South Africa and Kenya top tourist arrivals for Zanzibar in December 2024

Travel

Unguja. South Africa and Kenya have emerged as key tourist sources for Zanzibar in the month of December 2024 after the two emerged second and sixth respectively, as Italy maintained the number one spot.

Zanzibar’s tourism sector experienced a remarkable surge in December 2024, welcoming 91,611 international visitors, marking a significant 30.5 percent increase from the 70,186 recorded in the same month of 2023.

The increase reflects not only an uptick in global travel but also a 36.6 percent rise compared to the previous month, November 2024.

The latest statistics, released by the Office of the Chief Government Statistician and the Zanzibar Commission for Tourism, show that Europe remains the leading source of international visitors, accounting for 68.1 percent of arrivals.

Italian tourists led the charge, comprising 13.7 percent (12,552) of all visitors. However, African nations South Africa and Kenya also played a pivotal role in driving growth.

South Africa emerged as the second-largest market, contributing 7,252 visitors (7.9 percent), while Kenya followed closely, securing the sixth spot with 4,260 visitors (4.7 percent).

Notably, the majority of international visitors—89.7 percent—arrived by air. A total of 82,154 visitors flew into Zanzibar’s Abeid Amaan Karume International Airport during the month, with 69,779 arriving on international flights and 12,375 on domestic flights.

The remaining visitors (9,457) entered through the seaport, with 1,332 arriving by cruise ship and 8,125 by sea ferry from mainland Tanzania.

The primary motivation for travel remained leisure, with 99.2 percent of visitors coming for holidays. Only a small proportion traveled to visit friends and relatives (0.4 percent) or for other reasons (0.4 percent). Gender-wise, the island saw a higher proportion of female visitors, who made up 55.7 percent of the arrivals, compared to 44.3 percent male visitors.

Zanzibar’s tourism continues to attract working-age travelers, with 84.1 percent of visitors aged between 15 and 64. Children under 15 years accounted for 10 percent of visitors, and retirees aged 65 and older made up 5.9 percent.

Emerging markets also showed strong growth, with countries such as Poland, India, Russia, Israel, China, and Ukraine collectively recording a 26.6 percent increase in arrivals compared to December 2023.

Visitors in December 2024 stayed an average of 8 days, with 22.9 percent spending seven days on the island. The demand for accommodation remained robust, with Zanzibar’s hotels achieving an impressive bed occupancy rate of 92.4 percent, as 720,102 out of 779,216 available bed spaces were sold.

With its diverse visitor profile, Zanzibar’s tourism sector is well-positioned for continued growth, particularly as it draws an increasing number of tourists from both established markets in Europe and Africa, as well as from emerging economies.

Updated travel warnings issued for these 2 popular tourist destinations

Travel

STATEN ISLAND, N.Y. — Due to violent crime, the U.S Department of State has updated two travel notices for popular Central American tourist destinations.Travel advisories for Guatemala andBelize were issued in late December due to “violent crime” involving gangs, robbery and drug trafficking, according to the U.S Department of State.Guatemala remains under a level 3 “reconsider travel” alert, the second-highest warning delivered by the Department of State.Belize is under a level 2 “exercise increased caution” category. There, sexual assault, home invasions, armed robberies and murder are common even during the day and in tourist areas, the alert warned.Guatemala advisoryThose who plan to visit Guatemala are urged to reconsider, as several areas of the country “have problems with gangs, robbery, carjacking, drug trafficking and violence,” the State Department warned.“Local law enforcement may not always respond well to serious crimes, leading to low arrest and conviction rates,” the department said in its advisory.Tourists are not usually targeted, but they can still become victims of “opportunistic crimes,” according to the State Department.Areas of the country under a “Level 4: Do Not Travel” advisory include the San Marcos Department, Huehuetenango Department, Zone 18 in Guatemala City and Villa Nueva.People can still visit popular locations, such as Tikal, Antigua, Lake Atitlán and the Pacific coast areas in Santa Rosa and Escuintla, the advisory noted.Belize advisory Travelers are advised to exercise increased caution due to crime, and some areas of the country have an increased risk for violent crimes.The State Department warned travelers that violent crimes — including sexual assault, home invasions, armed robberies and murder — are common in Belize, even in broad daylight and in tourist areas.A “significant portion” of these crimes are gang related, the advisory said. And most crimes go unresolved by local police, as they “lack the resources and training” to respond effectively, it said.The State Department strongly encouraged travelers to be especially cautious when traveling to the south side of Belize City.People traveling to Belize are advised to:Be aware of their surroundingsAvoid walking or driving at nightNot to resist any robbery attemptBe vigilant when visiting ATMsRefrain from showing any signs of wealthEnroll in the Smart Traveler Enrollment Program to receive alerts to make it easier to be located in an emergency

St. Armands business dealing with cold snap amid rebuilding and reopening efforts post-hurricane season

