Author Archives: jackson kuan

A Breakthrough in Antibiotic Development

Did you know that not all types of bacteria in this world are harmful to humans? Some bacteria can be used in the production of cheese, and can even be used to manufacture antibiotics for human use. Dr. Jason Hedges and Dr. Katherine Ryan of the University of British Columbia took a look into finding new ways to produce antibiotics from bacteria. 

Their recent publication in 2019 showed how they were able to convert an amino acid (a building block of proteins) into a modern day antibiotic.

Antibiotics are used to cure bacterial infections by killing bacteria. For example,  an antibiotic called penicillin was used extensively in the 19th century to save thousands of lives.

As Amazing as they Sound, Antibiotics are not a Permanent Solution

The over-usage of antibiotics results in bacteria that can build resistance to them and cause the medication to be ineffective. 

The World Health Organization announced: “A serious threat is no longer a prediction for the future, it is happening right now in every region of the world and has the potential to affect anyone” on development of drug resistant bacteria.

Once a type of bacteria develops a resistance to a specific antibiotic, other antibiotics must be used in its place to treat the infection. 

Nitroimidazoles are a group of antibiotics which have been used for decades. Due to its low resistance by bacteria, it has been used extensively to treat bacteria that have developed a resistance to certain antibiotics.

This is the chemical structure of azomycin. Azomycin is a type of antibiotic that falls under the family of antibiotics labelled nitroimidazoles. It is used to treat drug resistant bacteria.

Diving into the Research

The researchers used bioinformatics, a data analysis tool, to find all previous work that has been done on this topic. Bioinformatic searches are performed on databases such as the NCBI.

They found that back in 1953, azomycin (a type of nitroimidazole) was produced by a strain of bacteria that is found in the soil. The researchers adapted this old method by applying modern techniques to it, in an attempt to produce azomycin in a different strain of soil bacteria called Streptomyces cattleya.

The two researchers aimed to find new ways to synthesize azomycin, and proposed that it could be done by using an amino acid called arginine. Once a pathway connecting arginine to azomycin had been developed, their end goal was to synthesize and extract azomycin in Streptomyces cattleya.

Hedges and Ryan were able to develop a multi-step pathway for the conversion of arginine to azomycin through experimentation. However, they were unable to detect any azomycin in the bacteria itself.

They noted that the bacteria of interest was unable to synthesize azomycin, and a separate drug or antibiotic may have produced in its place.

A simplified overview of converting an amino acid (Arginine) into an antibiotic drug (Azomycin).

A Bright Future

The significance of this research transcends the synthesis of azomycin. Although they failed to detect azomycin in Streptomyces cattleya, their work provides a stepping stone for further research to be conducted. 

This study provides insight on new biosynthetic pathways which is important to those currently in the field of life sciences and pharmacology. 

Furthermore, this study expands people’s knowledge of bacteria engineering and how antibiotics are created.

In the near future, researchers could test their synthetic pathway on other bacteria such as E. coli to determine if azomycin could be produced. This will allow for the production of more antibiotics, or even the discovery of new antibiotics.

 

Reference:

Hedges, J. B.; Ryan, K. S. In Vitro Reconstitution of the Biosynthetic Pathway to the Nitroimidazole Antibiotic Azomycin. Angewandte Chemie International Edition 201958 (34), 11647–11651.

 

– Adrian Emata, Vicky Gu, Jackson Kuan, Yicheng Zhu

Bacteria: Friend or Foe?

Did you know that not all bacteria is bad? In some cases, they cause diarrhea, stomach ulcers, and even intestinal diseases. However, what if I told you scientists have found a way to manufacture antibiotics that are used to treat these bacterial infections from bacteria themselves?

Scanning Electron Microscope view of bacteria. Retrieved from: NYTIMES

Dr. Jason Hedges and Dr. Katherine Ryan of the University of British Columbia took a look into finding new enzymatic pathways for synthesizing nitroimidazole, which is a component in the antibiotic, azomycin.

