SEARCHING ENDO-1,4-β-GLUCANASE ACTIVE PRODUCERS FOR BIODESTRUCTION OF PLANT RESIDUES

Abstract

Objective. Evaluate the activity of endo-1,4-β-glucanase in soil microorganisms Bacillus subtilis, Paenibacillus polymyxa, Chaetomium globosum and Trichoderma harzianum for their potential use as an enzyme source in biotechnological production and to create a biodestroyer of plant residues. Methods. Hole method based on the interaction between Congo red dye and polysaccharide containing β (1.4) or β (1.3) bonds (mannitol-yeast medium was applied for deep cultivation of B. subtilis and P. polymyxa, corn-molasses — for C. globosum and T. harzianum), and spectrophotometric method based on colorimetric determination of the optical density of ferricyanide solution, the excess of which remains after reaction with reducing substances present in the culture fluid (microorganisms were cultured on corn-molasses medium). Results. Both hole and spectrophotometric methods showed that the studied micromycete strains had higher endo-1,4-β-glucanase activity than bacterial strains. The activity of endo-1,4-β-glucanase of microorganisms is as follows: B. subtilis eko/206 — 0.0499 IU/ml, T. harzianum eko/101 — 0.0667 IU/ml; C. globosum eko/108 — 0.0673 IU/ml. The average diameters of the enlightenment zones are as follows: T. harzianum eko/101 — 27.00 mm; C. globosum eko/108 — 28.14 mm; B. subtilis eko/206 — 20.25 mm. No endoglucanase activity was detected in P. polymyxa eko/204. Conclusion. The study of endo-1,4-β- glucanase activity in strains of microorganisms showed that the highest enzymatic activity is observed in C. globosum eko/108 and T. harzianum eko/101, suggesting the prospects of using these strains to obtain endo-1,4-β-glucanase via biotechnology. Although B. subtilis eko/206 has the ability to produce cellulolytic enzymes but their number is relatively small, so its use as a producer of endo-1,4-β-glucanase is less appropriate. P. polymyxa eko/204 did not show endoglucanase activity.