Business News

ST. ARMANDS, Fla. (WWSB) – Some business managers and customers at St. Armands said the cold snap along the Suncoast has added an extra challenge to the new year. On Wednesday morning, foot traffic was minimal as many of the restaurants, stores, and shops remained closed. At the Blue Dolphin Cafe, business was brisk as bundled-up customers started off their mornings. “Yes, this cold snap has been unusual for us, we have customers coming in here, saying oh my gosh, it’s freezing, but this is a good place to warm up,” said Blue Dolphin Cafe manger Jahazieo Moreno.Moreno said he feels lucky to have a steady business along with a full staff and is hoping for the best for the businesses that have not reopened yet. “A lot of the stores aren’t open yet, so that brings in a lot of foot traffic and so that will be even better once more things are open again,” Moreno added. While the cold snap may have stopped some from coming out, others said bundling up is the least they can do to support the establishments still on the rebound. “We’re a little slower when it gets cold like this, but we know that it won’t last too long,” added Sarasota resident Shari Merrill.Copyright 2025 WWSB. All rights reserved.

Guelph artist’s first book stitches science from A to Z

Science and Health

With a desire to bring together her love for art and science, Guelph textile artist Lauren Wright Vartanian offers a colourful and informative introduction to science with the release of her first book, Stitching Science: Exploring Science from A – Z. 

“It’s really about education and offering an exciting way to educate people about science,” Wright Vartanian said. 

Stitching Science is an alphabet book for anyone who has an interest in art, science and how the two intersect.

“I think that everyone can enjoy it. You can start off really basic and explain it to younger kids. But it really is for all ages” 

Published by Firefly Books, Wright Vartanian said the goal is to grow enthusiasm for science in school-aged kids, and to rekindle a passion for learning in adults. 

“The art I have created for this book is meant to be approachable and intriguing but also didactic and sophisticated. My hope is that many people will appreciate it as an art book as well as an entry level science reference book,” she said. 

“It has little bits of humour and it’s conversational. And I do like that anyone interested in textiles can pick it up and appreciate it at the same time.”

Wright Vartanian operates her own business, Neurons and Nebulas. Her ‘diagrammatic’ brooches, magnets and framed pieces resemble textbook images recreated in felt. 

Each hand sewn and embroidered piece is influenced by anatomy, astronomy, biology, math or physics and are often seen displayed in offices of medical professionals. 

As for her newest passion project, Wright Vartanian said Stitching Science had been on her mind since 2016, when her daughter was still an infant. 

“The book stemmed from my business. I was already making all these art pieces and selling them at markets. When COVID hit in 2020, all the markets were cancelled, so I had the time to get started on this idea.”

Wright Vartanian began to work on the pieces in alphabetical order over the span of three years, teaching herself new techniques along the way.“This originally started out as a project for my daughter, and it grew as she did. She’s eight now but it started when she was four,” Wright Vartanian  said. 

“It started out fairly basic but then it got more complicated in theme and technique as I went along. Some pieces are more three dimensional.” 

What started off as a simple cloth book for ‘babies’, soon became a more complex educational book for older kids or just for anyone who, Wright Vartanian said, thinks ‘science is cool.’

“What I love about this art form is how immediate and tactile it is. It started when my daughter was an infant so it was easy to just pick up and put down,” Wright Vartanian said. 

“I’ve always loved working with my hands. I love the immediacy and the skill of it.”

Released in October, Stitching Science explores subjects that range from atom to zenith in physics, biology, chemistry, astronomy and mathematics. 

“The topics were ones that I was really interested in or really wanted to tackle. I found myself excited to get to the next one,” Wright Vartanian said. 

“There were a few that were crowd sourced within the Instagram community. They voted, and so I picked the ones that sparked something and that I could see coming about.”

Born and raised in Guelph, Wright Vartanian attended John F. Ross Collegiate Vocational Institute before heading off to Toronto to study at the Ontario College of Art & Design.

Her love for both art and science began at a young age. 

“I think I’ve always been sort of a science nerd or enthusiast. I always wanted to go into the sciences but I was also very much into art,” Wright Vartanian said. 

“It was always my favourite subject in school, and maybe biology, but my math grades were terrible. Once I got further into high school, chemistry started involving math, and I thought oh no!”

It wasn’t until near the end of her studies that Wright Vartanian became interested in blending art with science. 

“My major was drawing and painting. Textiles were completely different and something that I began, basically, after school,” she said. 

“I grew up with Bill Nye, my hero, so the whole ‘science communicator’ thing, that was my goal.” 

A member of Society for Embroidered Work, (SEW) Wright Vartanian is most active on Instagram. Older works can be seen on laurenwright.ca.

“I had a steady following on Instagram as I was doing the project. They kept me going and cheered me on. I received lots of encouragement,” she said. 

“People from B.C., Philadelphia, all over, have said that they have my book. That really is amazing. I am so pleased by the response to my work.”