So what is the point of this whole process and why do we even want to use bacteria to synthesize antibiotics?

By finding more ways to develop antibiotics from bacteria, this improves our knowledge on biosynthetic pathways. This is beneficial not only for the scientific community, but for the public as well. As bacteria develop resistances to antibiotics over time, the discovery of new antibiotics would be able to treat more patients suffering from bacterial infections.

How is this done?

Now how could something that sounds so complex be done? Let us take a look at their process step-by-step.

Like all scientists do, background research was performed to see how previous scientists went about finding ways to develop antibiotics from bacteria. To do so, a bioinformatics search was performed. Bioinformatics is essentially ‘googling’ information about a certain topic, but in this case, they would be using a scientific database such as the National Centre for Biotechnology Information (NCBI).

A cryptic gene cluster was found in the bacterial strain Streptomyces cattleya. This along with various enzymes were the main points of interest. Their goal was to use L-arginine; a fundamental building block of proteins, and find a way to convert this into nitroimizadole (a component of the antibiotic, azomycin

Theoretically, a blueprint on how L-arginine would be converted to nitroimidazole was developed. However, experiments must be conducted to see if the pathway would work in real life, and not just on paper.

Figure 1 – Biosynthetic pathway towards nitroimidazole. Retrieved from: Hedges and Ryan, 2019

Through experimentation, the pathway as shown in figure 1 was deemed to have synthesized nitroimidazole successfully. The next step was to determine whether or not azomycin could be synthesized from Streptomyces cattleya. Unfortunately, they were unsuccessful in detecting any levels of nitroimidazole in the bacteria samples. They concluded that potentially a different molecule had been synthesized, or that this specific gene cluster is silent (inactivate).

Although Hedges and Ryan were unable to find a definitive pathway to synthesizing azomycin utilizing bacteria, their work was able to disprove aa few reaction schemes in the scientific community, allowing for further research to be conducted.

Science is not always about success. In science, you must fail in order to succeed. Their work provides a stepping stone into further scientific research such a finding other biosynthetic pathways in the synthesis of other antibiotics.

 

Literature Cited:

Hedges, J. B.; Ryan, K. S. In Vitro Reconstitution of the Biosynthetic Pathway to the Nitroimidazole Antibiotic Azomycin. Angewandte Chemie International Edition 201958 (34), 11647–11651.

-Jackson Kuan

Eat with your… Environment?

We have all heard about eating with our eyes first, but no one ever talks about how our environment affects our meals. Mother Nature Network (MNN) indicate that your environment plays big factor in your perception of food. Whether it’s lighting, furniture, or noise, they all play a role.

Figure 1 – Chocolate Ice Cream Retrived from: HandletheHeat

This study published in October 2019 explored temporal changes in how chocolate ice cream was perceived when eaten at different locations. Each participant had their electrophysisological properties, emotions, and temporal changes in flavour monitored, with 5 minute breaks inbetween each measurement. The participants were randomly assigned different environments such as a university study area, a bus stop, a cafe, or a sensory testing laboratory.

Figure 2 – The 4 locations in which tests were conducted. A – Sensory testing laboratory B – University study area C – Bus stop D – Cafe Retrieved from: Figure 2 of Xu et al.

Electrophysiological Responses

3 electrophysiological responses were measured, including skin conductance (SC), blood volume pulse (BVP), and heart rate (HR). They found that SC and HR was significantly influenced by different environments. Using the Tukey-Kramer test, they found that eating chocolate ice cream in the study space compared to the laboratory significantly increases SC (F(3,156) = 3.149, p < 0.05). Furthermore, the HR was significantly lower after consumption in the study area compared to a bus stop (F(3,156) = 2.673, p < 0.05).

Figure 3 – Electrophysiological response measurements. n= 160 (50 males/110 females) Retrieved from: Figure 10 Xu et al.

