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Microbiology Indonesia
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Articles 292 Documents
Optimization Modeling of Ethanol Production from Shorgum bicolor grain: Comparison between Separate Hydrolysis Fermentation and Simultaneous Saccharification Fermentation CHRISNASARI, RUTH; SUSETYO, DAMIATI HARTINI; SUGIANTO, ADRIAN PRATAMA; PANTJAJANI, TJANDRA
Microbiology Indonesia Vol 7, No 1 (2013): March 2013
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.7.1.2

Abstract

Two different process configurations, simultaneous saccharification and fermentation (SSF), and separate hydrolysis and fermentation (SHF), were compared for ethanol production from Shorgum bicolor grain. Optimization modeling for glucoamylase and Zymomonas mobilis concentration in both of SSF and SHF were carried out to obtain optimal concentration of ethanol production. The optimum condition was achieved using 0.021 % (v/v) of glucoamylase, and 30.19% (v/v) of Z. mobilis for SHF. In contrast, the optimum condition for SSF was 0.021 % (v/v) of glucoamylase and 17.51% (v/v) of Z. mobilis. The model predicted SHF processing to be superior. The superiority of SHF over SSF was confirmed experimentally, the result showed ethanol yield of SHF was 134.80 g L-1 and ethanol yield of SSF was 115.66 g L-1 after 72 h incubation time. A high similarity was observed between the predicted and experimental results, demonstrating the accuracy of the model.
The Effect of a Mixed-Starter Culture of Lactic Acid Bacteria on the Characteristics of Pickled Orange-Fleshed Sweet Potato (Ipomoea batatas L.) YULIANA, NETI; NURDJANAH, SITI; MARGARETA, MIKA
Microbiology Indonesia Vol 7, No 1 (2013): March 2013
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.7.1.1

Abstract

In this study, fermentation process was carried out on orange-fleshed sweet potato cubes to produce sweet potato pickle using a mixed culture of Lactobacillus plantarum and Leuconostoc mesenteroides at 30 °C over 12 days period. Spontaneous fermentation was also performed as a control. Samples were withdrawn at various time intervals for analyses of reducing sugar content, total number of lactic acid and non-lactic acid bacteria, lactic acid concentration, pH, and sensory attributes. The results showed that using a mixed culture of L. plantarum and L. mesenteroides could greatly reduce contamination of non-lactic acid bacteria, retaining low amount of reducing sugar, rapidly producing lactic acid and consequently decreasing pH value of the pickle, as well as giving better sensory score. After 12 d of fermentation, sample of pickle inoculated with mixed culture showed the following characters: total lactic acid content 0.5%, total lactic acid bacteria 8.46 log10 CFU mL-1, total non-lactic acid bacteria 1 log10  CFU mL-1, total reducing sugar 0.84 g L-1, texture 64.92 mm 50 g-1 s-1, and hedonic sensory score for both taste and aroma 4 (like) in a scale of 5. These results indicated the potential ability of the mixed culture of lactic acid bacteria to improve the quality of the pickle fermented spontaneously.
Molecular Dynamics Analysis of Thermostable DNA Pol I ITB-1 HERTADI, RUKMAN; NURBAITI, SANTI; AKHMALOKA, .
Microbiology Indonesia Vol 1, No 3 (2007): December 2007
Publisher : Indonesian Society for microbiology

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Abstract

One of the thermostable enzymes, which has been widely used in the biotechnological research, is DNA polymerase. The coding sequence of local DNA Pol I gene from a local thermophilic bacterium, namely DNA Pol I ITB-1, has been cloned, sequenced, and overexpressed. However, study on thermostability of this enzyme is very limited. In the present study, thermostability of the protein was evaluated by thermal unfolding simulation at 300, 400, and 500 K. Our simulation revealed that the secondary and tertiary structures of the protein was not significantly affected by thermal perturbation at 300 K, but they were affected and even gradually unfolded by that perturbation at 400 and 500 K. Evaluation of the root mean square fluctuation (RMSF) of individual residues from the simulation at 400 and 500 K revealed the distribution of the thermostability regions in the protein structure. From the RMSF analysis at 400 K, we found that thermostability of the 3’-5’ exonuclease domain was lower compared to that of the other domains. Where as from the RMSF analysis at 500 K, we found that in each domain of DNA pol I ITB-1 there was a single extraordinary thermostable a-helix which was likely to be the core of each corresponding domain. Thus our simulation provides a thermostability map of DNA Pol I ITB-1. Such information will be very valuable for the next genetic engineering work in determining a mutation target to modify thermostability of this enzyme.
Production of Recombinant Vaccine Cb Peritrophin-42 of Screwworm Fly in Escherichia coli and Saccharomyces cerevisiae NATALIA, DESSY; MUHARSINI, SRI; MASDUKI, FIFI FITRIAH; WARDHANA, APRIL HARI; WARDANI, SAVIRA EKA; MARIA, ELIZABETH; VAN DEN HEUVEL, JOOP
Microbiology Indonesia Vol 1, No 3 (2007): December 2007
Publisher : Indonesian Society for microbiology

