Expanding the Use of a Fluorogenic Method to Determine Activity and Mode of Action of Bacillus thuringiensis Bacteriocins Against Gram-Positive and Gram-Negative Bacteria

Table 2

Inhibitory activity (UF) of bacteriocins synthesized by B. thuringiensis determined by fluorogenic method.

Strain	Bacteriocin activity
	Morricin 269	Kurstacin 287	Kenyacin 404	Entomocin 420	Tolworthcin 524	Culture media^*, ^°C^a
Gram-negative
Pseudomonas aeruginosa	74	109	120	81	106	TSB
Proteus vulgaris	110	78	67	93	52	TSB/BHI
Escherichia coli	77	97	120	68	100	TSB/LB
Streptococcus pyogenes	80	109	123	79	109	TSB
Klebsiella pneumoniae	76	96	114	82	115	TSB
Enterobacter cloacae	101	93	110	67	101	TSB
Salmonella sp.	70	126	61	63	39	TSB/TB
Salmonella typhimurium	71	105	128	82	121	TSB/TB
Serratia marcescens Nima	114	97	110	70	108	TSB
Serratia marcescens wf	95	93	110	75	100	TSB
Shigella flexneri	80	110	131	118	110	TSB/TB
Shigella sonnei	70	84	105	66	98	TSB/TB
Gram-positive
Staphylococcus xylosus	87	77	98	133	100	NB
Staphylococcus aureus	78	90	118	76	95	NB
Bacillus cereus 183	125	89	64	96	82^a	TSB/LB^a
Bacillus subtilis	72	106	129	83	110^a	TSB/LB^a
Listeria monocytogenes	103	96	110	67	96	NB
Micrococcus sp.	111	100	122	71	106^a	TSB/NB^a
Streptococcus agalactiae	106	90	73	91	50	NB/BHI
Enterococcus faecalis	109	98	125	73	104	MRSB

^* Culture media—TSB: Trypticase Soy Broth; BHI: Brain Heart Infusion; LB: Luria-Bertani Broth; TB: Tetrathionate Broth; NB: Nutrient Broth; MRSB: de Man, Rogosa and Sharp Broth.
^aAll bacteria were incubated at 37^°C, except B. cereus 183, B. subtilis, and Micrococcus sp., that were cultivated at 28^°C.