Masagus Muhammad Prima Putra, Muhammad Yaafi, Achmad Hanif Mardinsyah, Indun Dewi Puspita

Fish fermented products are popular products among coastal community in Indonesia. Generally, the products are naturally produced with the addition of salt without any selection of the bacterial community. This situation resulted on the variety of the final products quality. One strategy to overcome this problem is by adding a potential lactic acid (LAB), a good bacterium, in the fermentation process. We have conducted a screening of LAB from several local Indonesian fermented fish products namely Pakasam and Wadi. The first screening collected 28 isolates which characterized as LAB from Gram stain and catalase activity. The second screening was done to screen a LAB which possess antibacterial activity against common contaminant bacteria namely Staphylococcus aureus ATCC 6538, Salmonella sp. 230C, Escherichia coli 563 B, Citrobacter freundii CK1, Klebsiella sp. CK2, and Morganella morganii TK7. Among those 28 isolates, we selected one isolate with the highest antibacterial activity and successfully identified molecularly as Weisella sp. GMP 12. Further isolation of antibacterial substances targeted bacteriocin showed a good inhibition to Staphylococcus aureus ATCC 6538 with 3694 AU (Activity Unit), Salmonella sp. 230C with 2254 AU, Citrobacter freundii CK1 with 3166 AU but not to E. coli 563 B. This finding concluded that Weisella sp. GMP 12 isolated from Pakasam could be a potential candidate as a starter in the production of fermented fish products to enhance its quality. read more

Afrizal Syifa Kurnianto, Anjasmara Wahyu Wicaksana, Muhammad Prima Putra, Ragil Yuliatmo, Mohammad Zainal Abidin

ABSTRACT
The exploration of vegetable tanning’s natural resources is fascinating as an alternative to basic chromium sulfate for its natural abundance and considerable environmental impact. In this work, an attempt has been made to extract vegetable tannin from Caesalpinia sappan L. bark using water as a solvent with different levels of temperatures and incubation times. The highest yield efficiency was observed at 80 °C for 4 hours. The presence of tannin content and polyphenolic compounds were screened by the phytochemical analysis using Iron (III) chloride (FeCl3), sodium hydroxide (NaOH), and ensured by the thin layer chromatography (TLC), and the Fourier transform infrared (FTIR). The extracts were then determined by percentage of extract yield, phytochemical, tannin type, moisture, total solids, and tannin characteristics. The findings indicate that the extract of Secang contains 4.98±0.28% total moisture, 95.02 ± 0.28% total solids, and 72.12 ± 2.81% total soluble solids, 52.28 ± 1.79% tannins, and 19.84 ± 1.41% non-tannin. Moreover, Fourier transform infrared (FTIR) analysis revealed a clear functional group within Caesalpinia sappan L., as evidenced by the type of tannin that is condensed. The TLC assay exhibited a considerable intensity under UV lights. It included several shades of light blue and blue, which could indicate the presence of secondary metabolites and tannin. Compared to mimosa, as the commercial
standard for tanning agents in the leather industry, Caesalpinia sappan L. presents promise as an eco-friendly substitute for basic chromium sulfate and a new alternative source of vegetable tannin for the leather industry. read more

Mohamad Aji Ikhrami, Dini Wahyu Kartika Sari, Masagus Muhammad Prima Putra

Antibiotic resistance genes (ARGs) have recently become an emerging environmental contaminants. The aquatic environment, such as a river has already become the most polluted environment and can be a driver of ARGs. The water from irrigation canal has the potential to become a hotspot of ARGs through contamination from river pollutants carried along to the irrigation canal. However, the information regarding the cross-contamination of ARGs in fish farming systems integrated with irrigation canal in Indonesia needs further study. This study investigated the occurrence of ARGs sulfonamide (sul1), tetracycline (tetA), beta lactam (blaGES), and multi drug resistance (mexF) from body water samples along the irrigation canal and aquaculture ponds which utilize irrigation water for cultivation. Sampling sites are located in the Kulon Progo Regency (Indonesia) and samples were taken during the rainy season. Gene amplification was performed using Multiplex PCR. The results showed that sul1, tetA, and blaGES were detected in 67%, 63%, and 55% of all samples. Meanwhile, mexF was only found upstream and downstream irrigation canals, which accounted for 25% of the total samples. The results of this study indicated that the Sapon Irrigation Canal has the potential to cause the spread of antibiotic resistance genes. read more

Amir Husni, Mohamad Gazali, Nurjanah Nurjanah, Rina Syafitri, Abdul Matin, and Zuriat Zuriat

