Statistical optimization of chitinase production by Streptomyces rubiginosus SP24 and efficacy of purified chitinase to control root-knot nematode infection in Vigna radiata under controlled conditions

Chemical and Biological Technologies in Agriculture

Table 1 Actual and coded levels of independent variables used in the Plakett–Burman design

Factor	Name	Units (g/100 ml)	Low actual	High actual	Low coded	High coded
A	Colloidal chitin	%	0.1	1	− 1	1
B	Peptone	g	0.1	2	− 1	1
C	Beef extract	g	0.1	2	− 1	1
D	Xylose	g	0.2	2	− 1	1
E	Sucrose	g	0.2	2	− 1	1
F	Magnesium sulfate	g	0.1	0.5	− 1	1
G	Dihydrogen potassium phosphate	g	0.1	0.4	− 1	1
H	Calcium carbonate	g	0.1	0.5	− 1	1