Isolation anc characterization of actinophages of Thermoactinomyces and Micropolyspora

Two new actionphages infecting thermophilic actinomycetes were isolated from lysogenic cultures of Thermoactinomyces candidus and Micropolyspora faeni. The physiochemical properties, morphology, host range, electron microscopy, and immunology of the two phages, phi-115A (ATCC 29680-B1) and phi-150A (ATCC 29681-B1), are reported.     

The influence of hay-packing techniques on the presence of Saccharopolyspora rectivirgula

Environmental factors influencing the growth, distribution and viability of thermophilic actinomycetes, especially Saccharopolyspora rectivirgula as an agent of extrinsic allergic alveolitis in farms workers, were studied. Total microbial count, eumycetes and thermophilic actinomycetes were determined on 96 hay samples, randomly collected, from small prismatic and large cylindrical bales, 30 air samples before and after animal feeding, and various surfaces in two farms located in the province of Reggio Emilia, Italy. The number of thermophilic actinomycetes (potentially responsible for hypersensitivity pneumonitis) was higher in hay samples from large cylindrical bales than in those from small prismatic bales. The structural characteristics of the buildings (barns with stalls, poor ventilation) and the feeding practices (manual handling of hay, constant presence of hay in feedings corridors) contributed to the dispersion of high levels of thermophilic actinomycetes spores (potentially responsible for extrinsic allergic alveolitis). The ventilation system proved to be inadequate in reducing the number of microorganisms present.     

Transfection and transformation of protoplasts of the thermophilic actinomycete Faenia rectivirgula

Summary A procedure for the formation and handling of protoplasts of Faenia rectivirgula is described. Transfection with several phage DNAs demonstrated the high DNA uptake capacity of these protoplasts. The regeneration rate (0.1%) and the transformation rate (18 transformants in several experiments with the Streptomyces plasmid vectors pIJ702 and pWOR120) were low although Faenia turned out to have no considerable restriction barriers for foreign DNA. The two Streptomyces plasmids proved to be unsuitable for Faenia as they are extremely unstable in this host.     

Genetic characteristics and genome structure of Streptomyces coelicolor actinophages]

Actinophage phi C31 of Streptomyces coelicolor A3 (2) and two novel temperate actinophages phi C43 and phi C62 isolated from strains of blue actinomycetes group are homoimmune, serologically and functionally related. DNA molecules of phages phi C31, phi C43 and phi C62 have cohesive ends; sizes of DNAs of these phages and some mutants have been determined. The extent of homology between the DNAs of three phages is 93-96% as shown by heteroduplex analysis. The regions of non-homology are of a deletion-insertion type and of approximately 1500 base pairs in the length. Location of deletions in DNAs of mutant phages phi C31 vd and phi C31 c5 has been shown. Structural modifications in phage dnas have been found only to occur in the right part of molecules. Heteroduplex maps have been constructed for all phages studied.     

Physical mapping of Streptomyces coelicolar A3(3) actinophages. III. Restriction analysis

It has been shown that endonucleases HindII, HindIII, SalI and BsuI treatment of phiC62, or phiC43 and phiC31 DNAs forms more than 20 fragments. EcoRI cleaves phiC62, phiC31, phiC31c5 and phiC31c28 into seven fragments, but phiC311yg33 into six fragments. Comparison of molecular weights of DNA restricts obtained after hydrolysis of phage DNAs containing deletions by endonuclease EcoRI made it possible to determine the location of four fragments on restriction map and to orientate this map in relation to the molecule's ends. BamHI cleaves phiC43 DNA into two fragments. By heteroduplexing BamHi site was mapped within the phiC43 insertion sequence.