Moving charges due to electric current create electromagnetic waves, which generate electromagnetic fields (EMFs). The low frequency EMFs are unlikely to cause adverse effects on living organisms; however, health-related incidents have prompted researchers to investigate the biochemical characteristics in microorganisms. We hypothesized that a diverse variety of microorganisms, i.e., bacteria, will respond to EMF and bio-stimulate microbial metabolic products of commercial significance. An EMF generator that produces a 10-mT-strength magnetic field was built in-house to investigate the magnetic response of microbial communities from cave soil samples. 16S rRNA sequencing was employed to identify three EMF-responsive isolates: Streptomyces sp., Arthrobacter sp., and Lysinibacillus sphaericus, designated as EF1, EF2, and EF3, respectively. Streptomyces sp.-EF1 showed a dark brown pigment identified as melanin on nutrient agar plates supplemented with 0.4 % L-tyrosine and L-DOPA. We also investigated the bio-economics of melanin biosynthesis, which revealed that waste shredded paper ($33.29 /g melanin) followed by starch ($256.03 /g melanin) were among suitable substrates for melanin biosynthesis under non-EMF condition. The most time-efficient melanin formation was achieved by starch under submerged fermentation (3.52 h/μg/mL) conditions. Shredded, laser-printer paper was noticed to be a cost-efficient process ($33.29 /g melanin) for melanin biosynthesis.
- Electromagnetic field
- Office trash paper
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology