Characterization of a New Providencia sp. Strain X1 Producing Multiple Xylanases on Wheat Bran

Table 1

Screening test for selecting bacteria with high xylanase producing ability.

Isolate no.	Observation of plate assay^a			Xylanase activity^b (IU/mL)
	Clearance zone diameter (cm)	Colony diameter (cm)	Diameter ratio
X1	2.5	1.4	1.8	17.4±0.4
X2	1.3	1.3	1.0	9.6±0.2
X3	2.5	2.5	1.0	6.4±0.1
X4	2.4	1.3	1.8	9.4±0.2
X5	1.4	1.4	1.0	4.6±0.1
X6	2.3	2.1	1.1	7.2±0.1

aMedium used: Berg’s mineral salts-xylan agar; growth conditions: pH 7.0, 35°C, 48 h.
^bMedium used: Berg’s mineral salts-xylan broth; growth conditions: pH 8.0, 35°C, 48 h, 120 rpm.