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Abstract

The screwworm fly (Chrysomya bezziana) larva is an obligate parasite which causes myasis in mammals. Vaccination is thought to be a protective and an enviromentally friendly method for combating the pest. A gene encoding a peritrophic membrane protein Cb peritrophin-42 of C. bezziana was cloned and expressed in Escherichia coli and Saccharomyces cerevisiae.Cb peritrophin-42 fused with the outer membrane protein A signal sequence was produced as an aggregate in E. coli. Expression of an Cb peritrophin-42 gene fused with oligonucleotide of the invertase signal sequence in S. cerevisiae allowed the production of 14.4 mg l-1 soluble extracellular Cb peritrophin-42. Sheep vaccinated with recombinant Cb peritrophin-42 showed a strong immunological reaction. In vivo assay following vaccination with the recombinant Cb peritrophin-42 showed a 27% reduction in the weight of recovered larvae.
Thermostable Chicken Feather Degrading Enzymes from L-23 Isolate from Indonesia LINTANG, ROSITA; SUHARTONO, MAGGY THENAWIJAYA; HWANG, JAE KWAN; PYUN, YU RYANG
Microbiology Indonesia Vol 1, No 3 (2007): December 2007
Publisher : Indonesian Society for microbiology

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Abstract

The thermostable chicken feather degrading protease enzymes used here was extracted and partially purified from thermophilic bacteria L-23 isolated from a coastal hot spring in North Sulawesi, Indonesia. The L-23 was grown in the selective medium containing 1% chicken feather powder at 70 °C and pH 7. The cell-free culture was precipitated with ammonium sulphate at 80% saturation, followed by heating at 65 °C for 1 h before applied onto Sephadex G-100. The molecular weight of the two enzymes identified were estimated as 47 and 64 kDa. The optimum pH of the mixed enzymes preparation was 7 while the optimum temperature was 65 °C. Zymogram analysis showed that one of the enzymes was still active after being heated at 100 °C for 20 min and was also resistant towards organic solvents and SDS. The activity was enhanced by addition of 1 mM FeCl3.
Multiplex PCR for Rapid Detection of Rifampin and Isoniazid Resistance in Mycobacterium tuberculosis Isolated from Bandung, Indonesia NOVIANA, HERA; NURACHMAN, ZEILY; RAMDANI, MAELITA; NOER, AS
Microbiology Indonesia Vol 1, No 3 (2007): December 2007
Publisher : Indonesian Society for microbiology

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Abstract

Mycobacterium tuberculosis resistant to rifampin and isoniazid, known as multidrug-resistant M. tuberculosis (MDR-TB) strains, is an emerging problem of great importance to public health, with higher mortality rates than for drug-sensitive strains. Rifampin resistance is due to mutations on the hot spot region of the rpoB gene, especially at positions 526 and 531, and isoniazid resistance is due to mutation on katG at position 315. Mechanisms of resistance are an appropriate target for molecular genotyping diagnostic methods. Here we examined the multiplex PCR assays for the rapid detection targeting rpoB526, rpoB531, and katG mutations. Sixty-one M. tuberculosis strains were studied based on rpoB526, rpoB531, and katG315 assays employing multiplex PCR. Of the 61 strains, the susceptibility tests determined 42 isolates were MDR-TB strains, 10, 4, and 5 isolates were resistant to rifampin, isoniazid, and at least to six drugs which prescibed for TB, respectively. The mutation profiles of the 42 MDR strains assayed by multiplex PCR were 81 and 38.1% on rpoB and katG, respectively. Six rifampin-resistant isolates (60%) had a mutation on rpoB, 25% isoniazid-resistant isolates had mutation on katG, and 20% of the isolates that were sensitive to all drugs tested had a mutation on rpoB. Sequencing analysis revealed sensitivity of the multiplex PCR assay for rpoB was 98.4% and was 100% for katG. There was a 19% difference between phenotype and genotype properties of all isolates detected. In conclusion, the sensitivity of multiplex PCR method was sufficient for preliminary detection of rpoB and katG mutations, but resistance M. tuberculosis to rifampin and isoniazid were not always conferred by mutated alleles on rpoB and, especially, on katG.
Immunological Detection of Avian Influenza Virus in Infected Ducks by Monoclonal Antibodies Against AIV-H5N1 ASTAWA, NYOMAN MANTIK; WINAYA, IDA BAGUS OKA; AGUSTINI, LUH PUTU; HARTANINGSIH, NINING
Microbiology Indonesia Vol 1, No 3 (2007): December 2007
Publisher : Indonesian Society for microbiology

