What I gather from the newspapers it is going to be a major project that will swallow billions of RM and carried out over 15 years!! Is it going to be more a pipe dream or a reality? Can the project be guaranteed to be successful or is it going to be more money thrown into the polluted river? 15 years is a very long time…. Wonder if the guarantee if any will hold.
One of the most common erroneous assumption is that if the technology was successful for Thames or for the matter the mighty river Han, it does not mean it will be successfully applied for Sg Klang. (Maybe all the parties concerned have their own expert consultants to vouch that every thing will be ok! As for me it is far better to be realistic and prudent. The River Klang is very complex and have many problems. I for one would like to be proven that the project will work…
Would it not be better if the companies concerned are tested first for their ability by giving certain stretches of the rivers to be handled and their performance monitored? To me it is very logical that if the company cannot manage a small portion of the river, it will be questionable if they can rehabilitate the whole stretch of the rivers.
I would love to see the spirit of competition vying with one another in the race to rehabilitate the stretch of rivers given to them. Nothing could be more wrong if all the companies awarded are working in the same group. That is the reason why I like how the Petronas tenders are being awarded, with the Japanese and Koreans competing with each other to complete their own respective towers!
Rehabilitating the Klang river requires more than just mechanical equipment to remove trash or solid wastes. It is more than just building treatment plants along the river. The solution is complex and requires social engineering too. If not we will be back to square one after billions of RM has been pumped into the project.
I for one would not like to see the rehabilitation of Klang river as a very costly exercise in futility!
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Thursday, April 29, 2010
REHABILITATION OF SUNGAI KLANG- AN EXERCISE IN FUTILITY?
Monday, April 26, 2010
INDUSTRIAL PRODUCTION OF ENZYMES: PART 2 PRODUCING MICROBIAL ENZYMES USING FERMENTATION TECHNOLOGY
Fermentation technology has been used extensively in the production of microbial enzymes. There are three main objectives in the production of enzymes using microbes:
1 The enzymes must be produced in high volume
2 The enzymes must be pure
3 The enzymes must be stable especially with respect to its structure and functions
The key element in the production of enzymes using fermentation technology is:
1 The presence of microorganisms which have the capability of producing the desired enzymes
2 The choice of suitable bioreactors or fermentors that can be used to support the cultivation of the microorganisms that produce the enzymes
3 The optimum conditions, control and monitoring of the fermentation conditions for maximum enzyme production
In all the above the nature of the enzymes being produced are often the restricting factors in the production of the enzymes. The main problems are enzymes are basically large complex protein molecules which are not stable and easily denatured by certain extreme conditions such as temperature, salt, ph and other factors.
The production of the enzymes by the microbes are basically a physiological or metabolic function of the microbial cells and factors such as feedbacks and catabolite repression or metabolic inhibition will affect the process
THE PRODUCTION METHOD
The production method of these enzymes is governed primarily by location of the enzymes in the cell and whether the enzymes are inductive or constitutive by nature. Most industries that produce large volumes of enzymes are often involved in inductive enzymes. In such situations there is no need to break the cells or organelles to release the enzymes. As constitutive enzymes are sort of “part of the cell” the amount of enzymes are directly related to the amount of cells produced. In such situations it shows primary metabolites behavior and the growth curve is used to determine the right time to harvest the cells and the constitutive enzymes
In the case of inductive enzymes the process of producing enzymes is simpler. Enzymes that are produced are easily released off the cell into the fermentation media. However, in this method the presents of the substrate or inducer in the media in important to trigger the enzymes production.
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Monday, April 5, 2010
SUNGAI WAY RIVER REHABILITATION PROJECT
I happened to chance upon the studies on the rehabilitation of Sg Way River project. While the intention to take care of the river is noble, it is of utmost importance that such studies be carried out properly in proper scientific manner. Proper samplings, analyses and interpretation of the results must be carried out for the study to be meaningful.
In order for the study to be meaningful goes far beyond than just taking a few random samples from a few sampling stations along the river. Remember, the results obtained from the few samplings might be valid only for the samples taken but they could not be used to extrapolate to the water quality of the river itself (unless one can guarantee that the composition of the river is homogenous and does not change spatially or temporally)
I am a bit disturbed by the way the sampling plan were carried out ( if there were any?) In my opinion the number of sampling stations is too few in number and too far apart. Determining the number and location of the sampling stations are critical to the success of the study. Prior studies must be carried out on the flow and hydrodynamics of the river in order to come up with the most suitable locations that can yield representative samples of the river water.
