Establishment of axenic cultures of Anabaena flos-aquae and Aphanothece nidulans(cyanobacteria) by lysozyme treatment

Abstract

A new method using lysozyme for the production of axenic cultures of Anabaena flos-aquae De Brebisson and Aphanothece nidulans P. Richter was developed. Cyanobacterial growth was not inhibited at concentrations up to 1.2 g·L-1 of lysozyme, whereas the growth of heterotrophic bacteria was suppressed. At concentrations up to 0.8 g·L-1 of lysozyme, ampicillin caused a reduction of heterotrophic bacteria. The axenic cultures of these strains were acquired through a simple treatment using 1.0 g·L-1 of lysozyme without ampicillin. These cyanobacteria resisted digestion by lysozyme at our experimental concentrations, whereas bacteria were digested selectively. This method of purification seems to be especially useful with cyanobacterial species that are sensitive to antibiotics or other germicidal agents.