Biodesulfurization of the mixture of dibenzothiophene and its alkylated derivatives by Sphingomonas subarctica T7b

Organosulfur compounds classified as dibenzothiophenes (DBTs) and their derivatives are contained in petroleum. When used as fuel, these substances release SOx emissions, thus contributing to air pollution, acid rain, and climate change. Therefore, it is necessary to reduce the content of these organic sulfur compounds in fuels and one way to achieve this is through bacterial desulfurization. This study reports the biodesulfurization process of a mixture of DBT, 4-hexyl DBT, 4,6-dibutyl DBT, and various organosulfur compounds in light gas oil (LGO). The experiment was conducted by treating 1 mL of aromatic organosulfur compounds with 100 mg/L in \textit{n}-tetradecane or 1 mL LGO with 5 mL mineral salts in sulfur-free medium, incubated at 27 °C for 5 days with shaking at 273 rpm. Gas chromatography analyses revealed that the growing Sphingomonas subarctica T7b cells desulfurized and converted 88.29% of DBT to 2-hydroxybiphenyl as a metabolite while a mixture of DBT and 4,6-dibutyl DBT was desulfurized at 86.40\% and 7.00%, respectively. Furthermore, the mixture of DBT, 4-hexyl DBT, and 4,6-dibutyl DBT had a desulfurization percentage of 84.40%, 41.00%, and 6.66%, respectively, after five days of incubation. The compounds were observed to desulfurize slightly better as single compounds compared to when mixed with other aromatic sulfur compounds

Pemanfaatan Tepung Rumput Laut Gracilaria sp. pada Tempe sebagai Alternatif Pangan Sumber Yodium

Tempe merupakan produk pangan bergizi tinggi yang digemari dan diterima oleh masyarakat luas tetapi umumnya memiliki kadar yodium yang rendah. Rumput laut yang kandungan yodiumnya cukup tinggi dapat digunakan sebagai bahan fortifikasi yodium pada makanan. Penambahan rumput laut pada tempe diharapkan dapat menjadi alternatif pangan sumber yodium untuk menanggulangi masalah GAKY (Gangguan Akibat Kekurangan Yodium). Tujuan penelitian ini adalah untuk mengetahui pengaruh penambahan tepung rumput laut Gracilaria sp. terhadap kadar yodium pada tempe serta mengetahui karakteristik yang dihasilkan. Perlakuan yang dilakukan adalah perbandingan kedelai dan tepung rumput laut 100:0; 97,5:2,5; 95:5; 92,5:7,5; dan 90:10. Perbandingan kedelai dan tepung rumput laut 92,5:7,5 merupakan komposisi terbaik yang menghasilkan tempe dengan kadar yodium 0,26 mg/g; nilai sensoris hedonik rata-rata 5 (agak suka), serta 100 gram tempe tersebut memenuhi 17,47% angka kecukupan gizi (AKG) yodium orang dewasa per hari. Studi ini menunjukkan bahwa tempe tersebut dapat digolongkan sebagai pangan sumber yodium karena telah memenuhi 15% AKG orang dewasa. ABSTRACT Tempeh is a highly nutritious food that is popular and accepted by diverse community groups but has low iodine levels. Seaweed, with a high iodine content can be used as a fortification ingredient to increase the iodine levels of the foods. The addition of seaweed in tempeh is expected to be used as an alternative food source of iodine contents to overcome the IDD (Iodine Deficiency Disorders) problem. This study aimed to determine the effect of the addition of Gracilaria sp. seaweed flour to iodine levels in tempeh and to determine the characteristic of the product. The treatments were 5 (five) compositions of soybean and seaweed flour, in the ratio of (100:0), (97.5:2.5), (95:5), (92.5:7.5), and (90:10). The composition of soybean and seaweed flour in the ratio of 92.5:7.5 was the best composition that produces tempeh with an iodine content of 0.26 mg/g; hedonic sensory test results on average 5 (somewhat like) and 100 g of tempeh met 17.47% of the daily iodine requirements for the adults. This study showed that tempeh can be considered as an alternative food source of iodine content as it contributed to 15% of adult’s daily nutritional adequacy

