buccinidae). We found that tolerance of heating and cooling exceeded average daily maximum and minimum temperatures, by roughly 20°C in each case. Because habitat temperature is generally assumed to be the main selective factor acting on the fundamental thermal niche, the discordance between thermal tolerance and environmental temperature implies trait conservation following 'in situ' environmental change, or following novel colonisation of a thermally less-variable habitat. Whereas heat tolerance could relate to an historical association with the thermally variable and extreme marine intertidal fringe zone, cold tolerance could associate with either an ancestral life at higher latitudes, or represent adaptation to cooler, higher-altitudinal, tropical lotic systems. The broad upper thermal safety margin (difference between heat tolerance and maximum environmental temperature) observed in this snail is grossly incompatible with the very narrow safety margins typically found in most terrestrial tropical ectotherms (insects and lizards), and hence with the emerging prediction that tropical ectotherms, are especially vulnerable to environmental warming. A more comprehensive understanding of climatic vulnerability of animal ectotherms thus requires greater consideration of taxonomic diversity, ecological transition and evolutionary history.
As small bodied poikilothermic ectotherms, invertebrates, more so than any other animal group, are susceptible to extremes of temperature and low water availability. In few places is this more apparent than in the Arctic and Antarctic, where low temperatures predominate and water is unusable during winter and unavailable for parts of summer. Polar terrestrial invertebrates express a suite of physiological, biochemical and genomic features in response to these stressors. However, the situation is not as simple as responding to each stressor in isolation, as they are often faced in combination. We consider how polar terrestrial invertebrates manage this scenario in light of their physiology and ecology. Climate change is also leading to warmer summers in parts of the polar regions, concomitantly increasing the potential for drought. The interaction between high temperature and low water availability, and the invertebrates' response to them, are therefore also explored.
In order to invent a porcine gelatine detection device using microbial resources, bacterial enzymes with a preference towards porcine gelatine and their candidate genes were evaluated. Five (n = 5) bacterial strains isolated from hot spring water and wet clay, Malaysia were screened for their gelatinase activity. The gelatinase enzyme was extracted and purified using ammonium sulphate precipitation prior to performing gelatinase assay on porcine, bovine and fish gelatine medium substrates. The G2 strain or Enterobacter aerogenes (Strain EA1) was selected for whole genome sequenced after showing a consistent trend of preference towards porcine gelatine. The gelatinase candidate gene gelEA1_9 was cloned and expressed. Based on one-way analysis of variance (ANOVA) with POST-HOC Duncan test (α = 0.05), the final product of gelEA1_9 was identified as a novel gelatinase. This gelatinase presented no significant difference in activity towards porcine gelatine. Hence, the present study demonstrated an enzyme-substrate interaction for porcine gelatine identification.
The objective of this work was to study the influence of cellulose nanofibrils (CNF) on the physical, mechanical, and thermal properties of Jatropha oil-based waterborne polyurethane (WBPU) nanocomposite films. The polyol to produce polyurethane was synthesized from crude Jatropha oil through epoxidation and ring-opening method. The chain extender, 1,6-hexanediol, was used to improve film elasticity by 0.1, 0.25, and 0.5 wt.% of CNF loading was incorporated to enhance film performance. Mechanical performance was studied using a universal test machine as specified in ASTM D638-03 Type V and was achieved by 0.18 MPa at 0.5 wt.% of CNF. Thermal gravimetric analysis (TGA) was performed to measure the temperature of degradation and the chemical crosslinking and film morphology were studied using Fourier-transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). The results showed that when the CNF was incorporated, it was found to enhance the nanocomposite film, in particular its mechanical and thermal properties supported by morphology. Nanocomposite film with 0.5 wt.% of CNF showed the highest improvement in terms of tensile strength, Young's modulus, and thermal degradation. Although the contact angle decreases as the CNF content increases, the effect on the water absorption of the film was found to be relatively small (<3.5%). The difference between the neat WPBU and the highest CNF loading film was not more than 1%, even after 5 days of being immersed in water.
