Potensi Cendawan Xylaria sp. Sebagai Sumber Antioksidan

 AbstrakPencegahan radikal bebas di dalam tubuh dapat dilakukan dengan menggunakan antioksidan. Cendawan Xylaria memiliki kandungan senyawa bioaktif yang berasal dari metabolit sekunder yang berpotensi sebagai sumber antioksidan alami baru. Penelitian ini bertujuan menentukan potensi Xylaria sp. (strain F, D, C) sebagai sumber antioksidan melalui pengukuran aktivitas antioksidan dan kandungan total flavonoidnya. Cendawan ditumbuhkan pada media Potato Dextrose Yeast Extract Broth (PDYEB) dan diinkubasi 14 hari dengan kondisi gelap dan statis. Miselium cendawan digerus dengan bantuan nitrogen cair, kemudian ekstraksi dilakukan menggunakan pelarut metanol sebanyak dua kali ulangan. Penentuan aktivitas antioksidan menggunakan metode 2,2-Diphenyl-1-picrylhydrazyl (DPPH) dan kandungan total flavonoid ditentukan menggunakan metode alumunium klorida (AlCl3) yang dinyatakan ekuivalen kuersetin (QE). Seluruh sampel Xylaria sp. memiliki aktivitas antioksidan yang lemah dan kandungan flavonoid yang juga rendah. Xylaria sp. strain F memiliki aktivitas antioksidan tertinggi sebesar 1915,14 ± 24,73 µg/mL dan Xylaria sp. strain D memiliki kandungan total flavonoid tertinggi sebesar 2,41 ± 0,09 mg QE/g ekstrak. Senyawa flavonoid pada sampel Xylaria sp. tidak menjadi senyawa utama yang menunjukkan aktivitas antioksidannya.AbstractPrevention of free radicals in the body can be done by using antioxidants. Xylaria fungus contains bioactive compounds derived from secondary metabolites that have the potential as a source of new natural antioxidants. This study aims to determine the potential of Xylaria sp. (strains F, D, C) as a source of antioxidants by measuring their antioxidant activity and total flavonoid content. The fungus was grown on Potato Dextrose Yeast Extract Broth (PDYEB) and incubated for 14 days in dark and static conditions. The mycelium of the fungus was crushed with the help of liquid nitrogen, then the extraction was carried out using methanol as a solvent for two repetitions. Antioxidant activity was determined using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method and the total flavonoid content was determined using the alumunium chloride (AlCl3) method which is expressed as quercetin equivalent (QE). All samples of Xylaria sp. have the weakest antioxidant activity and lowest flavonoid content. Xylaria sp. strain F had the highest antioxidant activity of 1915,14 ± 24,73 µg/mL and Xylaria sp. strain D had the highest total flavonoid content of 2,41 ± 0,09 mg QE/g extract. The flavonoid compounds in the sample Xylaria sp. did not become the main compound showing antioxidant activity

Diversitas Pangan Fermentasi Berbasis-Susu di Indonesia dan Kandungan Gizinya

Indonesia has abundant and diverse food commodities, including fermented food. However, metadata analysis about the diversity of fermented foods has not been reported. In addition, a comparison of the nutritional content of milk-based fermented foods is also not yet available. Therefore, this study aims to reveal the diverse status of fermented foods, to determine the nutritional content, especially of fermented milk-based foods, namely dangke, and their comparisons between milk-based fermented products. The research method included literature study, making dangke, proximate analysis of dangke, and statistical data analysis. Literature studies show that fermented foods and beverages in Indonesia were most reported in 2017, 2018, and 2019 respectively. Although most fermented foods are not known for their area of origin, the microbial groups involved in their processing come from the bacterial group rather than fungi, mainly through the lactic acid fermentation mechanism. Microbes' role in fermented products is diverse and can be grouped into five groups. The primary role of microbes is to support bioprocesses. Among milk-based fermented products, dangke is one of the traditional products with a fat content that is significantly different fat content from yogurt, kefir, and dadih, and the protein is not significantly different from yogurt, kefir, dadih, and mozzarella cheese. This nutritional content analysis indicates differences in fat and protein content among fermented milk-based food products.   Keywords: dangke, fat content, metadata, protein content, proximate analysi

