One of the greatest nightmares in the fermentation industries is the fear of microbial contamination outbreak. Such outbreaks will not only mean financial disasters due to the loss of product and costly fermentation media but also problems of disposing the contaminated fermentation media which are generally rich in nutrients and are very polluting. There is also the fear that the fermentation products not only resulted in decrease of volume and concentration but could be hazardous to human health! This might lead to liability cases which might run into millions of dollars! Its simply a lose – lose situation in microbial contamination strikes the fermentation plant!
Removing or reducing the number of unwanted microbes is a big issue. If you don’t remove the microorganisms it will affect the fermentation process. To make it even harder, all those residual nutrients could support the growth of the contaminating microorganisms. So the issue is not only removing the microbes but removing the remnant nutrients as well.
To clean and remove the offending microbes and nutrients we have to reach almost every surface, nook and cranny. This activity is not only restricted to the fermentor but all inlets leading to or from the fermentors. And this is not easy as it is difficult to reach those far reaching hidden places to effectively clean and sanitise the system. This problem is accentuated by poor design of the fermentation system which protects and even helps in the propagation of the contaminants.
We can look at the problem of fermentor sanitation from the point of:
1 Materials used for the fermentation system
2 Finishing of surfaces
3 Design of fermentation system
4 Sanitary fittings
The cleaning process is a harsh process in terms of the effect of the cleaning chemicals on the surfaces as well the effect of physical removal of dirt and slime from the fermentation surfaces. The materials used to build the fermentation system must be able to with stand the treatment.
Stainless steel is often the choice as not only its being inert and do not react with the cleaning chemicals but also with the fermentation process
The surface finish is of great importance. It is often said the smoother the surface the less chance for the contaminants to stick. This would make cleaning easier and efficient.
In reality if you look under microscope even the smoothest finishing is rough and provides refuge for the microbes to survive the cleaning surface. So even though smoother surface is better but it is not a guarantee.
What is more important is the cleanability or the ease of cleaning the surface for effective cleaning
The design of fermentor systems should not encourage the presence of inaccessible areas for microbes to survive and propagate. Dead legs or dead spaces should be eliminated or minimized. Threaded screws should be avoided as it could backfire in providing refuge instead of preventing the entry of microbes. Valves and pumps should be simple in design and easily disassembled for CIP procedures.
The cleaning of fermentation systems should be based more on the understanding of the behavior of the microbes and a more integrative holistic approach should help in maintaining sanitary conditions of fermentation system
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Monday, October 31, 2011
BEING CLEAN IS BEING SANITARY IN THE FERMENTATION INDUSTRIES
Saturday, October 22, 2011
THE PROBLEMS OF CLEANING INDUSTRIAL FERMENTATION SYSTEMS
One of the significant steps to prevent microbial contaminations in industrial fermentation systems is keeping the fermentation systems clean not only from the presence of residues of fermentation but from the presence of unwanted microorganisms.
Effective sterilizations could only be achieved by first cleaning the fermentation systems. Proper cleaning of the fermentation systems require in depth study and understanding the structure and behavior of the properties of the foulings
Only by understanding these prerequisites can you develop cleaning regimes which are specific to the process in mind. This will not only give you effective sterilizations but even save you money in terms of chemicals used in cleaning, lower labour costs and less downtime. It will also give you assurance that your fermentation processes will be free from contaminations
Cleaning the fermentation systems is not as easy as it looks. There are dirts and particles which you cannot see with your naked eyes. Seeing it is ‘clean’ does not always mean its really clean.
The problems faced in cleaning the fermentation systems are:
1 How to detect the biofoulings
2 Methods to detect presence of microbes or its by products on surfaces
3 Looking for inaccessible places where its difficult to remove them
4 Using the right cleaning technology
5 Validating that the cleaning process have been really carried out
In the fermentation industries we are dealing the problems of cleaning at the level of microscopic or nano level. Surfaces exposed to dirt and contaminants occur microscopic level. What appears as a smooth shiny surface could under microscopic observation be rough and craggy giving protection and attachment to the microbes. It is not easy to remove such hidden microbes in the conventional way
Mot of the biofoulings are biofilms which have thick exopolysaccharide to protect the cells. Thus using chemicals does not always guarantee the removal of the cells
Sometimes you need special tools to observe the fouling such as using lights of different wavelength that can detect proteins and other metabolites
The use of wrong biocide regime could instead of removing the biofilm cause it to produce thick biofilms. This is contrary to the purpose
Proper research need to be done at laboratory level to determine the right cleaning regime before the method is applied
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Tuesday, April 29, 2008
ALL ABOUT CIP (CLEANING IN PLACE)
(PICTURE TAKEN FROM WWW.OPTEK.COM) and WWW. TSSTRELLEBORG.COM)
Cleaning and sterilizing are one of the most important activities carried out in the fermentation process. A good cleaning and sterilization ensures not only the removal of residues from previously operated fermentation but also reduces or removed the probability of microbial contamination. If fermentors or its ancillaries equipments and processes are not cleaned, the remaining organic residues not only provide nutrients for the growth of unwanted microorganisms and allow the proliferation of the microbial populations, it also protects the microorganisms from the full effect of sterilizations.