Abstract
Lung cancer is a malignant tumor that attacks the lungs generated by carcinogenic free radicals such as cigarette smoke. Seaweed contains bioactive compounds that have the potential to reduce cancer-causing free radicals. This study aimed to determine the phytochemical content and cytotoxic activity of Halimeda tuna seaweed extract against lung cancer cells (A549). The H. tuna sample was macerated using methanol for 24 h. Cytotoxic test of H. tuna crude extract used the MTT test against A549. The crude extract was phytochemically tested and analyzed using gas chromatography–mass spectrometry (GC-MS). The results showed that the H. tuna crude extract had cytotoxic activity against A549 with an IC50 value of 2771 µg/mL. The phytochemical test showed that H. tuna crude extract contained flavonoids and steroids. showed the presence of fatty acid compounds including palmitic acid, oleic acid, myristic acid, palmitoleic acid and stearic acid. Based on the results can be concluded that H. tuna extract had cytotoxic activity against A549 with low cytotoxicity to be used as a chemo-preventive agent. read more

Mohamad Gazali, Irwan Effendi, Amir Husni, Nurjanah Nurjanah, Sri Wahyuni, Ronal Kurniawan

Background
Strategies to increase body resistance and prevent disease in aquaculture include using vaccines, antibiotics, and probiotics. Today, the use of antibiotics with natural ingredients is becoming a trend. Sargassum sp is a natural ingredient that contains high antioxidants and antibiotics.

Methods
This research was conducted from March to May 2022 at the Biotechnology Laboratory, Faculty of Fisheries and Marine, Universitas Riau, in two stages: 1) the sensitivity of extracts of Sargassum sp. and 2) the application of Sargassum sp. extract orally in tilapia (O. niloticus). The parameters measured were clear zone, minimum inhibitory concentration, LD50 test of leaf extract of Sargassum sp. in tilapia (O. niloticus), hemoglobin levels, hematocrit, total leukocytes, total erythrocytes, leukocyte differentiation, and survival rate. Data on hematology parameters were tabulated and analyzed using a One-Way ANOVA followed by a Student Newman Keuls (SNK) test when deemed necessary. read more

May Khoirunnisa Setiadi, Amir Husni

Caulerpa lentillifera seaweed comprises several bioactive compounds that possess health-promoting properties, which make it suitable for incorporation into food items, including yogurt. The purpose of adding seaweed to yogurt is to enhance its flavor and boost its antioxidant activity. The objective of this study was to determine the optimal concentration of C. lentillifera seaweed to evaluate its chemical, microbiological, and antioxidant properties, as well as to assess the level of consumer acceptance of yogurt. To achieve this, seaweed yogurt was prepared by incorporating C. lentillifera seaweed at concentrations of 0, 5, 10, and 15% (v/v), and the pH, lactic acid, lactic acid bacteria, total phenols, and antioxidant activity (using the DPPH method) were analyzed. In addition, the level of consumer acceptance was evaluated. The findings of this study demonstrated that disparities in the amounts of C. lentillifera seaweed affected the chemical and microbiological traits, including total phenols, antioxidant activity, and consumer preferences for yogurt. The optimal treatment was achieved with the addition of 5% seaweed at a pH level of 3.97±0.035, lactic acid content of 1.08±0.09%, lactic acid bacteria count of 1.74×10^8 cfu/mL, and total phenol content of 39.62±0.49 mg GAE/g. Additionally, the antioxidant activity value was 39.32±0.45%, and the hedonic values for color (3.64±0.98), aroma (3.59±0.83), texture (3.44±0.91), and taste (3.45±1.16) were also favorable. According to the proximate analysis, which evaluated the moisture, protein, fat, and ash content of seaweed yogurt, the results were consistent with SNI 2981:2009. Furthermore, the inclusion of C. lentillifera in yogurt production enhanced both its flavor and antioxidant activity. read more

There is concern regarding the use of synthetic antioxidants which spurred the yearly increase of natural antioxidants to substitute synthetic ones. Fish protein hydrolysate (FPH), which has been reported to have potent antioxidant properties, could be utilized to solve this problem. This study aimed to utilize the by-product of snakehead fish (head) and determine the optimum hydrolysis conditions to obtain FPH with antioxidant activity. Two parameters were tested during the hydrolysis process: enzyme concentration (papain enzyme) and hydrolysis time. The optimum condition was evaluated by measuring dissolved protein, hydrolysis degree (DH), and antioxidant activity, including DPPH, ABTS, and FRAP. The optimal hydrolysis conditions were 5% enzyme concentration and 6 h of hydrolysis time at 55°C and pH 7.0. The DPPH, ABTS, and FRAP antioxidant activities were 50.70%, 66.67%, and 1.35 M Tr/mg, respectively. Based on the antioxidant activity, Snakehead fish head has the potential as a source of natural antioxidants.