Potensi Cendawan Asal Hydrilla verticillata Sebagai Pengendali Hayati Fusarium oxysporum dan Ganoderma boninense: Fungi from Hydrilla verticillata as Potential Biological Control Agents of Fusarium oxysporum and Ganoderma boninense

Hydrilla verticillata is an aquatic weed, can build symbiosis and also become a substrate of freshwater fungi. Some of freshwater fungi that live in association with H. verticillata are pathogenic fungi which were potentially used as controller for Fusarium oxysporum and Ganoderma boninense. The use of pathogenic fungi as a biocontrol is not consistent in the field. Therefore, this research aimed to find new fungus candidates that are stronger and more consistent in controlling pathogenic fungi. Freshwater fungi were isolated from H. verticillata. Identification was based on morphological characters. Molecular analysis was carried out for freshwater fungi which had the highest inhibition percentage to pathogenic fungi. The antagonism test was conducted by dual culture method. The mechanism of interaction of hyphae was observed under a microscope. Freshwater fungi was derived from H. verticillata stem are Aspergillus section flavi, Gliomastix sp., and Talaromyces sp. Antagonism test results showed that all fungi could inhibit the growth of pathogenic fungi. Based on molecular analysis used ITS region showed Talaromyces sp. could not identify to the level of species so that additional genes were required, namely beta-tubulin gene, in order to further identify Talaromyces sp.&nbsp

Monascus sp. Pigment Potency as Simple Preservative in Food Ingredients

Everyday foodstuffs such as tofu, chicken, and fish are ingredients that have a short shelf life if stored outdoors or in the open air. The fungus Monascus sp. is a fungus whose pigment is often used in giving color to food. This study aims to determine the potential of Monascus sp pigment isolated from commercial red rice (Angkak) as a preservative in tofu, chicken, and fish at room temperature. The methods used included isolation of the fungus Monascus sp from commercial red rice (Angkak), macroscopic and microscopic morphological characterization, solid fermentation using rice, harvesting pigments with water solvent, and pigment resistance tests on tofu, chicken meat, and fish. The results obtained from the application of the crude extract of the Monascus sp. pigment in fish survived for two days, chicken meat lasted up to three days, and tofu lasted four days. Each experiment had different results during the organoleptic test and compared to a positive control, namely turmeric, proving that turmeric was still better at resisting food spoilage. This research needs to be investigated further regarding the potential if the pure extract of the Monascus sp pigment is used

Isolasi Cendawan Mikoriza Arbuskula dari Rizosfer Tanaman Berkayu Asal Pulau Bangka dan Karakteristik Struktur Kultur Mikorizanya: Isolation of Arbuscular Mycorrhizal Fungi from Rhizosphere of Bangka Island Woody Plants and their Mycorrhizal Structure Culture Characteristics

Arbuscular Mycorrhizal Fungi (AMF) associate with a variety of plants including forest trees. Research on AMF in forestry in Indonesia is limited, especially on woody plants grown in Bangka Island. Therefore, the aim of this research was to isolate and identify AMF associated with woody plants from Bangka Island grown in the post-mining soil in greenhouse for 7 years. The Soil samples derived from 8 pots of the 7 years old woody plants were used as spore sources. Spore extraction from the soil used the wet sieving and decanting method. Fungal identification was carried out based on morphological characteristics, and fungal isolation used pot culture with Pueraria javanica as a host plant. Fungal structures within the root were analyzed after root staining with trypan blue. There were 18 spore morphotypes observed which belong to 5 types of Acaulospora and 13 types of Glomus. Seven single spore pot cultures were successfully isolated from species of Acaulospora sp.1, Acaulospora sp.4, Acaulospora sp.5, Glomus sp.2, Glomus sp.3, Glomus sp.6, and Glomus sp.11. AM fungal colonization structures observed within the root were Paris type arbuscules, internal hyphae, and vesicles. The AMF cultures obtained could be used as biofertilizer for woody plant seedlings production for post mining reclamation activities

Bioethanol Production from Non-Conventional Yeasts Wickerhamomyces anomalus (Pichia anomala) and Detection of ADH1 Gene

Bioethanol is an organic compound resulted from the fermentation of sugar substrates by microorganisms which is used as alternative energy sources.  During bioethanol fermentation yeast are exposed to various fermentation stresses, including temperature, osmotic, and oxidative stresess. Such conditions may decrease ethanol production. We previously isolated fermentation-stress tolerance yeast isolates from traditional Balinese beverages, identified as Wickerhamomyces anomalus BT2, BT5, and BT6. However no data available regarding the bioethanol production of those isolates. Our study indicates that these strains could utilize various sugar substrates (glucose, xylose, maltose, sucrose) in oxidative fermentative media. The highest value of substrate utilization efficiency following 48 hours fermentation was shown by BT6 on glucose (61.02%), BT 2 on xylose (55.44%) and maltose (60.90%). Measurement of ethanol production by Gas Chromatography showed that the strains were able to produce higher ethanol on the glucose substrate than other substrates. For instance, BT6 could produce the highest ethanol production (5.00 g/L) amongst strains tested by using glucose as substrate. Yet, the particular strains could only produce 0.30 g/L and 0.65 g/L by using xylose and maltose, respectively. For further genetic engineering purposes, we detected ADH1 gene from all three isolates, with high homology to the alcohol dehydrogenase from Saccharomyces cerevisiae, Geobacillus stearothermophilus and Pseudomonas aeruginosa. Further strain development can be carried out targeting the ADH1 gene, important for ethanol fermentation

Keragaman Cendawan Pascapanen pada Umbi Bawang Merah Varietas Bima Brebes

Diversity of Postharvest Fungi on Shallot Bulbs Variety Bima BrebesIn Indonesia, shallot (Allium ascalonicum) is horticultural main commodity after hot pepper. Significant yield losses can be caused by postharvest fungi infection. Research on the diversity of postharvest fungi on shallot bulbs has been conducted in some countries, unfortunately little is done in Indonesia. The study was aimed to obtain information on the diversity of postharvest fungi infecting shallot bulbs variety Bima Brebes from several traditional markets in Bogor City. Shallot bulbs were collected in January and February 2016. The study consisted of fungal isolation from shallot bulbs, fungal pathogenicity test, and identification of pathogenic fungi based on morphological and molecular characteristics. Morphology identification was based on the color of fungal colony, growth pattern, as well as somatic and reproduction structures. Several species of pathogenic fungi were successfully identified from shallot bulbs i.e. Alternaria alternata, Aspergillus niger, Colletotrichum gloeosporioides species complex, Fusarium fujikuroi species complex, F. oxysporum, F. solani, Penicillium citrinum and P. pinophilum.  Among these fungi, the highest pathogenicity was shown by C.  gloeosporioides species complex.</p

