Mangrove Streptomyces Research Articles

Growth optimization of mangrove Streptomyces for enhancement of actinorhodin production

The family Streptomycetaceae, notably species in genus Streptomyces, have long been the subject of investigation due to their well-known ability to produce secondary metabolites. Even though thousands of secondary metabolites have been discovered from Streptomyces, less attention has been given in understanding the bioprospecting of the secondary metabolites in Streptomyces living in mangrove ecosystem. Therefore, the current study was designed to investigate the production of actinorhodin from mangrove Streptomyces which was grown in different parameters. Phylogenetic analysis showed that the Streptomyces sp. K2-11 belongs to Streptomyces prasinus strain NRRL B-12521 with 99.62% similarity. High-performance liquid chromatography analysis has detected the presence of actinorhodin compound in Streptomyces sp. k2-11. The compound showed inhibitory activity to Bacillus subtilis and no activity against Streptococcus aureus based on disc diffusion assay. Streptomyces sp. growth in SMMS media was recorded to be the highest (1.49 × 108 cfu/ mL) compared with SYE and R2 media. The production of actinorhodin was tested on three different parameters: incubation temperature, pH and glucose levels. The highest production of actinorhodin was recorded at 33°C (1.95 × 10–6 mol/L), pH 5 (7.1 × 10–6 mol/L) and 50% w/v glucose (9.56 × 10–6 mol/L) for 60 h of incubation. The present finding suggested that mangrove Streptomyces sp. K2-11 produced high yield of actinorhodin under extreme or stress condition.

Bioactive Molecules from Mangrove Streptomyces qinglanensis 172205.

Five new compounds 15R-17,18-dehydroxantholipin (1), (3E,5E,7E)-3-methyldeca-3,5,7-triene-2,9-dione (2) and qinlactone A–C (3–5) were identified from mangrove Streptomyces qinglanensis 172205 with “genetic dereplication,” which deleted the highly expressed secondary metabolite-enterocin biosynthetic gene cluster. The chemical structures were established by spectroscopic methods, and the absolute configurations were determined by electronic circular dichroism (ECD). Compound 1 exhibited strong anti-microbial and antiproliferative bioactivities, while compounds 2–4 showed weak antiproliferative activities.

Whole genome sequence of Streptomyces humi strain MUSC 119T isolated from intertidal soil

Over the past few decades, microorganisms have made major contribution in natural product research, particularly those from the genus Streptomyces. Streptomyces humi MUSC 119T was previously isolated as novel streptomycete from mangrove soil in Malaysia. During the screening programme for bioactive strains, this strain was discovered to possess antioxidant activity – scavenging and reducing accumulation of free radicals in biochemical assays. Consequently, whole genome sequencing was performed to evaluate genomic potential of the strain. Based on our analysis, the genome size of MUSC 119T is described to be 10.01 Mbps with G + C content of 71.80%. Based on antiSMASH analysis, the strain possess great genomic potential, having nine biosynthetic gene clusters displaying high similarities to known gene clusters. These findings indicates that mangrove Streptomyces species like MUSC 119T may potentially play an important role in drug development process, while the availability of its whole genome sequences allows further manipulation to isolate and identify compound of interest.

An Iterative Module in the Azalomycin F Polyketide Synthase Contains a Switchable Enoylreductase Domain.

Detailed analysis of the modular Type I polyketide synthase (PKS) involved in the biosynthesis of the marginolactone azalomycin F in mangrove Streptomyces sp. 211726 has shown that only nineteen extension modules are required to accomplish twenty cycles of polyketide chain elongation. Analysis of the products of a PKS mutant specifically inactivated in the dehydratase domain of extension‐module 1 showed that this module catalyzes two successive elongations with different outcomes. Strikingly, the enoylreductase domain of this module can apparently be “toggled” off and on : it functions in only the second of these two cycles. This novel mechanism expands our understanding of PKS assembly‐line catalysis and may explain examples of apparent non‐colinearity in other modular PKS systems.

An Iterative Module in the Azalomycin F Polyketide Synthase Contains a Switchable Enoylreductase Domain

AbstractDetailed analysis of the modular Type I polyketide synthase (PKS) involved in the biosynthesis of the marginolactone azalomycin F in mangrove Streptomyces sp. 211726 has shown that only nineteen extension modules are required to accomplish twenty cycles of polyketide chain elongation. Analysis of the products of a PKS mutant specifically inactivated in the dehydratase domain of extension‐module 1 showed that this module catalyzes two successive elongations with different outcomes. Strikingly, the enoylreductase domain of this module can apparently be “toggled” off and on : it functions in only the second of these two cycles. This novel mechanism expands our understanding of PKS assembly‐line catalysis and may explain examples of apparent non‐colinearity in other modular PKS systems.

