We report here the discovery, isolation, and chemical and preliminary biological characterization of a new antibiotic compound, 7-O-malonyl macrolactin A (MMA), produced by a Bacillus subtilis soil isolate. MMA is a bacteriostatic antibiotic that inhibits a number of multidrug-resistant gram-positive bacterial pathogens, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and a small-colony variant of Burkholderia cepacia. MMA-treated staphylococci and enterococci were pseudomulticellular and exhibited multiple asymmetric initiation points of septum formation, indicating that MMA may inhibit a cell division function.The spread of resistance to antibiotics undermines the therapeutic utility of anti-infective drugs in current clinical use (1). For example, Staphylococcus aureus, a major cause of community-and hospital-acquired infections, has developed resistance to most classes of antibiotics. Methicillin-resistant S. aureus (MRSA) strains appeared in the hospital environment after introduction of the semisynthetic penicillin methicillin, leaving vancomycin as the last line of defense for MRSA treatment (7). S. aureus organisms intermediately susceptible to vancomycin were first isolated in 1997 in Japan (15) and later in other countries (8). With the recent appearance of vancomycin-resistant clinical isolates (32,36,38), no antibiotic class is effective against multiresistant S. aureus infections. The increase in vancomycin-resistant enterococci (VRE), important agents of nosocomial infections, is another cause of great concern (2,3,19,27). Therapy options for multiresistant gramnegative opportunistic bacterial pathogens are also diminishing. Such bacteria, like Pseudomonas aeruginosa and Burkholderia cepacia (6), are common environmental organisms and opportunistic pathogens having the capacity to infect essentially all tissues of patients with compromised host defenses (21).Compounding the problem of genetically determined transmissible antibiotic resistance is the development of phenotypically resistant, often slow-growing, forms in chronic bacterial infections. These may take the form of biofilm microbes or small-colony variants (SCV) (12; reviewed in reference 14), are known to include both gram-positive and gram-negative pathogens, and are usually associated with a worsening of the disease prognosis.Thus, new antibiotics and therapy options are urgently needed to improve the management of bacterial infections (29, 35), and a major challenge is to find drugs that act against SCV and/or bacteria growing in biofilms.In this study, we report the discovery and preliminary characterization of 7-O-malonyl macrolactin A (MMA), a new antibiotic having bacteriostatic activity against clinical strains of MRSA, VRE, and a SCV of Burkholderia cepacia. The parental wild-type (WT) and SCV pairs of P. aeruginosa and B. cepacia, as well as Stenotrophomonas maltophilia strain 1124, were isolated from cystic fibrosis patients in the Department of Medical Microbiology at the Medical School...

In our screening of Indonesian microorganisms for novel bioactive natural products we have isolated seven new compounds, designated as limazepines A, B1 and B2 (isolated as an isomeric mixture), C, D, E, and F, from the culture broth of Micrococcus sp. strain ICBB 8177. In addition, the known natural products prothracarcin and 7-O-succinylmacrolactin A, as well as two previously reported synthetic compounds, 2-amino-3-hydroxy-4-methoxybenzoic acid methyl ester and 4-ethylpyrrole-2-carboxaldehyde, were obtained from the extract. Chemical structures were determined by spectroscopic methods and by comparison with the NMR data of structurally related compounds. The limazepines belong to the growing group of the pyrrolo[1,4]benzodiazepine antitumor antibiotics isolated from various soil bacteria. Limazepines B1/B2 mixture, C, and E were active against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacterium Escherichia coli. Limazepine D was also active against S. aureus, but was not active against E. coli. Interestingly, only the limazepines B1/B2 mixture and D were active against Pseudomonas aeruginosa.

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Six new angucyclinone polyketides named panglimycins A-F were isolated together with the three known metabolites (+)-fujianmycin A, (+)-ochromycinone, and emycin C from the bioassay-guided fractionation of the extract of the Indonesian Streptomyces strain ICBB8230. The new compounds are highly oxygenated angucyclinones that appear to be biosynthetically derived from ochromycinone or fujianmycin. Their structures were determined by X-ray crystal analysis, interpretation of 1D- and 2D-NMR spectra, and comparison of the data with those of structurally related known natural products. Despite structural similarities to angucyclinones with antibiotic activities, the panglimycins did not exhibit any growth inhibition when tested against several bacteria and fungi.

