The cell con- day In order to examine of CO replenishment. The utilization with variable syngas compositions and pure rate of CO mass transfer in the bioreactor was conduct- carbon monoxide at atmospheric pressure.
The syngas ed at various gas flow rates and agitation speeds. The utilization of mix syngas is presented by C. There was no ljundahlii in the early part of Figure 4 days of contamination presented in the bioreactor. The CO operation. The uti- cell dry weight of 2. An increase in CO utilization was observed achieved with pure CO as the incoming carbon source.
The outlet gas composition of the bioreactor at for ethanol and acetate. The ability of C. The corresponding dahlii. The present data showed that the CO uptake acetate concentration reached zero due to the low gas rate at low agitation speed rpm caused insuffi- flow rate into the bioreactor. That was justified due to cient mass transfer that resulted from insufficient cell the high productivity of C.
However, the ethanol production showed a speeds. The ethanol concentration decreased from 4. The cell production rate 50 www. As a comparison, other experi- agitation speeds. The bioreac- mum CO consumption rates were However, the maximum CO uptake rate uid flow rate was kept at 0.
In addition, products yields of 0. The when the bioreactor was operated with pure CO and results of similar studies with C. These results showed that the operation of 1. Unlike CO con- dry weight concentration, agitation speed and volu- sumption and uptake rate, the high products yields metric gas flow rate. This fact is due to kinetic limita- were obtained with a high concentration of CO tions, the bioconversion of CO in the outlet of the Table 1.
The 0. However, the minimum acetate yield was 0. The minimum ethanol yield was obtained at 0. However, maximum ethanol inverse of the volumetric gas flow rate Fig. The was at 0. Furthermore, the values of K a were found to be bioreactor at all the agitation speeds. It can be conclud- L ed that the CO supplied at low flow rate was insuffi- 36, The CO bioconversion was illustrated as a func- Generally, solubility of the gaseous substrate at tion of gas flow rate and agitation speed in a CSTBR ambient temperature and pressure are very low.
The see Figs. At the volumetric liquid flow rate gaseous substrate is utilized by the biocatalysts only if of 0. To flow rate and agitation speed in the bioreactor. Similar improve transfer of gas into the culture media, studies were carried out by Eubacterium limosum mechanically agitated CSTBR is the preferred reactor KIST in a bubble column bioreactor with a work- configuration as it allows an efficient contact between ing volume of 0.
The vvm and initial pure CO pressure of 96 kPa. When the laboratory scale fermentor was used in these studies. The bubble size distribution also 51 www. The pH was automatically type, agitation speed and gas flow rate Vega et al. A maximum CO consumption and CO uptake rate However, a maxi- examined for gas liquid mass transfer in a stirred tank mum cell concentration and CO bioconversion of 2. The total the mean bubble size decreases. An increase in gas velocity also and agitation speed at rpm.
The maximum mass Schneeberger et al. Increase in interfacial area transfer coefficient KLa of h-1 at an agitation and KL at the high gas velocities predominates over the speed of rpm was achieved. The results of the decrease in the mass transfer coefficient because of the present study provided important implications of the shorter gas-liquid contact time, which resulted in an bioconversion of various CO concentrations as raw increase in KLa.
A number of researchers have charac- syngas and also off-gas from steel mills for the indus- terized the volumetric mass transfer coefficient Vega trial scale of the CO fermentation processes. Also it has Acknowledgements been recommended that to use the empirical equation The present research was made possible through an IRPA in order to estimate the KLa of a laboratory-scale biore- grant No. SigmaPlot5 was very beneficial for analysis of empirical correla- tion defined for the KLa value using syngas-fermenta- References tion media in a stirred tank bioreactor.
Biochem the effect of gas flow rate and agitation speed on KLa Engin J. Biochemical engineering fundamen- tals. New York: McGraw-Hill, A compara- tive study of gas hold-up, bubble size, interfacial area and mass transfer coefficients in stirred gas-liquid reactors and The results of this investigation showed that at an agi- bubbles columns.
Chem Engin Process. Then, the KLa molecular hydrogen and carbon dioxide. Arch Michrobiol. Process Biochem. Formulation of defined media for carbon monoxide fermentation by Eubacterium limosum kist and the growth characteristics The present study was conducted to evaluate C. J Biosci Bioengin. Greening the chemical industry: research and CO-rich gases such as synthesis gas and off-gas from development priorities for biobased industrial products. J Chem Technol Biotechnol. Carbon monoxide oxidation by process.
J Bacteriol. The opera- recycle elements and save energy. Resour Conserv Recy. Geankoplis CJ This gives molasses its principal value as an industrial raw material for fermentation to produce rum.
