Scientific Scribbles

The voice of UniMelb Science Communication students

Are You Ready to Eat the Lab-Grown Meat?

Photo by Drew Hays on Unsplash

Are you struggling to eat less or no meat for a more sustainable lifestyle even though you really enjoy the taste of cheeseburger and fried chicken? If the meat is cultured in a lab, producing less greenhouse gases but tasting just like the real meat, will you have it instead?

 

In 2013, a Dutch team of scientists claimed to have produced the first burger made by the meat grown in a lab. After that, more industries, like Yyson Foods, one of the biggest US meat processors, have started to invest in the lab-grown meat. It’s very likely that you can find it on the shelf soon when you’re shopping in your favourite supermarket.

 

What is lab-grown meat and why should we care?

It’s always reasonable to ask what the product is and what the benefits are before buying something new.

 

Lab-grown meat, also known as clean meat or cultured meat, refers to the way to produce animal protein by growing stem cells collected from animal tissue in a medium. Without harming any animals, the process cultivates stem cells into a mass of muscle tissue ready to be consumed.

 

The process may sound weird, but how does it taste anyway? A lady who has tried the cultured chicken in some lab said it tasted like a real chicken nugget. You can find more here.

 

So, what benefits can we obtain from consuming lab-grown meat?

 

According to FAO’s report, about 18% of total greenhouse gas (GHG) emissions were produced in the process of farming livestock. Around 80% of all agricultural land are used for grazing and feed production. Problems, like global warming, deforestation, water pollution, and food insufficiency, becomes increasingly severe with the growing demand for meat products.

Meat products in Aldi, by Yue Li

But imagine if most of us shift from eating real meat to eating lab-grown meat, what will happen? Theoretically, we can get more land to produce food to serve ourselves directly whilst producing less GHG emissions, especially methane. We may also not need to worry about animal welfare.

 

It does sound like a good option, isn’t it? Some scientists from University of Oxford would say hang on, it’s not the whole picture.

 

The magic cure or the Pandora’s box? The answer is unknown.

Researchers from University of Oxford argued in the long term, cattle farming in some cases may cause far less warming than cultivating the meat.

 

Because most of GHG emissions produced by cattle industries are methane which can only remain in the atmosphere for 12 years, while the carbon dioxide emitted in the process of manufacturing lab-grown meat will persist and accumulate for millennia. If the lab-grown meat production is energy intensive, the situation can go much worse.

 

Furthermore, since the lab-grown meat is so new, there’s few information about its health outcomes. What nutrients does it contain or lack? We don’t know the answer.

 

As scientists are still exploring ways to manufacture lab-grown mean fast and cheaper, we’ll look forward to more findings about the environmental impacts and health outcomes of the lab-grown meat from third-party organisations before we make decisions.


Circadian Rhythms – The Plants’ Events Calendar

We all know that plants don’t flower until a certain time of year, but have you ever wondered how they tell when the time is right?

The answer is circadian rhythms – a method of tracking time as it passes, through a process of hormones being released. In particular, the time a plant flowers is determined by what’s called a coincidence model.

It can be hard to wrap your head around at first, so to start, I’m going to use a metaphor.

I like to think of the plant as a baker, who will make a cake if he has the chance. Each day when the sun rises, he sets off town, which is twelve hours away. The shop with cake ingredients opens when the sun rises, and closes when the sun sets, regardless of time. On short winter days, the shop is closed by the time the baker reaches it. However, once the days start to lengthen, the shop is still open and he can buy his ingredients. When the baker and the ingredients are in the same place at the same time, a cake can be made. The baker will continue to make a cake every day with the ingredients he buys, until the days get shorter again and the shop is closed when he reaches it. Then he will have to wait until the next year to start making cakes again.

Now, how is this strange and fairly unrealistic story relevant? I’ll explain.

Every day when the sun rises, the plant begins producing a molecule called CO-mRNA (the baker). By the time twelve hours have passed, there is enough CO-mRNA to make proteins (he’s reached the town). However, it can only make proteins if the plant is still receiving energy from sunlight (the shop is open). If there is no sunlight after twelve hours, the CO-mRNA will degrade (the baker goes home empty-handed). If there is sunlight, however, the CO protein will be produced, which in turn leads to the production of another molecule called FT-mRNA (the cake is made).

 

What’s so special about FT-mRNA being produced? Well, FT-mRNA acts as a messenger, and once it’s created, it travels to the tips of the plant’s shoots and tells the cells there that it’s time for flowering to start. In response, the cells begin to change their purpose from growing taller to producing buds. Over time, the buds grow and develop into flowers, which open once they are ready.

