[en] Trichoderma reesei cells were immobilized on paper covered with hydrophobic monomer, trimethylpropane triacrylate by radiation polymerization. The effect of immobilization condition on enzyme productivity was studied by measuring filter paper and cellobiose activity. The cells were adhered and grew on the surface of the carrier with the polymer giving high enzyme productivity in the immobilized cells in comparison with the free cells. Optimum concentration and volume of the coating monomer for the preparation of the immobilized cells were obtained. (author)

[en] Application of fungi in the biosynthesis of silver nanoparticles is a green and feasible alternative to chemical and physical methods used for AgNPs synthesis. The fungus Trichoderma reesei is a non-pathogenic and environmentally friendly microorganism capable to produce extracellular enzymes and metabolites in high scale. An extracellular biosynthesis of silver nanoparticles (AgNPs) from AgNO₃ solution by using the cell-free extract of Trichoderma reesei biomass is presented in this study. Kinetics of the biotransformation is described by a second order reaction equation. Spherical or approximately spherical AgNPs that are well-dispersed and with a size between 3-4 and 15-17 nm have been produced at transformation degree of 30 % with respect to the initial silver ions concentration. The biosynthesized AgNPs show high stability against agglomeration even after storage for 60 days. Soluble xanthates, used in some industrial applications, are found toxic to aquatic biota even at low concentrations. The synthesized AgNPs are capable to immobilize potassium amyl xanthate from model wastewater. The pollutant adsorption is described by the Langmuir adsorption isotherm and the calculated maximum adsorption capacity is 4.67 mg/mg. The pollutant immobilization by AgNPs is much faster process and requires much less adsorbent (50 fold) in comparison with the activated carbon (chemical grade of purity).

[en] In this work, the study of biosorption of Cr(VI) from aqueous solution was conducted using Rhizopus oryzae, Bacillus firmus, and Trichoderma viride as microorganisms that can absorb Cr(VI). The research is focused on determination of optimum conditions including pH, the number of R. oryzae, B. firmus, and T. viride (inoculums), and initial concentrations of Cr(VI) used. Optimum pH was obtained at pH 5, 4.5 and 6, for biosorption of Cr(VI) with R. oryzae, B. firmus, and T. viride, respectively, in the capacity of 45.3%, 24.5%, and 90.3%. The highest amount of Cr(VI) adsorbed for biosorption with R. oryzae, B. firmus, and T. viride, were 55.4%, 18.5%, and 74.5%, respectively, using 6-mL inoculums. The equilibrium concentrations achieved for R. oryzae, B. firmus, and T. viride were 60 mg/mL, 40 mg/mL, and 40 mg/mL, with the amount of Cr(VI) adsorbed were 32.4%, 28.2%, and 89.3%, respectively. The adsorption capacity for R. oryzae, B. firmus, and T. viride were 45.3 mg/1×10⁶ colonies, 36.2 mg/1×10⁶ cells, and 77.8 mg/1×10⁶ colonies, respectively. Overall, the biosorbents effectivity order in the biosorption process of Cr(VI) are T. viride > R. oryzae > B. firmus. (paper)

[en] The relationships between doses-survival rate and doses-T-AOC of Blakeslea trispora and Trichoderma reesei by N⁺ ion implantation were investigated. The results showed that the curves of survival rate of T.reesei, Streptomyces hygroscupicus var. Jingganggensis Yen. and Bacillus coagulans were all represented 'double saddle shape' with increasing N⁺ implanted dose, which were different from the classic 'saddle shape' curves. And the dose-T-AOC curves of B.trispora and T.reesei revealed the same trend as the dose-survival rate ones. It can be suggested that the variation of T-AOC probably decided the microbe survival situation after being implanted by low-energy N⁺ ion. (authors)

[en] The present study dealt with the production of enzyme xylanase by solid substrate fermentation using Trichoderma viride-IR05. Different substrates such as wheat bran, rice polish, rice husk, soybean meal, sunflower meal, sugarcane bagasse or corn cobs were evaluated for enzyme production. Of all the substrates evaluated, sugarcane bagasse was found to be best for enzyme synthesis. The substrate, sugarcane bagasse pretreated biologically, 2% H₂SO₄, 2.5% KOH or 3%H₂O₂. However 2.5% KOH gave maximum yield of enzyme as evidenced by the SEM analysis of the pretreated substrate. The cultural conditions were optimized for the production of xylanase in 250 ml Erlenmeyer flask such as incubation period (seven days), substrate concentration (10 g), liquid to solid ratio (11:10), initial ph of diluent (4.5), incubation temperature (30 degree C) with inoculum size of 10%. Further supplementation of xylose, NaNO₃ or tryptone and tween-80 as additional carbon source, nitrogen and surfactant improved (72.4±1.42 U/g) the titer of xylanase by T. viride -IR05, respectively

[en] Considering the importance of a microbial strain capable of increased cellulase production, a mutant strain UP4 of Trichoderma viride was developed by ultraviolet (UV) and plasma mutation. The mutant produced a 21.0 IU/mL FPase which was 98.1% higher than that of the parent strain Trichoderma viride ZY-1. In addition, the effect of ultraviolet and plasma mutagenesis was not merely simple superimposition of single ultraviolet mutation and single plasma mutation. Meanwhile, there appeared a capsule around some of the spores after the ultraviolet and plasma treatment, namely, the spore surface of the strain became fuzzy after ultraviolet or ultraviolet and plasma mutagenesis.

