Bacterial subcultures

On the next day, subculture by diluting 1 100 into fresh 2X TY medium. Culture until OD = 0.4-0.5, and then infect with phage. If necessary, the bacterial culture can be kept on ice for a short period before infection (<30 min, see Note 2)... 

Take the medium from step d of the subculture procedure and centrifuge at 800 g for 15 min. Discard the supernatant. Using a platinum loop, place the sediment on a blood agar plate (Appendix 4) and incubate at 37°C for at least 2 days to check for bacterial growth (Chapter 9). 

Each of these 3 forms of SBP has to be delimited from secondary bacterial peritonitis. In bacterial ascites, several types of microorganisms, including fungi, can usually be identified after subculturing. As a rule, the cell count exceeds 10,000/mm, the LDH value is elevated (> 225 U/1), and the glucose concentration is < 50 mg/dl. 

When carrying out liquid enrichments, the cultures with bacterial turbidity are smeared onto the appropriate special media using a platinum loop or platinum needle. The subcultures are then incubated for 20 4 hours at 37 C, and suspect colonies are further identified. 

At the conclusion of the acclimation study, soils from the microcosms were used to inoculate enrichment media of die same composition as the treatments used in the acclimation study. The atrazine concentration was monitored by HPLC and the enrichments were subcultured when the atrazine concentration had declined by at least 25% relative to sterile controls. Enrichments were subcultured seven times, and then DNA was extracted from subsamples and subjected to PCR-DGGE analysis as in the acclimated soils. The DGGE profiles for soils and enrichment cultures difrmd. Sequencing results suggested that many phylotypes associated with afrazine treatments were not closely related to previously characterized atrazine-degrading bacterial isolates. 

The AO AC use-dilution method is most commonly used to register disinfectant products. In this test, bacterial inocula are dried onto stainless steel penicylinders before exposure to disinfectant. The penicylinders, with dried organisms, are exposed to the disinfectant for 10 min and are then transferred to a subculture containing a germicide neutralizer. The product passes the test if no more than 1 sample out of 60 replicates gives a positive growth [13]. 

---