Effect of low power microwave radiation on pigment production in bacteria

Vimla Chaudhari,Shreya Raval,Vijay Kothari,Haren Gosai

doi:10.4081/mr.2014.5511

Abstract

Effect of low power (90 W) microwave (MW) radiation (2450 MHz) on bacterial growth and pigment production was studied in three different bacteria. Microwave exposure of 2-6 min duration was able to alter growth and pigment production (prodigiosin production by Serratia marcescens , violacein production by Chormobacterium violaceum , and staphyloxanthin production by Staphylococcus aureus ) in the test organisms significantly. In this study, pigment production was estimated in the cell population originated from microwave treated inoculum, and not directly in the MW treated cells. Thus the alterations in pigment production and/or secretion might have been transferred from the originally MW treated cells to their daughter cells (who did not receive direct MW exposure), indicating the mutagenic influence of microwave radiation. Heavy prodigiosin overproduction observed in one of the test tubes inoculated with microwave treated S. marcescens could not be sustained by daughter populations corresponding to that tube, indicating the reversible nature of microwave induced mutation(s). The microwave effects observed in this study largely seem to be of athermal nature, as the thermal effect was minimized by use of ice during the microwave treatment.

Highlights

Chromobacterium violaceum (MTCC 2656), treatment was performed in an air-conditioned
The part of electromagnetic radiation Staphylococcus aureus (MTCC 737) were pro- Before MW treatment all the inoculum vials known as microwaves (MW), holds frequency cured from Microbial Type Culture Collection were put in ice for 5 min to nullify any variaranging from 300 MHz-300 GHz, and can exert (MTCC), Chandigarh
Ly Violacein n Following estimation of C. violaceum o growth by recording the OD at 625 nm the tubes were subjected to violacein extraction as e described in Choo et al.[8]

Summary

Materials and Methods

Test organisms and culture condition manuscript preparation was handled by VK and SR. Conflict of interests: the authors declare no potential conflict of interests. 2013 Licensee PAGEPress, Italy Microbiology Research 2014; 5:5511 doi:10.4081/mr.2014.5511 saline, whose turbidity was adjusted to that of 0.5 McFarland standard. Test cultures (5 mL)in sterile screw capped glass vials (15 mL; Merck) were exposed to MW radiation (90 W; 2450 MHz) in a domestic MW apparatus (Electrolux® EM30EC90SS) for 2, 4, and 6 min. Vials inside the MW apparatus were placed in a ice containing beaker (100 mL; Borosil®), so as to avoid any thermal heating.

Introduction

Pigment extraction and estimation

Results and Discussion

Prodigiosin Unit

Biological systems can exhibit resonance