Cucullanus sp. is a genus of nematode infecting Barbonymus schwanenfeldii. It is categorized under Family Cucullunidae. The genus Cucullanus sp consists of various species around the world, parasitizing freshwater, brackish-water or marine fishes. Cucullanus sp are mainly found in internal organs like stomach, intestine, kidney, and spleen. This parasitic organism can cause an economic impact, especially for animals with high market value, which are commercialized and used for human consumption. The objectives of this study are to study the morphological characteristics of Cucullanus sp and to identify genus of Cucullanus sp which are found on tinfoil barb, Barbonymus schwanenfeldii at Kenyir Lake, Terengganu. There is not enough data on Cucullanus sp on B. schwanenfeldii. Six samples of tinfoil barb were collected at Kenyir Lake from 25 to 27 October 2018. Each sample of fish was measured and recorded for length and weight using ruler and weighing balance respectively. The fish were examined at camping site at Lawit Resort, Kenyir Lake. The nematode species found were brought back to Health of Aquatic Organism laboratory. The abdominal and gastrointestinal tracts of the fishes were dissected and placed in petri dishes. The nematodes found were collected and observed under the dissecting microscope. The nematode specimen was placed on a glass slide with a drop of lactophenol and observed under the compound microscope fitted with dino-eye. The sample was later fixed with 70% alcohol. The morphological characteristic was drawn using camera lucida fitted to a compound microscope. (40X magnification). The picture of nematode was captured by using Advanced Research Microscope (Nikon Eclipse 80i) and measurements of the nematode was also made. Hence, the nematode found was identified as male Cucullanus sp.
The aim of this study was to determine the effect of different ratios of low protein flour to oyster mushroom (Pleurotus sajor-caju) powder on the physicochemical properties and sensory acceptability of edible tablespoon. Fresh grey oyster mushroom was dried in a convection oven at temperature of 55.0˚C ± 2.0˚C for 20 h prior to the grinding process. The low protein flour (LPF) was then incorporated with oyster mushroom powder (OMP) at different ratios of 100:0, 96:4, 92:8, 88:12 and 84:16, before being with vegetable oil, sugar, egg white and water in formulating the edible tablespoon. The proximate analyses were carried out in triplicate for calorie content, colour profile, hardness value and morphological structure of edible tablespoon. This study revealed that with decreasing LPF and increasing OMP in the formulation, the ash content (1.24% to 1.92%), crude fat content (8.98% to 10.40%) and fiber content (0.13% to 1.24%) were observed to have increased as well as the hardness value (2042.03g to 2844.57g) and pore’s size of the morphological structure of edible tablespoon. However, the carbohydrate content (78.64% to 75.56%) significantly decreased (p>0.05) together with L* value (from 68.47 to 61.71) when the decrease was in the the percentage of LPF and an increase the percentage of OMP. The calorie content, moisture content and protein content of edible tablespoon were not significantly (p>0.05) affected by different ratios of LPF to OMP. The edible tablespoon formulated with up to 8% of OMP was accepted by the sensory panelists but further increase in OMP addition significantly decreased the degree of likeness in terms of colour, odour, taste and overall acceptability of edible tablespoon. This study suggested that oyster mushroom edible tablespoon could be potential alternative disposable cutlery which will help to reduce the use of huge amount of non-biodegradable materials for environmental conservation.
This study aimed to determine the physicochemical properties of undulated surf clam (Paphia undulata) hydrolysate as affected by the degree of hydrolysis (DH). Three levels of DH of undulated surf clam hydrolysate were prepared which were DH 36.57% (without any enzymatic hydrolysis), DH 58.25% (0.5% Alcalase®; 5 min; pH 7.5; 60ºC) and DH 91.26% (1% Alcalase®; 30 min; pH 7.5; 60ºC). After protein hydrolysis, the undulated surf clam hydrolysates were centrifuged, and their supernatants were freeze-dried. This study found that the protein hydrolysate with lower DH (DH 36.57%) gave lower protein content and higher ash and fat contents compared to other samples (DH 58.25% and DH 91.26%). However, the carbohydrate content is similar in all samples (16.56-20.04%). This study also found that foaming properties (29.43-67.50%), emulsifying capacity (11.94-110.52%) and peptide solubility (57.61-94.08%) were affected by the DH. As DH increased, the emulsifying capacity decreased, while peptide solubility increased. While the foaming capacity increased with increasing DH until it reached a maximum value and level off afterwards. For colour parameters, although there were differences between L*, a* and b* values for all three samples, a fluctuating pattern was noted with DH. DH also did not affect the water-holding and oil-holding capacity of undulated surf clam hydrolysate. This study shows that certain physicochemical properties of undulated surf clam hydrolysate can be tailored by adjusting the degree of hydrolysis.
