THAKUR COLLEGE OF SCIENCE AND COMMERCE
Many environmental factors are known to influence the growth and metabolism of various life forms. Similarly, sound is one of the factors that influence the growth of microbes. Studies on the effect of sound waves on microbial growth have found that microbes can sense and respond to sound. Also, all microbes grow in different sound ranges.
Sound waves are longitudinal waves that travel through a medium like air or water. Sound waves with specific frequencies and intensities can have positive effects on various plant biological indices. High-frequency sound can kill microscopic pathogens.
As far as we know, the physical factors that contribute to the growth of microbes are moisture, pH levels, temperature, oxygen levels, osmotic pressure, etc. However, it was found that music is one of the contributing factors that help boost plant growth.
Different plants have different characteristics and different ways to grow. Some organisms might respond to sound stimulation with a positive effect on growth while some show inhibition effect (negative effect).
Indian Classical music comprises a different range of frequencies. Hence, the effect on microbial growth, production of certain important metabolites, and antibiotic susceptibility vary as per the frequency and the plant. These effects were observed in both prokaryotic and eukaryotic microbes. While studying this, all the bacteria and yeasts used as test organisms were found to have a positive effect on the sound, except Serratia marcescens which showed inhibited effect. Sometimes, control of microorganisms is essential to prevent the transmission of diseases and prevent unwanted microbial contamination. Microorganisms are controlled utilizing physical agents and chemical agents.
Music was also found to affect the production of bacterial pigments (prodigiosin and violacein) whose production is normally linked with quorum-sensing in the producing bacteria. All the test organisms exhibited an increased antibiotic susceptibility under the influence of music. Chromobacterium violaceum and S. marcescens were found to degrade cephazolin at a faster rate when incubated with music. The membrane permeability of the test organisms seemed to get altered owing to music treatment. The intracellular concentration of cations (calcium and potassium) and protein content of the music-treated cultures was also very significantly different than the control which was not treated. These two bacteria also showed increased production of violacein and alcohol respectively due to music treatment.
It has also been found that repairable damages to cells and steady cavitation are produced by low-intensity ultrasound. The living state of microbial cells leading to acceleration of their proliferation along with the production of metabolism is changed. However, in high-intensity ultrasound, it is found that it cannot provide effects of accelerating proliferation on microbial cells due to its irreparable damages.
Research in botany suggests that when music is played in a greenhouse environment, the plants that are growing with music genres are healthier than those growing in a popular genre. As in animals, there are ears to sense and respond to the sound stimuli, in microbes it seems that mechanosensory channels may be involved in sensing and responding to sound. Hence different ranges of sound frequency may lead to the growth of microbes. Hence, sound can be considered as one of the important factors for the growth of microbes and the production of metabolites.