NUTRITIVE COMPOSITION OF RED TILAPIA REARED IN FRESHWATER AND BRACKISHWATER

The aim of this research was to investigate the nutritive composition (especially fatty acids) in red tilapia that was reared in freshwater and brackishwater. The fatty acid contents were determined by gas chromatography. The fatty acids profile were -3 (linolenic acid, eicosapentaenoic acid/EPA, docosahexaenoic acid/DHA), -6 (linoleic acid, arachidonic acid/AA), and -9 (oleic acid). Red tilapia samples were obtained from Research Institute for Fish Breeding, Sukamandi, West Java (freshwater ponds) and Congot, Yogyakarta (brackishwater ponds; salinity 20 ppt). In this research, red tilapia reared in different ecosystems showed different fatty acid profiles. Red tilapia inhabiting brackishwater ecosystem has EPA (0.26±0.05%), DHA (3.42±0.26%), and linoleic acid (17.20±0.56%) content higher than freshwater ecosystem (EPA = 0%; DHA = 0.67±0.44%; linoleic acid = 9.08±4.76%), except for linolenic acid (0.30±0.15% vs 0.25±0.10%), arachidonic acid (0.77±0.39% vs 0.93±0.13%) and oleic acid (38.67±2.58% vs 37.44±0.74%). The ratio of -6/-3 in red tilapia inhabiting freshwater ecosystem was about 11/1. The culture tilapia in brackishwater ecosystem decrease -6/-3 ratio (4.5:1). So that for human health, it will be better to consume brackishwater red tilapia than freshwater red tilapia

Hubunagn kemampuan pergantian inang dengan plastisitas genetika pada cendawan blas padi (Pyricularia grisea)

The Digitaria ciliaris, wild grass grown around rice field, was a host for Pyricularia grisea (Cooke) Sacc., the fungi caused blast disease of rice. This fungi have a specific mechanism to regenerate new genetic variation in its life cycle. The aim of this research is to study the relation between the ability of the fungi to infect different species of host with its genetic plasticity. It was used three SCAR molecular markers Cutl, Pwl 1 and Erg2. P. grisea isolates (Dc4J1) originated from D. ciliaris at Jasinga-Bogor were able to infect rice cultivars Kencana Bali and Cisokan. The original Dc4Jl, from D. ciliaris, and the Dc4Jl that were reisolated from the infected rice cultivars (reisolates-1) had the same ability to infect Kencana Bali and Cisokan. Molecular technique showed that there was a different molecular marker genotype between the original Dc4J1, from D. ciliaris, and the Dc4Jl reisolated from infected rice cultivars. The original Dc4J1 owned Cutl but did not Pwl2 in contrary the reisolates Dc4J1 from rice cultivars (reisolates-1) had Pwl2 but did not Cutl. The Erg2 presented in both the original and the reisolated Dc4Jl. These results indicated that there were a change of genotype of P. grisea at the same time with the change of host species. The Dc4Jl isolates originated from Kencana Bali and Cisokan (reisolates-2) that were infected by reisolate-1, had the same genotype with the reisolates-1

Hubunagn kemampuan pergantian inang dengan plastisitas genetika pada cendawan blas padi (Pyricularia grisea)

The Digitaria ciliaris, wild grass grown around rice field, was a host for Pyricularia grisea (Cooke) Sacc., the fungi caused blast disease of rice. This fungi have a specific mechanism to regenerate new genetic variation in its life cycle. The aim of this research is to study the relation between the ability of the fungi to infect different species of host with its genetic plasticity. It was used three SCAR molecular markers Cutl, Pwl 1 and Erg2. P. grisea isolates (Dc4J1) originated from D. ciliaris at Jasinga-Bogor were able to infect rice cultivars Kencana Bali and Cisokan. The original Dc4Jl, from D. ciliaris, and the Dc4Jl that were reisolated from the infected rice cultivars (reisolates-1) had the same ability to infect Kencana Bali and Cisokan. Molecular technique showed that there was a different molecular marker genotype between the original Dc4J1, from D. ciliaris, and the Dc4Jl reisolated from infected rice cultivars. The original Dc4J1 owned Cutl but did not Pwl2 in contrary the reisolates Dc4J1 from rice cultivars (reisolates-1) had Pwl2 but did not Cutl. The Erg2 presented in both the original and the reisolated Dc4Jl. These results indicated that there were a change of genotype of P. grisea at the same time with the change of host species. The Dc4Jl isolates originated from Kencana Bali and Cisokan (reisolates-2) that were infected by reisolate-1, had the same genotype with the reisolates-1