Two or 3 liters of molasses produces 1 liter of rum. Acetone and butanol also are produced from molasses by fermentation with Clostridiurn bacteria. Food yeast Torulopsis utilis , is prepared from molasses, as are baker's and brewer's yeasts 2. The coconut palm finds many uses on the tropical islands of the Pacific.
Toddy is produced by tapping the unopened flower spathe of the coconut palm. The spathe is bruised slightly by gentle tapping with a small mallet and is tied tightly with fiber to prevent it from opening.
It is bent over gradually to allow the toddy to flow into a receptacle. About 5 centimeters is cut from the tip of the spathe after about 3 weeks.
Thereafter, a thin slice is shaved off once or twice a day and the exuding sap is collected. Palms are tapped for 8 months of the year and rested for 4 months. The average daily yield per palm is about 2 liters. The yield per spathe varies from 15 to 80 liters, and an average palm can yield liters during 8 months of tapping.
The fresh sweet toddy contains 15 to 20 percent total solids, of which 12 to Toddy ferments rapidly due to naturally occurring yeasts. Fermented toddy contains about 6 percent alcohol.
After 24 hours the toddy contains 4 to 5 percent acetic acid and is unpalatable as a beverage. It can be used for the production of vinegar. Fermented toddy can be distilled to produce arrack. Freshly fermented toddy is used instead of yeast in bread making. Constant tapping of coconut palms for toddy eliminates the nut crop. In in wine distilleries in Sri Lanka, over 49 million liters of toddy was fermented to give 4.
By tapping the male inflorescence of the oil palm, a sweet sap is obtained. The leaf subtending the immature male inflorescence is removed to provide access, the inflorescence is excised, and thin slices are cut once or twice daily.
The exuding sap is funneled into a calabash or a bottle. The fresh sap contains 15 percent sugar. Tapping is done daily for 2 to 3 months, yielding about 3. The sap ferments by the action of bacteria and natural yeast to produce a beverage with a milky flocculent appearance and a slight sulfurous odor known as palm wine. Palm wine is produced and marketed in considerable quantities in Nigeria.
The sap may be boiled to produce dark-colored sticky sugar or jaggery, which does not keep well. About 9 liters of juice produces 1 kilogram of jaggery. The fermented sap also yields yeasts and vinegar. A mean annual yield of 4, liters of sap per hectare of palms has been recorded in eastern Nigeria. This was estimated to have a value more than double that of oil and kernels from similar palms. Tapping, however, reduces the fruit yield. Sap can also be obtained by tapping the crown of the tree laterally or by felling the palm and drilling a hole through the growing point.
Both these methods are very wasteful since they kill the plant. The Palmyra palm yields about 2 liters of palm sap per day. Large palms with several tapped inflorescences give as much as 20 liters per day. A single palm of this type is estimated to produce 12, liters of sap during its tapping life. Grapes are the most common fruit used as raw material for alcoholic fermentation.
They are used in distilled liquor to make brandy. Historically, wine is the product of fermentation of grape species Vitis vinifera. The high sugar content of most V.
Their natural sugar content provides the necessary material for fermentation. It is sufficient to produce a wine with an alcohol content of 10 percent or higher. Wines containing less alcohol are unstable because of their sensitivity to bacterial spoilage. The grape's moderate acidity when ripe is also favorable to wine making. The fruit has an acidity of less than 1 percent, calculated as tartaric acid, the main acid in grapes, with a pH of 3.
The flavor of grapes varies from neutral to strongly aromatic, and the pigment pattern of the skin varies from light greenish-yellow to russet, pink, red, reddish violet, or blue-black.
Grapes also contain tannins needed to give bite and taste in the flavor of wines and to protect them from bacteria and possible ill effects if overexposed to the air. Other fruits can be used to produce wine. When fruits other than grapes are used, the name of the fruit is included, as in papaya or pineapple wine. Apples and citrus fruits with sufficient fermentable sugars are crushed, and the fermentable juices are either pressed out for fermentation or the entire mass is fermented.
Tropical fruits such as guava, mangoes, pineapple, pawpaw, ripe banana, ripe plantain, tangerine, and cashew fruit also contain fermentable sugars with levels varying from 10 to 20 percent. Overripe plantain pulp was reported to contain 16 to 17 percent fermentable sugar, with the skin containing as much as 30 percent 3.
The tropical climate prevailing in Africa is ideal for the growth and multiplication of microorganisms. The environment is abundant in biomass and in raw materials, which are high in starches and sugars and can be used for fermentation.
