Isolation and characterization of a novel bacterial strain Shewanella marinisediminis sp. nov. from deep-sea sediments.

A new bacterial strain designated DH39T was isolated from marine sediment collected from the East Sea, Korea. Phylogenetic analysis using the 16S rRNA gene sequence revealed that strain DH39T clustered with the genus Shewanella and is closely related to Shewanella canadensis HAW-EB2T, S. woodyi MS32T, and S. sediminis HAW-EB3Twith 98.1, 97.8, and 97.6% sequence similarities, respectively. The isolated bacterium was Gram-negative, rod-shaped, and aerobic. Its temperature range for growth was 4–30°C. The predominant fatty acids were 16:1w7, 17:1w8, 13:0-i, 16:0, and 15:0-i. The DNA G+C content was 45.0 mol%. DNA-DNA hybridization analysis showed that DNA-DNA relatedness values in the 16S rRNA phylogenetic tree of strain DH39T and its nearest neighbors S. hanedai and S. sediminis were 52.9 and 58.7%. Phylogenetic evidence and phenotypic characteristics suggest strain DH39T constitutes a novel Shewanella species. Therefore, we propose Shewanella marinisediminis sp. nov., with DH39T (KCCM 42936T = NCCB 100311T) as the type strain.

Isolation, Identification and Molecular Characterization of Rare Actinomycetes from Mangrove Ecosystem of Nizampatnam

Aims: Isolate and characterize the antimicrobial actinomycetes from sediments of Mangrove ecosystems of Nizampatnam located in the south coastal region of Andhra Pradesh, India. Methodology and Results: The Mangrove soil samples were collected, pre-treated and plated on asparagine-glucose agar medium. Identification of the strain was carried out by employing the polyphasic taxonomical studies including the 16S rRNA sequence based analysis. Phylogenetic tree was constructed using the Molecular Evolutionary Genetic Analysis (MEGA) version 5. The potent bioactive metabolite strain was isolated and designated as VUK-10. Further polyphasic studies revealed that the Isolate VUK-10 belongs to the genera Pseudonocardia. Phylogenetic analysis of 16S rRNA sequencing studies revealed that the strain is closely related to Pseudonocardia endophytica and the bioactive metabolites produced by the isolate inhibited Gram positive, Gram negative and Fungi. Conclusion, significance and impact of study: The isolation, characterization of the rare actinomycetes from the mangrove ecosystem will be useful for the discovery of the novel bioactive metabolites that are effective against wide range of pathogens.

Identification of fungi of the genus Aspergillus section nigri using polyphasic taxonomy

In spite of the taxonomy of the Aspergillus species of the Nigri Section being regarded as troublesome, a number of methods have been proposed to aid in the classification of this Section. This work aimed to distinguish Aspergillus species of the Nigri Section from foods, grains and caves on the basis in Polyphasic Taxonomy by utilizing morphologic and physiologic characters, and sequencing of ß-tubulin and calmodulin genes. The morphologic identification proved useful for some species, such as A. carbonarius and Aspergillus sp UFLA DCA 01, despite not having been totally effective in elucidating species related to A. niger. The isolation of the species of the Nigri Section on Creatine Sucrose Agar (CREA) enabled to distinguish the Aspergillus sp species, which was characterized by the lack of sporulation and by the production of sclerotia. Scanning Electron microscopy (SEM) allowed distinguishing the species into two distinct groups. The production of Ochratoxin A (OTA) was only found in the A. carbonarius and A. niger species. The sequencing of β-tubulin gene was efficient in differing most of the Aspergillus species from the Nigri Section with the exception of Aspergillus UFLA DCA 01, which could not be distinguished from A. costaricaensis. This species is morphologically similar to A. costaricaencis for its low sporulation capacity and high sclerotia production, but it differs morphologically from A. costaricaensis for its conidial ornamentation and size of vesicles. Equally, based on partial calmodulin gene sequence data Aspergillus UFLA DCA 01 differs from A. costaricaensis.

Research Progress on the Polyphasic Taxonomy of Acetic Acid Bacteria / 微生物学通报

Acetic acid bacteria are Gram-negative,obligate aerobic bacteria that have the ability to incompletely oxidize alcohols or sugars to organic acids as end products. The taxonomy of acetic acid bacteria has undergone many changes in the last 30 years. The early classification systems for these bacteria were based on morphological and biochemical characteristics. Today,the acetic acid bacteria are classified as the consensus result of a polyphasic analysis,combining phenotypic,chemotaxonomic and genotypic data. This paper reviewed the polyphasic taxonomy of acetic acid bacteria,mainly introduced the current classification of acetic acid bacteria,then discussed the application of phenotypic,chemotaxonomic and genotypic method in the taxonomy of acetic acid bacteria.

The Isolation and Identification of Strain Streptomyces xanthocidicus IMB-14 / 微生物学通报

The strain Streptomyces sp.,nominated IMB-14,was isolated from the soil sample of WuDang Mountain by the method of cellulose ester membrane filter.The studies on antibiotic activities,morphological characteristics,cultural characteristics,physiological characteristics,16S rDNA sequence analysis and the metabolite of strain IMB-14 showed that the strain IMB-14 was accordance with Streptomyces xanthoci-dicus.The study on the isolation and identification of strain Streptomyces xanthocidicus establishes a foundation on screening of novel antibacterial and antitumor agents.