Mycobacterium versus Streptomyces--we are different, we are the same.

Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
Current opinion in microbiology (Impact Factor: 7.22). 10/2009; 12(6):699-707. DOI: 10.1016/j.mib.2009.10.003
Source: PubMed

ABSTRACT At first glance, bacteria that belong to the two genera Streptomyces and Mycobacterium of the phylum Actinobacteria show no sign of similarity. Whereas Streptomyces species are generally classified as spore-forming, filamentous bacteria, species of the Mycobacterium genus have been considered non-sporulating, rod-like shaped. However, recent studies in genetics and cell biology of Streptomyces and Mycobacterium have revealed striking analogies in the developmental and morphological hallmarks of their life cycles. Understanding the mechanisms underlying these similarities, as well as variations in morphogenesis and development of these two groups of bacteria may not only provide important insights in the evolution of cell shapes in Actinobacteria, but also lead to medical interventions that impact human health.

Download full-text


Available from: Liem Nguyen, Jun 21, 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Bacteria have the ability to adapt to different growth conditions and to survive in various environments. They have also the capacity to enter into dormant states and some bacteria form spores when exposed to stresses such as starvation and oxygen deprivation. Sporulation has been demonstrated in a number of different bacteria but Mycobacterium spp. have been considered to be non-sporulating bacteria. We recently provided evidence that Mycobacterium marinum and likely also Mycobacterium bovis bacillus Calmette-Guérin can form spores. Mycobacterial spores were detected in old cultures and our findings suggest that sporulation might be an adaptation of lifestyle for mycobacteria under stress. Here we will discuss our current understanding of growth, cell division, and sporulation in mycobacteria.
    Antonie van Leeuwenhoek 05/2010; 98(2):165-77. DOI:10.1007/s10482-010-9446-0 · 2.14 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have known for 40 years that soils can consume the trace amounts of molecular hydrogen (H2) found in the Earth's atmosphere. This process is predicted to be the most significant process in the global hydrogen cycle. However, the organisms and enzymes responsible for this process were only recently identified. Pure culture experiments demonstrated that several species of Actinobacteria, including streptomycetes and mycobacteria, can couple the oxidation of atmospheric H2 to the reduction of ambient O2. A combination of genetic, biochemical, and phenotypic studies suggest that these organisms primarily use this fuel source to sustain electron input into the respiratory chain during energy-starvation. This process is mediated by a specialized enzyme, the Group 5 [NiFe]-hydrogenase, which is unusual for its high-affinity, oxygen-insensitivity, and thermostability. Atmospheric hydrogen scavenging is a particularly dependable mode of energy-generation, given both the ubiquity of the substrate and the stress-tolerance of its catalyst. This review summarizes the recent progress in understanding how and why certain organisms scavenge atmospheric H2. In addition, it provides insight into the wider significance of hydrogen scavenging in global H2 cycling and soil microbial ecology. Copyright © 2014, American Society for Microbiology. All Rights Reserved.
    Applied and Environmental Microbiology 12/2014; 81(4). DOI:10.1128/AEM.03364-14 · 3.95 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Ala-Pro-rich O-glycoprotein known as the 45/47 kDa or APA antigen from Mycobacterium tuberculosis is an immunodominant adhesin restricted to mycobacterium genus and has been proposed as an alternative candidate to generate a new vaccine against tuberculosis or for diagnosis kits. In this work, the recombinant O-glycoprotein APA was produced by the non-pathogenic filamentous bacteria Streptomyces lividans, evaluating three different culture conditions. This strain is known for its ability to produce heterologous proteins in a shorter time compared to M. tuberculosis. Three different shake flask geometries were used to provide different shear and oxygenation conditions; and the impact of those conditions on the morphology of S. lividans and the production of rAPA was characterized and evaluated. Small unbranched free filaments and mycelial clumps were found in baffled and coiled shake flasks, but one order of magnitude larger pellets were found in conventional shake flasks. The production of rAPA is around 3 times higher in small mycelia than in larger pellets, most probably due to difficulties in mass transfer inside pellets. Moreover, there are four putative sites of O-mannosylation in native APA, one of which is located at the carboxy-terminal region. The carbohydrate composition of this site was determined for rAPA by mass spectrometry analysis, and was found to contain different glycoforms depending on culture conditions. Up to two mannoses residues were found in cultures carried out in conventional shake flasks, and up to five mannoses residues were determined in coiled and baffled shake flasks. The shear and/or oxygenation parameters determine the bacterial morphology, the productivity, and the O-mannosylation of rAPA in S. lividans. As demonstrated here, culture conditions have to be carefully controlled in order to obtain recombinant O-glycosylated proteins with similar "quality" in bacteria, particularly, if the protein activity depends on the glycosylation pattern. Furthermore, it will be an interesting exercise to determine the effect of shear and oxygen in shake flasks, to obtain evidences that may be useful in scaling-up these processes to bioreactors. Another approach will be using lab-scale bioreactors under well-controlled conditions, and study the impact of those on rAPA productivity and quality.
    Microbial Cell Factories 12/2011; 10(1):110. DOI:10.1186/1475-2859-10-110 · 4.25 Impact Factor