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Articles by issue : Vol 2, No 2 (2008): August 2008
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Ecological Approach to Unravel Streptomycete Diversity as an Unsurpassed Sources of Natural Bioactive Products

SEMBIRING, LANGKAH, GOODFELLOW, MICHAEL

Microbiology Indonesia Vol 2, No 2 (2008): August 2008
Publisher : Indonesian Society for microbiology

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Abstract

Search and discovery for natural bioactive products have been so important to control the emergence of antibiotic resistant microbial pathogens. Therefore, novel microorganisms that produce such metabolites is extremely needed. The capacity of members of the genus Streptomyces to produce commercially significant bioactive metabolites, notably antibiotics remains unsurpassed. However, it is acknowledged that discovering commercially useful secondary metabolites from streptomycetes is becoming more difficult due to lack of knowledge on the ecology and complexity of streptomycete systematics. In fact, those are fundamental aspects for developing strategy and method for isolation. In order to devise an appropriate program for successful selective isolation of sreptomycetes, it is fundamentally important to understand their occurance and activity in nature. A multistep extraction procedure designed for representative sampling, called dispersion, and differential centrifugation technique in combination with the incorporation of antibiotics into isolation media has become one of the most important selective method for the isolation of streptomycetes from natural habitats. The availability of new procedures to selectively isolate representative of streptomycetes from natural habitats opens up the possibility to determine the extent of streptomycete diversity from various habitats. Hence, the capacity of well characterized streptomycete isolates to produce commercial novel active metabolites could be further assessed appropriately.

Ethnomedicinal Plant Terong Pungo (Solanum sp.)

HARDJITO, LINAWATI

Microbiology Indonesia Vol 2, No 2 (2008): August 2008
Publisher : Indonesian Society for microbiology

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Abstract

The leaf of terong pungo Solanum sp. had been used traditionally in Aceh to treat toothache and relieve pain. Based on traditional knowledge, this research was conducted to examine the biological activities of its extract as an antibacterial agent and topoisomerase-I inhibitor. The topoisomerase-I inhibitor is one of the target molecules for anticancer compounds. In addition, it is also a target molecule for antimicrobial compounds. The antibacterial activity was examined using disc diffusion assay against Staphylococcus aureus and Escherichia coli isolated from medical patients. Topoisomerase-I inhibitor activity was determined using the method reported by TopoGEN, and its toxicity was examined against Artemia salina. Chloroform, ethyl acetate, and methanol treatments yielded crude extracts of 1.44, 1.20, and 2.69%, respectively. The chloroform extract exhibited neither antibacterial nor topoisomerase-I inhibitor activities, while the ethylacetate and methanol extracts at a concentration of 300 μg/paper disk positively inhibited the growth of both target bacteria or enzyme activity of topoisomerase-I at a concentration of 50 μg ml-1. The ethylacetate extract showed better activity against target bacteria and was chosen for further investigation. The results suggest that the crude extract showed antibacterial and topoisomerase-I inhibitor activity. Identification of the isolated active fraction indicated that it contained a steroidal alkaloid compound. This investigation revealed that the leaf of terong pungo contains biologically active compounds of pharmacological relevance.

Distribution of Clavibacter michiganensis subsp. michiganensis in Various Tomato Production Centers in Sumatra and Java

ZAINAL, APRIZAL, ANWAR, ASWALDI, KHAIRUL, UJANG, SUDARSONO, .

Microbiology Indonesia Vol 2, No 2 (2008): August 2008
Publisher : Indonesian Society for microbiology

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Abstract

Bacterial canker, caused by Clavibacter michiganensis subsp. michiganensis is a newly introduced disease of tomatoes in Indonesia. Its existence was first officially reported in 2004. The objective of this research was to monitor the existence of C. michiganensis subsp. michiganensis in various tomato production centers in Sumatra and Java. Tomato samples showing symptoms of C. michiganensis subsp. michiganensis infection were collected from various tomato production centers in Sumatera and Java and the causal agents were isolated from these samples. Based on the occurrences of typical symptoms of C. michiganensis subsp. michiganensis infection in tomato, the incidence of suspected C. michiganensis subsp. Michiganensis infection ranged from 1-20%. From a total of 74 tomato plants sampled, 24 bacterial isolates exhibiting similar colony morphology to C. michiganensis subsp. michiganensis were obtained. After various physiological, hypersensitive response, and pathogenicity tests, 18 isolates derived from 14 tomato production centers in eight provinces in Sumatera and Java were identified as C. michiganensis subsp. michiganensis. Although the incidence was still low, results of these experiments further indicated that C. michiganensis subsp. michiganensis existed in Indonesia and had spread in a number of tomato production centers in Sumatra and Java. Positive results of C. michiganensis subsp. Michiganensis identification from suspected tomato samples should be a warning sign for all tomato production stakeholders in Indonesia, especially those responsible in regulating the seed trade, importation, and plant quarantine

A Supplement Based on Zn-Enriched Virgin Coconut Oil as an Antifungal agent for Vaginal Candidiasis Patients

HERY WINARSI, ., HERNAYANTI, ., PURWANTO, AGUS

Microbiology Indonesia Vol 2, No 2 (2008): August 2008
Publisher : Indonesian Society for microbiology

