Food Bioprocess Science "Rated 8.8/10 as TOP 20% course"

Microorganisms are microscopic organisms that are naked to the human eyes. Just because we do not see them, it does not mean they are all the same, because they are not. the larger category of microorganisms belong to the category of bacteria. Please view the lecture video to better understand on bacteria.

Another significant group belong of microorganisms comprises of yeast, mold and virus. Virus has been an interesting topic lately, attributed to the COVID-19 pandemic. I will add some of my YouTube videos in Resources below.

Another important category of microorganisms comprises of protozoa and algae, many are very useful in food bioprocessing. They are also generally larger in size and once produced in sufficient colony sizes, may be seen with the naked eyes. Please learn more about these microorganisms from the lecture video provided.

As we have learnt about the different categories of microorganisms, we should realize that all microorganisms play different functions and affect food and health in different ways. Imagine microorganisms as humans, we each have own uniqueness and abilities. Those who can sing will be a singer, those who are highly creative can be an artist.

Similarly, microorganisms that can benefit food bioprocessing can be harness to produce different types of bio-foods. Meanwhile, those that can cause harm should be identified and ways to eradicate must be implemented.

Lets call them the Good, Bad and Ugly.

Now, we have seen how microorganisms can benefit mankind, thus are called the "good" microorganisms. We will now look at microorganisms that causes detrimental effects. Those that does not harm humans but cause food spoilage (lets call them the "ugly").

There are also microorganisms that causes detrimental effects via harming humans, as once ingested via foods, they can cause health damages (lets call them the "bad").

Food fermentation has a long history of use and applications, and in most cases, discovered unexpectedly.

There are also many local fermented foods that are discovered and loved until today.

One of the main aim of food fermentation, as practiced traditionally, was to preserve foods so that they are kept longer.

Remember, there was no refrigerator traditionally. Lets watch a video to learn more.

Now, we know that fermented foods have a longer shelf-life than its original and non-fermented counterparts.

As we progress with advancement in technology, and better knowledge on controlled fermentation processes, we also realize that fermented foods serve another aim; to increase nutrient density.

What is nutrient density and how fermentation processes contribute to this matter?

Lets watch a video to learn more!

Humans need some basic requirement and conditions to live, such as oxygen, water, and food. In addition to basic living, humans need other conditions to operate optimally such as better performance at work, and this involves additional needs such as a clean home, conducive temperature range and certain foods to better provide energy. It is also important to note, that each individual will have different needs, although we are all grouped as HUMAN.

Similarly, microorganisms also have such needs. By better understanding these needs, which are unique to each microorganism, we can tailor bioprocessing to produce foods that suit our needs.

Lets start with carbohydrate sources that human needs. In the microorganisms' equivalent, its called "carbon sources".

As humans needs proteins, microorganisms need "nitrogen sources". While humans needs a conducive temperature and oxygen level, so do microorganisms.

There are various fermented food industries, both locally and globally. We tend to see many smaller scaled fermented food industries locally such as soy sauce, tempeh, mira and tempoyak, which are famous in South East Asia. In general, there are three major fermented food industries that are also related to each other, lets look at alcohol first.

Now, we have seen the importance of ethanol, both industrially and applications in our daily lives. How about acids? There are two major acid industries that are related to the utilization of microorganisms. More interestingly, these acids are also related to alcohol.

1. Lactic Acid

2. Acetic Acid

Genetically modified organisms (GMOs)

When we think of genetically modified organisms, or GMOs in short, we think of mutants and maybe some may think of those from X-Men. Well, less dramatic of course and we should realize that we are surrounded by GMOs, even in the foods that we consume daily.

Plants, crops and animals involved in the production of foods and feed, are one of the most common examples of GMOs. GMOs in foods were first developed to serve many purposes, primarily to grow crops that are healthier, less susceptible to damages from pests and weather and to create foods with added nutritional profiles. Lets look at some reasons why foods are genetically modified.

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Resistance towards insects

The European corn borer is an insect that loves corn. The larvae of European corn borer feeds on corn plant, causing much damage to the crop. The most severe damage is stalk breakage prior to harvest. Another type of damage is ear drop where cobs fall to the ground. The final type of damage may be the least obvious but can cause significant yield loss. By restricting nutrient flow in the plant, yield is affected by the production of smaller cobs.

There is a bacteria, named Bacillus thuringiensis which infects and kills corn borers, via the production of a molecule called Bt toxin. Bt toxin not only kills the corn borers but also some other pests. Over the years, farmers have tried to spray either the bacteria Bacillus thuringiensis itself to corn plants or the toxin which yielded much success in reducing corn borers damages to the corn crops. This is definitely safer to humans and the environment than chemical pesticides.

