Introduction 

Laboratory Glass Fermentors are useful laboratory fermentation units used for cell or microbial cultivation for producing enzymes, ingredients, biomass, vaccines, antibiotics, monoclonal antibodies, and therapeutic proteins. Fermentors provide an ideal environment for animal cells or microorganisms to grow and utilize a substrate of low value and convert it to a high-value product. 

They are typically useful for culture medium selection, stains verification, and fermentation process optimization. Moreover, tank contamination is eliminated using the laboratory glass fermentors, allowing the fermentation process to be completed effectively. 

There are three types of glass fermentors: fed-batch, batch, and continuous. In a fed-batch, the nutrients and the bioreactors are passed through the metabolic process. In batch fermentors, the culture is placed within a contained environment, and nothing is added till the procedures are completed. While in continuous fermentors, the product is continuously extracted from the culture by constantly adding the reactants inside. 

Conduct Science offers Laboratory Glass Fermentors in various sizes, including 3L, 5L, 7L, and 10L to meet different experimental needs. It is suitable for laboratories for research centers, institutes, universities, and private enterprises.

Apparatus 

These 3, 5, 7, 10L laboratory glass fermentors have a high-temperature borosilicate glass body with a maximum of 80% liquid load capacity and 0.2 Mpa design pressure. The high-precision brushless AC servo motor and a special mechanical seal are perfect for undisturbed fermentation. A fifteen-stage speed regulation supports 0 ~ 1200 rpm ± 1 rpm speed. It can be set at the required limit for the purpose. 

The touch screen and indicator light describes the changes within the unit. It comes with a mechanical or magnetic stirring method support. The peristaltic pump allows you to add the materials to the fermentor body. A thermostat water tank and the circulating pump are present for heating and circulating materials within the tank.

Protocol 

Carefully clean the glass fermentor before and after each use, using fresh hot water to avoid making it a breeding ground for bacteria. Ensure that you’ve cleaned the inside of the sampling tube and the nozzle corner, and the top of the tank. 

Afterward, begin the sterilization process. You can use dry heat sterilization, wet heat sterilization, filter sterilization, and radiation sterilization for physical sterilization. While for chemical sterilization, you can use chemicals such as phenol, formaldehyde, Xinjieer, permanganate, potassium, peroxyacetic acid, etc.

Let the material enter the tank through the material tube on the cylinder head. Ensure that you do not overflow the tank to prevent the fabric from splashing out during fermentation. Heat the fermentor while ensuring that the inlet pipe valve is closed, while the agitator and the steam valve are turned on. When the fermentor reaches the desired temperature, immediately close the steam valve, and after 2-3 minutes, close the stirrer. 

Cooldown the fermentor’s temperature by draining the remaining condensate and passing the refrigerant through the jacket. It will reduce the temperature of the fermentor. Lastly, start the stirrer according to the required temperature, adjust the valve, and maintain the temperature for proper insulation.  

Applications 

Laboratory Glass Fermentors are used in colleges, universities, scientific research institutes, and corporate microbiology laboratories for precision fermentation, microbial fermentation medium formula screening, fermentation process parameters optimization, strains, and production process verification. These glass fermentors are used in pharmaceutical industries (to develop various drugs like human growth hormones, interleukin-2, monoclonal antibodies, anti-hemophilia factors, recombinant hepatitis B vaccine, etc.) and in the field of environmental science (for the fortification of microorganisms in sewage treatment). 

Biodegradation of wool waste and keratinase production by Stenotrophomonas maltophilia BBE11-1

Fang, Zhang, Liu, Du, and Chen (2013) used a 3L batch fermentor to grow Stenotrophomonas maltophilia BBE11-1- a keratin degrading strain. The study aimed at reusing wool waste by keratinolytic strain S. maltophilia BBE11-1. They compared the fermentation process in 3L and 30L fermentors. They contained wool waste as the main medium in the fermentors to determine the cell growth rate. The strain was cultivated in the wool medium for 2-4 days at 9 pH. Then, the laboratory-scale batch fermentation fermentors were kept at 23 °C temperature, 1.51/min air flow rate, and 400 rpm agitation at the same pH. The growth rate was changed using three temperature-shift procedure strategies, the fed-batch process and two-stage DO control. However, at the end of the procedure, the glucose-fed batch 30L fermentor improved the keratinase production significantly up to 117.7% compared to the initial 3L fermentor and took a much shorter time. Significant structural changes and growth of the high level of amino acids from wool decomposition also occurred, proving the efficiency of usage of wool waste material in the fertilizer and wool waste management industry. 

