The genus Actinoallomurus and some of its metabolites

Abstract

In the search for novel antibiotics, natural products continue to represent a valid source of bioactive molecules. During a program aimed at identifying previously unreported taxa of actinomycetes as potential source of novel compounds, we isolated hundreds of different representatives of a new group, initially designated as 'Alpha' and independently described as Actinoallomurus. We report on a PCR-specific method for the detection of this taxon, on appropriate growth conditions and on a pilot-screening program on 78 strains. The strains produce antibacterial or antifungal compounds at a relatively high frequency. Four strains were characterized in further detail: one produced the aromatic polyketide benanomicin B and its dexylosyl derivative; a second strain produced N-butylbenzenesulfonamide; a third strain was an efficient converter of soymeal isoflavonoids from soymeal constituents; and a fourth strain produced several coumermycin-related aminocoumarins, with coumermycin A2 as the major peak, and with some new congeners as minor components of the complex. These data suggest that Actinoallomurus strains possess several pathways for secondary metabolism and represent an attractive source in the search for novel antibiotics.

Endophytic actinomycetes: promising source of novel bioactive compounds

“…Although antimicrobial activity of the isolates from plant roots was generally worse than that of soil-dwelling organisms, 50% of Sphaerisporangium strains, which were not isolates from rhizospheric soil performed bioactivity, additionally, the genera Microbispora, Actinoallomurus, Verrucosispora and others also produced antibiotics. Pozzi et al 32 concluded that Actinoallomurus strains produce antibiotic compounds at high frequency, and Tiwari et al 33 reported that rare actinomycetes possess the capacity to produce many useful metabolites and represent one of the most important sources of new bioactive compounds. We are very interested in endophytic actinomycete strains which is difficult to isolate from the soil.…”

Characterization of madurastatin C1, a novel siderophore from Actinomadura sp.

“…DSMZ 13491, prepared by inoculating a frozen cell stock into 30 ml of AFT medium (2% glucose, 0.2% yeast extract, 0.8% soybean meal, 0.5% tryptone, 0.1% NaCl, 0.4% CaCO 3 , adjusted to pH 7.2 with 0.1 N NaOH before sterilization) and incubating for 72-96 h, was transferred into 200 ml of fresh AFT medium. The production of antibacterial activity was monitored over time by depositing 10 ml of a microbial extract, prepared as described by Pozzi et al, 3 onto Muller Hinton Agar (Difco Laboratories, Detroit, MI, USA) plates, previously inoculated with 10 5 cfu ml À1 Staphylococcus aureus ATCC 6538P or Micrococcus luteus ATCC 10240. An inhibition halo was clearly observed on M. luteus plates after 24 h of cultivation, whereas only a weak activity was visible on the S. aureus plates.…”

Isolation of actinomycetes from the root of the plant, Ophiopogon japonicus, and proposal of two new species, Actinoallomurus liliacearum sp. nov. and Actinoallomurus vinaceus sp. nov.

“…Pozzi et al 5 reported that Actinoallomurus strains possess the ability to produce various bioactive compounds. Many Actinoallomurus strains have been found among our isolates.…”