Manas R. Swain

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 α-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 °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.

Extracellular α-Amylase Production by Bacillus brevis MTCC 7521

Alpha amylases have various applications in food processing industries, for example, baking, brewing and distillery industries. Studies of the Ca2+ independent α-amylase production were carried out by a strain of Bacillus brevis MTCC 7521 isolated from a brick kiln soil. The optimum temperature, pH and incubation period for amylase production were 50°C, 6.0 and 36 h, respectively. The enzyme secretion was at par in the presence of any of the carbon sources (soluble starch, cassava starch and cassava flour). B. brevis produced more amylase in presence of beef extract as nitrogen source in comparison to other organic nitrogen sources (peptone, yeast extract and casein) and asparagine, potassium nitrate, ammonium sulphate, ammonium nitrate and urea reduced the enzyme activity. The addition of Ca2+ (10–40 mM) or surfactants (Tween 20, Tween 40, Tween 60, Tween 80, and sodium lauryl sulphate at 0.02% concentration) in culture medium did not result in further improvement in the enzyme production. The purified enzyme had a molecular mass of 205 kDa in native SDS-PAGE.

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 50oC, respectively for optimum exo-PG production.

Production, characterization and application of a thermostable exo-polygalacturonase by Bacillus subtilis CM5.

Exo-polygalacturonase (exo-PG) (PG, EC 3.2.1.67) has various applications in food processing industries, such as in juice extraction and clarification, bakery, and distillery processing. This study reports the exo-PG production by Bacillus subtilis CM5 isolated from cow ruminant microflora, which was comparable to marketed pectinase (Pectinex®, Novozyme, Denmark). The optimum temperature, pH, and incubation period for optimum exo-PG production (82.0–83.2 units) were 50˚C, 7.0, and 36 h, respectively. B. subtilis produced more exo-PG in culture medium with peptone (1%) than other nitrogen sources such as beef extract, casein, yeast extract, ammonium sulphate, and ammonium acetate. However, ammonium chloride and urea (1%) inhibited enzyme production. In laboratory fermentor studies, exo-PG production by B. subtilis was 25.6% higher than shake flask cultures. Application of crude exo-PG from B. subtilis resulted in 13.3% increase in yield of carrot juice as compared to juice extracted with Pectinex.

Bioethanol Production From Corn and Wheat: Food, Fuel, and Future

Abstract Bioethanol has recently emerged as a major issue in energy policy to fulfill growing energy demand and sustainable economy. Ethanol as a fuel source today owes positive impact on rural America, the environment, and United States energy security. Bioethanol from corn and wheat is considered as the first-generation biofuel compared to other sources of biofuel because only hexose sugar is targeted for fermentation. High titer ethanol (>5%) can be achieved from corn and wheat by using simpler steps (grinding/milling, cooking, and liquefaction) before fermentation using the yeast strain (Saccharomyces cerevisiae). Recently, bioethanol from corn and wheat is adopted at industrial-scale in several developed and developing countries to fulfill the demands of the bioethanol. Fuel ethanol production is an energy-efficient process today, additional research is ongoing to improve its long-term economic viability.

Bio (Bacterial) Control of Pre- and Postharvest Diseases of Root and Tuber Crops

The term “root and tuber crops” is a very general “catch-all” for a wide cross-section of subterranean storage organs of which there are approximately 38 root, 23 tuber, 14 rhizome, 11 corm, and 10 bulb crops. The most important among them are potato, sugar beet, carrot, onion, and garlic (temperate root and tuber crops) and cassava, sweet potato, yams, and aroids (tropical root and tuber crops). Pre and postharvest losses of these crops are very high and, depending on the species cultivated and the storage environment, may be of the order of 30–60%. Bacterial control has been emerging as a promising alternative to chemical fungicide to control many pre- and postharvest diseases of these crops. The underlying mechanisms include antibiosis, competition for nutrients and space, and systemic resistance. The various strategies for use of antagonists and field uses (i.e., seed treatment, soil application, foliar spray, antagonistic mixture) have been discussed. In addition, certain mechanisms to improve performance of antagonists, such as addition of nutrients, use of antagonist mixture, and formulation of antagonist have been emphasized in this chapter.