Sampling is a science and not determined by the convenience of the samplers such as taking samples from the sides of the embankments! Proper sampling utensils or apparatus must be provided to obtain the proper samples. There are many more other considerations which must be considered….
For the complete data please refer to:http://www.waterproject.net.my/index.cfm?&menuid=15
With such few sampling stations, samples, the whole exercise would just remain as a feeble attempt in efforts trying to rehabilitate the river. In my opinion it would have been more proper if the study carried out over the stretch of the driver:
1 Identify the various point source or diffuse source of pollution into the river
2 measure the total maximum daily load from each source
Auditings like this will not only identify the stake holders but also the responsible polluters. It is sad that sometimes the innocent stake holders will have to do the cleaning up of the river while the polluters go away scot free!
I am very disturbed too by the interpretation of the water analyses as provided by the report especially with reference to the Dissolved oxygen, BOD and COD readings. The BOD readings for the three stations W1, W2 and W3 are 5, 4 and 10 mg’litre. Wow! Something is not right here. At such low BOD values the water of Sg Way river is clean and not polluted at all. ( But my eyes see the river as very polluted!) Unless something is wrong or inaccurate in the samples or analyses
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Monday, February 15, 2010
INDUSTRIAL PRODUCTION OF ENZYMES: PART 1 ENZYMES IN FERMENTATION INDUSTRIES
The good thing about the use of enzymes in various industrial processes amenable to enzyme activity is that the reactions are simpler, faster, easier to control and you do not have to worry much about unwanted side products or unwanted products downstream.
However in various industrial fermentations, the use of enzymes are restricted to a few steps which more than often are prelude steps before the real microbial fermentation process. The restrictions in the use of enzymes for industrial processes are often restricted by the type and suitability of the enzymes needed for the various processes in the complete fermentation process.
In industrial fermentations, the use of enzymes is more in the hydrolysis of substrates prior to its fermentation. This stage is often called the liquefaction stage where large molecules are broken down to simpler monomers to be easily used by the fermenting microorganisms. Enzymes too are widely used in the clarification process of various fermentation juices
Using the enzymes therefore help in making the fermentation process more efficient both technically and economically.
THE NATURE OF ENZYMES
Enzymes are basically catalysts, whose main function is to speed up the specific reactions. In a way, the enzymes are no better than the inorganic catalysts used in many of the industrial chemical reactions.
The differences between enzymes and the inorganic catalysts are more in the sense organic enzymes carry out their reactions under a less demanding conditions. Their reactions are more under gentler physiological conditions found in the normal metabolism of the cells.
Organic enzymes are usually large protein structures which are easily denatured by conditions of extreme ph, temperature and salts and metals. The activity of these enzymes are not stable as they are easily denatured . Their active sites where the reactants interact are very sensitive to such conditions
Industrial catalysts operate under very extreme conditions of pressure, temperature, chemical toxicities which would not be suitable for the living microorganisms.
There is high demand today for enzymes to be used in various food and beverage industries among others. One of the biggest outlet for the production of enzymes is by the use of fermentation technology where the enzymes itself is the sought fermentation products.
Before discussing further the production of enzymes using fermentation technology let us acquaint ourselves with the type and location of enzymes in the microbial cells.
Many new students tend to fantasize the enzymes as equivalent to the magic elixir that can transform almost anything to anything. As we have said earlier the function of enzymes are nothing more than speeding up certain biochemical reactions. The living cell which contains cytoplasm within the membrane sac is nothing more than a complex mixture or soup of enzymes. Without enzymes it’s doubtful life will persist!
In reality the function of enzymes are very limited to carry out certain chemical reactions which involve breaking or making new bonds between the chemical groups. We classify enzymes by the nature of the chemical reactions they carry out!
We also classify enzymes by their location that is they intracellular or extracellular. Or we can classify enzymes whether they are constitutive or inductive, or whether they are soluble or attached
The nature of thee enzymes as stated above will determine the conditions for the production of the enzymes and its downstream extraction isolation and purification
MICROBIAL ENZYMES
Most industrially important enzymes produced by microorganisms are those which are induced and secreted out by the cells into the fermentation broth. It is therefore of great importance and cautions that only suitable microorganisms are used in the production of enzymes using fermentation technology. Common microorganisms used are Bacillus subtilis and Aspergillus oryzae
Much work and research are needed before these microbial enzymes can be used in large fermentors. What is most important is that at least the microorganism chosen must have the ability to produce the desired enzymes. The productivity of the microorganisms can further be enhanced by using various techniques of biotechnology such as gene manipulation
The enzymes produced by these microorganisms do not come in market ready forms! A lot of work needs to be done especially in the downstream activities.
