RT Journal Article SR Electronic(1) A1 Singh, B. N.YR 1947 T1 Myxobacteria in Soils and Composts; their Distribution, Number and Lytic Action on Bacteria JF Microbiology, VO 1 IS 1 SP 1 OP 10 DO https://doi.org/10.1099/00221287-1-1-1 PB Microbiology Society, SN 1465-2080, AB SUMMARY: Myxococcus virescens, M. fulvus, Chondrococcus exiguus and Archangium sp. are widely distributed in the soils of Great Britain including some treated only with artificial fertilizers. Myxococcus virescens and Chondrococcus exiguus appear to be the dominant species. The numbers of myxobacteria ranged from 2000 to 76,400/g. of soil. In an actively decomposing compost of sludge and straw the number of Myxococcus fulvus was found to be over 500,000/g.; M. virescens and Chondrococcus exiguus were also present, but less abundantly. Variation of pH between 40 and 88 does not affect the growth of Myxococcus fulvus, M. virescens and Chondrococcus exiguus, and normal fruiting bodies were produced in the presence of suitable bacteria. Myxococcus fulvus and M. virescens do not attack filter paper. Both Gram-positive and Gram-negative bacteria growing on solid media may be lysed by extracellular secretions of M. virescens, M. fulvus and Chondrococcus exiguus. Of forty-seven Gram-positive and forty-seven Gram-negative strains of bacteria tested with three species of myxobacteria, a higher percentage of Gramnegative than of Gram-positive strains was attacked. Pigmented strains of bacteria are more resistant to the lytic action of myxobacteria than the non-pigmented strains. Different species of myxobacteria and different strains of the same species differ in their lytic action on a number of species of bacteria. The extracellular lytic substance produced by Myxococcus virescens passes through a cellophan membrane. A method of growing M. fulvus and M. virescens in mass cultures in liquid media to produce extracellular lytic secretions is described., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-1-1-1