A rapid method for the extraction and purification of DNA from environmental samples for molecular cloning applications was developed. The indigenous cells from plant debris, organic materials, sediments, and soils were lysed directly by using DAS-IZ solution and the nucleic acids were precipitated with isopropanol. A simple purification step using DAS-IIZ solution without binding matrix produced highly pure, colorless and undegraded DNA with molecular weight of more than 20 kb. The superiority of this method was tested for wide applications in molecular cloning, i.e., construction of genomic library by using Lambda DASHII Vector and GigapackIII XL, plasmid library, cloning of gene encoding protease, and molecular microbial diversity analysis. An additional advantage of this method is that only 0.1 g of sample is required, if analysis of many samples in short time should be done. To extract large amounts of environmental DNA for molecular cloning lasts only 30 min and to purify it less than 1 h.

Four new elaiophylin macrolides (1-4), together with five known elaiophylins (5-9), have been isolated from cultures of the Indonesian soil bacterium Streptomyces sp. ICBB 9297. The new compounds have macrocyclic skeletons distinct from those of the known dimeric elaiophylins in that one or both of the polyketide chains contain(s) an additional pendant methyl group. Further investigations revealed that 1 and 2 were derived from 3 and 4, respectively, during isolation processes. Compounds 1-3 showed comparable antibacterial activity to elaiophylin against Staphylococcus aureus. However, interestingly, only compounds 1 and 3, which contain a pendant methyl group at C-2, showed activity against Mycobacterium smegmatis, whereas compound 2, which has two pendant methyl groups at C-2 and C-2', and the known elaiophylin analogues (5-7), which lack pendant methyl groups at C-2 and/or C-2', showed no activity. The production of 3 and 4 in strain ICBB 9297 indicates that one of the acyltransferase (AT) domains in the elaiophylin polyketide synthases (PKSs) can recruit both malonyl-CoA and methylmalonyl-CoA as substrates. Bioinformatic analysis of the AT domains of the elaiophylin PKSs revealed that the ela_AT7 domain contains atypical active site amino acid residues, distinct from those conserved in malonyl-CoA- or methylmalonyl-CoA-specific ATs.

Two Indonesian Streptomyces strains, ICBB8309 and ICBB8415, were investigated for their ability to produce antibiotic compounds. In addition to the known antibiotics actiphenol, naramycin B, and sabaramycin, six new angucyclinones were identified. The isolation, structure elucidation and biological activities for the six new compounds are presented. The angucyclinones 7-deoxo-6-deoxy-7-hydroxy-8-O-methylrabelomycin, 1-deoxo-1-hydroxy-8-O-methylrabelomycin, and the angucycline 7-deoxo-7-hydroxy-1-O-a -rhamnosyl-8-Omethyltetrangulol have common angular backbones, while angucyclinone C, limamycin A, and limamycin B appear to be rearranged angucyclinones.

To investigate a suitable biological remediation approaches for anticipating oil spills in Cilacap sandy beach (Indonesia), some alternative strategies using biostimulation and a combination of biostimulation-bioaugmentation have been evaluated in inter tidal near shore Cilacap, Indonesia. The purpose of the study was to compare the efficacy of biostimulation using slow release fertilizer (SRF) only, combination of biostimulation-single strain bioaugmentation, and combination of biostimulation-consortium bioaugmentation, to enhance oil degradation. The experiment was conducted using sediment polluted 100,000 ppm Arabian Light Crude Oil in a mesocosm system for 90 days. The parameters measured were oil depletion, bacterial growth and changes in environmental conditions. The results showed that the affectivity on oil depletion of biostimulation-bioaugmentation combination was observed faster and higher than biostimulation only. At the 16 th day application, the biostimulation with the added consortium and single strain treatment, increased oil depletion percentage by 2.2 and 1.6 times that of the control, respectively. For a longer period of treatment, both of combination treatments showed similar efficacy in degrading oil contamination in sandy beach. It is proposed that combination of biostimulation-bioaugmentation with the consortium is relatively better alternative for combating oil-pollution for a short period.