Exo-polygalacturonase production by Bacillus subtilis CM5 in solid state fermentation using cassava bagasse / Produção de exo-poligalacturonase por Bacillus subtilis CM5 por fermentação em estado sólido empregando bagaço de mandioca

The purpose of this investigation was to study the effect of Bacillus subtilis CM5 in solid state fermentation using cassava bagasse for production of Exo-polygalacturonase (exo-PG). Response surface methodology was used to evaluate the effect of four main variables, i.e. incubation period, initial medium pH, moisture holding capacity (MHC) and incubation temperature on enzyme production. A full factorial Central Composite Design was applied to study these main factors that affected exo-PG production. The experimental results showed that the optimum incubation period, pH, MHC and temperature were 6 days, 7.0, 70 percent and 50ºC, respectively for optimum exo-PG production.

O objetivo desta investigação foi estudar a produção de exo-poligalacturonase (exo-PG) por Bacillus subtilis CM5 por fermentação em estado sólido empregando bagaço de mandioca. Empregou-se a metodologia de superfície de resposta para avaliar o efeito de quatro variáveis na produção da enzima: período de incubação, pH inicial do meio, MHC e temperatura de incubação. Os resultados experimentais mostraram que os ótimos de temperatura, período de incubação, MHC e temperatura para produção de exo-PG foram seis dias, 7,0, 70 por cento e 50ºC, respectivamente.

Statistical optimization of alpha-amylase production with immobilized cells of Streptomyces erumpens MTCC 7317 in Luffa cylindrica L. sponge discs.

The purpose of this investigation was to study the effect of Streptomyces erumpens cells immobilized in various matrices, i.e., agar-agar, polyacrylamide, and luffa (Luffa cylindrica L.) sponge for production of alpha-amylase. Luffa sponge was found to be 21% and 51% more effective in enzyme yield than agar-agar and polyacrylamide, respectively. Response surface methodology was used to evaluate the effect of three main variables, i.e., incubation period, pH, and temperature on enzyme production with immobilized luffa cells. The experimental results showed that the optimum incubation period, pH, and temperature were 36h, 6.0, and 50 degrees C, respectively. The repeated batch fermentation of immobilized cells in shake flasks showed that S. erumpens cells were more or less equally physiologically active on the support even after three cycles of fermentation (3,830-3,575 units). The application of S. erumpens crude enzyme in liquefying cassava starch was studied. The maximum hydrolysis of cassava starch (85%) was obtained with the application of 4ml (15,200 units) of crude enzyme after 5 h of incubation.

Exo-polygalacturonase production by Bacillus subtilis CM5 in solid state fermentation using cassava bagasse.

The purpose of this investigation was to study the effect of Bacillus subtilis CM5 in solid state fermentation using cassava bagasse for production of exo-polygalacturonase (exo-PG). Response surface methodology was used to evaluate the effect of four main variables, i.e. incubation period, initial medium pH, moisture holding capacity (MHC) and incubation temperature on enzyme production. A full factorial Central Composite Design was applied to study these main factors that affected exo-PG production. The experimental results showed that the optimum incubation period, pH, MHC and temperature were 6 days, 7.0, 70% and 50°C, respectively for optimum exo-PG production.

Statistical optimization of alpha-amylase production by probiotic Lactobacillus plantarum MTCC 1407 in submerged fermentation.

Production and purification of alpha-amylase by probiotic Lactobacillus plantarum MTCC 1407 has been investigated under submerged fermentation using Mann Rogassa Sharpe medium containing (1%) soluble starch in lieu of glucose (2%) as carbon source. Response Surface Methodology was used to evaluate the effect of main variables, i.e. incubation period, pH and temperature on enzyme production. A full factorial Central Composite Design was applied to study these main factors that affected alpha-amylase production. The experimental results showed that the optimum incubation period, pH and temperature were 36 h, 7.0 and 35 degrees C, respectively. The purified enzyme (by ammonium sulphate precipitation) had a molecular mass of 75 450 Da in SDS-PAGE.

Indole-3-acetic acid production and effect on sprouting of yam (Dioscorea rotundata L.) minisetts by Bacillus subtilis isolated from culturable cowdung microflora.

Bacillus subtilis strains (CM1-CM5) isolated from culturable cowdung microflora were investigated for indole-3-acetic acid (IAA) production in nutrient broth (NB). All the strains tested produced IAA in NB; albeit in very low concentrations (0.09-0.37 mg/l). The addition of L-tryptophan (0.1 - 1.0 g/l) into NB substantially enhanced IAA production (6.1 - 31.5 folds) indicating that L-tryptophan was the precursor for IAA biosynthesis by these bacterial strains. Maximum IAA production was observed after 8 days of incubation (in late stationary phase of bacterial growth). The variation in IAA production was attributed to the genetic make up of these strains as evaluated by RAPD analysis of these isolates and B. subtilis type strain MTCC 441. Application of B. subtilis suspension (8 x 10(9) CFU/ml) on the surface of yam (Dioscorea rotundata L.) minisetts increased the number of sprouts, roots and shoots length, root and shoot fresh weights and root: shoot ratio over those minisetts not treated with bacterial suspension. Fresh cowdung slurry treatment on yam minisetts also produced similar results as obtained with B. subtilis application.

Partial characterization and optimization of production of extracellular alpha-amylase from Bacillus subtilis isolated from culturable cow dung microflora.

Studies of alpha-amylase production by Bacillus subtilis (CM3) isolated earlier from cow dung microflora, were carried out. The optimum temperature, pH and incubation period for amylase production were 50-70 degrees C, 5.0-9.0 and 36 h, respectively. Enzyme secretion was very similar in the presence of any of the carbon sources tested (soluble starch, potato starch, cassava starch, wheat flour, glucose, fructose, etc.). Yeast extract and ammonium acetate (1%) as nitrogen sources gave higher yield compared to other nitrogen sources (peptone, malt extract, casein, asparagine, glycine, beef extract), whereas ammonium chloride, ammonium sulphate and urea inhibited the enzyme activity. Addition of Ca+2 (10-40 mM) to the culture medium did not result in further improvement of enzyme production, whereas the addition of surfactants (Tween 20, Tween 40, Tween 80, and sodium lauryl sulphate) at 0.02% resulted in 2-15% increase in enzyme production. There were no significant variations in enzyme yield between shaked-flask and laboratory fermentor cultures. The purified enzyme is in two forms with molecular mass of 18.0 +/- 1 and 43.0 +/- 1 kDa in native SDS-PAGE.