Sometimes the process of cleaning the fermentors and its ancillary equipments are often confused with the sterilization process. In the cleaning process the activity centred on washing the equipments and removal of organic matters or soiled components. Sterilization is more in the killing and the removal of the microorganisms. This explains why CIP is often confused with SIP.
In most fermentation industries both SIP and CIP are carried out concurrently.
There are two kinds of cleaning often carried out in the fermentation industries; COP and CIP. COP refers to cleaning of the fermentors by removing and dismantling the fermentor components before cleaning it. The fermentor components are then reassembled after the cleaning process
CIP is the kind of cleaning carried out in situation where there is no dismantling or reassembling of the fermentor components. Cleaning is carried out with the fermentor component in tact. CIP is only carried out where the scale of the fermentor is too large and complex and the industry does not have the time, expertise to carry the COP
In both CIP and COP the basic principles of cleaning are the same. Both CIP and COP usually follow standard cleaning and sanitizing procedures such preliminary rinsing, draining, washing, rinsing and drying. However in CIP this procedure is a bit more complex as there is no ready access for cleaning and dismantling and require special procedures and methods of executing CIP.
It is strange that when the topic of CIP for fermentors are carried out, two common views are often held:
1 The first view is the picture of a worker scrapping or brushing the inner walls of the fermentor
2 A brief comment of passing hot steam through the pipes leading to and from the fermentor
CIP is more than the above standard views. CIP is a standard procedure or a system which are attached to and form part of the fermentation system.
The first CIP cleaning was rather quite primitive and manual in approach. The CIP involves the use of vessels as the solution tank, portable pumps, and hoses to connect the equipment and piping into circuits for recirculation of flush, wash and rinse solutions.
Temperature in CIP was accomplished by inserting a low-pressure steam hose into the solution tank and the “finger test”, or a thermometer reading.
The early CIP practises is a mixture of CIP and COP. CIP were quite restricted to the few long pipelines such as the receiving line or a supply line to the process plant. All other shorter pipelines, connections to equipment, and fittings and valves were manually cleaned, as in COP
Its only lately that CIP have become independent of COP and are fully automated to improve the efficiency of the process.
Modern CIP and SIP are systems designed for automatic cleaning and disinfecting without major disassembly and assembly work. Additionally, a well designed CIP system using a double seat block and bleed valve technology and process integration will allow cleaning of one part of the plant while other areas continue to function.
Modern CIP system saves money in terms of higher plant utilization and savings in CIP liquid through recycling of cleaning solutions, water reuse and conservation and man-hours.
In any CIP the most important components are the manipulation and control of the three parameters:
1 Time
2 Temperature
3 Concentration
In the application of CIP is also the interplay of hydraulics such as flow velocity and flow rate, number and volume of tanks, number of CIP circuits, type of detergent and sanitizing chemicals among others. Each CIP is custom made for the particular system
The design of a specific automatic CIP requires the integration of the design into the process. Such system usually have:
1 the addition of spray systems, tank cleaners, nozzles, and seals into the cleaning process.
2 advanced wash liquid preparation unit handling all filtering, preheating, mixing, and pumping of water, detergents, and demineralized water.
3 continuous monitoring and control of cleaning parameters, including flow rate, detergent concentration, temperature, and wash time.
Wednesday, January 2, 2008
WASHING AND CLEANING FERMENTORS
Washing and cleaning fermentors seems to be the most mundane and least liked job in fermentation industries. Yet, it is one of the most crucial steps in ensuring that the fermentation process in the fermentors will succeed. It will ensure that is little or no chance of microbial contaminations occurring in the subsequent fermentation process. Yet it is strange to admit that despite the great importance of washing and cleaning on the success of any fermentation run, little considerations are given during the design and implementation stage of the fermentor. Wahing and cleaning are more considered as after thought or at the end of the process.
Washing and cleaning not only show its importance in reducing microbial contaminations and increasing the efficiency of sterilizing the actions of the autoclaving process, but a very efficient cleaning process will cut down the turn around time of fermentors. This means that we can use the fermentors back again and start the next fermentation sooner.
Proper washings not only saves time, money but even labour.
It should be stressed at this early point in the discussion of the subject that, washing and cleaning of fermentors are not the kind of jobs equivalent in restaurants or car wash which could just be executed by almost anyone with minimal education and training. Washing and cleaning of fermentors is a very highly skilled job which requires someone very knowledgeable in microbiology or food technology degrees.
The person trusted with washing and cleaning the fermentors must know:
1 The anatomy of the fermentor, opening and putting back the fermentor
2 Know the materials of the the fermentor and possible side reactions occuring during washing, cleaning and sterilization
3 Know the hot spots within the fermentor which are likely to provide safe haven for the microorganisms
4 Know the use of correct surfactants or chemicals that will give efficient cleaning and toxicity hazards
5 Know how to validify that the cleaning has been effectively carried out by using microbiological testings
The main difference between washings and cleanings in restaurants, kitchens or car washes is that in cleaning fermentors it is just not enough seeing the surfaces clean. A clean surface visually does not guarantee there are no microbial contaminants or redidues from previous fermentation runs!
