Isolation, identification of a strain decomposing corn stalk and characterization of its cellulose

Abstract:

[Objective] The cellulose-decomposing strains for corn stalk were screened. [Methods] Agar dilution method was used to screen strains decomposing corn stalks from soil samples. Strains were identified by their morphological, physiological and biochemical properties and internal transcribed spacer sequence analysis. Then we compared the activities of cellulose and lignin degrading enzyme of the isolated strains with that of Penicillium spp. (CICC40361), studied the influence of different factors on cellulase activity, as well as the K_m values of the cellulase. [Results] A strain named PL2# was identified as Penicillium lanosum. The activities of cellulase and lignin enzyme of strain PL2# were higher than that of Penicillium spp. Conditions for optimal enzyme activity of strain PL2# was at 1% of carboxy methyl cellulose concentration, pH 4.8, 50 ℃, enzyme reaction time 60 min and 2 mL of DNS (3,5-dinitrosalicyclic acid) agent. [Conclusion] Strain PL2# (Penicillium lanosum) was better than the control strain Penicillium spp. in the degradation of corn straw cellulose.

Key words:Strain|Corn stalk|Cellulose|Enzyme activity