Purwandhani, Siti Nur
Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Published : 3 Documents

Found 3 Documents

Potensi Lactobacillus plantarum yang Diisolasi dari Dadih dalam Meningkatkan Kadar Folat Susu Fermentasi

Agritech Vol 37, No 4 (2017)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

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Folate is a B vitamin that participates in one-carbon transfer reactions of metabolism process, particularly purine and pyrimidine biosynthesis (DNA and RNA). Some strains of lactic acid bacteria are known to produce folic acid through the conversion of guanosine tri phosphate and the presence of precursor p-amino benzoic acid and glutamic acid. In this study, skim milk was fermented using Lactobacillus plantarum Dad-13, G-3, and H-1 to increase the levels of folate. Fermentation was conducted at 37 °C for 18 hours. The aims of this study were to investigate the population of  L. plantarum during fermentation period, the change in pH and the levels of folate in fermented milk. The results showed that during the fermentation period using L. plantarum G-3, H-1, and Dad-13 cell count increased from 107 to 108 for G-3 and H-1, while Dad-13 into 109. The pH value decreased and the levels of folic acid in early fermentation increased rapidly but after approaching the end of fermentation, it began to stagnate. The folate level of skim milk was 23.70 ± 3.25 µg/L. Increased levels of folate in fermented milk after 18 hours fermentation using L. plantarum Dad-13, G-3, and H-1 were 32.04 ± 1.85 µg/L (135.19%), 28.21 ± 0.28 µg/L (118.99%), and 25.13 ± 1.27 µg/L (106.03%), respectively.ABSTRAKFolat merupakan vitamin B yang berpartisipasi dalam reaksi transfer satu-karbon dalam proses metabolisme, terutama biosintesis purin dan pirimidin (DNA dan RNA). Beberapa strain bakteri asam laktat diketahui mampu memproduksi asam folat melalui konversi guanosin tri pospat dan dengan adanya prekursor p-amino benzoat serta asam glutamat. Pada penelitian ini, susu skim difermentasi menggunakan Lactobacillus plantarum Dad-13, G-3, dan H-1 untuk meningkatkan kadar asam folatnya. Fermentasi dilakukan pada 37 °C selama 18 jam. Tujuan penelitian ini adalah untuk mengetahui pola pertumbuhan sel, perubahan pH, dan kadar asam folat susu selama fermentasi. Hasil penelitian menunjukkan bahwa selama fermentasi menggunakan L. plantarum Dad-13, G-3, dan H-1 jumlah sel meningkat dari 107 menjadi 108 untuk G-3 dan H-1, sedangkan Dad-13 menjadi 109. Nilai pH mengalami penurunan dan kadar asam folat pada awal fermentasi meningkat dengan cepat tapi setelah mendekati akhir fermentasi mulai stagnan. Kadar asam folat susu skim adalah 23,70 ± 3,25 µg/L. Dibandingkan dengan kadar asam folat susu skim, peningkatan kadar folat susu fermentasi setelah 18 jam fermentasi dengan starter L. plantarum Dad-13, G-3, dan H-1 secara berturut-turut 32,04 ± 1,85 µg/L (135,19%), 28,21 ± 0,28 µg/L (118,99%), dan 25,13 ± 1,27 µg/L (106,03%).

Isolasi dan Seleksi Lactobacillus yang Berpotensi sebagai Agensia Probiotik

Agritech Vol 23, No 2 (2003)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

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Lactic acid bacteria are important in food fermentation, in producing antimicrobial substances responsible for food preservation, and in balancing the microflora composition in gastrointestinal tract which contributing many healthful benefits (as probiotic agent). Disturbance due to pathogenic bacteria colonization in intestine as well as sterilisation of intestine due to antibiotic ingestion can be overcome by consumption of probiotic lactic acid bacteria. The objective of this study was to isolate Lactobacillus which potential for probiotic agent from intestinal material of healthy infant baby. Isolation was conducted using peptone glucose yeast extract media added with 0,2 % oxgall at pH 5, followed by incubation at 37 0C for 48 hr. Identifications were carried out based on Grain, morphological, biochemical and physiological characters, peptidoglycan types and protein profile on SDS-PAGE. Selection of probiotic agents were on based their antagonisms toward pathogenic bacteria, their resistance to antibiotics, and their survival at different oxygen availabilities. Based on morphological, biochemical and physiological characters among 12 lactobacilli strains obtained during isolation, 8 of them were identified as Lactobacillus acidophilus and the rest as Lactobacillus reuteri. However based on protein profile, L. acidophilus group has two different profiles, the first, consist of 7 strains and the second, consists of one strain. All isolates inhibited the growth of pathogenic bacteria including Shigella sp., Escherichia coli sp., Escherichia coli FNCC 009 I, Proleus sp., Salmonella choleraesius JCM 3919, Staphylococcus aureus FNCC 0047, Vibrio parahaemoliticus JCM 2147, Bacillus cereus ATCC 0057 and Listeria monocytogenes ATCC 7644, as shown by the inhibition zone ranging from 0,5-8 mm. Eight isolates of L. acidophilus were not resistant to antibiotics tested, while 3 isolates of L. reuteri were not resistant to chloramphenicol, rifampin and ampicillin, however they were resistant to tetracycline and elkosin. At reduced oxygen and anaerobic conditions all the isolates grew well, but at aerobic condition the growth was relatively slow. Strains of Lactobacillus acidophilus could be used for probiotic agents.



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Folate, an important B-group vitamin, participates in many metabolic pathways such as DNA and RNA biosynthesis and amino acid inter-conversions. Mammalian cells cannot synthesize folate; therefore, an exogenous supply of this vitamin is necessary to prevent nutritional deficiency. Folic acid is a composite molecule, being made up of three parts: a pteridine ring system (6-methylpterin), para-aminobenzoic acid , and glutamic acid . The folate biosynthesis pathway in micro-organisms can be divided in several parts. The pteridine proportion of folate is made from GTP, that is synthesized in the purine biosynthesis pathway. p-Aminobenzoic acid originates from chorismate and can be synthesized via the same biosynthesis pathways required for the aromatic amino acids, involving glycolysis, pentose phosphate pathway and shikimate pathway. The third component of a folate molecule is glutamate, that is normally taken up from the medium. This review will focus on biosynthesis and folate production by lactic acid bacteria and the folate level production in fermented product.