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Abstract

In order to establish a detection method for avian influenza virus (AIV) infection in ducks, monoclonal antibodies (MAbs) against the virus were produced. The virus used for the production of the monoclonal antibodies was AIV-H5N1 of Indonesian origin. Immortal mouse myeloma were fused with the lymphocytes derived from the spleen of mice immunized with the virus. The MAbs were tested for their specificity by enzyme linked immunosorbent assay (ELISA) and western blotting using formaldehyde inactivated virus and normal allantoic fluid as a negative control. Twelve MAbs which were specific against AIV were isolated and 8 of them were used for detecting of AIV antigen in duck’s tissues. AIV antigen was detected in paraffin embedded tissues of AIV-infected ducks by immunohistochemistry using MAbs. AIV antigen was not detected in ducks, which were confirmed to be AIV negative. In the infected ducks, high intensity of AIV infection was detected in proventricle gland and small intestine. The AIV antigen with a lesser intensity was also detected in lungs, spleen, and bursa of Fabricius, but hardly detected in muscle, brain, and several other issues. This study shows a clear evidence that MAbs produced in this study are applicable for use in immunological detection of AIV in infected duck tissues.
Selection and Identification of Cellulase-Producing Bacteria Isolated from the Litter of Mountain and Swampy Forest WIZNA, .; ABBAS, HAFIL; RIZAL, YOSE; DHARMA, ABDI; KOMPIANG, I PUTU
Microbiology Indonesia Vol 1, No 3 (2007): December 2007
Publisher : Indonesian Society for microbiology

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Abstract

The isolation and selection of cellulase-producing bacteria was conducted to identify the species of cellulolytic Bacillus. The bacteria were isolated from the litter of swampy forest in Pesisir Selatan and mountain forest in Lembah Anai Tanah Datar.  These bacteria were cultivated in selective media to obtain bacteria from the genus Bacillus. Six Bacillus isolates were obtainedfrom swampy forest and three Bacillus isolates from mountain forest. These isolates were cultivated in agar medium with carboxymethylcellulose as the carbon source. Colonies which produced clear zones were assumed to be cellulolytic Bacillus.  Based on biochemical and morphological examinations the result indicated that these two isolates were Bacillus coagulans and B. amyloliquefaciens. The cellulase activity of B. coagulans and B. amyloliquefaciens were 0.812 and 1 200 unit ml-1 to C1(b-exoglucanase) respectively, 0.368 and 0.488 unit ml-1 to Cx(b-endoglucanase) respectively.
Isolation and Screening of Endophytic Microbes from Morinda citrifolia and their Ability to Produce Anti-Microbial Substances KUMALA, SHIRLY; SISWANTO, ENDRO BUDI
Microbiology Indonesia Vol 1, No 3 (2007): December 2007
Publisher : Indonesian Society for microbiology

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Abstract

Assaying for, and isolation and screening of endophytic microbes from the Morinda citrifolia plant and their ability to produce anti-microbial substances was carried out. Endophytic microbes are microorganisms that live asymptomatically within the living tissue of host plants. Microorganisms such as bacteria, fungi, and yeast can be associated with the host and produce secondary metabolites. These secondary metabolites may be enzymes and other bioactive substances with medicinal activity such as anti-arthritic, anti-cancer, and anti-microbial compounds. The aims of these experiments was to investigate the ability of endophytic microbes isolated from M. citrifolia to produce secondary metabolites which can act as anti-microbial agents. A direct seed inoculating technique was used by planting the plant sample onto the surface of Nutrient Agar and Potato-Dextrose Agar. Assessment of their ability to produce anti-microbial substances was conducted by growing the endophyte isolates in Muller Hinton Broth for bacterial isolates, and in Potato-Dextrose Yeast Broth for fungal isolates. The agar diffusion method using paper disk was applied to assay the anti-microbial activity of each substance. The results of the endophyte isolation in these experiments gave five bacterial isolates and eleven fungal isolates. All of the bacterial isolates showed a broad antimicrobial spectrum while ten of the fungal isolate demonstrated broad anti-microbial activity and four out of the ten fungal isolates had activity towards Candida albicans.
Host Plant Mediated the Effect of Phosphorus on the Growth of External Hyphae of Gigaspora margarita ROHYADI, AGUS
Microbiology Indonesia Vol 1, No 3 (2007): December 2007
Publisher : Indonesian Society for microbiology

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5454/mi.1.3.8

Abstract

The effect of soil phosphorus (P) administered to the host plant on the growth of external hyphae of Gigaspora margarita was investigated in a glasshouse experiment using pots divided into three compartments i.e. one for donor plants (DPC), one for external fungal hyphae (EHC) and one for receiver plants (RPC) respectively. The DPC was filled with a sterilized soil/sand mix previously set up to have 5, 16 or 26 mg Bray-1 P kg-1 soil (P1, P2,or P3; categorized as low, intermediate or high level of P-availability) at pH 5.3 and inoculated with and without the fungal inoculums, while the RPC was filled with P3 without inoculation. Two pre-germinated seeds of cowpea were then grown there for 2 weeks before filling the EHC with the original sterilized soil/sand mix having pH 4.6 and 12 mg Al3+ kg-1 soil. These plants were harvested after further grown for 4-8 weeks. P fertilizer induced different growth conditions of host plants, which could control the production of external hyphae by the fungal partner. In supporting G. margarita to develop an optimum extent of external hyphae in acidic soils with a toxic level of Al3+, cowpea plants required soil P availabilities at about the intermediate level.

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