TOKSISITAS GLISEROL ATAU SUKROSA PADA SEL KHAMIR accharomyces cerevisiae YANG DISEMPAN PADA SUHU RENDAH BEKU

The effect of cryoprotectants glycerol and sucrose on cell viability and fermentation rate of Saccharomyces cerevisiae after freezing (-30 °C) and Chawing (30 °C) were studied.Both freezing and thawing were done rapidly. The mortality of cells treated with low concentrations of cryoprotectans (2.5, 5, and 10 %) after 15 and 30 days of cryopreservation, was remarkably higher than that of control and higher concentration (20% and 40%).Glycerol or sucrose with concentration of 20 % and 40 % protected cells from severe mortality only after 90 days of cryopreservation.Fermentation rate of cells treated with 20 % or 40 % of the two cryoprotectants were higher than that of control after 60 and 90 days of cryopreservation.The data indicated that in certain circumstance cryoprotectant could be toxic for the cells during freezing and thawing.Since biomembrane is not permeable to sucrose, therefore we proposed that target of sucrose toxicity may be extracellular, whereas glycerol, which penetrate cells,targets of the toxicity may be both extracellular and intracellular domains.Interaction between cryoprotectant and cell membranes is discussed

THE COMMUNITY OF SOIL YEASTS IN GUNUNG HALIMUN NATIONAL PARK

Fifty-two isolates were isolated from Gunung Halimun National Park on the basis of morphological and some physiological characteristics.Those isolates were belonged to three groups namely, ascomycetous, basidiomycetous and imperfect yeasts.Rhodotolum sp.was only found in Ciptarasa site at 1500 m asl, ascomycetous yeasts was only isolated from deteoretic root in Gunung Botol site, while Candida sp.(small globose shaped cells) was only isolated from soil at 1800 m asl of Gunung Botol site. Type of plant species appeared has no effect on yeasts diversity as shown by similar yeasts diversity was observed at rhizosphere soil of three dominating plant (Schima waallichii, Castanopsis javanica and Altingia excelsa) at Cikaniki study site

Metagenomic Analysis of Bacterial Community in the Gut of Blister Beetle Mylabris pustulata Thunberg

Blister beetles are an important object of study in the field of agriculture and health. Despite being known to be important for the host animal, the gut bacteria of blister beetles have not been investigated deeply. This study aimed to provide the first initial description of the gut bacterial community of Mylabris pustulata as one species of blister beetles, based on a culture-independent technique. Adult blister beetles of the same colony were sampled and confirmed as Mylabris pustulata Thunberg. The gut content was used in high throughput sequencing, targeting the V3-V4 regions of 16S rRNA gene, and in the cultivation of resident bacteria. The results showed that higher bacterial richness was present in the gut communities when compared to the grown bacterial culture. Proteobacteria was confirmed as the most abundant phylum in the gut of M. pustulata, whereby most reads belonged to the class of Gammaproteobacteria. The dominant bacterial genera were determined as Enterobacter, Acinetobacter, Enterococcus, Klebsiella, and Pseudomonas. In addition, our cultivation attempts led to successful isolation of members of Klebsiella and Enterococcus. The subject of this study could be explored further to find the potential roles of these microbiota in the gut of the specific beetles and their bioprospects

IDENTIFICATION OF YEASTS ISOLATED FROM GUNUNG HALIMUN NATIONAL PARK*[Identifikasi Khamir pada Taman Nasional Gunung Halimun]

Dua puluh sembilan isolat khamir diisolasi dari tanah Taman Nasional Gunung Halimun. Sumber isolat berasal dari batang pohon lapuk, akar lapuk yang diambil dari Gunung Botol, Cikaniki, dan Cipta Rasa untuk dipelajari aspek taksonominya. Berdasarkan atas karakter morfologi dan fisiologi, isolat-isolat tersebut digolongkan kepada kelompok ascomyceteous, basidiomyceteous dan imperfect khamir. Selanjutnya ketiga golongan tersebut dimasukkan ke dalam sepuluh kelompok (Kelompok 1 sampai X). Dari 29 isolat tersebut, 7 isolat dimasukkan ke dalam kelompok I diindentifikasi sebagai Debaryomyces hansenii, 6 dalam kelompok II sebagai Candida sp, 2 dalam kelompok III sebagai Pichia membranafaciens, 5 isolat dalam kelompok IV sebagai Candida galacta, 1 dalam kelompok V sebagai Candida sake, 4 dalam kelompok VI sebagai Cryptococcus humicolus, 1 dalam kelompok VII sebagai Rhodotorula minuta, 1 dalam kelompok VIII sebagai Candida sp, 1 dalam kelompok Candida sp, dan 1 dalam kelompok X dalam Candida sp. Macam sampel tampaknya tidak berpengaruh kepada keragaman jenis khamir seperti ditunjukkan oleh jenis yang sama diisolasi dari berbagai jenis sampel. Dari banyaknya jenis khamir yang diisolasi menunjukkan bahwa keragaman jenis khamir di Taman Nasional Gunung Halimun tergolong tinggi

