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Articles by issue : Vol 8, No 1 (2014): March 2014
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Articles
Effect of Spontaneous Lactic Acid Fermentation on Physico-Chemical Properties of Sweet Potato Flour

YULIANA, NETI ( Department of Agricultural Product Technology (THP), Agriculture Faculty, Universitas Lampung, Jalan Sumantri Brojonegoro No 1, Bandar Lampung 35145, Indonesia ) , NURDJANAH, SITI ( Department of Agricultural Product Technology (THP), Agriculture Faculty, Universitas Lampung, Jalan Sumantri Brojonegoro No 1, Bandar Lampung 35145, Indonesia ) , SUGIHARTO, RIBUT ( Department of Agricultural Product Technology (THP), Agriculture Faculty, Universitas Lampung, Jalan Sumantri Brojonegoro No 1, Bandar Lampung 35145, Indonesia ) , AMETHY, DEARY ( Department of Agricultural Product Technology (THP), Agriculture Faculty, Universitas Lampung, Jalan Sumantri Brojonegoro No 1, Bandar Lampung 35145, Indonesia )

Microbiology Indonesia Vol 8, No 1 (2014): March 2014
Publisher : Indonesian Society for microbiology

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Abstract

Native sweet potato flour is usually has low whiteness index and limited application to food systems due to its  inherent functional properties. Therefore,  it needs modification process  to  improve  this property. In  this study, sweet potatoes cubes were  lactic spontaneously fermented for 120 h before being processed  to flour  to modify  its properties. Selected physico-chemical properties of flour were then determined and compared with the control (without fermentation). The results showed that lactic acid fermentation significantly caused more changes on flour properties. The lactic acid fermentation caused an alteration in the starch granules as evident by Scanning Electron Microscopy. When compared to the control flour, spontaneous fermented flour had lower solubility, higher swelling power, and paste viscosity.  The results suggested lactic spontaneous fermentation within 120 h period of  time could provide a greater extent of  flour modification.

Klebsiella pneumoniae from Indonesian Tempeh were Genetically Different from that of Pathogenic Isolates

AYU, EVELINE ( Department of Biology, Faculty of Biotechnology, Universitas Katolik Atma Jaya, Jalan Jenderal Sudirman 51, Jakarta 12930, Indonesia ) , SUWANTO, ANTONIUS ( Department of Biology, Faculty of Biotechnology, Universitas Katolik Atma Jaya, Jalan Jenderal Sudirman 51, Jakarta 12930, Indonesia Department of Biology, Faculty of Mathematics and Natural Sciences, Institut Pertanian Bogor , Darmaga Campus, Bog ) , BARUS, TATI ( Department of Biology, Faculty of Biotechnology, Universitas Katolik Atma Jaya, Jalan Jenderal Sudirman 51, Jakarta 12930, Indonesia )

Microbiology Indonesia Vol 8, No 1 (2014): March 2014
Publisher : Indonesian Society for microbiology

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Abstract

Tempeh  is  important  traditional  Indonesian  fermented  food made  from  soybeans  employing Rhizopus oligosporus or R. microsporus. During the process of tempeh production, some bacteria from the environment and tempeh starter become an integral part of tempeh, and even have important roles in determining   the final quality of tempeh it self. Several studies reported the presence of Klebsiella pneumoniae in tempeh as one of vitamin B12 producing bacteria in tempeh. However, K. pneumoniae also known as opportunistic pathogens causing pneumonia and liver abscess in human. In this study, Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction  (ERIC-PCR) was  employed  to  determine  genetic  diversity  of K.  pneumoniae isolated from tempeh and compared them with medical isolates. The result indicated that isolates from tempeh were genetically distinct  from  those of medical  isolates.

Characterization of Thermoplasma Species Cultured from Sampling on Tangkuban Perahu, Indonesia

MALIK, AMARILA ( Faculty of Pharmacy, Universitas Indonesia ) , SANTOSO, IMAN ( FMIPA,Universitas Indonesia ) , YEHUDA, ANDI ( FMIPA, Universitas Indonesia ) , FREISLEBEN, SERUNI K.U. ( FMIPA, Universitas Indonesia ) , WANANDI, SEPTELIA INAWATI ( FK, Universitas Indonesia ) , HUBER, HARALD ( Department of Microbiology, Archaea Centre, University of Regensburg, Germany ) , LUTHFA, ZESSINDA ( FMIPA, Universitas Indonesia ) , SALEH, ROSARI ( FMIPA, Universitas Indonesia ) , FREISLEBEN, HANS-JOACHIM ( FK, Universitas Indonesia )