Ethanol Production from Food Waste Using 3L Fermentor and Vacuum Recovery Technology

Huang, Qureshi, Chen, Liu, and Singh (2015) performed a study to investigate the feasibility of ethanol production from food wastes at high solids content. They developed a vacuum recovery system consisting of a 3L fermentor and used it to remove ethanol via fermentation broth and reduce yeast ethanol inhibition. The conventional food fermentation process produced a high amount of ethanol. When the vacuum recovery system was applied, the control of ethanol concentration below 100 g/L reduced yeast ethanol inhibition. At the end of the experiment, the experimenters found the incomplete utilization of glucose in conventional fermentation as the residual glucose was found. However, the vacuum recovery system supported fermentation showed complete utilization of glucose. Also, the ethanol yield in the latter was found to be 358 g/kg (higher than conventional fermentation, which offers about 327 g/kg of food waste). 

Single-step ethanol production from raw cassava starch using a combination of raw starch hydrolysis and fermentation

Krajang, Malairuang, Sukna, Rattanapradit, and Chamsart (2021) carried out a single-step process for ethanol production from raw cassava and produced it in high quantity. This single-step ethanol production was carried out in a 5L fermentor at 34 °C.  

Strengths and Limitations 

Strengths 

Laboratory glass fermentors are nontoxic, smooth, corrosion-proof, and transparent, thus allowing us to inspect the vessel contents easily. They are useful in laboratories involved in cell biology and cell, tissue, and microbial cultures. 

Limitations 

While laboratory glass fermentors are extremely helpful in laboratory fermentation processes, there are some limitations to using them. For instance, these fermentors are brittle and fragile and break easily, so they need careful handling. Also, they are heavy-weight, so they can sometimes be difficult to handle.  

Precautions 

• Clean the glass fermentor before and after use to avoid the growth of bacteria. 
• Sterilize the fermentor well before starting the fermentation process. 
• The temperature must be kept constant during the fermentation process till it gets completed. It is important for the proper insulation and error-free fermentation process. 
• Carefully handle the fermentors to protect them from breaking. 

Summary 

1. Laboratory glass fermentors are used for cell biology, tissue, cell, and microbial cultures. 
2. They are used for the production of enzymes, ingredients, biomass, vaccines, antibiotics, monoclonal antibodies, and therapeutic proteins.
3. The 3L, 5L, 7L, and 10L laboratory glass fermentors are used for precise fermentation experiments in microbiology laboratories for research centers, institutes, universities, and private enterprises.
4. These 3, 5, 7, 10L fermentors have a high-temperature borosilicate glass body with a maximum of 80% liquid load capacity and 0.2 Mpa design pressure.
5. 3L glass fermentors can be used in ethanol production from food waste and Biodegradation of wool waste and keratinase production by Stenotrophomonas maltophilia BBE11-1. 
6. 5L glass fermenters can be used in single-step ethanol production from raw cassava. 

References 

1. Fang, Zhang, Liu, Du, & Chen (2013). Biodegradation of wool waste and keratinase production in scale-up fermentor with different strategies by Stenotrophomonas maltophilia BBE11-1. Bioresource Technology 140, 286-291. https://doi.org/10.1016/j.biortech.2013.04.091.
2. Huang, H., Qureshi, N., Chen, M. H., Liu, W., & Singh, V. (2015). Ethanol production from food waste at high solids content with vacuum recovery technology. Journal of agricultural and food chemistry, 63(10), 2760–2766. https://doi.org/10.1021/jf5054029
3. Krajang, M., Malairuang, K., Sukna, J. et al. (2021). Single-step ethanol production from raw cassava starch using a combination of raw starch hydrolysis and fermentation, scale-up from 5-L laboratory and 200-L pilot plant to 3000-L industrial fermenters. Biotechnology for biofuels, 14(1). https://doi.org/10.1186/s13068-021-01903-3
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