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Abstract

This research was conducted to investigate the amount of Candida albicans in vaginal secretion of Vaginal Candidiasis patients administered with Zn-enriched virgin coconut oil. Thirty respondents were selected based on several criteria as follows: the number of C. albicans colonies in the vaginal secretion was more than 105 cfu.ml-1, voluntary, healthy, willing to sign the informed consent and resided in Purwokerto. In Group A, 10 women were administered 2 tablespoons per day of Zn-enriched virgin coconut oil. In Group B, 10 women were administered 1 tablespoon per day of Zn-enriched virgin coconut oil; and in Group C, 10 women served as control group. Vaginal secretions were taken 3 times, before intervention (at baseline time), at 1 month and 2 months after intervention. Samples were taken by collecting vaginal secretions from the vaginal proximal region using a sterile cotton bud, which was then put into a tube containing sterile carrier media. The vaginal secretions were tested for the number of total C. albicans using Pour Plate Method. Two months after treatment, the number of colonies decreased from 4.4x106 to 2.5x106 cfu ml-1 (p=0.03) in Group A. There was no significant difference in the number of colonies between Group A and Group B, the number of C. albicans colonies was still above the normal range. Therefore, the recommended dosage of intervention with Zn-enriched virgin coconut oil is one tablespoon a day.

Optimum Concentration of Glucose and Orange II for Growth and Decolorization of Orange II by Enterococcus faecalis ID6017 under Static Culture

MEITINIARTI, V. IRENE, SOETARTO, ENDANG S., SUGIHARTO, EKO, TIMOTIUS, KRIS HERAWAN

Microbiology Indonesia Vol 2, No 2 (2008): August 2008
Publisher : Indonesian Society for microbiology

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Abstract

Growth and decolorization performance of bacterial grown on azodyes-containing-medium is influenced by various concentrations of carbon sources and azodyes. The optimum level of glucose and Orange II concentration for growth and Orange II decolorization by Enterococcus faecalis ID6017 are reported in this paper. The experiments were carried out in liquid static culture as batch experiments. Glucose and Orange II concentrations used in these experiments were 0.45, 0.90, 1.80 g l-1, and 40, 80, 120 mg l-1, respectively. The specific growth rate and decolorization rate of Orange II by E. faecalis were highest on the medium which contained at least 0.90 g l-1 glucose. It is necessary to note that glucose above 0.90 g l-1 gave no significant difference. On the medium containing 0.90 g l-1 glucose and 80 mg l-1 Orange II, E. faecalis grew with the highest specific growth rate (0.28 h-1) and Orange II decolorization rate (0.47 h-1). The maximum specific growth rate of biomass (μmax) and the halfsaturation coefficient (KS) under optimal conditions were 0.25 h-1 and 1.5 g.l-1, respectively. The kinetics of decolorization indicated that the process followed first order kinetics with respect to the initial concentration of Orange II. The inhibition constant (KI) was found to be 750 mg l-1 Orange II, indicating that Orange II concentration at e” 750 mg l-1 would inhibit bacterial growth to decolorize Orange II..

Ecological Role of A Softcoral-Associated Bacterium Arthrobacter sp. on Marine Biofilm-Forming Bacteria

RADJASA, OCKY KARNA, SABDONO, AGUS

Microbiology Indonesia Vol 2, No 2 (2008): August 2008
Publisher : Indonesian Society for microbiology

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Abstract

A marine bacterium species associated with softcoral Sinularia sp. collected from vicinity of Peucang island, Ujung Kulon, West Java, was successfully screened for estimating its ecological role through inhibiting marine biofilm-forming bacteria isolated from the surrounding colonies of Sinularia sp. and was identified as closely related to Arthrobacter nicotianae based on its 16S rDNA structure. The bacterium was found to inhibit the growth of four biofilm-forming isolates (Vibrio harveyi, V. fortis, Staphylococcus sciuri, and Tenacibaculum marilutum) indicating the significance of secondary metabolite production which may provide important defensive functions against fouling microorganisms. The isolate was capable of amplifying gene fragments of non-ribosomal peptide synthetases. A 416 bp long DNA fragment was obtained and the deduced amino acid sequence showed conserved signature regions for the peptide synthetases and revealed a high similarity to that of Actinoplanes teichomyceticus (62.5% identity).

Population Density of Wolbachia Bacteria and the Induction of the Popcorn-Effect in Drosophila melanogaster

KUSMINTARSIH, ENDANG SRIMURNI

Microbiology Indonesia Vol 2, No 2 (2008): August 2008
Publisher : Indonesian Society for microbiology

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Abstract

Drosophila melanogaster is known to harbour Wolbachia bacteria that cause the early death of its adult host. The death occurs early as a result of cell rupture caused by the proliferation of Wolbachia within it. However, the number of Wolbachia causing the early death in D. melanogaster is unknown. In order to determine whether the number of Wolbachia is related to the early death of its host, the quantity of Wolbachia and nuclei were examined using the real-time PCR procedure. The results showed that an egg cell contains at least 2-3 bacterial cells. A 4 day old larva contains at least 45 cells. The number of Wolbachia in adult flies of 1, 5, 8, and 12 days old were 422, 535, 964, and 610 per host cell, respectively.