Screening, purification and characterization of thermostable, protease resistant Bacteriocin active against methicillin resistant Staphylococcus aureus (MRSA)

Table 2 Antibacterial activity of BAC-IB17 against methicillin resistant Staphylococcus aureus after treatment with various physical and chemical parameters

Treatment	% Relative Antibacterial Activity				Treatment	Antibacterial Activity (AU ml^− 1)
Control	100				Control	80
a. Temperature (°C)	Exposure Time (hours)				Control	80
a. Temperature (°C)	1.0	2.0	3.0	4.0	d. Surfactants ^b
40	100	100	100	100	d. Surfactants ^b
60	100	100	100	96	Tween 20 (10 mM)	160
80	97	83	80	75	Tween 80 (10 mM)	160
100	70	50	nil	nil	EDTA (100 mM)	160
b. pH	Exposure Time (minutes)				SDS (01 mM)	160
b. pH	15.0	30.0	60.0	120.0	Triton X-100 (0.25 mM)	nil
5.0	nil	nd	nd	nd	e. Organic Solvents ^c
6.0	60	60	60	60	e. Organic Solvents ^c
7.0	100	100	100	100	DMSO (100 mM)	160
8.0	80	80	80	80	Ethanol (05 mM)	160
9.0	75	75	75	75	Methanol (100 mM)	80
c. Metal Ions ^a	Concentration (mM)				Formaldehyde (20 mM)	80
c. Metal Ions ^a	1.0	5.0	10.0		Chloroform (100 mM)	40
Ba^+ 2	100	100	100		Isopropanol (100 mM)	20
Cu^+ 2	100	nil	nd		f. Enzymes ^d	37 °C		50 °C
Mn^+ 2	100	90	90		f. Enzymes ^d	02 h	24 h	02 h	24 h
Cs^+ 2	100	90	90		Protease (0.5 U)	80	40	80	40
Ca^+ 2	100	100	100		Proteinase K (20.0 U)	80	40	80	40
Mg^+ 2	95	95	90		Pepsin (15.0 U)	80	40	80	40
Ni^+ 2	80	80	80		Lysozyme (150,000 U)	40	nil	40	nil
Zn^+ 2	70	30	nil		Amylase (30.0 U)	40	nil	40	nil
Co^+ 2	60	nil	nd		Ribonuclease A (90.0 U)	80	80	80	80
Hg^+ 2	nil	nd	nd		Catalase (11,000 U)	80	80	80	80

nd Not determined
nil No antibacterial activity
^aMetal ions used as chloride salts
^bNone of the surfactants alone (−ve control) in the above mentioned concentration inhibited the indicator strain except Triton X-100
^cNone of the organic solvents alone (−ve control) in the above mentioned concentration inhibited the indicator strain
^dFinal Concentration of each enzyme: 1.0 mg

ISSN: 1471-2180