Hi.I worked in this. Pls see my project in my profile.

Well, I am currently working on Bacillus Amyloliquefaciens which is aerobic. Following is the protocol I use for genomic DNA isolation from this and other bacterial cultures with excellent results.

1. Aliquot ~1-2 ml of liquid microbial culture and centrifuge at 5000-8000 rpm for 10 minutes.

2. Discard supernatant.

3. Add 500μl of TE buffer (10 mM Tris, 1 mM EDTA) and dissolve the pellet in buffer.

4. Add 100μl of 10% Sodium-dodecyl Sulfate (SDS).

5. Pipette the solution for a few minutes to ensure the cells are properly lysed. While some frothing is inevitable due to presence of SDS, excessive frothing must not occur.

6. Let the solution stand in room temperature for 10 minutes.

7. Add 100μl of 5M Potassium Acetate (CH3COO-K+).

8. Mix well, pipette if necessary. Protein precipitation will occur in this step.

9. Incubate at RT for 10-20 minutes depending upon the size of your pellet and protein concentration in the solution.

10. Centrifuge at 12000-13000 rpm for 10 minutes at 4°C (maintaining 4°C after this step is necessary to protect DNA from degradation)

12. Transfer the supernatant to a fresh tube using a pipette(preferably 1.5 ml tube) and put the tube on ice. Make sure not to transfer protein precipitate in the process.

13. Add equal volume of chilled 100% isopropanol or double volume of chilled 100% ethanol. (i.e. if you have transferred 500μl of supernatant, you will add 500μl of chilled isopropanol or 1 ml of chilled ethanol). Make sure that isopropanol or ethanol are placed in refrigerator or ice prior to beginning the experiment.

14. Close the lid of eppendorf's tube and slowly mix the the two solutions. If sufficient amount of DNA was present in the supernatant, white threads of DNA will be visible which will gradually form a spool as you gently tilt the tube alternately to each side and mix the solution.

15. (optional)If you got a spool, GREAT! Move to step 16. If not, incubate the solution in -20°C (if available) or in ice for 1 hr.

16. Centrifuge at 14000-15000 rpm for 10 minutes at 4°C. A white pellet should be visible at the bottom of the tube if everything has gone well.

17. Discard the supernatant; make sure you keep an eye on your pellet.

18. Wash the pellet with 70-75% ethanol. Make sure you tap and pellet and dislodge it and tap it a little more to make sure all impurities (such as SDS, Potassium acetate) are dissolved in the solution.

19. Centrifuge at 14000-15000 rpm for 5-10 minutes. Discard supernatant.

20. (optional) Repeat steps 18 and 19 two more times. Repeated washing ensures that DNA is free of SDS.

21. Vaccum dry or air dry the pellet to ensure all ethanol is removed. No trace of ethanol should remain before the pellet is redissolved. Although I wouldn't recommend it, many people also smell the aliquots to determine whether or not all ethanol is evaporated. Make sure that the pellet doesn't over dry or it will stick to the walls of the tube and not dissolve later.

22. Dissolve the pellet in 30-40μl Nuclease-free Water(NFW) or TE buffer. (optional) If your work requires that DNA be free of RNA, you can add ~1U of RNase to 30μl solution and incubate it at 37°C for half an hour. (Please refer to RNase product sheet for exact info on concentration and incubation time/temperature).

This is a very cheap and standardized method I use for extraction of high quality genomic DNA from bacteria. Aside from RNAse (which is largely optional), none of the reagents listed here are expensive and can be found in any molecular biology/biochemistry laboratory.

Good luck with your project. I hope I was of some help.

I had used the given below protocol to isolate genomic DNA from Streptomyces griseus Hope it helps...

Genomic DNA isolation

Procedure

1. S. griseus NBRC 13350 was grown in 5 ml Bennett’s broth for 48 hours in an incubator shaker at 28°C at 200 rpm.

2. Then, empty MCTs were weighed and 5 ml culture was transferred to empty MCTs and centrifuged at 2,500g for 10 min. (This step was repeated to harvest 5 ml culture in one MCT).

3. The supernatant was then discarded and the pellet was weighed.

4. Pellet was then resuspended in 250 µl 1X TE and lysozyme was added according to the weight of the cell pellet (25 mg/ g of pellet) and then the MCTs were incubated for an hour at 37°C with mixing in between after every 10-15 min.

5. After incubation, 60 μl of 0.5M EDTA and 9 µl of 10 mg/ml proteinase K was added in a tube and incubated for 5 min at 37°C.

6. Then, 35 µl of 10% SDS was added and incubated at 37°C for 2 hours.

7. An equal volume of Tris-saturated phenol was then added and mixed by gentle inversion. The MCT was spun at 16,000g for 3 min and then the aqueous phase was transferred to new MCT. This step was repeated again. (If thick aqueous phase was obtained, 100 µl of 1X TE can be added to it and heated at 70°C and then vortexed for 30 sec to solubilize. Vortexing and heating step can be repeated 3 times).

8. To the aqueous phase, an equal volume of chloroform was added and the MCT was spun at 6,500g and the aqueous phase was transferred to new MCT.

9. To the MCTs, added 1/10th volume of 5M NaCl, mixed by inverting the tubes and DNA was precipitated by adding double the volume of 100% ethanol and incubated for 1 hour in ice.

    (At this step, sample can be kept overnight at -20°C).

10. MCT was spun for 10 min at 16,500g and supernatant was discarded.

11. Pellet was washed with 500 µl 70% ethanol (ice-cold) for 10 min at 16,500g and supernatant was discarded. This step was repeated 2 times.

12. Pellet was then air-dried and resuspended in 50 µl 1X TE and stored at -20°C and checked by running on 1% agarose gel.

You could also use a "boiling lysis" method.  It's not a super clean prep, but it's fast, cheap and gets the job done.