Biosafety

• Genetic engineering is nothing new. Farmers have used cross-fertilization and selective breeding for millennia to alter plants and animals to promote desirable features that increase food production and meet other human requirements.
• Traditional fermentation methods have been used by artisans to turn milk into cheese, beer, and bread from grains. Such deliberate alteration of the natural environment has greatly improved human welfare. But in the last 30 years, advances in biotechnology have fundamentally changed our capacity to modify living things. 
• The ability to extract and transfer DNA strands and complete genes, which contain the biochemical instructions guiding an organism's development, from one species to another has been developed by scientists. 
• They are able to precisely modify the complex genetic makeup of individual living cells using cutting edge technology.
• For illustration, they can employ bacterial DNA to make corn resistant to herbicides or introduce genes from a coldwater fish into a tomato to produce a frost-resistant plant. Living modified organisms (LMOs), also referred to as genetically modified organisms (GMOs), are the end result (GMOs).
• A tomato that has had its genes altered through genetic engineering is referred to as a transgenic tomato or genetically modified tomato. The Flavr Savr tomato, which was created to have a longer shelf life, served as the first experimental genetically modified food and was available for a brief period of time starting on May 21, 1994.
• Cotton bt the only genetically modified crop now farmed in India is Bt cotton, which is spread across 10.8 million hectares. In India, bt cotton had first been utilised in 2002.
• For many individuals, this quickly developing knowledge poses a complex set of moral, environmental, social, and health concerns. They claim that because contemporary biotechnology is still so young, there are many unanswered questions regarding how its products could function, develop, and interact with other species. 
• Could GM crops' capacity for tolerating pesticides, for instance, be transferred to related wild species? Could plants that have undergone genetic modification to stave off pests also damage helpful insects? Could a GMO harm ecosystems that are rich in biological diversity because to its improved competitiveness?

Biosafety and precaution

        The term "biosafety" refers to a variety of practices, guidelines, and laws for reducing the dangers that biotechnology could bring to the environment and public health. For biotechnology to provide the most advantages while posing the fewest hazards, reliable and practical protections for GMOs must be established. As soon as possible, while biotechnology is still a developing field, these protections must be put in place. Industry, governments, and civil society are currently promoting biosafety in various ways. The Cartagena Protocol has made a special contribution to ensuring global biosafety by:

“an adequate level of protection in the field of the safe transfer, handling and use of living modified organisms resulting from modern biotechnology that may have adverse effects on the conservation and sustainable use of biological diversity, taking also into account risks to human health, and specifically focusing on transboundary movements”.

The Biosafety Protocol in action

An Advance Informed Agreement procedure

• The most rigorous procedures are reserved for GMOs that are to be introduced intentionally into the environment. These include seeds, live fish and other organisms that are destined to grow and that have the potential to pass their modified genes on to succeeding generations.
• The exporter starts by giving the government of the importing country detailed written information, including a description of the organism, in advance of the shipment. 
• A Competent National Authority in the importing country acknowledges receipt of this information within 90 days and then explicitly authorizes the shipment within 270 days or states its reasons for rejecting it – although the absence of a response is not to be interpreted as implying consent.

A simplified system for agricultural commodities

• Bulk exports of genetically modified maize, soybeans, and other agricultural products meant for direct use as food or feed or for processing rather than as seeds for fresh crop growth make up the largest category of GMOs in international trade.
• The Protocol establishes a less complicated mechanism in place of mandating the adoption of the Advance Informed Agreement procedure for certain commodities. Governments must inform the international community of their choice to allow these products for domestic use via the Biosafety ClearingHouse under this arrangement. They must also give thorough details regarding their choice.
• Additionally, nations may decide whether or not to import certain goods based on their domestic legal framework, but they must then declare these choices through the Clearing-House. The Protocol aims to keep the additional costs for commodities producers and dealers to a minimum while preserving the openness of the global trading system.

Risk assessments

• While it is the responsibility of the country considering allowing the import of a GMO to ensure that a risk assessment is carried out, it has the authority to demand that the exporter perform the job or foot the bill. For many developing nations, this is especially crucial.

