Aetherobacter fasciculatus gen. nov., sp. nov. and Aetherobacter rufus sp. nov., novel myxobacteria with promising biotechnological applications

Abstract

containing decaying plant material. The organisms were recognized as myxobacteria by growthstage characteristics, forming swarming colonies and fruiting bodies on agar and on filter paper. These strains were unusual for their ring-like or halo colony appearance in an agar. Both isolates were characterized as bacteriolytic, non-cellulolytic, mesophilic, aerobic and chemoheterotrophic and showed resistance to various antibiotics. GC-MS analysis of their cellular fatty acids revealed rather large quantities of docosahexaenoic acid, and they also both contained eicosapentaenoic acid, arachidonic acid and docosapentaenoic acid. Strain SBSr003 T was previously identified as the producer organism of a novel class of potent antiviral metabolites that were called aetheramides. The G+C content of the genomic DNA was 68.0-68.9 mol%. Phylogenetic analysis revealed that both strains belong within the family Polyangiaceae, suborder Sorangiineae, order Myxococcales. Their 16S rRNA gene sequences showed the highest similarity (97-99 %) to sequences derived from clones of uncultured bacteria, 95-96 % similarity to Byssovorax cruenta and Sorangium cellulosum and 94 % similarity to Chondromyces apiculatus.

Myxobacteria in high moor and fen: An astonishing diversity in a neglected extreme habitat

“…Particularly in times of increasing antibiotic resistances the discovery and development of new antibiotics is of high importance. In the past, particularly new myxobacterial families and genera turned out to be reliable sources for new bioactive metabolites (Garcia, Stadler, Gemperlein, & Müller, ; Jansen, Mohr, Bernecker, Stadler, & Müller, ; Karwehl et al., ; Mohr, Garcia, Gerth, Irschik, & Müller, ; Plaza et al., ; Sood et al., ; Steinmetz et al., ). But based on cultivation, approximately only 1% of the naturally occurring bacterial diversity has been isolated and characterized so far (Muyzer, ).…”

Antiviral Compounds from Myxobacteria

“…They all revealed high activity by suppressing HIV-1-mediated cell death in the MT-4 cell assay with EC 50 values of 9 and 8 in the nanomolar range, whereas thiangazole ( 7 ) had an impressive EC 50 value in the picomolar range, making it a possible lead compound for anti-HIV therapy ( Table 2 , Figure 2 ) [ 39 ]. In another assay involving measuring ATP levels as a parameter of cell viability of TZM-bl cells aetheramide A ( 10a ) and aetheramide B ( 10b ) isolated from the recently described genus Aetherobacter , inhibited HIV-1 infection with IC 50 value of 0.015 and 0.018 µM, respectively [ 40 , 41 , 42 ]. Concurrently, the aetheramides were reported to be moderately antifungal and cytotoxic [ 41 ].…”

“…In another assay involving measuring ATP levels as a parameter of cell viability of TZM-bl cells aetheramide A ( 10a ) and aetheramide B ( 10b ) isolated from the recently described genus Aetherobacter , inhibited HIV-1 infection with IC 50 value of 0.015 and 0.018 µM, respectively [ 40 , 41 , 42 ]. Concurrently, the aetheramides were reported to be moderately antifungal and cytotoxic [ 41 ]. The chemical structures of 10a and 10b are rare, containing a polyketide moiety and two amino acid residues, thus forming a new class of antivirals [ 40 , 41 , 42 ].…”

“…Concurrently, the aetheramides were reported to be moderately antifungal and cytotoxic [ 41 ]. The chemical structures of 10a and 10b are rare, containing a polyketide moiety and two amino acid residues, thus forming a new class of antivirals [ 40 , 41 , 42 ]. This discovery of new antivirals from the recently described myxobacteria genus, Aetherobacter , represents an example of the enormous biosynthetic capabilities of myxobacteria and their importance to drug discovery efforts [ 42 ].…”

Enantioselective Synthesis of the C23–C33 Fragment of Aetheramide A and Its C32 Epimer

“…Research in the area of natural products provides a large palette of novel compounds possessing versatile biological activity that drives the development of new drugs. Aetheramides A (Scheme ) and B are secondary metabolites of the novel myxobacteria genus Aetherobacter rufus ( Aether was a god of light in Greek mythology) that were isolated and characterized by Müller's group in 2012 . Aetheramides are macrocyclic compounds possessing six stereogenic centers and comprise a polyketide moiety and two amino acids.…”