Emotional Response

In a pilot study, the emotional responses were reported among 97 individuals. Positive emotions were noted such as happiness, cheerfulness, and joy. In addition, negative emotions were noted as well, such as tenseness, unhappiness, and anxiousness. Using a Cochran Q-test, they found that a significant number of negative emotions were associated with the bus stop compared to the other 3 environments. Furthermore, a significant number of positive emotions were expressed after consuming chocolate ice cream at a cafe or university compared to a bus stop.

Figure 4 – Both positive and negative emotions associated with eating chocolate ice cream in 4 different environments. Data adapted from: Xu et al.

Taste

The dominance of different attributes were measured and converted to a percentage of time it spent as a dominant factor. Sweetness the dominant attribute across all environments (46% lab, 33% university, 48% cafe, 38% bus stop). Interestingly, the dominance of sweetness subsided overtime, and other attributes became dominant. Other factors such as creaminess, roastedness, and bitterness was noted as well. At the bus stop, bitterness became the most dominant factor after sweetness, while the other 3 locations reported either creaminess, cocoa, or vanilla flavours were dominant.

How do I improve my next meal?

Next time you’re at the dinner table, try some of these tricks to improve the taste of your meal. By listening to higher pitched music, sour and sweet flavours are highlighted, while lower pitched music enhances bitter flavours. Even something as simple as the way food is arranged on the plate will impact its flavour.

-Jackson Kuan

Deep Brain Stimulation on Patients with Parkinson Disease

Deep Brain Stimulation (DBS) is a form of neurological stimulation and is used as a form of treatment for those suffering from Parkinson’s Diesease (PD). PD is a neurodegenerative brain disorder which hinders dopaminergic neurons, resulting in impaired mobility. DBS involves a surgical process of implanting a small battery operated device and a electrodes into the brain.

Figure 1 – Deep Brain Stimulation Retrieved from – GAPS

This study published in August 2006 highlights the efficacy of DBS. 156 patients were randomly paired (78 pairs) and were subjected to different treatments. One was subjected to treatment from pharmaceuticals and the other underwent DBS. To test the efficacy of DBS, the patients’ quality of life was assessed using the Parkinson’s Disease Questionaire (PDQ-39). Additionally, numerous symptoms associated with PD were measured using the Unified Parkinson’s Disease Rating Scale, part III (UPDRS-III).

Efficacy of DBS

Out of the 78 pairs of patients, the patient who underwent DBS in 50 of the pairs saw an improvement in their PDQ-39 and UPDRS-III scores compared to their partner who was only provided with pharmaceutical drugs.

Figure 2 – How DBS and Pharmaceuticals affected the PDQ-39 and UPDRS-III scores in patients immediately after treatment. In 50 of the 78 pairs, those who underwent DBS showed improvement in their scores compared to their partners who took medication. Data from Deuschl et al.

Furthermore, the patients were assessed again in six months. Those who underwent DBS saw a 25% increase (a lower score) to their PDQ-39 score, while there we no significant changes to those who took medication.

Figure 3 – PDQ-39 Scores immediately after treatment (baseline), and 6 months after treatment. Error Bars represent standard deviation. Data adapted from Table 3 of Deuschl et al.

Benefit of DBS Compared to Medication on Treating Depression

There are additional benefits of DBS on other aspects of PD. This study published in March of 2005 highlights how DBS is able to treat depression, which is a symptom associated with PD. Patients who were treated by DBS noted a decrease in depression-like symptoms 1 month after treatment, and up to 1 year. In contrast, medication can only treat depression in the short-term.

Figure 4 – A visual interpretation of depression Retrieved from – ConsumerReport

So why is DBS better than Prescription Medication?

The results of both studies indicate that DBS is capable to treating PD with a higher efficacy compared to medication. Additionally, medication is kept constant and can be used to treat one specific issue. In contrast, the strength of DBS can be altered (stronger/weaker pulses) to treat different symptoms that may arise. Consequently, DBS results in long-term benefits, while medication is only able to provide short-term benefits.

