Quorum Sensing

2 Materials

2.1 Extraction
of Butyrolactones
from Solid Culture

1. Trace element solution [17]: 0.1 g/l ZnSO 4 ·7H 2 O, 0.1 g/l
   FeSO 4 ·7H 2 O, 0.1 g/l MnCl 2 ·4H 2 O, 0.1 g/l CaCl 2 , 0.1 g/l
   NaCl. Sterilize by filtration. Store at 4C and prepare fresh
   every 6 months.


2. Supplemented minimal medium solid (SMMS) [17]: Prepare
   1000 ml of a 0.2% (w/v) casamino acids (Difco) and 25 mM
   TES buffer at pH 7.2 and transfer 200 ml into five different
   250 ml conical flasks containing 3 g of agar (Difco) each.
   Autoclave all five flasks. Right before usage, melt the medium
   and add 0.5 mM NaH 2 PO 4 , 0.5 mM K 2 HPO 4 , 5 mM MgSO 4 ,
   50 mM glucose, and 0.2 ml of trace element solution (this
   section,item 1).

Fig. 1Schematic representation of a kanamycin bioassay reporter plasmid (pTE1062). The gene product of
scbR(red arrow) binds to Site R and Site A (open boxes). In the presence of GBLs, ScbR is released from Site A
and allows transcription of aminoglycoside phosphotransferase from Tn5 (green arrow) downstream of the
kasOpromoter (kasOp)

Butyrolactones inStreptomyces 119