ABSTRACT
Aims: Sclerotium rolfsii is a pathogen of agricultural crops such as tomatoes. Trichoderma viride has been shown to control this pathogen effectively but the optimum conditions of this biocontrol agent need to be determined. This piece of research was therefore aimed at studying the conditions that could be maintained in maximizing the full potential of T. viride. Methodology and results: Malt extract agar was separately supplemented with different carbon sources (glucose, sucrose, maltose, lactose, and mannitol), nitrogen sources (peptone, ammonium nitrate, zinc nitrate and sodium nitrate) as well as salts (NaCl, CaCl2, KI, BaCl2) at different concentrations. Effect of different temperature and pH ranges was also evaluated. All the carbon used supported the growth of both S. rolfsii and T. viride at all concentrations. The growth of S. rolfsii was less than 90 mm at 3% of all the carbon used compared to the plates in which no carbon sources were added whereas the growth of T. viride was 90 mm. There were morphological changes in the growth of both T. viride and S. rolfsii with increase in concentrations of peptone and ammonium nitrate. The greenish colour of T. viride was completely lost while S. rolfsii became fluffier. For peptone, the percentage reduction ranged from 68.52 to 63.33 while for zinc nitrate and sodium nitrate, the percentage reduction ranged from 85.19 to 80.74 and 55.00 to 43.70 respectively. Also, there was increase in antagonistic property of T. viride with the inclusion of salts (NaCl, CaCl2 and KI) at all concentrations used. However, barium chloride was toxic to T. viride at 2-5% (w/v). The optimum temperature and pH for the antagonistic property of T. viride appeared to be 37 °C and 6.0 respectively. Conclusion, significance and impact of study: Inclusion of different carbon, nitrogen and salts increased the antagonistic activities of T. viride against S. rolfsii although lactose appeared to be the best carbon source while zinc nitrate and CaCl2 were the best nitrogen and salt respectively. Barium chloride was toxic to T. viride at 2-5% (w/v).
ABSTRACT
Aims: The escalating demands for traditional fossil fuels with unsecured deliverance and issues of climate change compel the researchers to develop alternative fuels like bioethanol. This study examines the prospect of biofuel production from high carbohydrate containing lignocellulosic material, e.g. sugarcane bagasse through biological means. Methodology and Results: Cellulolytic enzymes were collected from the culture filtrate of thermotolerant Trichoderma viride grown on variously pre-treated sugarcane bagasse. CMCase and FPase enzyme activities were determined as a measure of suitable substrate pre-treatment and optimum condition for cellulolytic enzyme production. The highest CMCase and FPase activity was found to be 1.217 U/ml and 0.109 U/ml respectively under the production conditions of 200 rpm, pH 4.0 and 50 °C using steamed NaOH treated bagasse as substrate. SEM was carried out to compare and confirm the activity of cellulolytic enzymes on sugarcane bagasse. Saccharification of pre-treated bagasse was carried out with crude enzymes together using a two-factor experimental design. Under optimized conditions the pre-treated bagasse was saccharified up to 42.7 % in 24 h. The hydrolysate was concentrated by heating to suitable concentration and then used for fermentation by an indigenous isolate of Saccharomyces cerevisiae. With 50 and 80 % brix containing liquor the concentration of alcohol was 0.579 % and 1.15 % respectively. Conclusion, significance and impact of study: This is the first report in Bangladesh for the production of cellulosic ethanol using local isolates. Though the rate of alcohol production was very low, a great impetus in this field can maximize the production thereby meet the demand for fuel in future.
ABSTRACT
In the present study, cultural and nutritional conditions for enhanced production of xylanase by a local soil isolate of Trichoderma viride, using various lignocellulosic substrates in submerged culture fermentation have been optimized. Of the lignocellulosics used, maize straw was the best inducer followed by jowar straw for xylanase production. The highest activity achieved was between 14 to 17 days of fermentation. A continuous increase in xylanase production was observed with increasing level of lignocellulosics in the medium and highest activity was observed with maize straw at 5 percent level. Xylanase production with higher levels of lignocellulosics (3 to 5 percent) of maize, jowar and barseem was found to be higher as compared to that with commercial xylan as carbon source. Sodium nitrate was the best nitrogen source among the six sources used. Maximum xylanase production was achieved with initial medium pH of 3.5-4.0 and incubation temperature of 25ºC.The enzyme preparation was effective in bringing about saccharification of different lignocellulosics. The xylanase production could be further improved by using alkali treated straw as carbon source.