Microbiology Indonesia Vol 8, No 1 (2014): March 2014
Publisher : Indonesian Society for microbiology

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Abstract

Archaea is an organisme with unique feature because of its ability to inhabit an extremophyle conditions. Our expeditions to Tangkuban Perahu, West Java aimed to obtain archaealstrains from the solfatara fields located in Domas crater. From the samples, we intended to culture Thermoplasma species growing around 55 °C below pH 2, which until now have not yet been fully characterized. We collected five samples from mud holes with temperatures from 52 °C to 57 °C and pH below 2. In serial cultures of up to 8 transfers in Freundt’s medium we grew tetraetherlipid synthesizing Thermoplasma species as documented by phase contrast microscope. Total membrane lipid extracts were analysed by thin layer chromatography; the pattern matched total lipid extracts from Thermoplasma acidophilum DSM 1728 membranes. For confirmation, 16S rDNA identification performing PCR and sequencing were carried-out. Analysis using BLAST showed T. acidophilum identities as the highest similarity of 99%, followed by T. volcanium, also with99% similarity (ANKF776908 and ANKF776909). This is the first report of culturing cell-wall-less thermoacidophilicarchaea,in particular Thermoplasma species in Indonesian laboratories.

Abundance of Culturable Bacteria Isolated from Maize Rhizosphere Soil Using Four Different Culture Media

HIDAYATI, ERNIN, WAHYUDI, ARIS TRI, SUWANTO, ANTONIUS, WIDYASTUTI, RAHAYU

Microbiology Indonesia Vol 8, No 1 (2014): March 2014
Publisher : Indonesian Society for microbiology

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Abstract

Composition and abundance of culturable bacteria of four soil samples (Ktr50II, D50II, G50II, and A50II) were analyzed. The soil samples were collected from maize rhizosphere that planted in dryland Lombok Island. Each soil sample give different growth performance of maize in greenhouse experiment. This study was to investigate the relation of maize growth performance with culturable bacterial community of their rhizosphere and the effect of culture media on number of bacterial isolates recovery. The rhizosphere bacteria were cultured and isolated on commercial media (SEA) and non commercial modification media (NAln, NAln-SE and NAln- RE). Thirty four strains rhizosphere bacteria were obtained from four maize rhizophere soil samples. D50II is the soil sample that caused the better growth performance to the maize, contrary to Ktr50II. D50II has significantly highest number of culturable bacterial types, while significantly lowest on Ktr50II. In D50II, at least 17 bacterial isolates contributed to better growth performance in maize and have relative abundance of dominant isolate not more than 35.34%. In comparing the rhizosphere bacteria recovered using different culture media, bacteria cultivated on SEA have different growth characteristic compared with bacteria cultivated on NAln, NAln SE and NAln-RE. Six bacterial isolates showed antagonistic ability when grew on SEA but not in all of three media. Compared with commercial media, non commercial modification media can increase total isolates recovery about 70.6%.

Characterization of Antimicrobial Bacteriocin Produced by Bacillus cereus SS28 Isolates from Budu, a Traditionally Fermented Fish Product of West Sumatera

YUSRA, YUSRA, AZIMA, FAUZAN, NOVELINA, NOVELINA, PERIADNADI, PERIADNADI

Microbiology Indonesia Vol 8, No 1 (2014): March 2014
Publisher : Indonesian Society for microbiology

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Abstract

Bacillus cereus SS28 isolated from budu, a fermented fish product from West Sumatra, produced antimicrobial compound that had broad spectrum of inhibition against five microorganisms (Escherichia coli, Staphylococcus aureus, Salmonella thypi, Bacillus subtilis, and Listeria monocytogenes). The aims of this research are characterization of Bacillus cereus SS28 antimicrobial activity and observation of its effect to the cellular morphology of Staphylococcus aureus with electron microscope. Antimicrobial compound produced by Bacillus cereus SS28 was stable at pH range between 2 and 11 and to heating at 121 °C for 15 min. Maximum antimicrobial activity was expressed at pH 2-3 and 70 °C for 45 min. The activity remained after 15 min exposure to UV light. The main changes observed under SEM and TEM were the alteration of Staphylococcus aureus structural cell membrane 48 h after exposure to the antimicrobial compound from Bacillus cereus SS28.