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Articles by issue : Vol 9, No 4 (2015): December 2015
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Articles
Screening, Purification, and Characterization of Cellulase from Fungi Isolated from Used Mushroom Substrate

SASKIAWAN, IWAN, HASANAH, NUR

Microbiology Indonesia Vol 9, No 4 (2015): December 2015
Publisher : Indonesian Society for microbiology

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Abstract

Alarge number of microorganism especially filamentous fungi has ability to degrade cellulose. The purpose of this study was to conduct screening, purification, and characterization of cellulase from fungi which was isolated from used paddy straw mushroom substrate. Screening of cellulytic activity using CMC medium shown that 11 out of 20 isolates of fungi produced a clearing zone surrounding fungal colony. Among them isolate number JMF 12 showed the highest cellulase activity and was further used for purification and characterization. The cellulase was purified to electrophoretical homogeneity by ammonium sulfate precipitation, dialyzed by Novagen D-Maxi TubeTM Dialyzer, and Sephadex G-100 gel filtration chromatography. The recovery and purification fold was 3.82 % and 1.98 respectively, after Sephadex G-100 gel filtration chromatograph. The o purified cellulase had an optimal pH and temperature at 6 and 45 C. The Km and Vmax of cellulase was 11.43 mM and 0.006mmol/min respectively. The purified cellulase was activated by Na+ and Zn++ but inhibited by Ca++, Co++, Fe++, and  Hg++ .

ITA registration form and back cover

Helianti, Is ( 1. BPPT 2. Indonesian Society for Microbiology )

Microbiology Indonesia Vol 9, No 4 (2015): December 2015
Publisher : Indonesian Society for microbiology

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Abstract

Antibiotic Use Is Not a Risk Factor of Infection by Extended-Spectrum Beta-Lactamase Producing Bacteria in Dr. Soetomo Hospital Surabaya

FITRI, NADHYA NUR ( Faculty of Medicine, Universitas Airlangga ) , RUSLI, MUSOFA ( Department of Internal Medicine, Faculty of Medicine, Universitas Airlangga ) , WAHYUNITISARI, MANIK RETNO ( Department of Clinical Microbiology, Faculty of Medicine, Universitas Airlangga )

Microbiology Indonesia Vol 9, No 4 (2015): December 2015
Publisher : Indonesian Society for microbiology

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Abstract

Infection by Extended-Spectrum Beta-Lactamase (ESBL) producing bacteria confers a major challenge for clinicians due to limited treatment options and poor prognosis. Inappropriate antibiotic use is thought to cause the emergence of this resistant strain through selective pressure mechanisms. This study aims to describe the proportion of ESBL-producing bacteria and characteristics of patients with ESBL-producing bacterial infection, and to analyze the risk factors of infection by ESBL-producing bacteria in Dr. Soetomo Hospital, Surabaya. A cross-sectional study was conducted on medical records of inpatients of Internal Medicine Ward of Dr. Soetomo Hospital. Samples were classified into ESBL-positive or ESBL-negative groups. Demographic data, clinical data and previous antibiotic use of 66 samples (33 in each group) were retrospectively obtained. As many as 30 patients (45.5%) were male. Mean age of patients in the ESBL-positive and negative group were 53.57 (±16.77) and 54.27 (±14.88) years, respectively (p>0.05). The median pre-infection length of stay was 4 and 3 days for ESBL-positive and negative group, respectively (p>0.05). Type 2 diabetes mellitus was the most common comorbid disease (33.3%). The most frequent bacteria obtained from clinical isolates was Escherichia coli (49.3%). Proportion of ESBL producers amongst E.coli and K. pneumoniae isolates were 75% and 38.5%, respectively. The most frequently prescribed empirical antibiotic was ceftriaxone. None of the antibiotic used were risk factors for infection by ESBL-producing bacteria. Although none of the assessed variables were risk factors for ESBL-infection was discovered, this study finds a significantly larger proportion of ESBL-E. coli compared to non-ESBL producing E. coli. Further studies should include larger sample size and quantitatively measured antibiotic use.