Physicochemical Characteristics of Fresh-cut Tropical Fruit during Storage

Fresh-cut tropical fruit is increasingly popular currently, stimulated by public awareness of health and practical lifestylefresh-cut fruit presenting consumers' convenience, safety, and quality. Tropical fruit contains functional components that are quite varied and good for health. Mangosteen, Mango, and Rambutan are three exotic tropical fruits that have high economic value and are liked by foreign people. They have a nonedible relatively high and potentially processed into fresh-cut fruit—the process of stripping cutting and slicer, causing wounds that spur damage. During storage, fresh-cut fruits undergo physical-chemical changes—increased respiration rate, ethylene production, oxidation, and browning processes that can shorten shelf life. The damage will be faster if stored at an improper temperature. Fresh-cut fruit is preferably stored at cold temperatures, to extend the shelf life. The research aims to determine the physicochemical characteristics of fresh-cut tropical fruits during cold storage. The research uses a pattern of random group three replicate. The first factor is fruit type (Mango, Mangosteen, Rambutan); the second factor is storage time in cold temperatures (0, 5, 10 days). The variables observed in the study included physical characteristics color (L*a*b*), weight, and texture. Observations of chemical characteristics include moisture content, pH, total acids, vitamin C levels, and total dissolved solids. Freshcut tropical fruit has different physicochemical characteristics and experiences deterioration during cold temperatures. The characteristics of tropical fruit have changed significantly on day 5. Mango shows more significant changes than others, seen from variable moisture content, vitamin C, color, and texture. Meanwhile, based on the physicochemical analysis, rigidity of fresh-cut Mango higher than Mangosteen and Rambutan

Selection and the Growth Condition Optimization of Ethanol‐Producing Microbes Isolated from Ragi Tapai

Ethanol is a biofuel produced from renewable resources, which potentially plays an important role in solving future fuel problems. This study aimed to select the highest ethanol-producing isolate from candidates obtained from previously isolated candidates from ragi and cassava tapai. The selection process was conducted in 2 stages, namely: 1) Selection of the highest ethanol-producing isolate from seven isolate candidates using PYG media containing peptone, yeast extract, and glucose at 0.75%, 0.75%, and 15%, respectively and was followed by: 2) Optimization of the growth conditions of the highest ethanol-producing isolate, which was conducted at various temperatures of 27, 30, 33, 35, 37, and 40°C with the combination of various pH of 3.5, 4.5, 5.5, and 6.5. The experimental results showed that the R5I3 isolate was the highest ethanol-producing performance isolate, which yielded approximately 4.69±0.25% (v/v). Following the temperature and pH optimization of the fermentation processes, the optimum growth conditions were at 35°C and pH 5.5, where the ethanol produced was increased to 8.63 ± 0.04% (v/v). With these results, this new strain has the potential to be used in bioethanol production processes and other industrial applications

Identification of Contaminant Fungi on Pedetan, an Dry Fish Product of Lemuru (Sardinella lemuru)

Dry fish products of Lemuru (Sardinella lemuru) known in Bali under the name "pedetan" is one kind of dried seasoned processed products that is quite popular among the people of Bali, especially in Jembrana Regency.  In general the process is done through drying lemuru fish in the sun so it is possible for them to grow and develop the contaminant fungi that may affect the health of consummers.  This study aims to isolate and identify fungi that contaminate pedetan.  Pedetan samples were taken from 10 villages which are the pedetan production centers in Jembrana Regency. The identification was done macroscopically, microscopically, and molecularly through analysis of 18S rRNA gene. The results of this study indicate that there are four types of fungi that are found as contaminants of pedetan, namely Aspergillus flavus, Aspergillus aculeatus, Aspergillus niger, and Aspergillus tubingensis. Efforts are needed to improve the composition of spices in order to maximally reduce the population of contaminant fungi in pedetan. Keywords: Sardinella lemuru, pedetan, contaminant fung

Ecogel incorporated with nano-additives to increase shelf-life of fresh-cut mango

Fresh-cut mango is a very popular product commonly consumed due to its health and safety benefits to the community. The rise in cutting results, which increases respiration, ethylene production, oxidation, and browning processes, tends to shorten its life. Edible coating of aloe gel (Ecogel) serves as an additive matrix to extend the life of fresh-cut mango with the incorporation of antioxidant, acidulant, and antimicrobial additives. The edible coating ability is strongly influenced by molecular structure, size, and chemical constituents, with the nanoparticle used to determine the edible coating capability. This study, therefore, aims to determine the influence of incorporation nano-additive material and its concentration to extend the shelf life of the mango. The complete random design was used to determine the factorial pattern of citric, ascorbic, and potassium sorbate acid using a concentration of 0.15, 0.3, and 0.45 %. The mixture of nano-additives consists of citric acid, ascorbic acid, and potassium sorbate at a concentration of 0.15 %, which is the best formulation for Ecogel. The characteristics of fresh-cut fruit coated with Ecogel are suitable at a temperature of 7 ± 1 C until day 6. Therefore, Ecogel prolongs the shelf-life of fresh-cut mango

Physicochemical and antioxidant properties of Apis cerana honey from Lombok and Bali Islands

