Latest Research News on Actinomycetes: Jan – 2020

Lignocellulose-degrading actinomycetes

Increasing interest within the exploitation of plant biomass as a natural resource has provided an impetus for research on microbial degradation of lignocellulose. This has traditionally been targeting the fungi, but lignocellulose-degrading prokaryotes are starting to receive more attention. Strain improvement by genetic manipulation, and large-scale cultivation are more easily achieved in prokaryotes, and therefore the actinomycetes are not any exception. additionally , their growth as branching hyphae is well adapted to the penetration and degradation of insoluble substrates like lignocellulose. [1]

Distribution of Menaquinones in Actinomycetes and Corynebacteria

Menaquinones were the sole isoprenoid quinones found in 48 corynebacteria and actinomycete strains examined. Dihydromenaquinones having nine isoprene units were the most components isolated from Gordona, Mycobacterium, Coryne-bacterium bovis, Corynebacterium glutamicum and a strain labelled Nocardia farcinica, but dihydromenaquinones having eight isoprene units were characteristic of other Corynebacterium species and representatives of the ‘rhodochrous’ complex. Tetrahydromenaquinones having six and eight isoprene units were found in Nocardia strains and during a single strain of Micropolyspora brevicatena, which also contained mycolic acids similar in chain length to those of Nocardia. Menaquinones having nine isoprene units with from one to 5 double bonds hydrogenated were the most components in Actinomadura madurae, Actinomadura pelletieri, Micropolyspora faeni, Oerskovia turbata and Streptomyces strains. Actinomadura dassonvillei strains had a characteristic pattern of di-, tetra- and hexahydromenaquinones with 10 isoprene units which was slightly different from the pattern in mixtures of comparable quinones from Actinomyces israelii and Actinomyces viscosus. [2]

Medical mycology; the pathogenic fungi and the pathogenic actinomycetes.

This is the second edition of the book which, since its introduction in 1974, has become established together of the foremost texts in medical mycology to be used by medical students, practitioners, and microbiologists throughout the planet . Professor Rippon is to be congratulated upon what’s essentially an updating operation, but with a wider range of illustrations and a few expanded sections on selected topics. a replacement venture is that a lot of of the illustrations are now available as colour transparencies within the sort of 3 film strips, totalling 220 separate frames, suitable for teaching.

As within the first edition, the book begins with a neighborhood dedicated to actinomycetes and therefore the diseases they cause, and there’s a greatly extended introduction to the present group, with a useful summary of their taxonomy. Also, as within the first edition, the author has solved the difficult problem of the various aetiologies of mycetoma by including during this section the descriptions of these true fungi which also cause mycetoma. [3]

Acidophilic actinomycetes from rhizosphere soil: diversity and properties beneficial to plants

Three hundred and fifty-one isolates of actinomycetes were recovered from 21 rhizospheric soil samples using acidified media of pH 5.5. They were evaluated for his or her antifungal, siderophore production and phosphate solubilization activities. the entire count of actinomycetes growing on acidified starch casein agar and Gause no. 1 agar were below 2.48 × 104 CFU g−1 soil. 2 hundred and twelve isolates were assigned to acidophiles and therefore the remaining 139 isolates were neutrophiles. of those actinomycetes, 57.8, 32.5 and 50.4%, showed antagonistic activity against three rice pathogenic fungi; Fusarium moniliforme, Helminthosporium oryzae and Rhizoctonia solani, respectively. [4]

Characterization of Antibiotics Inhibitory to Methicillin Resistant Staphylococcus aureus (MRSA) from Soil Actinomycetes

Actinomycetes are subgroup of actinobacteria which include Streptomyces, a source of the many important antibiotics. Methicillin-resistant Staphylococcus aureus is one among the emerging infectious diseases which pose a big health and occupational risk worldwide. The aim of this work was designed to isolate and characterize antibiotic producing actinomycetes from soil capable of inhibiting methicillin-resistant Staphylococcus aureus. Soil samples collected from rhizosphere of plants, agricultural soil and hospital dump soil cultured on starch casein agar yielded just one (1) isolate showing antibacterial activity against a diameter of zone of inhibition for Methicillin-resistant Staphylococcus aureus (12 mm), Bacillus subtilis (16 mm), Escherichia coli (15 mm) and Pseudomonas aeruginosa (14 mm). [5]

Reference

[1] McCarthy, A.J., 1987. Lignocellulose-degrading actinomycetes. FEMS Microbiology Reviews, 3(2), (Web Link)

[2] Collins, M.D., Pirouz, T., Goodfellow, M. and Minnikin, D.E., 1977. Distribution of menaquinones in actinomycetes and corynebacteria. Microbiology, 100(2), (Web Link)

[3] Rippon, J.W., 1982. Medical mycology; the pathogenic fungi and the pathogenic actinomycetes. Eastbourne, UK; WB Saunders Company. (Web Link)

[4] Acidophilic actinomycetes from rhizosphere soil: diversity and properties beneficial to plants
Nalin Poomthongdee, Kannika Duangmal & Wasu Pathom-aree
The Journal of Antibiotics volume 68, (Web Link)

[5] Abdullahi, U., Solomon Obidah, J. and Mahmoud Jada, S. (2018) “Characterization of Antibiotics Inhibitory to Methicillin Resistant Staphylococcus aureus (MRSA) from Soil Actinomycetes”, Asian Journal of Research in Medical and Pharmaceutical Sciences, 4(2), (Web Link)

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