In my last post, I discussed some research that seemed to show bacteria can proliferate under the effects of some types of sound. Since then I have found that sound can also have the reverse affect: to inhibit bacterial growth. Specifically, the study I saw used a sound frequency to protect C. elegans (a type of worm) from a virulent bacterial infection. They also found that exposure to microwave radiation had a similar effect. Could such treatment possibly be used as an alternative to antibiotics in treating bacterial infection? This could be an important find in the struggle against antibiotic resistance. However, the study reported that the protection of the sound exposure only seemed to work against some of the several bacterial infections tested and not the others. A further understanding of the mechanisms of sound stimulation in bacteria is called for.
Meanwhile, to my great disappointment, I had two batches of kombucha go moldy. One I had tried to dye red by steeping red berry tea bags with green tea; the other was with black tea. In both I used dried SCOBY to start.
Several things could have gone wrong here. It’s possible that some oil in the red berry tea did not get along well with the SCOBY, but this seems unlikely as I only put the herbal tea in one of the two batches (and as far as I know it did not have any oil in it). It could also be that the dried SCOBY did not reawaken and start working quickly enough, or they expired, or I accidently let them see direct sunlight. However, I think it is most likely because I did not add starter tea until about two days after starting them. Starter tea (or vinegar, if you do not have starter tea) contains the acidity needed to keep the mold from growing while the kombucha brews. In the subsequent batch I added distilled white vinegar and am hoping it has the desired effect. So if you are making kombucha, be sure to add the proper proportion of acidic liquid at the very beginning!