Novel propanamide analogue and antiproliferative diketopiperazines from mangrove Streptomyces sp. Q24

A new propanamide analogue (1), along with one known alkaloid (2) and four known diketopiperazines (3–6), was isolated from a cultured broth of the actinomycete Streptomyces sp. Q24 that was obtained from a sample of mangrove soil. The structures of these isolates were characterised as 3-acetylamino-N-2-thienyl-propanamide (1), N-acetyltryptamine (2), cyclo-(l-phenylalanine-l-4-hydroxyproline) (3), cyclo-(l-leucine-l-4-hydroxyproline) (4), cyclo-(l-phenylalanine-d-4-hydroxyproline) (5) and cyclo-(l-leucine-l-proline) (6) based on their NMR and HRESIMS data as well as optical rotation. Three diketopiperazines (3, 4, 6) showed activity in inhibiting the proliferation of human glioma U87-MG and U251 cells. This type of the new propanamide analogue (1) is first found from a nature source and the antiproliferative property of these three diketopiperazines against glioma cells is also reported herein for the first time.

New azalomycin F analogs from mangrove Streptomyces sp. 211726 with activity against microbes and cancer cells.

Seven new azalomycin F analogs (1–7) were isolated from the broth of mangrove Streptomyces sp. 211726, and respectively identified as 25-malonyl demalonylazalomycin F5a monoester (1), 23-valine demalonylazalomycin F5a ester (2), 23-(6-methyl)heptanoic acid demalonylazalomycins F3a ester (3), F4a ester (4) and F5a ester (5), 23-(9-methyl)decanoic acid demalonylazalomycin F4a ester (6) and 23-(10-methyl)undecanoic acid demalonylazalomycin F4a ester (7). Their structures were established by their spectroscopic data and by comparing with those of azalomycins F3a, F4a and F5a. Biological assays exhibited that 1–7 showed broad-spectrum antimicrobial and anti HCT-116 activities.

Mangrove Streptomyces sp. BDUKAS10 as nanofactory for fabrication of bactericidal silver nanoparticles

Biosynthesis has led to the development of various biomimetic approaches for the fabrication of nanoscale materials. The present study reveals a unique procedure for the biosynthesis of bactericidal silver nanoparticles (AgNPs) using a novel Streptomyces sp. BDUKAS10, an isolate of mangrove sediment. Aqueous silver nitrate (AgNO3) solution was treated with cell free supernatant (CFS) of the isolate to synthesize bactericidal silver nanoparticles. Initial characterization was performed by visual observation for color change to intense brown color. UV–visible spectrophotometry (UV–vis) for measuring surface plasmon resonance indicated a maximum absorption peak at 441nm. Fourier Transform Infrared Spectroscopy (FTIR) analysis provides evidence for proteins as possible reducing, and capping agents. Energy dispersive X-ray (EDAX) spectroscopy analysis showed elemental silver as major signal. Transmission Electron Microscopy (TEM) study indicated spherical silver nanoparticles in the size range of 21–48nm. Compared to the CFS, the biosynthesized AgNPs exemplified superior bactericidal efficacy towards the tested bacterial strains. Results from this study suggested that Streptomyces sp. BDUKAS10 can be advantageous for the synthesis of AgNPs by extracellular method in the view of sustainable and ecofriendly approach.

A Novel Benzo[f][1,7]Naphthyridine Produced by Streptomyces Albogriseolus from Mangrove Sediments

Mangrove Streptomyces represent a rich source of novel bioactive compounds in medicinal research. A novel alkaloid, named 1-N-methyl-3-methylamino-[N-butanoic acid-3′-(9′-methyl-8′-propen-7′-one)-amide]-benzo[f][1,7]naphthyridine-2-one (1) was isolated from Streptomyces albogriseolus originating from mangrove sediments. The structure of compound 1 was elucidated by extensive spectroscopic data analyses and verified by the 13C-NMR calculation at the B3LYP/6-311+G(2d,p) level of theory.

Identification of new antibiotic producing strains from mangrove Streptomyces by targeted screening of halogenases

Identification of new antibiotic producing strains from mangrove Streptomyces by targeted screening of halogenases

Geldanamycin derivatives and neuroprotective effect on cultured P19-derived neurons

Geldanamycin ( 1), an antifungal and anticancer ansamycin, was reported as a neurotrophic and neuroprotective substance against antineoplastic drugs, paclitaxel, vincristine, and cisplatin, on cultured dorsal root ganglion neurons from chick embryos. In this study, 1 in a large quantity, together with a known 17- O-demethylgeldanamycin ( 2), and a new 17- O-demethylgeldanamycin hydroquinone ( 3) were obtained from a mangrove Streptomyces sp. A series of O-alkyl and N-alkyl derivatives of 1 were prepared by modification of C-17 and/or C-19 on the quinone ring and were evaluated for in vitro activity against P19-derived neurons. Compound 1 and 19- O-methylgeldanamycin ( 7) at a very low dose (1 nM) enhanced survival and neurite outgrowth of P19-derived neurons and prevented neurotoxicity of paclitaxel and vinblastine. Compound 7, possessing the lowest cytotoxicity and neurotoxicity, is serving as the most promising candidate in neurodegenerative therapy against neurotoxic anticancer drugs.