A new idea emerges. What if the corn can express Bt toxin itself and defend itself against the invasion and damages of corn borers? This will be beneficial as farmers will not need to keep repetitive sprays which can also be washed away by rain. Thus, corn crops were genetically modified to express an insecticidal protein Cry1Ab isolated from Bacillus thuringiensis, which made the corn crop capable of producing its own Bt toxin that protects against the attack by corn borers.

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Development of new technologies

Poly-hydroxy-alkanoates, or in short PHAs, are biodegradable biopolymers naturally synthesized and accumulated as intracellular energy and carbon reserves by a wide range of bacteria. PHAs have properties similar to those of conventional petrochemical plastics. In addition, products made of these materials are natural, nontoxic, renewable and biocompatible, which make them more attractive than nonbiodegradable petrochemical plastics. The first observed and most studied PHA is poly-hydroxy-butyrate, or in short PHB. PHB is stiff and brittle, however, in the form of fibers behaves such as elastic material. One of the greatest advantages of PHB is air impermeability, water insolubility, non-toxic and thus, making it a very attractive material as a replacement for conventional plastics. However, the whole process of bioplastic production is still more expensive than obtaining petrochemical based plastics products mostly due to high costs of nutrient substrates for bacteria.

One of the possibilities is to try to obtain transgenic plants that would be used as natural bioreactors. Arabidopsis thaliana, which is considered as a weed often seen by the road-side, was transformed with genes encoding the enzymes needed for the production of PHB. This PHB gene was isolated from Alcaligenes eutrophus, a Gram-negative soil bacterium. The transformation has successfully brought about PHB accumulation in leaves of Arabidopsis thaliana, up to 40% of dry mass. Since then, bioprocess technology has merged molecular techniques and plant tissue culture technologies, to produce genetically modified plants as bioreactors for the production and accumulation of PHAs in various plant organs. This includes seeds of rapeseed, leaves of tobacco plant, whole plant of cotton plant, stem of flax, hairy roots of sugar beet, and seed coat of soybean.

Enhance nutrient composition

Vitamin-A deficiency is a pervasive and silent killer of malnourished children and pregnant mothers, typically in third world nations. Each year, nearly a million children and women go blind or die for lack of vitamin-A. Vitamin-A is primarily available in meat and leafy vegetables, which are often seen as expensive and rarely available in daily diets of poorer nations. Rice, a staple food in many parts of the world has been a model for GMO, with fortification of beta-carotene, the precursor of vitamin-A. The human body then converts beta carotene into Vitamin-A. This yellow colored GMO rice with beta-carotene is also known as the golden rice.

Golden rice was created by transforming rice with two beta-carotene biosynthesis genes, namely:

1. psy (phytoene synthase) from daffodil

2. crtI (phytoene desaturase) from the soil bacterium Erwinia uredovora

The psy and crtI genes are expressed in the endosperm. The psy gene transforms geranylgeranyl-PP to phytoene & 2-pyrophosphate. The crtl gene completes the pathway, catalyzing multiple steps in the synthesis of carotenoids up to lycopene. The plant's endogenous enzyme lycopene cyclase processes lycopene to beta-carotene in the endosperm, giving rice the distinctive yellow color.

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Increase resistance to diseases

Mad cow disease or BSE in short has killed thousands of cattle in the 1980s and 1990s. It is a progressive neurological disease causing brain and nervous system damages leading to increased aggression, nervousness and eventually death. From the word spongiform, we know that BSE causes a sponge-like and holes condition in the cow’s brain. During the peak in 1993, almost 1000 new cattle were infected each week. In rare cases, BSE has infected humans. The human form is called variant Creutzfeldt-Jacob disease, with symptoms such as trembling, dementia, trouble walking and eventually a coma.

At experimental stages, cattle have been genetically engineered to exhibit resistance to mad cow disease. BSE is caused by a prior, which are proteins that are naturally produced in animals. However, an abnormal form of prion causes uncontrolled folding of other proteins in the brain of cows, leading to neurological disorders. As this disease targets a particular protein in the brain, the initial idea was to produce cows that simply will not have this targeted protein, by disabling or knocking out the gene for the protein. A first dozen calves were produced as announced by The U.S. Department of Agriculture's Agricultural Research Service in 2007, all lacking brain protein. In theory, these cloned cows, without this gene could not get the disease or transmit it.

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Increase yield

Developers of the fast-growing genetically engineered salmon first applied for approval with the United States (US) Food and Drug Administration (FDA) in 1995. In 2019, the FDA clears the final regulatory hurdle to allow sale of AquAdvantage salmon.

Canadian researchers created the fast-growing genetically engineered salmon with a growth hormone gene from Chinook salmon and a gene promoter from ocean pout. Researchers microinjected the transgene into fertilized eggs of wild Atlantic salmon. The promoter from pout was chosen because the genes it controls are continuously expressed, as compared to the salmon promoter for growth hormone, which is only expressed under certain favorable environmental conditions.