Limited honey production worldwide leads to higher market prices, thus making it prone to adulteration. Therefore, regular physicochemical analysis is imperative for ensuring authenticity and safety. This study describes the physicochemical and antioxidant properties of Apis cerana honey sourced from the islands of Lombok and Bali, showing their unique regional traits. A comparative analysis was conducted on honey samples from Lombok and Bali as well as honey variety from Malaysia. Moisture content was found slightly above 20% in raw honey samples from Lombok and Bali, adhering to the national standard (SNI 8664:2018) of not exceeding 22%. Both honey types displayed pH values within the acceptable range (3.40–6.10), ensuring favorable conditions for long-term storage. However, Lombok honey exhibited higher free acidity (78.5±2.14 meq/kg) than Bali honey (76.0±1.14 meq/kg), surpassing Codex Alimentarius recommendations (50 meq/kg). The ash content, reflective of inorganic mineral composition, was notably lower in Lombok (0.21±0.02 g/100) and Bali honey (0.14±0.01 g/100) compared to Tualang honey (1.3±0.02 g/100). Electric conductivity, indicative of mineral content, revealed Lombok and Bali honey with lower but comparable values than Tualang honey. Hydroxymethylfurfural (HMF) concentrations in Lombok (14.4±0.11 mg/kg) and Bali (17.6±0.25 mg/kg) were slightly elevated compared to Tualang honey (6.4±0.11 mg/kg), suggesting potential processing-related changes. Sugar analysis revealed Lombok honey with the highest sucrose content (2.39±0.01g/100g) and Bali honey with the highest total sugar content (75.21±0.11 g/100g). Both honeys exhibited lower glucose than fructose content, aligning with Codex Alimentarius guidelines. The phenolic content, flavonoids, and antioxidant activity were significantly higher in Lombok and Bali honey compared to Tualang honey, suggesting potential health benefits. Further analysis by LC-MS/MS-QTOF targeted analysis identified various flavonoids/flavanols and polyphenolic/phenolic acid compounds in Lombok and Bali honey. The study marks th

PENGARUH BERBAGAI MERK DRIED YEAST (Saccharomyces sp.) DAN pH AWAL FERMENTASI TERHADAP KARAKTERISTIK WINE SALAK

The purpose of this research were to find out the effect of different of dried yeast and initial pH of fermentation on the characteristic of salacca wine, and to determine the appropriate of kind of dried yeast and initial pH of fermentation to produce salacca wine with the best characteristic. This research used Randomized Block Design with factorial pattern. The first factor was the kind of dried yeast brand that consisted of 3 kinds namely Lalvin, Levure and Alcotec. The second factor consisted of 5 levels of initial pH, namely 3.5; 4; 4.5; 5; and 5.5. Each treatment was done 2 times, in order to obtain 30 trial units. The data obtained was analyzed using ANOVA followed by Duncans test. Interactions between treatments had very significant effect on the ethanol content, reduction sugar content, and pH, but had significant effect on acid total content. The best treatment was to use the Alcotec brand dried yeast with a treatment of initial pH as 4, with the following characteristics: ethanol content 12.40%, negative content of methanol, reduction sugar content 5.87%, acid total content 0.20%, pH 3.5 after the fermentation, the color was enough pure yellow, the flavor was strong enough, the taste was strong enough, and rather liked over all acceptance

The Presence of Mercury Resistant Bacteria in Sediment of Gold Processing Plant at Waekerta Village of Buru District, Maluku Province and Their Activity in Reducing Mercury

ABSTRACT Mercury was one of the heavy metal polute in environment and had the toxic characteristic to the living creatures. Golden mining in Waeapo subdistrict used mercury to extract the gold and exile the waste to the environment freely. Several precedented research showed that waste sediment of gold processing contains mercury resistance bacteria. Mercury resistance bacteria can be used as bioremediation agent because those bacteria can reduce mercury. Mercury resistance bacteria has mer operon which contained in plasmid. The goal of this research is to isolate mercury resistance bacteria which is able to grow on medium nutrient agar (NA) containing 500 ppm of HgCl 2 and to analyze the capability in HgCl 2 reduction in nutrient broth (NB) medium. Bacteria isolation was done by platting method on Nutrient Agar containing 10 ppm of HgCl 2 . Bacteria identification was done by kit Microgen TM GnA + B-ID System and to know bacteria capability in reducing mercury was done by CV-AAS (Cold Vapour Atomic Absorption Spectrophotometer). Result showed, that the bacteria found in this research were Bacillus sp and Aeromonas hydrophila. Both of these bacteria were able to reduce HgCl 2 in the amount of 98,7% for Bacillus sp and 98,33% for Aeromonas hydrophila. In the future those bacteria can be use as bioremediation agent