Neste estudo, otimizou-se as condições culturais e nutricionais para produção aumentada de xilanase por uma cepa local de Trichoderma viride isolada de solo, empregando-se vários substratos lignocelulósicos, em fermentação submersa. Entre os substratos utilizados, o melhor indutor de produção de xilanase foi palha de milho, seguido de palha de sorgo. A atividade mais alta foi obtida entre 14 e 17 dias de fermentação. Com palha de milho observou-se um aumento contínuo na produção de xilanase com o aumento da concentração dos substratos lignocelulósicos no meio, sendo que a melhor atividade foi obtida com 5 por cento de palha de milho. A produção de xilanase com níveis mais altos de (3 a 5 por cento) de milho, sorgo e forragem verde (barseem) foi mais levada do que com xilana comercial como fonte de carbono. Entre as fontes de nitrogênio testadas, a melhor foi nitrato de sódio. Produção máxima de xilanase foi obtida quando o pH inicial do meio foi 3,5 4,0 e a temperatura de incubação 25ºC. A enzima foi eficiente na sacarificação de diferentes substratos lignocelulósicos. A produção de xilanase poderia ser aumentada empregando-se álcali ao invés de palha tratada como fonte de carbono.
Subject(s)
In Vitro Techniques , Nitrogen , Soil Microbiology , Sorghum , Trichoderma/isolation & purification , Xylans/analysis , Fermentation , Methods , Substrates for Biological TreatmentABSTRACT
The effects of surfactants on the production of cellulase by Trichoderma viride in liquid substrate fermentation process were investigated. Straw was used as the sole carbon source and the surfactants were biosurfactant rhamnolipid from Pseudomonas aeruginosa and Tween 80. The changes of FPA,CMCase,Avicelase and surface tension with time were analyzed under different concentrations of the two surfactants. The results showed that the surfactants can enhance the enzyme activity of Trichoderma viride. The FPA,CMCase,Avicelase were promoted 1.08,1.6 and 1.03 times higher than the controls by rhamnolipid. The enhancement of the enzyme activity by rhamnolipid was much higher than that of Tween 80. At the same time,rhamnolipid was not degraded prior to other substrate.
ABSTRACT
To study the chemical components and the antifungal activity of extraction from conidia of Trichoderma viride LTR-2.The extraction were obtained by distilling with Methylene dichloride from conidia of Trichoderma viride LTR-2 cultured on wheat bran solid matrix.Antifungal activity were determined by mycelium growth method.The chemical components of the extraction were analysed by GC-MS,the relative components in the extraction were determined by area normalization.The extraction not only have broad-spectrum control,showed antibiosis against eleven different plant fungal pathogens in PDA dish,such as Rhizoctonia solani,Alternaria brassica,Verticillium dahliae,Macrophoma kawatsukai,Fusarium moniliforme,Botrytis cinerea,Rhizoctonia cerealis,Fusarium oxysporum f.sp.vasinfectum,Bipolaris sorokinana,Fusarium graminearum,Alternaria.mali,but also have high inhibitory effect,and had 89.3% suppressive rate to Rhizoctonia cerealis.About sixty components were separated and identified by GC-MS,majority components were Hydrocarbon,the number of the Hydrocarbon were fourty-three kinds.Ergosterol was the major chemical components of the extract,and has 41.90% content.Other components comprised:Ketone,Organic acid,Alcohol,Ene,et al.Conclusion:The extraction from conidia of Trichoderma viride LTR-2 have antifungal activity.The extration comprised 2H-Pyran-2-one,5,6-dihydro-6-pentyl,it has 2.35% content.reference others literature,2H-Pyran-2-one,5,6-dihydro-6-pentyl may be the suppressive component of the extration.