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Abstract

N‐acetylglucosamine (NAG) is the monomer product of chitin, which has been widely used as a bioactive com‐ pound in applications such as anti‐tumor, anti‐microbial, and antioxidant activities. In production, biological processes using enzymes are preferable to chemicals due to environmental issues. This study aims to determine the activity, purity level, and molecular weight of purified chitinase from Micromonospora sp. AR17 determines the concentration of NAG produced by purified chitinase that has been characterized. Chitinase was produced by fermentation in colloidal chitin broth at 40 °C, pH 7, for 7 days, while chitinase activity was checked every 24 h. The optimal fermentation time was used to produce chitinase for a further purification step. Enzyme purification was carried out by ultrafiltration, ammonium sulfate precipitation, ion exchange chromatography (Q Sepharose Fast Flow), and gel filtration (Sephacryl S‐300). The purified enzyme was then char‐ acterized for optimum time, pH, and temperature to produce NAG. The results suggested that the fourth day was the optimal time for chitinase production, with chitinase activity of 0.0040 U/mL and a NAG concentration of 7.62 µg/mL. The purifica‐ tion step successfully increased the purity by 6.82 times with chitinase‐specific activity at 1.4648 U/mg. Production of NAG with purified chitinase produced a NAG concentration of 32.472 µg/mL with an incubation time of 30 min at 40 °C and pH 7.

Keywords: Chitinase; Micromonospora sp. AR17; N‐acetylglucosamine; Purification

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Seaweed belongs to marine biota and contains nutrients and secondary metabolites beneficial for health. This study aimed to determine the antidiabetic activity of extracts and fractions of green seaweed Halimeda tuna. The H. tuna sample was extracted with the maceration method using methanol and then partitioned using ethyl acetate and water to obtain ethyl acetate and water fractions. The methanol extract, ethyl acetate fraction, and water fraction of H. tuna were tested for their inhibitory activity against α-amilase and α-glucosidase. The methanol extract and the fractions with the highest inhibitory activity were phytochemically tested and analyzed using gas chromatography–mass spectrometry (GC-MS). The results showed that the ethyl acetate fraction (IC50 = 0.88 ± 0.20 mg/mL) inhibited α-amylase relatively similar to acarbose (IC50 = 0.76 ± 0.04 mg/mL). The methanol extract (IC50 = 0.05 ± 0.01 mg/mL) and the ethyl acetate fraction (IC50 = 0.01 ± 0.00 mg/mL) demonstrated stronger inhibitory activity against α-glucosidase than acarbose (IC50 = 0.27 ± 0.13 mg/mL). Phytochemical testing showed that the methanol extract and the ethyl acetate fraction contained secondary metabolites: alkaloids, flavonoids, steroids, and phenol hydroquinone. The compounds in methanol extract predicted to have inhibitory activity against α-amylase and α-glucosidase were Docosanol, Neophytadiene, Stigmasta-7,22-dien-3-ol,acetate,(3.beta.,5.alpha.,22E), Octadecanoic acid,2-oxo-,methyl ester, and phytol, while those in the ethyl acetate fraction were n-Nonadecane, Phytol, Butyl ester, 14-.Beta.-H-pregna, Octadecenoic acid, and Oleic acid.

Keywords: Halimeda tuna; α-amylase; α-glucosidase; methanol extract; ethyl acetate fraction

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Optimization Concentration of Irgacure® 2959 as Photo-initiator on Chitosan-Kappa-Carrageenan Based Hydrogel for Tissue Sealant

Fiskina Zulfa Kamala, Wiratni Budhijanto, Eko Purnomo, Prihati Sih Nugraheni

Hydrogel is a three-dimensional network of hydrophilic polymers widely used in the biomedical field, one of which is a tissue sealant. The material that can be used in the manufacture of hydrogels is chitosan. The ability of chitosan in the formation of hydrogel is still limited by its swelling and adhesive properties, so it requires other materials such as crosslinkers, one of which is kappa-carrageenan which can stabilize and increase the viscosity of the hydrogel. The addition of Irgacure^® 2959 as a photo-initiator to the hydrogel can produce free radicals that can bind to the active group of the polymer. This study aims to determine the effect of adding Irgacure^® 2959 in the manufacture of hydrogel based on a chitosan-kappa-carrageenan solution formulated as a colon tissue adhesive. The treatments given were the addition of Irgacure^® 2959 as much as 0%, 1%, 2%, 3%, and 4%. The characteristics of the hydrogel tested qualitatively (simulation adhesion test), degree of swelling, resistance to water, degree of crystallinity, and ability to inhibit bacterial growth. The addition of Irgacure^® 2959 did not show significantly different results from the control that indicating it cannot increase the crosslinking between chitosan and kappa-carrageenan. This is predicted due to the presence of steric hindrance from kappa-carrageenan, causing very limited crosslinking due to the molecular size difference between chitosan and kappa-carrageenan. Further, it is necessary to optimize the ratio of the chitosan and kappa-carrageenan to get the balance ratio that supports the occurrence of cross-linking. read more