All of this is reliant on FT-mRNA being made, which can only happen during long days when there is more sunlight. Hence the name coincidence model – the presence of enough CO-mRNA and the presence of sunlight need to coincide for the signal to be sent.

 

(image created by author)

(edit: I don’t know why it made the image so tiny, I’m trying to fix it!)


Who is the biggest winner under climate change?

Bigfin Reef Squid Sepioteuthis lessoniana.(Source: Montereybayaquarium)

The water temperature in oceans or seas rises by 2 degree along with global warming. Two degrees higher in oceans and seas for aquatic organisms are more similar to two degrees higher of our body temperature.  So how about organisms soaking in the seas? Are they suffering?

A herd of scientists are doing research on the conditions of ‘arm monsters’ – cuttlefish. New scientific evidence shows that cuttlefish still live a good life, even though the earth is facing dramatic climate change.  They are less likely to die out and they can even exist longer than human beings.

Some marine biologists assumed that cuttlefish will suffer with the increase in the concentration of CO2 in oceans. This idea makes some sense because marine water is acidised with the increasing concentration of CO2 and cuttlefish are very sensitive to pH in the water. Acidised marine environment might make cuttlefish lack oxygen supply.

Acidised Marine Environment. (Source: National geographic)

The latest research finding, however, shows cuttlefish may be flourishing when facing global warming. Researchers did experiments on how cuttlefish will be influenced by the concentration of CO2 in oceans. They chose two tropic cuttlefish species, Tropical Pygmy Squid Idiosepius pygmaeus and Bigfin Reef Squid Sepioteuthis lessoniana and caught some for research purposes. These cuttlefish were fed in different water containers with different concentration of CO2.

Scientists found that high CO2 concentration did not affect the performance of aerobic exercise and the recovery after strenuous exercise among examined cuttlefish. The development of these cuttlefish might be prosperous in changing ecosystems according to the results. At least, foraging process may be easier for cuttlefish, if both their predators and prey get injured by climate change.

We may witness some species that can be adaptive to climate change quickly and cuttlefish may benefit the most from global warming!


Will You Choose “Artificial Meat”?

What do you usually think when you walk into a burger fast food restaurant? Double-layered patties with bacon and cheese? Fried chicken drumsticks wrapped in bread crumbs? Or climate change and ecological protection? Maybe you would not think about the last point, but perhaps we should begin to think about it now.

 

Recently, the fast food brand “Burger King” has launched a giant beef burger made by “artificial meat” in more than 7,000 stores. According to market research firm reports, Burger King’s customers in April was increased by 18.5%. So what is “artificial meat” and why it becomes popular?

Image by JESHOOTS.com via stocksnap

 

What is “artificial meat”?

The “artificial meat” burger is close to the traditional meat burger, and its appearance and taste are also similar to conventional meat. In terms of composition, artificial meat is mainly divided into two types.

 

One is “plant-based meat”, which is made of plant protein such as soybean. Also, it uses plant materials to imitate the taste and even the nutritional value of meat. “Plant-based meat” has even been welcomed by vegetarians. The other is made from animal stem cells called “Lab-grown meat“. Using cell culture techniques, directly culture the muscle cells and fat cells of the animal to form food. Although this “Lab-grown meat” is real meat, it is not growing on animals, but are cultivated in the laboratory.

No animal required, but would people eat artificial meat? By Clive Phillips & Matti Wilks via freepik

 

So which kind of “artificial meat” is introduced by Burger King? It belongs to the upgraded version of “plant-based meat”. Food developers use the right combination of protein and fat to achieve the flavour and mouthfeel of protein and fat in beef. To imitate the taste, they added some modified wheat starch and potato starch as well.

 

Why do we eat “artificial meat”?

First, to protect the environment. Replacing real meat with “artificial meat” can save resources and reduce greenhouse gas emissions. The artificial meat product strips out the basic components of the meat: protein, fat, water and trace minerals. After that, it rebuilds the meat through the plants, so it has only a small impact on the environment.

 

Specifically, the water use in the production of “artificial meat” is 75%-99% lower than that of ordinary burgers. Also, the use of land is reduced by 93-95%, and greenhouse gas emissions are reduced by 87-90%. The energy consumed is almost halved as well.

 

Studies have shown that livestock carbon emissions are staggering, and evidence from the FAO shows that livestock emissions account for 14.5% of global emissions. If all cows lived into one country, it will be the third-largest emitter of greenhouse gases in the world.