Dyes are aromatic organic compound which have an affinity towards the substrate to which they are being applied to. The presence of dyes in wastewater samples is not safe for human even at low level. The presence of dyes in wastewater which are discharged from textile industry must be analysed. Hence, a precise, fast, accurate, simple and inexpensive analytical method with low detection limit is needed for the determination of dyes in wastewaters. The differential pulse anodic stripping voltammetric (DPASV) technique using bare glassy carbon electrode (GCE) as a working electrode and phosphate buffer at pH 4.2 as a supporting electrolyte has been proposed for Reactive Black 5 (RB5) determination. Several experimental voltammetric parameters were being optimized for obtaining a maximum response before analytical validation of the proposed technique being carried out. The optimum parameters were initial potential (Ei) = +0.3 V, end potential (Ef) = +1.0 V, scan rate (v) = 0.04 V/s, accumulation time (tacc) = 50 s, accumulation potential (Eacc) = 0.4 V and pulse amplitude = 0.075 V. The well-defined anodic peak appeared at 0.77972 V. The response was linear from 0.5 to 1.25 mg/L (R2=0.9986) with LOD of 0.050 mg/L. The relative standard deviation (RSD) achieved were 0.08 %, 0.62 % and 0.50 %, respectively for three consecutive days. The % recovery range achieved was from 89.71 % to 111.15 %. It can be concluded that the proposed technique is precise, accurate, inexpensive, fast and has a potential to be an alternative analytical technique for RB5 analysis. The proposed method will in the future be tested for the amount of RB5 in the wastewater samples from textile industry.
Tomatoes have a short shelf life thus they pose a big challenge for growers to maintain the quality of tomatoes to increase customer acceptance. In this study, fungi associated with tomato disease symptoms were isolated and the potential of kaffir lime aqueous extract was evaluated in maintaining post-harvest quality of tomatoes. For this purpose, healthy tomatoes were dipped in 10% aqueous kaffir lime extract before evaluating the post-harvest parameters namely weight loss and firmness. A fungus namely Rhizophus stolonifer was isolated from the symptomatic tomatoes. Subsequently, it was confirmed to be pathogenic on healthy tomato fruits with 100% disease severity. Application of aqueous kaffir lime extract showed that tomato fruits dipped in 10% aqueous kaffir lime extract recorded higher weight loss and higher firmness as compared to untreated tomato fruits. The results showed that treatment with this concentration of plant extract did not help to reduce the weight loss, but it retained the firmness of the tomato fruits stored at room temperature at 27+2oC. Higher transpiration process would lead to shrinkage, weight loss, changes in texture and appearance of the fruits. Therefore, this study suggested an increased concentration of aqueous kaffir lime extract as a treatment agent in order to have a better effect in maintaining the quality of tomato fruits.
Thelohanellus nikolskii, Achmerov, 1955 is a well-known myxozoan parasite of the common carp (Cyprinus carpio L.). Infection regularly manifests in numerous macroscopic cysts on the fins of two to three month-old pond-cultured carp fingerlings in July and August. However, a Thelohanellus infection is also common on the scales of two to three year-old common carp in ponds and natural waters in May and June. Based on myxospore morphology and tissue specificity, infection at both sites seems to be caused by the same species, namely T. nikolskii. This presumption was tested with molecular biological methods: SSU rDNA sequences of myxospores from fins of fingerlings and scales of older common carp were analysed and compared with each other and with related species available in GenBank. Sequence data revealed that the spores from the fins and scales represent the same species, T. nikolskii. Our study revealed a dichotomy in both infection site and time in T. nikolskii-infections: the fins of young carp are infected in Summer and Autumn, whereas the scales of older carp are infected in Spring. Myxosporean development of the species is well studied, little is known, however about the actinosporean stage of T. nikolskii. A previous experimental study suggests that aurantiactinomyxon actinospores of this species develop in Tubifex tubifex, Müller, 1774. The description included spore morphology but no genetic sequence data (Székely et al., 1998). We examined >9000 oligochaetes from Lake Balaton and Kis-Balaton Water Reservoire searching for the intraoligochaete developmental stage of myxozoans. Five oligochaete species were examined, Isochaetides michaelseni Lastochin, 1936, Branchiura sowerbyi Beddard, 1892, Nais sp., Müller, 1774, Dero sp. Müller, 1774 and Aelosoma sp. Ehrenberg, 1828. Morphometrics and SSU rDNA sequences were obtained for the released actinospores. Among them, from a single Nais sp., the sequence of an aurantiactinomyxon isolate corresponded to the myxospore sequences of T. nikolskii.
