Low level chemiluminescence from liquid culture media

Abstract

Low level chemiluminescence (CL) can be observed from autoclaved liquid culture media, as used in microbiology. The light emission is oxygen-dependent and arises from reactions following auto-oxidation of reducing Maillard products which are formed during autoclaving. The inhibition of this CL by radical scavengers and antioxidants has been studied. As superoxide radicals and hydrogen peroxide are predominantly involved in the initiation of the CL, the investigation of CL from culture media offers a convenient tool for the detection of exogenous (medium-mediated) oxidative stress being imposed onto micro-organisms in culture. Transition metal ions showed, dependent on concentration, both inhibitory and stimulating effects on the CL, which was also affected by the presence of complexing agents. Iron porphyrins and related complexes displayed a very efficient quenching of the CL, which may be of particular importance, as aerobic micro-organisms have been previously shown to be very efficient in quenching the CL from culture media.

Use of the chemiluminescent probe lucigenin to monitor the production of the superoxide anion radical in a recombinant Aspergillus niger (B1‐D)

“…One is the high LDCL background in the disrupted cell solutions, and another is that the amount of SOD required for an efficient quenching of chemiluminescence is relatively high and far above the amount usually required for the scavenging of O 2 и− in a model system, due to competition with a ubiquity of other reaction partners in the medium, which allows O 2 и− to escape dismutation. This latter viewpoint is supported by the work of Vogel and Sussmuth (1999). Accordingly, we examined the effects of addition of inhibitors of Cu,Zn-SOD and Mn-SOD, diethyldithiocarbamate and sodium azide, to the intact pellet suspensions, and observed that this resulted in an increased LDCL.…”

“…Another reason is that the culture medium may quench LDCL of fungal pellets to some extent for a variety of reasons. Regarding this, Vogel and Sussmuth (1999) found that low-level chemiluminescence can be observed from autoclaved liquid culture media, as used in microbiology. The light emission is oxygen-dependent, and O 2 и− and H 2 O 2 are predominantly involved in the initiation of the chemiluminescence.…”