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Monday, February 8, 2010
Friday, February 5, 2010
BIRD’S EYE VIEW OF FERMENTATION PROCESS
One of the first things the students taking fermentation technology will be the outline of the fermentation process flow. He will learn that the complete industrial fermentation process will be made up of three main stages:
1 Upstream activities
2 Midstream activities
3 Downstream activities
In any industrial fermentation process is seen as a pipeline of activities originating upstream with the fermentation products finally being obtained at the end of the pipe or at the downstream stage.
Thus in a simplification in the process flow we see masses being introduced into the process and as it flow down the pipe these masses are being transformed to the desired fermentation products by the fermentation microorganisms.
At each stage of the transformation optimal conditions are implemented not only to obtain the highest yield of the products but also in terms of energy and economic efficiency. This attempts can only be carried out if we assumed that the flow of substrates through the fermentation process will pass through various unit processes which could be identified and optimized.
In such situation, it is important that:
1 The flow of masses from the beginning stages to the final products will be smooth and not interrupted. To achieve this hydrodynamic flow restrictions imposed by various volumetric and hydrodynamic restrictions must be overcome by using different bioreactor or volumetric configurations
2 That each unit process is working under its optimal operating parameters such as temperature, mixing, ph, seeding etc
3 Elimination of physical and physiological bottlenecks in terms of pumping and even removing the effect of catabolite repressions or inhibitions
4 That the impact of any changes in upstream activities will affect the efficiency of the downstream activities. Any improvement or changes in upstream activities will affect downstream and not vice versa
5 That there must be allocation or allowances for changes even within this narrow range of optimized parameters
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Monday, February 1, 2010
PROBLEMS OF HIGH CELL DENSITY FERMENTATION
The microorganisms are important components in any microbial fermentation. The microorganisms in the fermentation process are either the agents of change which convert the substrate to valuable fermentation products or they themselves are the products sought in the fermentation process.
In either situation the objective of the fermentation process it selves is to obtain the highest number of microbes per unit volume. This trend is termed as achieving high cell density fermentation.
If we can achieve high cell density it is akin to saying that we have higher number of cells to carry out the transformation of substrate to products. More cells mean more “factory workers” to carry out the production. Thus more products will hopefully be produced over the period of fermentation process.
It should be noted although increasing the number of cells can increase the amount of fermentation products formed, that does not mean that the real efficiency of the fermentation process has increased in terms of fermentation yield by the unit cell. It is only the numbers of cells has increased leading to more conversions.
Only new strains or improved strains of producing microorganisms will increase the fermentation yield.
Logically, it is a good option to increase the fermentation product formation by increasing the number of microorganisms that will transform the fermentation substrates to fermentation products. However, this is not easily achieved in reality as there are many physical and physiological constraints that will try to prevent this objective.
The microbial cell is unique in its own right. During the process of fermentation not only it transforms the fermentation substrates to fermentation products, it will in the process of metabolism extract energy and carbon from the substrate to produce new biomass and undergo microbial growth.
In a way this would be ideal in achieving the high cell density fermentation, but such growth is not infinite and will ultimately slow down as in the typical sigmoid growth curve of the batch culture fermentation
Even before achieving this stationary phase the cells will it selves undergoes major changes in its metabolism or physiology will be of negative impact to the fermentation process and product formation
So how can we achieve the optimal high cell density fermentation? How shall we operate so that the fermentation of high cell density will be at optimum fermentation product formation in terms of economic and efficient control?
The whole idea of obtaining high cell density fermentation is ideal when:
1 You can have high density or number of microbial cells in the bioreactor
2 The high density protocol will not negatively affect the fermentation process or the products in terms of the quantity, quality and stability of products
3 That the fermentation process will be able to be carried out efficiently and economically in terms of substrate usage and efficient mass transfers
There are various strategies which could be applied in trying to obtain high density cell fermentation not only through feeding mode but also bioreactor configurations and physiological manipulations of the microbial populations
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