Sclerotium rolfsii Sacc causing foot rot disease which is one of the major limiting factor for betelvine cultivation in Bangladesh. In this study, we have evaluated the antifungal activity of ...medicinal plant extracts, chemical fungicides, and antagonistic fungal isolates on mycelial growth of Sclerotium rolfsii. Among the tested medicinal plants, the highest percent inhibition was exhibited by leaf extracts of Datura metel and Lowsonia inermis L. in all three solvents (aqueous; ethanol and acetone) and concentrations. The chemicals fungicides - Bavistin DF (Carbendazim) and Dithane M-45 (Mancozeb), effectively inhibited the growth of the S. rolfsii. However, at lower concentrations, other tested fungicides were found to be less effective. Among the six biological control agents, Trichoderma harzianum showed the highest percent inhibition of radial growth of S. rolfsii. The secondary metabolites of T. harzianum and T. viride significantly reduced the mycelial growth of S. rolfsii.
The recent interest in bioconversion of agricultural and industrial wastes to chemical feedstock has led to extensive studies on cellulolytic enzymes produced by microorganisms. In the present study ...three lignocellulosic substrates viz. sugarcane bagasse, sawdust and water hyacinth were pre-treated with alkali and enzyme and their effect on bioconversion has been investigated. The ability of selected substrates for induction of cellulase enzyme by A. oryzae ITCC 4857.01 and for the potentiality of the induced enzyme to saccharify the substrates were also assessed. The maximum degree of conversion of substrate (0.415%) and improved specific substrate consumption (0.99 g substrate/g dry biomass) was exhibited in sugarcane bagasse after alkali treatment at 96 hrs. Both alkali-treatment and enzyme-treatment, water hyacinth was the best for cellulase induction and showed maximum endoglucanase activity of 11.42 U/ml. Reducing sugar yield ranged from 1.12 mg/ml for enzyme treated sawdust at 48 hrs to 7.53 mg/ml for alkali treated sugarcane bagasse at 96 hrs. Alkali-treated sugarcane bagasse gave the highest saccharification rate of 9.03% after 96 hrs. The most resistant substrate was sawdust which produced 5.92% saccharification by alkaline treatment. The saccharification of lignocellulosic substrates by enzyme produced by A. oryzae ITCC 4857.01 indicates the enzymes specificity towards the substrates. The use of such enzyme in lingo-cellulose hydrolysis will lead to efficient conversion of cellulose materials to other important products.
Purification and characterization of intracellular cellulase produced by A. oryzae ITCC-4857.01 are reported. The enzyme was purified by ion-exchange chromatography using DEAE-cellulose followed by ...Gel filtration. The purification achieved was 41 fold from the crude extract with yield of 27%. The purified enzyme showed single band on poly acrylamide gel. The molecular weight as determined by SDS-PAGE and gel filtration was 38 KDa and 38.6 KDa respectively and contained only one subunit. The enzyme is glycoprotien as nature and contained 0.67% neutral sugar. The apparent Km value of the enzyme against cellulose was 0.83%. The enzyme showed the highest relative ativities on CMC followed by avicel, salicin and filter paper. The optimum pH of activity was 5.5 and very slight activity was observed at or above pH 7.5 as well as bellow pH 3.5. The optimum temperature of the activity was 45℃ and the highest activity was exhibited in 35 to 45℃. The enzyme lost their activities almost completely (95~100%) at 80℃ or above and as well as bellow 25℃.
Trichoderma strains were evaluated under field conditions to assay their efficacy in suppressing Alternaria fruit rot disease and promoting chili plant growth. The experiment was conducted at the ...Botanical Garden, Rajshahi University, Bangladesh from July 2006 to March 2007. Application of Trichoderma harzianum IMI 392432 significantly (p = 0.05) suppressed the disease compared to Alternaria tenuis (T2) treatment and improved both growth and yield. The treatment T4 (T. harzianum IMI-392432 + A. tenuis) was most effective in reducing disease percentage (72.27%) compared to A. tenuis (T1) treatment. The highest seed germination rate (85.56%) and the highest growth and yield (12.5 g/plant) was also recorded in the same treatment (T4), followed by T5 (T. harzianum IMI-392433 + A. tenuis), T6 (T. harzianum IMI-392434 + A. tenuis), T2 (T. virens IMI-392430 + A. tenuis), and T3 (T. pseudokoningii IMI-392431 + A. tenuis) treatment, while single treatment with A. tenuis significantly decreased these values.
The recent interest in bioconversion of agricultural and industrial
wastes to chemical feedstock has led to extensive studies on
cellulolytic enzymes produced by microorganisms. In the present study
...three lignocellulosic substrates viz. sugarcane bagasse, sawdust and
water hyacinth were pre-treated with alkali and enzyme and their effect
on bioconversion has been investigated. The ability of selected
substrates for induction of cellulase enzyme by A. oryzae ITCC
4857.01 and for the potentiality of the induced enzyme to saccharify
the substrates were also assessed. The maximum degree of conversion of
substrate (0.415%) and improved specific substrate consumption (0.99 g
substrate/g dry biomass) was exhibited in sugarcane bagasse after
alkali treatment at 96 hrs. Both alkali-treatment and enzyme-treatment,
water hyacinth was the best for cellulase induction and showed maximum
endoglucanase activity of 11.42 U/ml. Reducing sugar yield ranged from
1.12 mg/ml for enzyme treated sawdust at 48 hrs to 7.53 mg/ml for
alkali treated sugarcane bagasse at 96 hrs. Alkali-treated sugarcane
bagasse gave the highest saccharification rate of 9.03% after 96 hrs.
