Good day. I am looking for standard growth curve for L. lactis subsp. Cremoris (NZ9000) of 600 nm optical density versus 10^7 cfu/ml with. Purpose is to see when this LAB reaches its' log phase. If anyone can inform me with a reference will be very helpful for me. Thank you in advance.
Hi,
Do it the old fashioned way. Make serial dilutions, each a log, from your stock which you measured on a microplate reader or any other system. Plate the bacteria on a proper medium and count colonies. I suggest you start from 10^5 dilution of your overnight culture. After calibration, use it forever.
Each system is different and you have to calibrate it on your equipment.
Hello, if you have microscope and hemocytometer or sell counting-chamber you can made your own suspension from stock culture and you can count real number of sells in suspension by counting chamber. With counting minimum 3 suspensions made by decimal dilutions you can create calibration curve at 600nm. And then by measurement OD of each suspension you can find cfu/ml. Liner range for this measurement in 0-1.5 OD at 600nm.
Hope this info will help you.
Good luck!
If you wanted to do it in a fast way, you can use McFarlands standard. You might find more detailed procedure at page 20-22 , Thesis Microfluidic single-cell physiology analysis of Corynebacter...
Most people count that way. OD600 is typically converted to a path of 1 cm and the number of colonies - it depends on the volume.
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