Deoxyribonuclease activities in Myxococcus coralloides D

Abstract

Myxococcus coralloides D produced cell-bound deoxyribonucleases (DNases) during the exponential phase of growth in liquid medium. DNase activity was much higher than that detected in other myxobacterial strains and was fractionated into three different peaks by filtration through Sephadex G-200. The DNases were named G, M and P. The optimum temperatures were 37 degrees C, 33 degrees C and 25 degrees C respectively, although high activities were recorded over the temperature range 20-45 degrees C. The pH range of high activity was between 6.0 and 9.0, with an optimum for each DNase at 8.0. DNases M and P were strongly inhibited by low concentrations of NaCl, but activity of DNase G was less affected by NaCl. The three activities required divalent metal ions as cofactors (especially Mg2+ and Mn2+); however, other metal ions (Fe2+, Ni2+, Zn2+) were inhibitors. The molecular weights were estimated by gel filtration chromatography and SDS-PAGE as 44 kDa (DNase G), 49 kDa (DNase M) and 39 kDa (DNase P).

Partial purification and biochemical properties of acid and alkaline phosphatases from Myxococcus coralloides D

“…Obviously, for a micro-organism living in the soil the ability to produce this variety of enzyme must provide an important ecological advantage. Myxococcus coralloides D produces and secretes high levels of phosphatases, deoxyribonucleases (Martinez-Caiiamero et al 1991) and a-amylase (Firez-Vidal et al 1992).…”

Localization of acid and alkaline phosphatases in Myxococcus coralloides D

“…Myxococcus coralloides is a gliding bacterium that produces a great variety of enzymes, such as amylases, nucleases and phosphatases (Gonzilez et al 1990;Martinez-Caiiamero et al 1991;Firez-Vidal et al 1992). It is well known that various enzymes of Gram-negative bacteria exist and function outside the cytoplasmic membrane ; hydrolytic enzymes are most frequently found in the periplasm (Nikaido and Vaara 1985).…”