The effect of poor cleaning of fermentors is costly. You will only realized the full disaster after thousands of litres of fermentation broth is wasted or the fermentation products formed are contaminated.
Washing of fermentors are usually carried out at the end of the fermentation run when the fermentation process is terminated and the fermentation broth is poured out of the fermentor. It is the essential step in preparing the fermentor for the next run. Only after satisfactory cleaning is achieved will the fermentor be sterilized and ready for the next fermentation run.
Poor cleaning will result in remnants of microbes and residues of previous to remain in the fermentor. The presence of these residues have important implications to subsequent fermentation:
1 It provide nutrients for the microbes to grow and proliferate before sterilization process.
2The solid residues will act as a shield or barrier that will prevent effective sterilizations and killing of the microorganisms. It is possible that some of the microorganisms will survive the sterilization process and be a serious microbial threat in the following fermentation
3 The residues will also allow other microorganisms to grow on the remnant broth
4 It is possible that the residues will taint the quality of the next fermentation products by setting of unwanted biochemical reactions
5 These residues will react especially with oxidizing biocides thus reducing the efficiency of the chemical disinfectants.
It is advisable that immediately at the termination of the fermentation run, that the fermentors be washed and cleaned immediately and not to be left in such a septic state over prolonged period. If such actions are not done there is high possibility of the fermentation residues becoming a dried up cake. When this happened more time, energy and chemicals will be needed to clean the fermentors
As we have said earlier washing of fermentors is not similar to washings of dishes in restaurants or in a car wash. A fermentor need to be washed and cleaned in a standard operating procedure to ensure that the fermentors have reached a high level of cleanliness.
CIP AND COP CLEANINGS OF FERMENTORS
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In cleaning and washing fermentors we often come across these two terms; CIP and COP. CIP refers to Cleaning In Place and COP refers to Cleaning Out of Place. In CIP, all the essential cleaning of the fermentors are mainly carried out with minimum opening up of the fermentor. The fermentor is still intact and remaining in place. This type of cleanings are usually carried out for large fermentors such as industrial scale fermentors where it is almost next to impossible to dismantle and rebuild back the fermentor.
In COP, it is usually carried out with small scale laboratory fermentors. Main components of the fermentors are dismantled and cleaned thoroughly. This kind of cleaning is of course more thorough and effective.
In large fermentors CIP is usually carried out by using by powerful steam pressure balls which will give efficient cleaning. This is carried out as part of the cleaning SOP.
Effective washings involve the interactions of the four following parameters
Temperature
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Temperature is critical in increasing the chemical activity of the chemicals used in cleaning and increasing the solubility of solids
Chemical Concentration
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The more concentrated the chemical used for washing the more effective is the reactions
Fluid Motion/Agitation
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Fluid motion and agitation represents the physical and mechanical force that help remove the solids from surfaces
Time
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Time is the essence that allows the contact time to occur between the washing chemicals and cause more effective reactions for better cleaning
SOP FOR CLEANING AND WASHING FERMENTORS
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The effective cleaning and washing usually involve the following steps:
1. Rinsing
2. Chemical Solution
3. Rinsing
4. Chemical solution
5. Rinsing
Routine SOP for washing and cleaning fermentors would probably be carried out in the following steps:
1 End of fermentation, broth poured out fermentor
2 Removal of sensors and electrodes
3 Flushing with water under pressure to remove solids and residues
4 Wash with surfactants thoroughly
5 Wash with water again
6 Rinse with clean water
7 Allow to stand dry before sterilization steps
STERILIZATION AS PRE CLEANING STEP
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It is recommended that sterilization of the vessel with just water inside the fermenter be carried out. This will help in softening or removing hard organic solids at the same time killing the microorganisms still existing in the fermentor
During washings and cleanings it is important that procedures be followed such as:
1 Washing from top to bottom of fermentor
2 Use proper pressure incleaning the fermentors
3 Use the right ph and temperature for washing with surfactants
PHYSICAL CLEANINGS
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It is important during cleaning of the internal surfaces of the fermentor not to scratch the surfaces as it will lead to niches which the microbes will exploit. Do not use hard brushes
USE OF LOW OR HIGH FOAM SURFACTANTS
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There are a wide choice of surfactants and cleaners for cleaning fermentors. Ensure the proper chemicals are used. The use of surfactants are often associated with foams. High concentration of surfactants will result in high foaming which may require efforts and time in removing the surfactants
ENSURE CROSS CONTAMINATIONS DO NOT OCCUR DURING WASHINGS AND CLEANINGS
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Using excessive pressure may generate aerosols and dispersion of microorganisms which might affect subsequent fermentation process
USE VERY CLEAN WATER FOR FINAL RINSINGS
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Two deleterious effects can result from poor quality water. The first is that the chemical cleaning solution may be impacted by the chemicals/ components present in the source water.
The second is that the effectiveness of the rinsing steps may be compromised by contaminants present in the water.