Metagenomic Analysis of Bacterial Community in the Gut of Blister Beetle Mylabris pustulata Thunberg

Blister beetles are an important object of study in the field of agriculture and health. Despite being known to be important for the host animal, the gut bacteria of blister beetles have not been investigated deeply. This study aimed to provide the first initial description of the gut bacterial community of Mylabris pustulata as one species of blister beetles, based on a culture-independent technique. Adult blister beetles of the same colony were sampled and confirmed as Mylabris pustulata Thunberg. The gut content was used in high throughput sequencing, targeting the V3-V4 regions of 16S rRNA gene, and in the cultivation of resident bacteria. The results showed that higher bacterial richness was present in the gut communities when compared to the grown bacterial culture. Proteobacteria was confirmed as the most abundant phylum in the gut of M. pustulata, whereby most reads belonged to the class of Gammaproteobacteria. The dominant bacterial genera were determined as Enterobacter, Acinetobacter, Enterococcus, Klebsiella, and Pseudomonas. In addition, our cultivation attempts led to successful isolation of members of Klebsiella and Enterococcus. The subject of this study could be explored further to find the potential roles of these microbiota in the gut of the specific beetles and their bioprospects

Analisis Variasi Genetik Saccharomyces Cerevisiae Dl Tahan Etanol Dengan Rapd (Random Amplified Polymorphic Dna)* [Genetic Variation Analysis of Ethanol Tolerance Yeast, Saccharomyces Cerevisiae Dl by Using Rapd]

Genetic variations among 3 cultures, which were treated with or without Mn of Saccharomvces cerevisiae D1, were analyzed using RAPD (Random Amplified Polymorphic DNA ) technique. The Mn-treatment of three cultures were as follows: the culture KMn was D1 strain, the culture Mn+ was D1 strain colony survived in ethanol 20%, which was previously treated with 0,5 mU MnSOt and the culture Mn- was a D1 colony survived in ethanol 20% without MnSOi treatment. Polymorphism of total DNA of the three cultures may indicate that mutation may occur in cells which were tolerant to ethanol. The locus or base change was not identified. However, since the oxygen uptake rate of the three cultures at catabolite derepression state were identical,the results suggest that the locus may not be in mitochondrial DNA encoding respiratory chain proteins. The relation between DNA polimorphic and ethanol tolerant cell is still to be clarified

The Community of Soil Yeasts in Gunung Halimun National Park

Fifty-two isolates were isolated from Gunung Halimun National Park on the basis of morphological and some physiological characteristics.Those isolates were belonged to three groups namely, ascomycetous, basidiomycetous and imperfect yeasts.Rhodotolum sp.was only found in Ciptarasa site at 1500 m asl, ascomycetous yeasts was only isolated from deteoretic root in Gunung Botol site, while Candida sp.(small globose shaped cells) was only isolated from soil at 1800 m asl of Gunung Botol site. Type of plant species appeared has no effect on yeasts diversity as shown by similar yeasts diversity was observed at rhizosphere soil of three dominating plant (Schima waallichii, Castanopsis javanica and Altingia excelsa) at Cikaniki study site

Penguraian Parasetamol oleh Sel dan Protein Ekstraselular Khamir Candida Tropicalis dan Rhodotorula Minuta

Yeast can be used as cell model to study toxicity in mammalian cell. In the previous study we demonstrated that yeast Candida tropicalis was able to metabolize analgesic drug paracetamol causing oxidative stress. This phenomenon is similar to that in mammalian cell. In mammalian cell system, enzymes responsible in paracetamol metabolism are at least cytochrome P450 (P450) and peroxidase. In order to understand the possible role of peroxidase enzyme in paracetamol metabolism in yeast, research on the effect of peroxidase inhibitor of sodium cyanide (KCN) and a peroxidase substrate peroxide (H2O2) on paracetamol degradation by cell suspension and extracellular protein of C. tropicalis and Rhodotorula minuta was carried out. Paracetamol was degraded by cells or extracellular protein in both of yeast. Paracetamol degradations were significantly inhibited by KCN (0.01 μM) or H2O2 (3 μM). Since P450 is generally located inside the cell (in cell membrane) while no activity of P450 in extracellular, the data indicated the presence of soluble enzyme which is able to metabolize paracetamol that is inhibited by KCN or H2O2. The possibility of presence of peroxidase in the soluble protein by which paracetamol is metabolized and its inhibition by peroxide via competitive substrate or peroxide toxicity is discussed. The results supported use of yeast for studying toxicity of paracetamol in cell level