[en] This study is focused on the screening of eight wheat varieties against Fusarium graminearum and Rhizoctonia solani root rot fungal diseases and their management through biological control agets (BCA) treatments under greenhouse conditions in Department of Plant Pathology, University of Nebraska, Lincoln (USA). These two soil-borne pathogens contributing to significant yield reduction and enhanced growth and yield of Wheat varieties (WVs) after BCA treatments. Experimental trails were set up by applying agar plug inoculation and BCA culture suspension techniques. Highest rating against R. solani was observed in WV Seher-2006 (5.0A) while lowest shown by Galaxy-2013 (1.5FG). On the other hand, maximum rating was observed in Seher-2006 (6.25A) while minimum in Punjab-2011 (3.0B-E) against F. graminearum. It was observed that T3 and T4 reduced maximum DS of V1 as indicated 1.5B and 1.75B. Treatment T4 also showed maximum fresh weight (FW) (0.11g) and dry weight (DW) (0.28g) of root after BCA treatments against R. solani. Maximum FW and DW (0.49g, 0.35g) of V1 roots were also measured against T3 treatment while minimum mass (0.05g and 0.04g) was calculated against T7 (check). However, maximum fresh and dry weight of V7 and V8 roots were observed against T4 treatment. It was noted that all varieties treated with BCA showed more FW and DW of roots as comparison to control (-ve control). However, BCA treatments against all analyzed WVs did not show significant difference. So, all treatments were reduced DS of WVs and increased biomass and yield of wheat plants. Galaxy-2013 variety (V8) was declared as resistance against R. solani for year 2016-17 and three varieties (Faisalabad- 2008, Millat-2011 and Punjab-2011) were announced as moderately resistant to R. solani root rot. Comparatively, it was estimated that F. graminearum was more vulnerable as comparison to R. solani. The biological control activity of Trichoderma viride and Bacillus subtilis secreted enzymes and secondary metabolites in wheat plants and induced systemic disease resistance against Fusarium graminearum and Rhizoctonia solani. Therefore, it is concluded that BCA treatments are very effective techniques for the management of fungal pathogens without climatic pollution as in chemical spray form. (author)

[en] In the present study, out of 51 fungal strains isolated from the cellulosic wastes, only 19 were CMCase-producers. Aspergillus, Fusarium and Penicillium were the most common fungal genera isolated from the cellulosic wastes. Fusarium neoceras, Aspergillus fumigatus and Fusarium oxysporium produced CMCase activity than Trichoderma viride. Out of 23 gamma-irradiated survivors from A.fumigatus and F. neoceras showing CMCase production, only two mutant strains A.fumigatus 8G-2 and F. neoceras 4G-2 produced the highest levels of CMCase than the parent strains. The results indicated that the maximum level of of CMCase activity was produced by A.fumigatus and F. neoceras strains under optiminizing conditions.

[en] The indoor microclimate quality is an important factor affecting the human body. Inappropriate microclimate parameters and air pollutants can cause health problems or even be life-threatening. In addition, it can reduce work productivity and learning efficiency. In the article, the analysis of the rooms in the nursery building ventilated by a mechanical system equipped with air ionizers was conducted. The results of research were compared with the research results for rooms of the same type, but equipped with the passive stack ventilation. Fungi were detected in the analyzed building that does not pose a threat to the lives of people, but they can cause allergies and asthma. With regard to the reference objects, in the analyzed building, the microclimate was free from fungi species yeast-like fungi and Trichoderma viride, which occurred in the reference rooms. The indoor relative humidity was kept at a level not conducive to the development of fungi. The concentration of the carbon dioxide in rooms where children stayed permanently did not exceed the permissible value. Slight excessive concentration levels were observed only in the cloakroom. Only the internal air temperature exceeded 25 °C, which favors the development of fungi. This means that it would be appropriate to lower the indoor air temperature.

[en] Cellulase is the most important enzyme in the world enzyme market, which can be synthesized by growing fungi on lignocellulosic substrates. In this study, cellulase was produced by using Trichoderma species. Twenty-three Trichoderma species were isolated and screened out for their cellulase-producing ability. Selected species, Trichoderma reesei, was further optimized on Leptochloa fusca, a perennial grass. For the higher production of enzyme, different culture conditions were optimized in flask fermenters. Our study points out that overall cellulase production was highest as 1.165 IU/ml/min at 70% moisture level, 120-h incubation period, 30 °C incubation temperature, 6 initial pH, 20% inoculum size, 0.3% NH₄NO₃ concentration and 0.3% concentration of surfactant (Tween 80), respectively. Under solid-state fermentation, the recovery of the cellulase from fermented substrate was optimized which yielded 1.785 IU/ml/min. Among different solvents tested, optimal extraction was attained by using citrate buffer. The optimal conditions for extraction were 90 min soaking time, 1:5 solid-to-solvent ratio, 140 revolution per minute agitation. It was detected that two washes were enough for maximum leaching of the enzyme. Results specify the admirable scope of utilizing kallar grass for biosynthesis of cellulase in solid-state fermentation employing Trichoderma reesei commercially.