Isolation and Identification of Hydrocarbon-Degrading Bacteria from Polychaete Marphysa moribidii

Marine contamination caused by anthropogenic activities has side effects and causes severe contamination to the environment. Polychaetes are benthic organisms that live in the sediment and can be a good indicator of sediment contamination by organic compounds. In this study, bacterial strains were isolated and identified from the gut of polychaete worm Marphysa moribidii and the potential of the bacteria was evaluated to degrade hydrocarbon compounds. The isolated bacteria were primary and secondary screened on Minimal Salt Media (MSM) agar supplemented with 1% v/v of diesel oil. Diesel degradation analysis was performed by inoculating potential bacterium into MSM broth with 1% v/v diesel oil and incubated at 37 oC for 20 days. Diesel degradation percentage was analyzed using the gravimetric method, while the bacteria cell densities were measured using the standard plate count method. Then, the selected isolates were identified based on their morphological characteristics and 16S rDNA sequences. As a result, two bacteria isolates coded as Isolate 6 and Isolate 8 were able to degrade diesel oil up to 52.29% and 39.24% after 20 days of incubation. The 16S rDNA sequence analysis revealed that it was identified as Bacillus sp. strain UMTFA1 (RB) and Staphylococcus kloosii strain UMTFA2 (RS). Our result showed that these strains have the potential in oil-degrading processes, which will provide new insight into bioremediation process and decrease environmental pollution in soil and water contaminated with hydrocarbons.

Quality Changes in the Adductor Muscle of Ezo Giant Scallop Mizuhopecten yessoensis (Jay, 1857) During Refrigerated Storage

Recently, the popularity of scallops consumption and the preference to eat them raw have been increasing worldwide. Therefore, maintaining its freshness and quality is important. It is necessary to investigate the changes in quality, particularly umami-related component parameters and perform a comprehensive evaluation to assess scallop quality over time. In this study, the distinction in the abundance of microorganisms, K value, pH, color value, glycogen content, and ATP-related compound levels (i.e., ATP, ADP, AMP, IMP, HxR, Hx, and glutamic acid levels) were investigated to determine the quality of Ezo giant scallops. The parameters were evaluated every day for six days at 4°C post mortem of the scallops. The total viable aerobic count of marine bacteria increased from 1 to 3 log CFU/g over six days, and the K value increased sharply from 18% on day 2 to 66% on day 4. The pH decreased from 7.0 on day 0 to 6.0 on day 3, but the color value did not change during the six days of observation. The AMP content increased over three days and then decreased during the last three days of storage. IMP was not detected; meanwhile, the glycogen and glutamic acid levels were stable during the observation. Based on these results, the best recommendation is to serve the refrigerated scallops as sashimi for not more than two days and cook by the third day to preserve the quality.

Molecular characterization of Caulerpa racemosa (Caulerpales, Chlorophyta) from Indonesia based on the Plastid tufA Gene

The green seaweed Caulerpa racemosa is a seaweed of high prospect that is being given emphasis by the Indonesian government. However, C. racemosa in Indonesia may include multiple species level-entity exhibiting morphological overlap and require molecular analysis for species identification. Molecular documentation of species richness of indigenous populations of C. racemosa is essential to underpin cultivar development and conservation of the species to avoid overharvesting. The present study aimed to determine the genetic diversity of C. racemosa and document the haplotype network of the specimens from four different locations (Bintan Island, Jepara, Takalar and Osi Island) using the chloroplast tufA gene. Twenty individuals from four areas were collected and amplified with the chloroplast-encoded gene tufA for species identification against publicly available data. The identification of C. racemosa based on the tufA gene showed that the species found in four locations were C. cylindracea (previously C. racemosa var. cylindracea), C. macra (previously C. racemosa var. macra), C. racemosa, and C. oligophylla (previously C. racemosa var. lamourouxii). This study records the existence of C. cylindracea in Takalar and Jepara, Indonesia for the first time. The most diverse C. racemosa species was in Osi Island, where the exploitation of this seaweed is very low. In contrast, the lowest number of C. racemosa varieties were found in Takalar, where exploitation is very high. There were only minor light variations of Caulerpa species in the tufA gene in four different sites with only four haplotypes found, and each haplotype corresponded to another species.

