3.4. Selection of pretreatment condition
Five different conditions of substrate were used to check the
maximum xylanase production. The substrate used were raw
sugarcane bagasse, biologically treated bagasse, 2% H2SO4
treated bagasse, 2.5% KOH treated bagasse and 3%H2O2
treated bagasse was investigated. Maximum xylanase activity
of 72.4 1.42 U/g was observed with 2.5% KOH treated bagasse
with protein secretion of 0.88 0.11 mg/ml. Lowest enzyme
activity of 26.4 0.91 U/g was observed in 3%H2O2 treated
bagasse which was 50% low yield as compared to untreated
bagasse. Acid (2% H2SO4) treated bagasse improved enzyme
production with yield of 71.0 1.02 U/g which was higher as
compared to untreated bagasse as shown in Fig. 4a. The substrate
was further analyzed by advanced techniques such as
scanning electron microscopy (Fig. 4b) indicating alteration in
structure which lead to fully attacked by the microorganism
which ultimately increased enzyme synthesis. Alkali was also
used for the pretreatment of lignocellulosic biomasses and its
action depends upon the lignin content present in the
biomass (Fan, Gharpuray, & Lee, 1987; McMillan, 1994). The
xylanase production could be further improved by using alkali
treated straw as carbon source