-Jackson Kuan

A Bright and Sunny Future – Revised

Dye-Sensitized Solar Cells (DSSCs) are efficient and with low manufacturing costs, they are an ideal solution to our need for sustainable energy. This paper published in October 2012 reviews the fundamentals of DSSCs.

A DSSC. Retrieved from: engadget

DSSCs utilize sunlight as its source of energy, which is converted into usuable energy. It contains a light sensitizer connected to a semiconductor that faciliates the excitation of electrons which are able to enter a series of redox reactions. The continuous cycle of electrons through the circuit generates energy which can be used in our daily lives, or for other practical uses within industries.

In a separate study published in October 2019, Huang et al. proposed to optimize the counter electrode (CE) from a Pt CE, to a 2D nanosheet composed of Co-Ni-Se. This turned out to be successful as the Co-Ni-Se complex catalyzes the reduction of the I3electrolyte more effectively compared to the traditional Pt CE that is typically used. This increases the rate at which energy is generated and stored for industrial or personal use.

Schematic Diagram of a DSSC. Retrieved from: Gamry

How can this be applied to us in everyday life?

DSSCs can be installed on the roof of our houses to supply electricity during the day. This decreases our dependency on fossil fuels for energy, which are harmful to both terrestrial and marine life. It can also be used to generate energy and be stored within a battery pack for portable charging of cellular devices.

DSSCs on the Roofs of Buildings. – Retrieved from RedNewsWire

Why Should we Invest in DSSCs?

The U.S Energy Information Administration (EIA) projects that energy consumption will increase by approximately 28.6% between 2020 and 2050. This increases the demand for sustainable energy along with the depletion and harmful environmental effects of fossil fuels. Solar energy is an abundant and clean source of energy which makes photovoltaics such as DSSCs a desirable product. More money should be allocated for the research and development of DSSCs as they may be the solution to our energy crisis in the long term.

– Jackson Kuan

A Bright and Sunny Future

Climate change has been a hot topic throughout the latter half of the decade, and one of the questions is how do we create sustainable energy. This study published in October 2019 indicated that the solution may come from the development of Dye-Sensitized Solar Cells (DSSCs). DSSCs are efficient and with low manufacturing costs, they make the ideal source for sustainable energy. This research group highlights a strategy of controlled synthesis of hierarchical materials, thus providing new applications to the development of sustainable energy products.

A DSSC Retrieved from: engadget

DSSCs utilize sunlight as its source of energy, which is then converted into usuable energy. Within its compartments, it contains a light sensitizer which is connected to a semiconductor that faciliates the excitation of electrons which are able to enter a series of redox reactions. The continuous cycle of electrons through the circuit generates energy which can be used in our daily lives, or for other practical uses within industries. Huang et al., proposed to optimize the counter electrode (CE) that is present from a Pt CE, with a 2D nanosheet composed of Co-Ni-Se. This turned out to be successful as the Co-Ni-Se complex catalyzes the reduction of I3- electrolyte more effectively compared the traditional Pt CE that is typically used.

Schematic Diagram of a DSSC. Retrieved from: Research Gate Figure 2.

How can this be applied to us in everyday life?

Currently, greenhouse gases release CO2 into the atmosphere causing the earth to warm, and  subsequently acidifying the ocean affecting marine life as well. As a society, we must be more conscious of our carbon footprint as all our decisions have an environmental impact. DSSCs can be installed on the roofs of our houses to supply electricity during the day, instead of relying on sources like fossil fuels for energy. It can also be used to generate energy and stored within a battery pack for portable charging of cellular devices.

It is not difficult to find alternatives to our current problems to climate change, and one aspect more money should be invested in is the research and development of sustainable and renewable energy sources.

– Jackson Kuan