Isolation, Identification and Screening of Antimicrobial Properties of the Marine-Derived Endophytic Fungi from Marine Brown Seaweed

WONG, CHANGI ( University of Technology Sarawak Campus ) , PROKSCH, PETER, TAN, LEE TUNG, LIHAN, SAMUEL, MUJAHID, AAZANI, MÜLLER, MORITZ

Microbiology Indonesia Vol 9, No 4 (2015): December 2015
Publisher : Indonesian Society for microbiology

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Abstract

Marine seaweeds are known to produce valuable medicinal compounds such as antioxidants and anticoagulants, and have been reported to display antimicrobial activity against gram positive and gram negative bacteria. Several studies have identified so-called endophytic fungi living inside their hosts as the source of active compounds. In this study marine brown seaweed, Padina sp., was studied with regards to their endophytic fungi to assess if they are the source of the reported antimicrobial activity. Twenty fungal isolates were isolated from Padina sp. collected off Talang-Talang Island, Sarawak, Malaysia. All isolates were screened for their antimicrobial properties and 11 out of 20 isolates displayed positive results. DNA was successfully extracted for five isolates and sequence analysis grouped all of them with other endophytic fungi. “Fungus 2” seems to be related to a so far uncultured endophytic fungus. “Fungus 19” showed the most promising antimicrobial properties and was chosen for further agar well assay and cytotoxicity testing. Its ethyl-acetate extract showed positive results in the agar well assay and also a cytotoxic effect on Artemia nauplii. The extract was screened using HPLC and showed a compound similar to a known anti-cancer compound, dihydromyricetin, which is also an anti-intoxicant, anti-inflammatory and anti-oxidative agent which may be responsible for the observed antimicrobial activity.

Orchid Mycorrhizal Fungi: Identification of Rhizoctonia from West Kalimantan

SURYANTINI, ROSA, WULANDARI, REINE SUCI, KASIAMDARI, RINA SRI

Microbiology Indonesia Vol 9, No 4 (2015): December 2015
Publisher : Indonesian Society for microbiology

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Abstract

Orchid is an ornamental plants with high economic value. The excessive exploitation of orchids threatened or even endangered the species, especially those of the epiphytic orchids (Appendiculla sp., Calanthe vestita, and Bulbophyllum beccarii) in West Kalimantan. The discovery of the interaction between orchids and mycorrhizal fungi raises the possibility of ex situ conservation of orchids and it will ensure the success of orchid conservation. Orchid mycorrhizal fungi belongs to the group of Rhizoctonia-like,in which comprised of different genus such as Ephulorhiza, Ceratoriza, and Tullasnela. So far, there is no report on the identit of orchid mycorrhiza associated with the epiphytic orchids in West Kalimantan. The purpose of this study was to identify Rhizoctonia-like associated with Appendiculata sp., Calanthe vestita, and Bulbophyllum beccarii roots in the forest of Raya Pasi and Gunung Bawang, West Kalimantan. The methods were isolation and identification of Rhizoctonia-like from healthy orchids root based on their morphological characteristics (such as the colony colour, hyphal cell size, sclerotial, concentric circles and monilioid cell, number of nuclei per cell), observation of peloton in root tissue and grouping of isolates. Based on identification of orchid mycorrhiza on the roots of the three species of orchids from West Kalimantan, it was observed that Ceratorhiza sp. was associated with Appendiculla sp.,Ephuloriza sp. with C. vestita, and Tullasnela sp. with B. beccarii roots, respectively. This result is preliminary information and it is still need to be further studied, especially on the role of Rhizoctonia-liker as orchid mycorrhizal fungi in association with the epiphytic orchid for conservation. 

Heavy Metals Biosorption by Copper Resistant Bacteria of Acinetobacter sp. IrC2

IRAWATI, WAHYU, PARHUSIP, ADOLF JN, SOPIAH, NIDA

Microbiology Indonesia Vol 9, No 4 (2015): December 2015
Publisher : Indonesian Society for microbiology

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Abstract

 Heavy metal pollution is a serious problem because it cannot be degraded by natural processes and persist in soil, water, and sediment. Many indigenous microorganisms isolated from heavy metal contaminated sites had tolerance to heavy metals toxicity and could be used for bioremediation agent because of its capability to biosorb heavy metals. The aim of this research was to study the potency of copper resistant bacteria Acinetobacter sp. IrC2 as a biosorbent of heavy metals. Biosorption was determined by measuring the heavy metals concentration on growing medium by using atomic absorption spectrophotometer. The research showed that Acinetobacter sp. IrC2 was capable of growing in medium containing each of 2 mM of copper, zinc, lead, cadmium, and the mixture of those heavy metals. The addition of copper and lead in the medium changed morphological appearance of colonies to green and brown, respectively, suggesting that the survival mechanism of the isolate was by biosorbing copper or lead inside the cells. The percentage of heavy metals biosorption efficiency using live cells of Acinetobacter sp.IrC2 were up to 64.31% of copper, 24.73% of zinc, 62.79% of lead, and 11.56% of cadmium. Acinetobacter sp. IrC2 also reduced copper, lead, and cadmium concentration up to 24.30, 75.93, and 16.38%, respectively, in medium supplemented with 1 mM of the mixture of these heavy metals. The findings of this study indicated that Acinetobacter sp. IrC2 was a promising bacterium for removal of heavy metals.