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This study aims to determine the effect of liquid media composition on the inhibitory activity of α-glucosidase from endophytic fungus Aspergillus elegans SweF9 isolated from seaweed (Macroalgae Euchema sp). Fermentation was carried out in three types of liquid media, namely: potato dextrose broth (PDB), potato malt peptone (PMP), and Czapek-dox broth (CDB), which was incubated for 10 days at room temperature, with static conditions. Ethyl acetate solvents were used to extract active metabolites from fungal biomass and filtrate from each media. Antidiabetic activity was measured based on inhibition of enzyme α-glucosidase. The results showed that filtrate extract of A. elegans SweF9 which was cultured on the media PDB showed highest inhibitor activity to the α-glucosidase enzyme with an IC50 value of 1.74 µg / mL compared to other extracts. Based on these results, the PDB media is an appropriate medium for culturing A. elegans SweF9 to produces secondary metabolites that can be used as a new source of antidiabetic agents.

Kombucha is a fermented beverage product using SCOBY (Symbiotic Culture of Bacteria and Yeast). This beverage has several health effects such as antioxidants and antibacterial. Aim of this study was to produce Kombucha probiotic drinks made from beet (Beta Vulgaris L.) and can be used to prevent natural digestive infections and free radicals. Beet extract Kombucha fermentation was conducted for 12 days at room temperature. The results showed that fermentation for 12 days produced Kombucha beet with total composition of 0.30% polyphenols, 1.73% total acid, 10.07% total solids, 15.36 mg/mL dissolved protein, pH 3.64, antibacterial activity against Escherichia coli (E. coli) of 15 mm with an index activity value of 53.57% compared to Streptomycin sulfate at concentration of 1% and potentially prevention of free radicals of 86.29%.

Dead-End Stirred Filtration Cell (DESFC) has potential use in separating organic acids from beetroot (Beta vulgaris L.) fermented by Kombucha culture. This experiment activity aims to find out optimization of separation process using microfiltration (MF) membrane (pore size 0.15 µm) at room temperature, stirrer rotation speed (SRS) of 200, 300 and 400 rpm and transmembrane pressure (TMP) of 20, 30 and 40 psia for 30 minutes. The results show that through this process, retentate (concentrate) and permeate produce the best composition, especially organic acids and characteristics to prevent increasing natural cholesterol. The experiment result showed that the best treatment was achieved at SRS 400 rpm and TMP of 20 psia. This result gave retentate (concentrate) and permeate with total organic acids calculated as total acids of 1.20 and 0.30 %, reducing sugars of 23.58 and 15.74 mg/mL, total solids of 9.94 and 9.30 %, dissolved protein of 23.08 and 22.57 mg/mL and betacyanin of 0.16 and 0.16 µg/mL, meanwhile particle size distribution in retentate (concentrate) and permeate indicated particle size of 2,018.8 and 5,181.3 nm at particle index (PI) of 0.600 and 0.905. Identification on rentetate and permeate monomer of fermented rootbeet by means of LC-MS displayed domination of organic acids monomer as butyric acid with molecular weight (MW) of 177.19 and 177.43 Dalton (Da.) (M++) and relative intensity of 100 %. MF membrane (pore size 0.15 µm) fitted in DESFC technique at the optimum condition is able to separate organic acids in retentate (concentrate) of 140 % or 1.4 folds as compared to feed.

Fermentation by lactic acid bacteria (LAB) is one promising alternative to improve the benefits of various food and beverages. This research aims to examine the consequence of lactic acid fermentation of banana juice to antioxidant activity, total polyphenol contents, total LAB, pH, titratable acidity, reducing sugar and dissolved protein. The identification of gallic acid and lactic acid monomers was conducted on the most optimal condition of the fermentation by using LC-MS. Banana juice underwent fermentation for 48 hours at 37°C using 2 distinctive cultures: Bifidobacterium bifidum and mixed cultures of LAB. The application of cultures in test subject modified the properties of banana juice with respect to the observed parameters. Mixed cultures of LAB introduced for 32 hours resulted in the highest DPPH (2,2-Diphenyl-1-Picrylhydrazyl) inhibition activity (67.95%) compared to unfermented fresh banana juice (30.66%) and juice fermented using Bifidobacterium bifidum (51.16%). Significant improvement of total polyphenol content was also observed in juice fermented with mixed cultures for 32 hours. Sample’s pH decreased following the increased total LAB and total acid during fermentation. Meanwhile, the values of reducing sugar and dissolved protein tended to fluctuate. Identification of gallic acid monomer at optimal condition revealed the dominant monomer had molecular weight of 171.34 Da whereas identification of lactic acid monomer found that the dominant monomer had molecular weight of 91.27 Da. Our research proposes that fermentation of banana juice using lactic acid bacteria can improve the polyphenol content and antioxidant activity of the juice.