Even though the inserted growth hormone gene is always expressed, it doesn’t have much of an effect unless the fish have access to food. Under conditions of sufficient foods, juvenile AquAdvantage salmon can grow nearly 3 times longer than conventional juvenile Atlantic salmon.

While AquAdvantage salmon grows faster, they do not grow larger overall. The adult AquAdvantage salmon and adult conventional Atlantic salmon are the same size. The genetically engineered fish just get to that size faster and thus, reduce the need for more feed. The overall total amount of feed required to produce the same fish weight was reduced by 25% for AquAdvantage salmon.

Increase resistance to environmental changes

Drought is one of the largest environmental factors leading to reduced crop yields. Approximately one-third of the Earth’s land area lacks sufficient water supply, and this is aggravated by widespread water pollution and unpredictable climatic change. Agricultural drought causes much damage such as reducing plant and crop production attributed to reduced leaf size, stem extension and root proliferation, and also disturbing plant water and nutrient relations. For example, the average annual yield loss of maize attributed to drought is approximately 15 % while drought reduces annual soybean yield by approximately 40 %. During periods of severe drought, these losses can be much higher and can potentially result in complete crop failure. Obviously, drought is currently the leading threat to the world’s food security. It is a big challenge to achieve an average annual increase in cereal production of 44 million metric tons per year for meeting the demand of 9 billion people by 2050.

Thus, developing crops that grow and thrive with limited water is crucial to maintain plant growth and productivity. In addition, drought-tolerant crops can be cultured in drought susceptible areas, thereby expanding the area for agricultural production.

During the development of corn, it is crucial that each kernel or corn has a milky inner fluid that changes to a "doughy" consistency due to continuous starch accumulation in the endosperm. This starchy and moisture content relationship will determine the final yield of kernel weight upon maturity. Stressors such as drought cause biomass losses due to grain filling losses but this can be partially compensated for if sufficient rains return. Prolonged drought stress however, leads to the abortion of individual grains known as kernel abortion, with an irreversible impact on yield.

Drought tolerant corn contains the gene for “cold shock protein B” or cspB, isolated from the bacteria Bacillus subtilis. From the name, we know that cold shock proteins were named so due to their ability to rapidly accumulate in cold shocked bacterial cells. These proteins help to maintain normal physiological performance during stress events such as drought, so that cells can function and grow normally. Upon exposure to drought stress right after flowering, when cereals are most susceptible to yield losses, non GMO maize suffered from a 50% reduction in growth rate relative as compared to a well-watered control, while maize with the cspB gene exhibited a 24% increase in growth rate. While non GMO maize suffered from kernel abortion, maize with the cspB gene had a 11.7% increase in the number of kernels per plant. Thus, the GMO corn had less kernel abortion, a very important component of yield loss under drought. Drought tolerant maize also provides extra 9 months of food for farming families in Zimbabwe.

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Resistance towards herbicides

Soybean is a very important crop. While soybean is a crucial ingredient in most Asian diets, soybean also covers 70% of vegetable proteins used for the production of animal feed. In order to plant soybean successfully, weed control is crucial. Prior to sowing soybeans in the soil, weeds need to be removed from the soil. Normally, farmers will plough the land, traditionally via manual methods and now using machines. However, ploughing land can cause soil erosion leading to some loss in soil nutrients as well. Thus, GM soybeans were produced to tolerate herbicides. When a farmer sprays herbicides to remove weeds, the soybean plants are not damaged altogether. Without the need for excessive ploughing, soil erosion is prevented and the soil remains nutritious in more planting cycles.

The herbicide tolerance of soybean plant is also commonly known as glyphosate herbicide tolerance, where soybean plants express a glyphosate-tolerant form of the plant enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) isolated from the soil bacterium Agrobacterium tumefaciens CP4.

In 2019, the world was introduced to a new threat - Covid-19. This virus, which would go on to cause a global pandemic, brought the concept of viruses into sharp focus for many people. A virus is a microscopic infectious agent that can only replicate inside the living cells of a host organism. It is made up of genetic material, either DNA or RNA, surrounded by a protein coat. Viruses are obligate intracellular parasites, meaning they rely entirely on the host's cellular machinery to reproduce. They hijack the host's cells, using them to create more copies of themselves, which can then infect other cells. This process often leads to damage to the host's tissues and the onset of various symptoms. In the case of Covid-19, the virus primarily targets the respiratory system, causing a range of symptoms from mild cold-like symptoms to severe respiratory distress and even death in some cases. The emergence of Covid-19 in 2019 served as a stark reminder of the power and potential danger of viruses, highlighting the importance of understanding these tiny yet potent pathogens.