Multiplexed activity metabolomics for isolation of filipin macrolides from a hypogean actinomycete

Chemical and biological stimulus screening in a hypogean actinomycete was used to elicit secondary metabolism. Optimal biosynthesis of bioactive natural products was identified using Multiplexed Activity Profiling for determining dose-dependent activity via six single-cell biological readouts. Bioactive extracts were fractioned to establish candidate compounds for isolation using Multiplexed Activity Metabolomics by correlating microtiter well-isolated phenotypes and extracted ion current peaks. This guided the isolation of four filipin polyene macrolides including a new metabolite filipin XV, an alkyl side-chain hydroxylated congener of the filipin chainin, with substantially attenuated cytotoxicity. Filipin-specific cytotoxicity was confirmed using flow cytometry and fluorescence microscopy.

An Update on the Novel Genera and Species and Revised Taxonomic Status of Bacterial Organisms Described in 2016 and 2017

Recognition and acknowledgment of novel bacterial taxonomy and nomenclature revisions can impact clinical practice, disease epidemiology, and routine clinical microbiology laboratory operations. The Journal of Clinical Microbiology (JCM) herein presents its biannual report summarizing such changes published in the years 2016 and 2017, as published and added by the International Journal of Systematic and Evolutionary Microbiology Noteworthy discussion centers around descriptions of novel Corynebacteriaceae and an anaerobic mycolic acid-producing bacterium in the suborder Corynebacterineae; revisions within the Propionibacterium, Clostridium, Borrelia, and Enterobacter genera; and a major reorganization of the family Enterobacteriaceae. JCM intends to sustain this series of reports as advancements in molecular genetics, whole-genome sequencing, and studies of the human microbiome continue to produce novel taxa and clearer understandings of bacterial relatedness.

Spirosoma pomorum sp. nov., isolated from apple orchard soil

A Gram-negative, motile, rod-shaped, aerobic bacterial strain, designated S7-2-11^T, was isolated from apple orchard soil from Gyeongsangnam-do Province, Republic of Korea, and was characterized taxonomically using a polyphasic approach. 16S rRNA gene sequence analysis indicated that strain S7-2-11^T belongs to the family Cytophagaceae in phylum Bacteroidetes, and is closely related to Spirosoma luteolum 16F6E^T (94.2% identity), Spirosoma knui 15J8-12^T (92.7%), and Spirosoma linguale DSM 74^T (91.0%). The G + C content of the genomic DNA of strain S7-2-11^T was 49.8 mol%. Strain S7-2-11^T contained summed feature 3 (C_16:1 ω7c/C_16:1 ω6c; 35.1%), C_16:1 ω5c (22.4%), C_15:0 iso (13.9%), and C_17:0 iso 3-OH (10.6%) as major cellular fatty acids, and MK-7 as the predominant respiratory quinone. The main polar lipids were phosphatidylethanolamine, an unidentified aminophospholipid, and two unidentified polar lipids. Phenotypic and chemotaxonomic data supported the affiliation of strain S7-2-11^T with the genus Spirosoma. The results of physiological and biochemical tests showed the genotypic and phenotypic differentiation of the isolate from recognized Spirosoma species. On the basis of its phenotypic properties, genotypic distinctiveness, and chemotaxonomic features, strain S7-2-11^T represents a novel species of the genus Spirosoma, for which the name Spirosoma pomorum sp. nov. is proposed. The type strain is S7-2-11^T (= KCTC 52726^T = JCM 32130^T).

Spirosoma flavus sp. nov., a novel bacterium from soil of Jeju Island

A novel, Gram-staining negative, yellow pigmented bacterial strain, designated 15J11-2^T, was isolated from soil sample on Jeju Island, Republic of Korea. The strain was subjected to a taxonomic study using a polyphasic approach. The strain was able to grow at temperature range from 10°C to 30°C, pH 7-8, and in presence of 0-1% (w/v) NaCl. Comparative 16S rRNA gene sequence analysis showed that strain 15J11-2^T belongs to the genus Spirosoma and levels of 16S rRNA gene sequence similarity ranged from 91.5% to 89.8%. The genomic DNA G + C content of strain 15J11-2^T was 46.0 mol%. The isolate contained phosphatidylethanolamine and an unidentified aminophospholipid as the main polar lipids, menaquinone MK-7 as the predominant respiratory quinone, and summed feature 3 (C_16:1 ω6c/C_16:1 ω7c; 39.4%), C_16:1 ω5c (27.1%), and C_16:0 (13.0%) as the major fatty acids, which supported the affiliation of strain 15J11-2^T to the genus Spirosoma. The results of physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain 15J11-2^T from recognized Spirosoma species. On the basis of its phenotypic properties, genotypic distinctiveness, chemotaxonomic features, strain 15J11-2^T represents a novel species of the genus Spirosoma, for which the name Spirosoma flavus sp. nov. is proposed. The type strain is 15J11-2^T (= KCTC 52026^T = JCM 31998^T).