• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1341-1341
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• 2016

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.825-833
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• 2017

Strain IMCC26207 was isolated from the surface layer of Lake Soyang in Korea by the dilutionto-extinction culturing method, using a liquid medium prepared with filtered and autoclaved lake water. The strain could neither be maintained in a synthetic medium other than natural freshwater medium nor grown on solid agar plates. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain IMCC26207 formed a distinct lineage in the order Acidimicrobiales of the phylum Actinobacteria. The closest relative among the previously identified bacterial taxa was "Candidatus Microthrix parvicella" with 16S rRNA gene sequence similarity of 91.7%. Here, the draft genome sequence of strain IMCC26207, a freshwater actinobacterium, is reported with the description of the genome properties and annotation summary. The draft genome consisted of 10 contigs with a total size of 3,316,799 bp and an average G+C content of 57.3%. The IMCC26207 genome was predicted to contain 2,975 protein-coding genes and 51 non-coding RNA genes, including 45 tRNA genes. Approximately 76.8% of the protein coding genes could be assigned with a specific function. Annotation of the IMCC26207 genome showed several traits of adaptation to living in oligotrophic freshwater environments, such as phosphorus-limited condition. Comparative genomic analysis revealed that the genome of strain IMCC26207 was distinct from that of "Candidatus Microthrix" strains; therefore, we propose the name "Candidatus Limnosphaera aquatica" for this bacterium.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.303-305
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• 2019

An actinobacterial strain designated Gordonia sp. MMS17-SY073 (=KCTC 49257) was isolated from a coastal soil of an island, and its complete genome was analyzed. A single contig consisting of 5,962,176 bp with the G + C content of 67.4% was obtained, and the annotation resulted in 5,201 protein-coding genes, 6 rRNA genes and 45 tRNA genes. Strain MMS17-SY073 was closest to the type strain of Gordonia soli based on the 16S rRNA gene sequence comparison, sharing 98.5% sequence similarity. A number of biosynthetic gene clusters for secondary metabolites, non-ribosomal peptide synthetase types in particular, could be identified from the genome.

• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.807-822
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• 2016

Starting as a glutamate producer, Corynebacterium glutamicum has played a variety of roles in the industrial production of amino acids, one of the most important areas of white biotechnology. From shortly after its genome information became available, C. glutamicum has been applied in various production processes for value-added chemicals, fuels, and polymers, as a key organism in industrial biotechnology alongside the surprising progress in systems biology and metabolic engineering. In addition, recent studies have suggested another potential for C. glutamicum as a synthetic biology platform chassis that could move the new era of industrial microbial biotechnology beyond the classical field. Here, we review the recent progress and perspectives in relation to C. glutamicum, which demonstrate it as one of the most promising and valuable workhorses in the field of industrial biotechnology.

• Natural Product Sciences
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• v.19 no.1
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• pp.71-75
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• 2013

Actinofuranone C (1), a new 3-furanone-bearing polyketide, was isolated from an actinobacterium (Amycolatopsis sp.) associated with a female of the dung beetle, Copris tripartitus Waterhouse. The structure of actinofuranone C was elucidated by the spectroscopic interpretation of NMR, mass, UV, and IR data. The discovery of actinofuranone C indicates that chemical investigation of insect-associated microorganisms would be an effective strategy to explore natural chemical diversity.

• Journal of Microbiology and Biotechnology
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• v.34 no.2
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• pp.457-466
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• 2024