Image by Lucas Allmann via stocksnap

 

Besides, the livestock industry needs to consume a lot of water. A beef burger weighing about a quarter of a pound used an average of 1,695 litres of water during production from scratch, which includes all aspects of planting food, animal husbandry and treating beef. However, our demand for meat is still rising. The FAO pointed out that global meat consumption is expected to increase by 76% by 2050. Unless we change our behaviour from now on, we will have to pay a large environment and human resources costs.

 

Second, it is for health. Although the meat is delicious, overeating can cause high blood pressure, high blood fat and other diseases. “Artificial meat” made from plant proteins such as soybeans contains low levels of cholesterol. With the continuous improvement of living standards, people’s health awareness has also been improving. Many people have become staunch vegetarians for their health.

 

“Artificial meat” is healthier than the traditional one, because it contains lower energy and fat content, higher protein content, and contains heme iron, calcium, and B vitamins in meat. Therefore, the nutritional structure of vegetarian meat is more reasonable than traditional meat.

 

However, the technology of making “artificial meat” is still needed to be improved. The human can only make minced meat, which is used to make burger patties, sausages, meatballs in current technology, but can not make more advanced food. Now many food research and development companies are developing a whole piece of “artificial meat” technology, and hope that they can make a breakthrough as soon as possible.


THE CURE for HIV by gene editing? On the way.

 

Out of millions of people with HIV, only two patients are cured up to date. The current treatment can only limit the HIV level to undetectable level, but not eradicate it completely from your body. It is extremely difficult to eliminate HIV from your body.

 

Why so challenging?

The human immunodeficiency virus (HIV) belongs to a group called retrovirus. This group of viruses inserts their genome into the genome of their host and then starts replicating. After the insertion, the viruses have become a part of your genome in the infected cell just like a spy! The inserted viral genome is composed of the same material as your own. The inserted virus can hide in your own cells until for your immune defence is impaired. As you may tell straightaway, it is challenging to target the inserted viral genome specifically. Furthermore, HIV infects a type of critical cells of your immune system. Without the help of the powerful immune system, HIV is particularly difficult to be cured.

 

How HIV patients survive?

The current treatment is called antiretroviral therapy (ART). The drugs in ART target the replication of HIV by blocking functions of HIV essential proteins required for its lifecycle. ART is extremely effective for reducing active viral load and can prolong the expected life span of the patients effectively. However, ART can only target active viruses rather than the dormant viruses inside your cells. Therefore, once you stop taking ART drugs, HIV will take over your body in just a few weeks. Moreover, ART drugs are to be taken daily. It is not only expensive for life long usage but also has a range of side effects that will impair your life quality.

 

Credit: Ernesto del Aguila III, National Human Genome Research Institute, NIH via Flickr

 

What has been found by researchers?

The researchers have eradicated the inserted HIV genome in humanized mice, published in Nature Communications. They utilised a combination of long-acting slow-effective release ART and CRISPR-Cas9 to achieve the elimination. CRISPR is a DNA sequence that recognises DNA of the bacteriophage. The Cas9 is a protein that cleaves the DNA sequence recognised by the CRISPR. This combination serves as the immune system of the bacteria. The CRISPR-Cas9 system itself is unable to catch up the replication speed of HIV, this is where the ART intervenes. The ART can limit the replication of HIV effectively and leaving dormant HIV. Then the CRISPR-Cas9 can find the dormant viruses precisely and ‘kills’ the viruses. The HIV loads of some mice are remained undetectable after stopping the ART. This means the eradication of HIV is achievable! This new treatment is proceeding to be tested by experiments on the primate, where the biology is more related to the human.

 

Too good to be true?

Although this research points out a promising method for the eradication of HIV, there are still a considerable amount of problems to be solved. Two major problems are the off-target effect and mutations of HIV genes. The off-target effect is a problem for using CRISPR gene editing technique. The target gene sequence and the other gene sequences can be very similar. The CRISPR confuses the target gene and the ‘innocent’ genes. The off-target effect is too hard to predict because it is a random process. This effect sometimes can generate serious problems. The CRISPR-Cas9 system may increase the chance of getting cancer in the worst scenario. Furthermore, the HIV makes ‘mistakes’ itself during the replication called mutation. The mutation of the target gene can make it unable to be recognised by CRISPR anymore. These HIV viruses can escape from the fate of being eliminated in this way.

 

Anyway, it is still a long way to go to win the combat between human and HIV, but the future is bright. “These findings do provide a new reason for increased hope that an actual cure may ultimately be found”, said Dr Francis Collins, director of the National Institutes of Health (NIH) in Bethesda, Maryland, United States.

 

Links to the research paper published in Nature Communications:

https://www.nature.com/articles/s41467-019-10366-y

 


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