Risk management and emergency procedures

• No human endeavour or piece of technology is fully risk-free. People adopt new technology because they think the advantages could exceed the disadvantages.
• When a government learns that GMOs under its control may cross international boundaries owing to unlawful commerce or release into the environment, the Protocol mandates that government notify and consult any other impacted or potentially affected nations. 
• They will be able to take emergency action or other necessary action as a result. To enhance international coordination, governments must create formal points of contact during emergencies.

others - Export documentation, The Biosafety ClearingHouse (BCH), Capacity-building and finance, Public awareness and participation

Governments cannot achieve biosafety on their own: they need the active involvement and cooperation of the other stakeholders.

Industrial production of Acetic acid

Acetic acid is a crucial platform substance. Only 10% of the world's production, which is used to make vinegar, is made by bacterial fermentation. It is primarily created synthetically. Acetic acid can be produced by a variety of microorganisms, some of which also incorporate CO into the process. 

Definition:

   Although it may have been preceded by certain fermented foods derived from milk, acetic acid (also known as ethanoic acid or methyl carboxylic acid) has been generated since the invention of winemaking, which goes back to at least 10,000 BC. Given that the Latin term acetum denotes sour or sharp wine, it is generally accepted that the first vinegar, which is an aqueous solution of acetic acid, was produced as a byproduct of the damaged wine. It served as a drug at first and was perhaps the very first antibiotic ever discovered. For the majority of human history, all acetic acid was produced using the same traditional method, which involved fermenting sugar to ethyl alcohol and then oxidizing it by microbes to generate vinegar. 

Acetic acid, which has the molecular formula CH3COOH, is also referred to as ethanoic acid, ethylic acid, vinegar acid, and methane carboxylic acid. Vinegar gets its distinctive smell from acetic acid, a byproduct of fermentation. In water, vinegar contains 4-6 percent acetic acid.

Two stages of fermentation were used to create this product. The process begins with anaerobic fermentation, which is the alcoholic conversion of carbohydrates into ethanol by yeasts and continues with aerobic fermentation (oxidation of ethanol into acetic acid by AAB). Before alcoholic fermentation can begin, the basic materials - starch or complex carbohydrates - need to be saccharified in order to release fermentable sugars. Due to the growing demand for vinegar, technical advancements were required to produce the product. Currently, three main techniques are used to produce vinegar: the submerged process, the generator process, and the slow surface culture fermentation, which is known as the "Orleans" or "traditional process."

Acetic Acid Production:

i. Chemical-based method:

Acetic acid as an industrial chemical is produced from fossil fuels and chemicals by three processes: acetaldehyde oxidation, hydrocarbon oxidation, and methanol carbonylation.

ii. Biology-based method

    i. Aerobic process production:

Food-grade acetic acid is produced by the two-step vinegar process. The first step is the production of ethanol from a carbohydrate source such as glucose. This is carried out at 30°C using the anaerobic yeast Saccharomyces cerevisiae. The second step is the oxidation of ethanol to acetic acid. Although a variety of bacteria can produce acetic acid, only members of Acetobacter are used commercially, typically the aerobic bacterium Acetobacter aceti at 27-37°C. This fermentation is incomplete oxidation because the reducing equivalents generated are transferred to oxygen and not to carbon dioxide:

C6H12O6 + 2CO2 + 2CH3CH2OH.

The overall theoretical yield is 0.67 g acetic acid per gram of Glucose. At the more realistic yield of 76% (of 0.67, i.e., 0.51 g per gram glucose), this process requires 2.0 pounds of sugar or 0.9 pounds of ethyl alcohol per pound of acetic acid produced. Complete aeration and strict control of the oxygen concentration during fermentation are important to maximize yields and keep the bacteria viable. Submerged fermentation has almost completely replaced surface fermentation methods. The draw-and-fill mode of operation can produce acetic acid at concentrations up to 10% wt/wt in continuous culture at pH 4.5 in about 35 hours.

2CH3CH2OH + 02 -+ 2CH3COOH + 2H20.  

    ii. Anaerobic process production:

    In 1980 another process for the production of acetic acid emerged based on anaerobic fermentation using Clostridia. These organisms can convert glucose, xylose, and some other hexoses and pentoses almost quantitatively to acetate according to the following reactions:

C6H12O6 + 3CH3COOH, 2C5H10O5 + 5CH3COOH.

Typical acidogenic bacteria are Clostridium aceticum, Clostridium thermoaceticum, Clostridium formicoaceticum and Acetobacterium woodii. Many can also reduce carbon dioxide and other one-carbon compounds to acetate.