Katuk (Sauropus androgynus) is one of local plants that contains high chlorophyll content and large amounts of antioxidants, which are very useful to prevent free radicals and premature aging. Katuk leaves can be directly consumed as vegetables or be processed as fermented health beverage. This study aimed to evaluate antioxidant activity of formulated functional drinks derived from katuk leaf extracts. The activity of the functional drinks was optimized by varying fermentation conditions, such as kombucha culture level, sucrose level, and fermentation time, using response surface methodology (RSM). Katuk leaf was extracted using sterile hot water (leaf:water ratio, 1:10) with concentration of kombucha culture varied from 10–20% (w/v), sucrose addition varied from 10–20% (w/v), and fermentation time varied 0-12 days. The optimization was done by using Box-Behnken Design Response Surface Methodology (RSM) to evaluate and select optimal process conditions from a combination of factor levels which results in an optimal response. Based on RSM Box-Behnken Design, it was found that the above-mentioned three factors greatly influenced the response value. Optimum conditions were obtained with culture concentration of 13.75%, sucrose addition of 20% (w/v) and fermentation time of 5.66 days with the percentage inhibition of antioxidant was 80.27% (DPPH method), Feric reducing antioxidant power was 217.78 mg ascorbic acid/mL, pH was 4.57 and total polyphenols was 1,31 mg GAE/mL and reducing sugar 20,78 mg/mL.

Folic acid (Vitamin B9) involved in numerous metabolisms. Folate deficiency is responsible for some negative health problems. The fermentation of foodstuffs to produce rich content of folic acid beverages using lactic acid bacteria (LAB) is an effort to overcome the health issues. This study aimed to determine the effect of banana juice fermentation using LAB on the folic acid content of the banana juice. Banana juice was fermented for 48 hours at 37 o C with monoculture of Lactobacillus plantarum and mixed LAB cultures of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, Bifidobacterium bifidum and Bifidobacterium breve. The changes of folic acid characteristics were observed every 8 hours during 0 – 48 hours of fermentation, as well as the change in pH, total acid, soluble protein, and reducing sugar. The identification of folic acid monomers was conducted at the most optimal condition of the fermentation by using LC-MS. The result showed fermentation affect the folic acid content, pH, total acid, reducing sugar and soluble protein of banana juice. During fermentation, pH of the sample decreased with the increasing of total acid. Reducing sugar and soluble protein content tended to fluctuate. Optimal condition for folic acid enhancement was obtained by 32 hours of fermentation with mixed LAB, in which it yielded folic acid 34 . 07 μg/mL, pH . ,00, total acid 0 . 51%, reducing sugar 119 . 17 mg/L, dissolved protein 0 . 43 mg/mL. Folic acid identification on the optimal condition revealed that it was dominated by compound with a molecular weight of 441.49 Dalton. Keywords: banana, fermentation, folic acid, lactic acid bacteria ABSTRAK Asam folat (Vitamin B9) terlibat dalam berbagai metabolisme. Kekurangan folat bertanggung jawab atas beberapa masalah kesehatan. Fermentasi bahan pangan untuk menghasilkan minuman kaya asam folat menggunakan bakteri asam laktat (BAL) merupakan upaya untuk mengatasi masalah kesehatan akibat defisiensi folat. Penelitian ini bertujuan untuk mengetahui pengaruh fermentasi jus pisang menggunakan BAL terhadap kandungan asam folat jus pisang. Jus pisang difermentasi selama 48 jam pada suhu 37 o C dengan kultur tunggal Lactobacillus plantarum dan kultur campuran BAL yaitu Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, Bifidobacterium bifidum dan Bifidobacterium breve. Perubahan karakteristik asam folat diamati setiap 8 jam selama 0-48 jam fermentasi. Selain itu, diamati pula perubahan pH, total asam, protein terlarut dan gula pereduksi. Identifikasi monomer asam folat dilakukan pada kondisi fermentasi paling optimum dengan menggunakan LC-MS. Hasil penelitian menunjukkan bahwa fermentasi dapat mempengaruhi kandungan asam folat, pH, total asam, gula pereduksi dan protein terlarut dari jus pisang. Selama fermentasi, pH sampel menurun diikuti dengan peningkatan total asam. Nilai gula pereduksi dan protein terlarut cenderung berfluktuasi. Kondisi optimum peningkatan kandungan asam folat diperoleh pada fermentasi menggunakan mix kultur LAB selama 32 jam dengan kandungan asam folat 34,07 mg/mL, pH 4,00, total asam 0,51%, gula pereduksi 119,17 mg/L dan protein terlarut 0,43 mg/mL. Identifikasi monomer asam folat pada kondisi optimum fermentasi didominasi senyawa dengan berat molekul 442,49 Dalton (Da). Kata kunci: asam folat, bakteri asam laktat, fermentasi, pisang