Characteristics of Irradiated Hydrogel Formulated from Composite i/k-carrageenan Combined with Polyvinyl Alcohol

Eucheuma seaweed from tropical waters habitat mainly contains carrageenan, a type of hydrocolloid potential for hydrogel production. This study aims to determine the characteristics of hydrogel formulated from composite i- and k-carrageenan combined with polyvinyl alcohol (PVA) which, could be used further for wound dressing application. The concentrations of composite i/k-carrageenan used were 1.0%, 1.5%, 2.0%, 2.5% and 3.0% w/w, and the PVA concentration was 12.5% w/w. Composite i/k-carrageenan in a proportion of 6:4 by weight. The hydrogel was irradiated using 60Co g-rays with the irradiation dose of 25 and 2 kGy.h-1. The concentration of composite i- and k-carrageenan influenced the gel fraction, water holding capacity, tensile strength, elongation, and surface morphology of the hydrogel. The optimum formula of irradiated composite hydrogel was obtained from 3.0% w/w of composite i/k-carrageenan. The formula had a gel fraction of 61.67%, water holding capacity of 1067.12%, tensile strength of 32.37 x 10-3 MPa, and elongation of 251.67%. Interestingly, the product with the optimum formula had a porous surface morphology and transparency, which are applicable for wound dressing purposes.

Nutrient Composition, Antioxidant and Antibacterial Activities of Ulva prolifera O. F. Müller

Seaweeds are marine organisms capable of producing diverse kinds of chemical compounds with promising pharmacological use. The study evaluated the proximate and elemental composition and the potential antioxidant (using CUPRAC, ABTS+, and DPPH assays) and antibacterial activities (using microtiter plate dilution assay) of Ulva prolifera O. F. Müller. The seaweed has a total phenolic content of 829 ± 2.00 mg GAE/g. Antioxidant efficiency of U. prolifera exerted high ability of reducing copper ions, potent ABTS+ and DPPH scavenging activities in a concentration-dependent manner with IC50 value of 24.7 mg GAE/mL, 43.52 mg GAE/mL, and 54.1 mg GAE/mL, respectively, more effective than ascorbic acid. In vitro antibacterial activity assay showed that U. prolifera exhibited inhibitory activity against bacterial pathogens such as Methicillin-resistant Staphylococcus aureus (MIC = 125 mg/mL), S. epidermidis (MIC = 125 mg/mL), and Pseudomonas fluorescens (MIC = 500 mg/mL). This investigation is the first documented report regarding antibacterial activity of U. prolifera against P. fluorescens. In addition, results showed elemental composition to be in decreasing order of Ca K Mg Na Mn Fe Zn Cu Pb Cd Cr. Proximate composition of U. prolifera showed high carbohydrate and protein content with a percentage composition of 36.20 ± 0.27% and 23.72 ± 0.31% (dry weight), respectively. This study is the first report in the Philippines that shows the potential of U. prolifera as an excellent candidate organism as source of chemical compounds with relevant application to the pharmacological industry.

Antipathogenic Activity of Acroporid Bacterial Symbionts Against Brown Band Disease-Associated Bacteria

The coral reefs’ condition in most regions in Indonesia has been declining due to coral diseases, such as Brown Band Disease (BrBD). A treatment for BrBD involves the use of biological control agents that have antagonistic properties against disease-causing agents. This study aimed to isolate bacteria from healthy hard coral, those associated with BrBD, and those that had bioactivities against BrBD. Sampling and identification of corals and BrBD were carried out in March 2015 at the Marine National Park of Karimunjawa. Bacteria from healthy and infected corals were isolated and purified. The isolates were subjected to antipathogenic assay using overlay and agar diffusion methods. Finally, molecular identification of active bacteria was carried out using the 16S rRNA gene amplification. As many as 57 bacterial isolates were obtained from healthy coral, as well as four bacterial isolates from coral with BrBD symptoms. A total of 15 bacterial isolates (26%) showed antipathogenic activity against BrBD-associated bacteria. Three isolates with the strongest antipathogenic activities, i.e., GAMSH 3, KASH 6, and TAPSH 1 were identified by 16S rRNA gene sequences. The results showed that they were aligned to Virgibacillus marismortui (97%), Oceanobacillus iheyensis (97%), and Bacillus cereus (96%), respectively.

