“Without music, life would be a mistake” beautifully quoted by Friedrich Nietzsche. Music not only has the power to influence the mood and emotion of human being but also affects the various biological mechanisms of microbes. The correlation between the sound waves and life under microscope are usually neglected, although this field of research has great potential. Even though microbes lack nervous system, they behave differently on getting exposed to music and also have the property of producing sound waves.
Two audible sound tracts “Blue for Elle” and “Far and Wide” of 60 dB intensity when applied on a microalgae Haematococcus pluvialis enhances its growth rate, amount of chlorophyll as well as the rate of photosynthesis. This unicellular microalga contains an antioxidant providing pigment astaxanthin which is very good for central nervous system, anti-aging, immune system, health of eye and fertility. Classical music base together with natural sounds produced by water, wind, birds and insects compose the Green music. In a study on milk fermentation, a culture containing Streptococcus thermophilus, Lactobacillus delbrueckii and a mixed culture containing L. acidophilus LA-5, Bifidobacterium lactis BB-12 along with the 1st two bacteria in two different set up when exposed to the Green music of 75±5 dB intensity, showed significant elevated fermentation rate.
Promotion in the growth of most useful bacteria E. coli can also be obtained by incubating them with sound of frequency 1 kHz, 5 kHz and 15 kHz. The commercially important Yeast S. cerevisiae which is mainly used in alcohol fermentation also reported that alteration in their growth, biomass as well as metabolite production get induced by different sound frequencies. A group of researchers reported that on exposing Prevotella melaninogenica to a divine music ‘Om’ at 70-75 dB, promoted its growth by 5.88-62.93%. They also found that when the Indian classical music ‘Raag Malhar’ of frequency 41-645 Hz and ‘Raag Kirwani’ applied on the culture of different microbes, production of prodigiosin and violacein pigments has been observed.
The synthesis of these pigments mainly occurs during quorum sensing, thereby we can conclude that sonic treatment might also interfere with the interactions within the microbes.
Music also tends to elevate the antibiotic susceptibility of microbes, which suggests that combination treatment with music and drug can be used for more promising results. Disruption of pathogenic biofilms also has been seen when low frequency vibration therapy of 12-20 kHz together with antibiotics were administered on Pseudomonas aeruginosa. Although sonic treatment is associated with numerous benefits, this area needs more exploration and implementation in industries and research. The characterizations of secondary metabolites produced, the effect of music produced by different instruments and the mechanisms associated with the sonic treatment are still a grey area.
Microbes can also sing! It has been found that marine macroalgae during photosynthesis produce sound. In another study, sound frequencies between 8-43 kHz produced by Bacillus subtilis was detected, which is basically a growth regulatory signal within the cells. Our knowledge about cell to cell communication in the microbes is restricted to only chemical signalling pathways but physical conversations within the microbes are yet to be excavated. Understanding the physical interactions between the microbes might bring a new area of research.