FadR1, a pathway-specific activator of fidaxomicin biosynthesis in Actinoplanes deccanensis Yp-1.

Fidaxomicin, an 18-membered macrolide antibiotic, is highly active against Clostridium difficile, the most common cause of diarrhea in hospitalized patients. Though the biosynthetic mechanism of fidaxomicin has been well studied, little is known about its regulatory mechanism. Here, we reported that FadR1, a LAL family transcriptional regulator in the fidaxomicin cluster of Actinoplanes deccanensis Yp-1, acts as an activator for fidaxomicin biosynthesis.

Bidirectional Regulation of AdpA in Controlling the Expression of and in the Natamycin Biosynthesis of L10.

AdpA, an AraC/XylS family protein, had been proved as a key regulator for secondary metabolism and morphological differentiation in . Here, we identify AdpA, an ortholog of AdpA, as a "higher level" pleiotropic regulator of natamycin biosynthesis with bidirectional regulatory ability in L10. DNase I footprinting revealed six AdpA-binding sites in the - intergenic region.

Paracoccus siganidrum sp. nov., isolated from fish gastrointestinal tract.

A bacterial strain, designated M26(T), was isolated from a fish gastrointestinal tract, collected from Zhanjiang Port, South China. 16S rRNA gene sequence analysis indicated that strain M26(T) belongs to the subclass α-Proteobacteria, being related to the genus Paracoccus, and sharing highest sequence similarity with Paracoccus alcaliphilus JCM 7364(T) (98.1 %), Paracoccus huijuniae FLN-7(T) (97.

Micromonospora wenchangensis sp. nov., isolated from mangrove soil.

An actinomycete, strain 2602GPT1-05(T), was isolated from a composite mangrove soil sample collected from Wenchang, Hainan province, China. Strain 2602GPT1-05(T) showed closest 16S rRNA gene sequence similarity to Micromonospora haikouensis 232617(T) (99.05 %), and phylogenetically clustered with Micromonospora haikouensis 232617(T), Micromonospora matsumotoense IMSNU 22003(T) (98.

Micromonospora sonneratiae sp. nov., isolated from a root of Sonneratia apetala.

A novel endophytic actinomycete, strain 274745(T), was isolated from a root of Sonneratia apetala collected in a mangrove forest in Sanya, Hainan province, China. The 16S rRNA gene sequence of strain 274745(T) showed the greatest similarity to Micromonospora pattaloongensis TJ2-2(T) (98.3 %).

Actinoallomurus acanthiterrae sp. nov., an actinomycete isolated from rhizosphere soil of the mangrove plant Acanthus ilicifolius.

A novel actinobacterium strain, 2614A723(T), was isolated from rhizosphere soil of mangrove plant Acanthus ilicifolius collected at Touyuan, Wenchang, Hainan province, China. A phylogenetic analysis based on 16S rRNA gene sequences indicated that strain 2614A723(T) formed a distinct phyletic line in the genus Actinoallomurus, the 16S rRNA gene tree sharing similarities of 98.35%, 98.

Molecular characterization of Antarctic actinobacteria and screening for antimicrobial metabolite production.

The present study aimed to isolate actinobacteria from soil samples and characterized them using molecular tools and screened their secondary metabolites for antimicrobial activities. Thirty-nine strains from four different location of Barrientos Island, Antarctica using 12 types of isolation media was isolated. The isolates were preceded to screening of secondary metabolites for antimicrobial and antifungal activities.

Barrientosiimonas humi gen. nov., sp. nov., an actinobacterium of the family Dermacoccaceae.

Three novel actinobacteria, strains 39(T), 40 and 41, were isolated from soil collected from Barrientos Island in the Antarctic. The taxonomic status of these strains was determined using a polyphasic approach. Comparison of 16S rRNA gene sequences revealed that strain 39(T) represented a novel lineage within the family Dermacoccaceae and was most closely related to members of the genera Demetria (96.