Introduction: This study aims to investigate different residue sizes of β-tricalcium phosphate (β-TCP) micro-granules as carriers to assess antibacterial activity and drug-control release behavior of ampicillin (AMP-) and antimycotic (AMC-). Incorporation of antibiotic into the β-TCP micro-granules and it sustain release behavior could be used as alternative solution to reduce the risk of osteomyelitis and bone infections risks. Methods: Three different residue sizes (less than 300 µm, 300 µm and 600 µm) were prepared and coated with antibiotics solution (20 µg/µl of ampi- cillin and 100X antimycotic solution) by using two methods; dip and stream coating. After 72 h, 1.5 mL of distilled water was added to the treated (β-TCP) micro-granules at two different pH value (5.0 and 7.4). The extracted solution was further analyzed by Kirby Bauer disc diffusion test and spectrophotometer assay. Results: The solution con- taining AMC-(β-TCP) micro-granules with the size of 300 µm residue produced the largest inhibition zones against Escherichia coli (E. coli). All residue sizes coated with AMP- showed no antibacterial activity against both strains; Staphylococcus aureus (S. aureus) and E.coli. Additionally, the release behavior of AMC-(β-TCP) micro-granules was found not depending on the pH, but on the size of residue. Complete drug release was rapidly observed within 48
h. Conclusion: Based on this findings, it showed AMC-(β-TCP) micro-granules had an antibacterial activity against Gram-negative strain. Specifically, it can reduced the growth rate of E. coli and the rapid release behavior of AMC- (β-TCP) micro-granules help in minimizing the risk-infections in early stage of implantation.
Introduction: The compatibility of denture cleanser is crucial in the prevention of failure of adhesion between silicone soft liner and acrylic denture base, thus ensuring the durability of the prosthesis. This scanning electron microscope (SEM) study was to determine the mode of failure and measured the gap formation between silicone soft liners and Polymethylmethacrylate (PMMA) denture base after immersion in denture cleansers. Methods: A total of 135 specimens of PMMA denture base lined with three different silicone soft liners (GC Reline Soft, Mollosil and Tokuyama Sofreliner Tough) were immersed into denture cleansers (Polident® and Stearadent) daily and stored in distilled water at 37±1°C. Specimens were examined and sectioned at 2.5mm and 5.0mm from the margin after 1 day, 30 days and 90 days before analyzed. Results: No significant difference detected in the mode of failure and gap formation after one-day immersion. Adhesive failure was the commonest failure at the margin after 30 days (71.11%) and after 90 days (95.56%). However, 33.33% of specimens showed mixed failure at 5.0mm sectioned after 90 days. A significant difference of gap formation was demonstrated from Mollosil in Steradent at the margin and at 2.5 mm sectioned after 30 days and after 90 days (p
Mangrove located near urban area is exposed to various industrial discharge including heavy metals. Mangrove soil is capable of accumulating and storing these heavy metals. Heavy metals are toxic and non-biodegradable, so their accumulations affect water quality, while bioaccumulation and bio-assimilation of heavy metals in mangrove organisms negatively impact the food chain. Bacteria-derived biosurfactants are compounds capable of removing heavy metals from soil and sediment. Furthermore, environmentally friendly properties, such as biodegradability and low toxicity, exhibited by biosurfactants make them a suitable replacement for chemical surfactants for remediation efforts. This study was conducted to investigate the lead- (Pb) and zinc- (Zn) removing capability of rhamnolipid (RL), a type of biosurfactant produced by marine bacterium, Pseudomonas aeruginosa UMTKB-5. Rhamnolipid solutions of three different concentrations (25 mg/L, 50 mg/L and 75 mg/L) were added to mangrove soil and incubated for 7 days. The removal of Pb from soils was up to 18.3% using 25 mg/L RL solution, while 50 mg/L RL solution removed 48.3%, and 75 mg/L RL solution removed 75.9% Pb over time. Meanwhile, zinc removal of 25 mg/L RL solution was up to 24.9%, while 50 mg/L removed 16.5%, and 75 mg/L RL removed 30.5% of Zn. The results showed that RL from P. aeruginosa UMTKB-5 could be a potential biomaterial to be used to remediate heavy metals in sediment.