Cellobiose dehydrogenases (CDHs) are a group of enzymes belonging to the hemoflavoenzyme group, which are mostly found in fungi. They play an important role in the production of acid sugar. In this research, CDH annotated from the actinobacterium Cellulomonas palmilytica EW123 (CpCDH) was cloned and characterized. The CpCDH exhibited a domain architecture resembling class-I CDH found in Basidiomycota. The cytochrome c and flavin-containing dehydrogenase domains in CpCDH showed an extra-long evolutionary distance compared to fungal CDH. The amino acid sequence of CpCDH revealed conservative catalytic amino acids and a distinct flavin adenine dinucleotide region specific to CDH, setting it apart from closely related sequences. The physicochemical properties of CpCDH displayed optimal pH conditions similar to those of CDHs but differed in terms of optimal temperature. The CpCDH displayed excellent enzymatic activity at low temperatures (below 30℃), unlike other CDHs. Moreover, CpCDH showed the highest substrate specificity for disaccharides such as cellobiose and lactose, which contain a glucose molecule at the non-reducing end. The catalytic efficiency of CpCDH for cellobiose and lactose were 2.05 × 10⁵ and 9.06 × 10⁴ (M^-1 s^-1), respectively. The result from the Fourier-transform infrared spectroscopy (FT-IR) spectra confirmed the presence of cellobionic and lactobionic acids as the oxidative products of CpCDH. This study establishes CpCDH as a novel and attractive bacterial CDH, representing the first report of its kind in the Cellulomonas genus.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.200-208
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• 2017

Actinobacteria are prolific producers of a large number of natural products with diverse biological activities. In the present study, an actinobacterium isolated from sunflower rhizosphere soil sample collected from Medak, Andhra Pradesh, South India was identified as Amycolatopsis thermoflava strain SFMA-103. A pigmented secondary metabolite in culture broth was extracted by using methanol and it was further purified by silica gel column chromatography with methanol-chloroform solvent system. Structural elucidation studies based on UV-visible, 1D and 2D-NMR, FT-IR, and mass spectroscopic analyses confirmed the structure as 1-methoxy-3-methyl-8-hydroxy-anthraquinone. It showed significant in vitro anticancer activity against lung cancer and lymphoblastic leukemia cells with $IC_{50}$ values of 10.3 and $16.98{\mu}M$, respectively. In addition, 1-methoxy-3-methyl-8-hydroxy-anthraquinone showed good free radical scavenging activity by DPPH method with an $EC_{50}$ of $18.2{\mu}g/ml$. It also showed other promising superoxide radical scavenging, nitric oxide radical scavenging and inhibition of lipid peroxidation activities. This is a first report of anti-proliferative and antioxidant activities of 1-methoxy-3-methyl-8-hydroxy-anthraquinone isolated from A. thermoflava strain SFMA-103 which may find potential application in biotechnological and pharmaceutical fields.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.607-620
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• 2023

The biocontrol approach using beneficial microorganisms to control crop diseases is becoming an essential alternative to chemical fungicides. Therefore, new and efficient biocontrol agents (BCA) are needed. In this study, a rhizospheric actinomycete isolate showed unique and promising antagonistic activity against three of the most common phytopathogenic fungi, Fusarium oxysporum MH105, Rhizoctonia solani To18, and Alternaria brassicicola CBS107. Identification of the antagonistic strain, which was performed according to spore morphology and cell wall chemotype, suggested that it belongs to the Nocardiopsaceae. Furthermore, cultural, physiological, and biochemical characteristics, together with phylogenetic analysis of the 16S rRNA gene (OP869859.1), indicated the identity of this strain to Nocardiopsis alba. The cell-free filtrate (CFF) of the strain was evaluated for its antifungal potency, and the resultant inhibition zone diameters ranged from 17.0 ± 0.92 to 19.5 ± 0.28 mm for the tested fungal species. Additionally, the CFF was evaluated in vitro to control Fusarium wilt disease in Vicia faba using the spraying method under greenhouse conditions, and the results showed marked differences in virulence between the control and treatment plants, indicating the biocontrol efficacy of this actinomycete. A promising plant-growth promoting (PGP) ability in seed germination and seedling growth of V. faba was also recorded in vitro for the CFF, which displayed PGP traits of phosphate solubilization (48 mg/100 ml) as well as production of indole acetic acid (34 ㎍/ml) and ammonia (20 ㎍/ml). This study provided scientific validation that the new rhizobacterium Nocardiopsis alba strain BH35 could be further utilized in bioformulation and possesses biocontrol and plant growth-promoting capabilities.