Effects of different methods on the formation of fruiting bodies and isolation of myxobacteria

Abstract:

[Objective] We modified myxobacterial isolation methods based on the in-situ simulation, the nutritional requirements of cultured myxobacteria and myxobacterial interactions with bacteria inferred from co-occurrence network, to obtain more cultured myxobacteria. [Methods] We set experiment by adding soil extract into isolation medium, using Gram-positive bacteria as bait and changing the inoculation method of bait, with traditional methods as control. [Results] More types of myxobacteria fruiting bodies were induced by the modified methods than traditional methods. A total of 40 myxobacteria strains were isolated from 9 soil samples including subtropical forest soil, saline-alkaline soil, and wetland sediment. The isolated myxobacteria were from genera of Archangium, Chondromyces, Corallococcus, Myxococcus, Nannocystis, Polyangium and Pyxidicoccus. [Conclusion] Compared with traditional methods, the addition of soil extract and bait inoculated by spotting can obviously increase the types of fruiting bodies. Although the strains of bait showed little effect on the fruiting bodies, Gram-positive bacteria could induce specific fruiting bodies. In this study, we modified isolation methods of myxobacteria and greatly increased the types of fruiting bodies, but the number of purified myxobacteria were far less than that of fruiting bodies observed, indicating that the improvement of purification is required to obtain more cultured myxobacteria.

Key words:myxobacteria isolation;purification;fruiting body;soil extract;prey bacteria