Neuritogenic Activities of Various Kappaphycus alvarezii Extracts in Hippocampal Neurons

The carrageenophyte Kappaphycus alvarezii seaweed is known to have neuritogenic activities. Post-harvest treatment of seaweed affects its biological activities. Five drying treatments of K. alvarezii, including oven-drying, sun-drying, freeze-drying, shade-drying, and salting followed by shade-drying, were evaluated for their effects on neuritogenic activities. We also evaluated the neuritogenic activity of different parts of K. alvarezii thalli and its carrageenan waste. Neuron cells of the 19th day pregnant rat fetuses were collected from the hippocampus by brain dissection. Neuron cells were isolated by dissociation of the hippocampal tissue. Cells were plated onto poly-DL-lysine-coated glass coverslips in 24-well plates and treated with extracts. All tested extracts were obtained from maceration using 95% ethanol. Freeze and shade-drying extracts exhibited significantly higher neuritogenic activities (p 0.05) compared to that of the vehicle control. Carrageenan waste also significantly promoted the neuritogenic activities (p 0.05) with an optimal dose at 1 µg mL-1. Old and young thalli showed insignificant differences in neuritogenic activities. The carrageenan waste extract retained neuritogenic activities. Thus, the utilization of carrageenan waste for neuritogenic material provides added value to the waste in the carrageenan industry. Freeze and shade dried K. alvarezii can be used as a neuritogenic agent to provide optimum biological activity.

Molecular Identification, Nutritional Profile and Heavy Metals Content of Edible Caulerpa from Binuangeun Coast, Banten

Two species of Caulerpa, locally known as “Pedesan” and “Latuh” have been traditionally consumed by coastal communities at Binuangeun, Banten. This study aimed to identify “Pedesan” and “Latuh” using the DNA barcoding method and to evaluate their nutrient and heavy metal contents. Fatty acids were determined by Gas Chromatography Flame Ionization Detector (GC FID), amino acids using Ultra Performance Liquid Chromatography (UPLC), and minerals using Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES). Based on the tufA gene sequences, the “Pedesan” was identified as Caulerpa racemosa var. macrophysa and “Latuh” as Caulerpa chemnitzia. Thirteen fatty acids were detected in C. racemosa var. macrophysa and twelve fatty acids in C. chemnitzia. Of the total fatty acid content, C. racemosa var. macrophysa contained 41.0% unsaturated fatty acids, dominated by linolenic acid and eicosapentaenoic acid. Meanwhile, C. chemnitzia contained 47.5%, dominated by oleic acid. Both seaweeds contained fatty acids with the w6/w3 ratio lower than 10, which could prevent heart disease risk based on World Health Organization (WHO) recommendation. The primary amino acids content in C. racemosa var. macrophysa were glutamic acid, alanine, serine and aspartic acid, while those in C. chemnitzia were glutamic acid, serine, aspartic acid, and glycine. The high content of glutamic acid in both samples indicated their potential use as food flavor enhancer. The Na/K ratio of C. racemosa var. macrophysa (40.31) and C. chemnitzia (27.48) were higher than those recommended by WHO. Heavy metals were not detected in either “Pedesan” nor “Latuh”, indicating that they are safe for consumption.

Seasonal and Spatial Water Pollution Status at The Rivers Estuaries in Cirebon Region

Cirebon has 18 rivers that flow into the Java Sea. The Cirebon rivers play an important role in several sectors such as industrial, agriculture, household, and also aquaculture. The increasing anthropogenic activities, may have affected the health and quality of the Cirebon rivers and the surrounding area. This study aimed to determine the water pollution level of Cirebon rivers based on the Storage and Retrieval (STORET) and Pollution Index approaches. The study was conducted at seven different rivers located in the districts (kabupaten) and municipals (kotamadya) of Cirebon. The observation was performed during the end of the west monsoon (March 2019) as well as the beginning (July 2019) and the end of the east monsoon (November 2019). The STORET score of the Cirebon district rivers were between -10 and -20, which is categorized as lightly to moderately polluted. Similarly, most of the Cirebon municipal rivers were moderately contaminated throughout the year (-18 to -30). In contrast, the Pollution Index (PI) values of all observed rivers were between 1.0 to 5.0 which are categorized as lightly polluted.

Initial Properties Identification of Refined- and Semi Refined-Carrageenans as Raw Materials for Biodegradable Plastic Production

Powdered refined- and semi-refined carrageenans (RC and SRC) have been characterized as alternative raw materials for industrial bioplastic production. Several basic parameters, i.e., the melting temperature, crystallinity, chemical structure (FTIR), and tensile properties, were observed. The melting temperature of RC was slightly higher than that of SRC, i.e., 176 °C and 172 °C, respectively. These temperatures were corresponded to their crystallinity degree (performed by X-ray diffraction). Nonetheless, the SRC demonstrated an overall higher thermal stability during heating. RC produced a clear transparent film. Meanwhile, SRC was yellowish and less transparent. The overall mechanical properties showed that RC produced more flexible film than SRC. However, both materials showed relatively equal tensile strength. In general, RC and SRC could be potentially used for biodegradable film production with different applications. RC was suitable for a flexible and clear plastic film, whereas SRC was suitable for rigid plastic film applications.