The most resistant substrate was sawdust which produced 5.92%
saccharification by alkaline treatment. The saccharification of
lignocellulosic substrates by enzyme produced by A. oryzae ITCC 4857.01
indicates the enzymes specificity towards the substrates. The use of
such enzyme in lingo-cellulose hydrolysis will lead to efficient
conversion of cellulose materials to other important products.
Solid state fermentation was carried out by Pleurotus sajor-caju, micro-filamentous fungi and culture filtrate of P. sajor-caju with different combinations to improve nutritional qualities of rice ...straw. The acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents of the fermented rice straw were significantly reduced in mixed culture with filamentous fungi and P. sajor-caju. The cellulose and hemicellulose contents also reduced in similar manner. P. sajor-caju showed strong lignolytic activity resulting cellulose/lignin ratio of 5:1 when rice straw and PKC were supplemented. The protein content increased from 5.86 - 11.12, 12.98 and 13.14%, respectively. The maximum and significant amount of soluble protein 11.84 mg/g and glucosamine 18.50 mg/g was recorded in mixed culture at 30% palm oil kernel cake (PKC) supplementation. The maximum reducing sugar of 18.76 mg/g and endoglucanase activity 11.54 U/ml was recorded in same treatment. The mineral contents K, P, Ca, Mg and Fe were significantly higher in fermented sample while Cu and Zn were non-significant. The antioxidant activity improved by 45% and significantly varied between fermented and unfermented samples. DOI: http://dx.doi.org/10.3329/bjb.v42i2.18039 Bangladesh J. Bot. 42(2): 333-341, 2013 (December)
Trichoderma strains were evaluated under field conditions to assay their efficacy in suppressing Alternaria fruit rot disease and promoting chili plant growth. The experiment was conducted at the ...Botanical Garden, Rajshahi University, Bangladesh from July 2006 to March 2007. Application of Trichoderma harzianum IMI 392432 significantly (p = 0.05) suppressed the disease compared to Alternaria tenuis (T2) treatment and improved both growth and yield. The treatment T4 (T. harzianum IMI-392432 + A. tenuis) was most effective in reducing disease percentage (72.27%) compared to A. tenuis (T1) treatment. The highest seed germination rate (85.56%) and the highest growth and yield (12.5 g/plant) was also recorded in the same treatment (T4), followed by T5 (T. harzianum IMI-392433 + A. tenuis), T6 (T. harzianum IMI-392434 + A. tenuis), T2 (T. virens IMI-392430 + A. tenuis), and T3 (T. pseudokoningii IMI-392431 + A. tenuis) treatment, while single treatment with A. tenuis significantly decreased these values.
Farklı habitatlardan toplanan Trichoderma spp.'nin yerli populasyonlar karakterize edilmiş ve miktarları
belirlenmiştir. Tanımlanan suşlar, T. harzianum (IMI-392432, 392433, 392434); T. ...pseudokoningii (IMI-392431) ve T.
virens (IMI-392430) olarak isimlendirilmiştir. Beş suş arasından, T. harzianum bütün habitatlarda en yaygın olanıdır.
Trichoderma türlerinin koloni oluşturan birimleri (cfu'ler) farklı habitatlarda önemli bir şekilde (P = 0,05) değişmiş ve
olumlu bir şekilde habitatın fiziko-kimyasal özellikleri ile ilişkilendirilmiştir. Trichoderma'nın asidik bir habitata adapte
olduğu bulunmuştur. Etkili biyolojik dönüşüm ajanı denenerek mutfak atığı ayrıştırmasında en etkili türün T. har izanum
olduğu bulunmuştur. Spor süspansiyonu ile muamele edilen atıklardaki en yüksek hacim (% 31,80) ve ağırlık kayıpları
(% 30,80) bulunmuştur. Gelecek vaadeden sonuçlar, kontrolden %18 daha fazla ayrıştırma ile sonuçlanan Trichoderma'nın
farklı suş ve türleri ile kombine edilmiş bir uygulama kullanılarak da bildirilmiştir.
The native population of Trichoderma species collected from different habitats was quantified and characterised.
The identified strains are T. harzianum (IMI-392432, 392433, 392434); T. pseudokoningii (IMI-392431) and T. virens
(IMI-392430). Out of five strains, T. harzianum was the most common in all of the habitats. Colony forming units (cfu's)
of Trichoderma species varied significantly (P = 0.05) in different habitats and were positively correlated with the physico-
chemical characteristics of the habitat. Trichoderma was found to have adapted to an acidic habitat. In testing for an
efficient bioconversion agent, T. harzianum (IMI-392432) was found to be the most effective in kitchen waste
decomposition. It provided the highest volume (31.80%) and weight (30.80%) losses in waste treated with spore
suspension. Promising results were also noted using a combined treatment with different strains/species of Trichoderma,
which resulted in 18% greater decomposition of waste than the control.
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