Butyrolactone I (BL-I) has been reported as inhibitor of α-glucosidase and antioxidant compound isolated from culture broth of Aspergillus terreus. The purpose of this study was to determine the effect of various liquid media compositions on production of BL-I from A. terreus LS07. Fermentation was conducted in four liquid medium: potato dextrose broth (PDB), potato malt peptone (PMP), malt extract (ME), and Czapek-Dox broth (CDB), which were incubated for seven days at room temperature, with agitation of 70 rpm. Ethyl acetate (EtOAc) was used to extract the active metabolite from each broth. Glucosidase inhibitory activity was measured by the inhibition of yeast α-glucosidase, while antioxidants measured by testing the total phenol and DPPH free radical scavenger activity. The results showed that the EtOAc extract on CDB had strong inhibition activity against the enzyme α-glucosidase and strong antioxidant with IC50 values 6.45 and 24.05 μg/mL, respectively. The CDB extract also showed the highest content of total phenols (349.66 mg Gallic Acid Equivalent (GAE)/g extract) and BL-I (58.5% w/w). Based on these results, among the four kinds of medium used, Czapek-Dox broth is an ideal culture medium of A. terreus LS07 that could be applied for increase production of BL-I as natural antidiabetic source from terestrial fungi

Lovastatin is an anti-cholesterol agent that was produced by Aspergillus terreus using solid state fermentation (SSF). During this fermentation process, sulochrin is also produced as an unwanted co-metabolite. However, our previous result showed that sulochrin had potential as antidiabetes because it is an inhibitor agent of α-glucosidase. In this paper, we reported our observation on lovastatin and sulochrin production pattern in relation with inhibitor α-glucosidase activity during eleven days fermentation of A. terreus koji (SSF) ethyl acetate extract. Koji obtained from solid state fermentation with rice as the substrate and incubated at room temperature, sample is taken daily for eleven day (D-1 to D-11). Lovastatin and sulochrin production was measured by Liquid Chromatography- Mass Spectrometer based on their molecular weight m/z 404.5 and 332.3 respectively. The inibitory activity is measured by inhibition model of koji extract against α-glucosidase (EC 3.2.1.20) from Saccharomyces cereviceae. The results show that lovastatin production was started on the day 2 (0.04 mg/g) and achieving the optimal production on day 7 (11.46 mg/g), while sulochrin production was started on day 4 (0.60 mg/g) and keep produced until the end of fermentation period at Day 11 (3.11 mg/g). Koji extract was started to show inhibitory to α-glucosidase activity on Day 5 (IC50= 23.34 μg/mL) and keep showed activity until Day 11 (IC50=3.33 μg/mL). These results suggest that inhibitory activity of koji extract to α- glucosidase activity have relation with sulochrin biosynthesis production.

Ethanol is a potential industrial chemical as a very promising biofuel to replace fossil fuels. Its capability to increase octane number and improve the emissions quality of gasoline drives the researches in efficient ethanol production. A rapid fermentation leading to high ethanol concentration; therefore a yeast strain with a good specific ethanol production rate becomes the main consideration. Due to several advantages presenting by the using of cell immobilization, such as increased productivity, reduced risk of contamination, biocatalyst recycling, rapid product separation and others, the interest of cell immobilization for ethanol production has increased in the last decades. The great importance to find cheap, abundant, and non-destructive immobilization supports, rice flour and white glutinous rice flour were tested as support for yeast immobilization in the present work. Three commercial yeast strains were used in the experiments, labelled A, B, and C. The fermentation runs were carried out with glucose as substrate in 250 mL Erlenmeyer flask containing 100 mL of medium and 5% of immobilized enzyme loading and statically incubated at 32oC for 72 hours. Fermentations were carried out in duplicate and fermentations under the same conditions described above were also performed without support addition for comparison. The results showed that white glutinous rice flour was great potential for use as immobilization support during the ethanol production by the C yeast strain culture.