The available literature is sufficient in information on conditions and control measures required for optimum microbial activity in the various microbial processes. Convincing research results are also available to support utilization of microorganisms in the production of high-quality products of commercial importance.
What is lacking, however, is organization of the available information to enable selection of appropriate microbial processes that can be put together to form an integrated system to harness desirable microorganisms as a labor force for industrial exploitation.
Below an account is given of an attempt to organize four microbial processes into a production system to produce fruits, wines, and alcohol in an experimental project. An experimental project was established aimed at providing adequate conditions and control measures in four separate biological subsettings to produce quality products through the action of microorganisms. An attempt was then made to synchronize the activities of the subsettings into an integrated system for the production of fruits, wines, and alcohol with jam production as an integral part of the production system.
The four biotechnological subsettings used were: a compost pile, stimulated microbiological activity in the soil for release of nutrients, yeast activity in extracted fruit juices for the production of wines, and yeast activity in juice extracted from pineapple by-products for the production of alcohol. In a two-compartment wooden structure measuring 2 x 1 x 1 meters was constructed to hold two piles of composting material.
Cut grass, straw, dried leaves, and other high-carbon organic wastes were collected from the neighborhood. They were layered with chicken manure to provide a nitrogen source to form compost piles within the compartments.
Kitchen waste and, later, wastes from fruit processing were also added to the piles. The piles were kept sufficiently moist by sprinkling with water. To encourage optimum microbiological activity, the piles were aerated by constant turning. Observation of heat generation and the rates at which the piles were digested were used to indicate effective microbial activity.
The lack of offensive odor from the piles was considered a sign of adequate control conditions within the piles. The clay soil was removed, and mixed with compost.
The mixture was placed into the holes to form raised beds for planting. Two guava seedlings obtained from the research station at Njombe were added to other fruit seedlings nursed in pots. These were transplanted into the prepared sites. As more compost was made available, more fruit seedlings were transplanted into position. By mid the backyard plot was planted with the following fruit trees: six soursops, five guavas, three pawpaw, eight carambola bushes, one mango, and one avocado pear.
The fruit trees were interplanted with plantains, cocoyam, pepper, and a few winged bean plants to form a multistory system as usually obtained in traditional cropping systems in Africa. Sufficient compost was applied regularly to the soil to encourage microorganisms and other soil dwellers to function and to enhance mycorrhizal fungi association with root hairs, to provide nourishment and protection and for the well-being of the plants.
The compost was applied by removing the topsoil around the plant to expose the roots. Two to three loads of compost were distributed evenly around the roots and were covered with the topsoil.
Fallen leaves around the yard were raked and used as mulch to cover the top of the disturbed soil to prevent it from eroding away during heavy rains. The leaf mulch was also used to protect the soil surface from the pounding rains. It also kept the soil cool during the dry season and helped to conserve soil moisture when the plants are irrigated.
Ethanol is generally referred as common alcohol. Fermentation is a chemical breakdown of a substance by bacteria, yeasts or other microorganisms. The fermentation of carbohydrates into alcohol is one of the oldest processes of fermentation. The fermentation starts by mixing source of sugar, yeast, water and then allowing yeast to act in oxygen free environment. So the basic objective of the test is to carry out the production of Ethanol by the process of fermentation.
Chemicals: Corn steep glucose. Apparatus: Fermenter. Commercially fermentation is the initial step for production of wine, beer, cider. Ethanol fermentation. Yeasts perform the conversion in the absence of oxygen because of which alcoholic fermentation is considered as an anaerobic process.
Media preparation. After the selection of the desired yeast Saccharomyces cerevisae and its isolation in pure form, the inoculum is prepared under aseptic conditions. The yeast is first cultured in flask to increase the size of the inoculums as it will be suitable for inoculation.
For fermentation, continuous fermentation is used. For continuous fermentation, the growth of microbes is maintained in the Fermenter for a long period of time; in the meantime the media is added at regular intervals. Ethanol gets evaporated at temperature above 27 o C. Firstly aeration is required for good growth of organisms; later anaerobic condition is created by withdrawal of oxygen coupled with the production of carbon dioxide.
Recovery of ethanol. The mass is separated by centrifugation in a centrifuge. Ethanol from fermentation broth can be recovered by distillations. Glycolysis and alcoholic fermentation. Algae is one of the greatest sources of biodiesel because of its high rate of growth without competing for Transgenesis is the process of introducing transgene into living organism, as a result of which the organism will exhibit The principle behind this experiment is the reaction between diphenylamine and deoxyribose sugar that produces blue colour complex.
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