Parameter for AAB::

pH

pH The optimum pH for the growth of AAB is 5.5 to 6.3. However, these bacteria can survive at low pH values of between 3.0 and 4.0, and some strains have been isolated from an aerated media containing acetate that could grow at pH values as low as 2.0 to 2.2. It was postulated that there are three groups of strains that might exist in vinegar production, namely, acidophilic strains that grow only at a pH value of about 3.5, acetophobic strains that only grow at pH levels higher than 6.5, and acetotolerant strains that can grow at both these values. There may be a gradual development from acetophobic to acetotolerant strains and, with prolonged exposure to low pH and high acetic acid concentrations, to acetophilic strains. This suggests the development of a gradual acid resistance in these bacteria.

Temperature

The optimum growth temperature for most AAB is 25◦C to 30◦C. The maximum temperature for the growth of A. aceti wasfound to be about 35◦C. Thermotolerant AAB that are able to grow at 37◦C to 40◦C have also been isolated. These bacteria were able to oxidize ethanol at 38◦C to 40◦C at the same rate that mesophilic strains do at 30◦C, as well as being able to oxidize ethanol more rapidly than the mesophilic strains at the higher temperatures. AAB can also be active at lower temperatures, and weak growth was observed even at 10◦C.

Production of Acetic acid

Batch fermentations in 16-L vessels with automatic pH control were conducted as a basis for predicting continuous fermentor performance at different dilution rates. Continuous fermentations in 0.3-L chemostats were performed to determine for C. thermoaceticum. Batch fermentations were conducted in pH-, temperature-, and gas-controlled New Brunswick 16-L Microferm fermentors. These units had provisions for homogeneous mixing, constant headspace flushing with CO2, gas, sterile sampling, automatic pH control, and in-place sterilization. Chemostats with a working volume of 333 mL were set up for continuous work. The units contained provisions for flushing the headspace with gas and sparging with C02 or N,, plus pH control with 10% NaOH. The headspace of the feed medium reservoir was also flushed with N, to maintain its anaerobic state.

German Method 

In 1832, German chemist Schutzenbach established the German process which is one of the quick processes (trickling method). It is also one of the oldest methods of acetic acid production. Acetic acid bacteria are Gram-negative and aerobic bacteria. The acetic acid bacteria were grown and fermented thick slim coating beech wood shavings occurs in 5000-6000 liters of wood /steel tank while the alcoholic liquid distributes of spray mechanism covered with AAB. During, the pH was maintained in the range between 2.5-3.2 and they produced at 27-30◦C of 88-90% of acetic acid from ethanol and the remaining substrate is used in biomass production. Depending on the size of the acetifier, production capacity was 70000- 100000 at 10% acidity. The acetic acid yield is approximately 1-2 kg/m^3.h. A high yield of acetic acid was produced in surface culture of 57 611 mg/L with inoculum techniques. 

Parameters: 

    (i) mash circulation, 

    (ii) cooling water through heat exchanger, 

    (iii) amount of air passed through the system.

 The advantages is it requires low space requirements, Low costs, and high acetic acid concentration. Drawbacks, high risk of clogging because of cellulose and high loss of ethanol by evaporation, and difficulty to producing AA production.

Application:

1. Antibacterial property for injuries like burns. -  Therapeutic effects
2. Used to prevent growth, spoilage and preserve. - Beverages industry
3. Food condiment and preserving meats and vegetables. - Food industry
4. Defensive effect and decrease fatality - Cardiovascular diseases
5. Used for diabetic treatment and decrease blood sugar levels. - Antidiabetic effect
6. Used in paper coatings, emulsion, resins for paints. - Petrochemical industry
7. Laboratory washing. - Machineries
8. Used in laundry detergents - Homecare
9. Managing soft tissues injury - Orthopaedic surgery

Reference:

1. Cheryan, M., Parekh, S., Shah, M., & Witjitra, K. (1997). Production of Acetic Acid by Clostridium thermoaceticum. Advances in Applied Microbiology, 1–33. doi:10.1016/s0065-2164(08)70221-1 

2. Li, P., Li, S., Cheng, L., & Luo, L. (2014). Analyzing the relation between the microbial diversity of DaQu and the turbidity spoilage of traditional Chinese vinegar. Applied microbiology and biotechnology, 98(13), 6073-6084.

3. Bayan, L., Koulivand, P. H., & Gorji, A. (2014). Garlic: a review of potential therapeutic effects. Avicenna journal of phytomedicine, 4(1), 1.