On Jan. 9, in partnership with Royal City Science and The Bookshelf, Wright Vartanian will celebrate the official book launch of Stitching Science at Royal City Brewing. 

The family event will include a presentation from author and former editor of OWL Magazine, Keltie Thomas, who contributed to the book. 

There will be a hands-on, friendly competition with an activity that combines crafting, math and physics as well as a chance to win trivia game prizes.  

The Bookshelf will be on hand selling copies of the book. With every book sale, a donation will be made to Royal City Science’s fund towards the building of a science centre.

“It should be a lot of fun. I’m so happy that The Bookshelf and Royal City Science is involved. Everyone is coming together for this event,”  Wright Vartanian said. 

“It really feels like the community is behind me.” 

Tickets are available through the Eventbrite page. 

The book is also available online and in stores through all major and independent retailers. 

Stitching Science has been nominated for an award from the the Science Writers and  Communicators of Canada. 

Wright Vartanian is already beginning to brainstorm a second book.  

“This one includes the alphabet. The next one will be numbers, including equations, and I will try to explain them,” she said. 

The original artworks used in Stitching Science can be viewed at the Idea Exchange library (old post office) in Cambridge until March 30.  

“What I have loved about this whole process is the feeling of accomplishment,” Wright Vartanian said. 

“It feels so great to be recognized.”

Trump’s DHS Secretary Pick Prioritizes Tech to Boost Security

Technology

President-elect Donald Trump’s pick for Department of Homeland Security (DHS) Secretary and South Dakota Governor Kristi Noem has supported investments in emerging tech, cyber and border security during her state tenure to advance state and national security.
Homeland Security leaders ranked cybersecurity and artificial intelligence as its top two priorities for their cross-cutting needs and efforts five months after releasing its Innovation, Research and Development Strategic Plan. DHS has been developing innovative tools like biometric technology, unmanned systems and quantum to secure the border.
“Locally, through our collaboration with the Office of Consumer Protection, we inform, alert, educate and assist our citizens in all matters related to cybersecurity,” Noem said on her website. “But we need to think even bigger. When I first became Governor, I said that I wanted to help bring the next big industry to our state. With the threats that our state and our nation face from cybercriminals, I know that cyberresearch is that industry.”
If confirmed by the Senate, Noem, in concert with Trump’s recently named “border czar” and former police officer, immigration official and political commentator Tom Homan, would inherit DHS’ modernization initiatives.
“She will work closely with ‘Border Czar’ Tom Homan to secure the Border, and will guarantee that our American Homeland is secure from our adversaries,” Trump said on Truth Social.
Following Trump’s nomination, Noem said she was committed to tackling the security issues involving the U.S. border.
“I look forward to discussing our nation’s security challenges and my commitment to addressing them head-on,” said Noem on her website. “This position oversees the federal agencies responsible for our immigration system and millions of illegal immigrants have poured over our southern border … everything that I do will be focused on making America safe again.”
Advancing Quantum to Drive Security
2024 saw a heightened focus on quantum computing with DHS agencies like the U.S. Customs and Border Protection (CBP) increasing investments in post-quantum cryptography (PQC) and the United Nations declaring 2025 the year of quantum.During her time as Governor, Noem has also made investments in the tech to fund South Dakota’s next frontier in quantum research and development.
In Noem’s proposed budget last year, she proposed a $6 million investment in a new Center for Quantum Information Science & Technology (C-QIST). The center aimed to achieve four primary objectives:

Develop research and programs that advance quantum computing in cybersecurity, agriculture, health care and materials science.
Implement degree programs in quantum information science and technology.
Advance fields of AI and ML with quantum computing.
Provide resources for citizens and private institutions on the application of quantum.

“This new field can do exponentially more than a regular computer can do. Imagine a task that it would take regular computers 20 years to accomplish. A quantum computer could handle that task in just a matter of seconds,” said Noem said announcing the investment.
CBP has a jump start when it comes to preparing for PQC after adopting the first quantum-related standards released by the National Institute of Standards and Technology (NIST) in 2024.
CBP has urged other agencies how to prepare for “Q-Day,” which tech experts believe will happen over the next decade. They warned that the computing power will become so advanced that it will break current encryption methods and introduce critical vulnerabilities in systems.
“CBP is one of the first federal agencies to explore post-quantum cryptography to harden security within its systems,” noted CBP CIO Sonny Bhagowalia in a recent update. “It is necessary to strengthen our agency’s data through post-quantum cryptography encryptions now, in order to be prepared for the security threats of the future.”
Biometric Tech Advancements
DHS is in the process of utilizing biometric technology to boost its operations in heavily populated environments. Security, inclusivity and connectivity are three major areas the agency is focusing on to enhance its tech capabilities.
During his first administration, Trump leveraged and expanded biometric technology to increase border security.
The fiscal year 2016 Consolidated Appropriations Act provided up to $1 billion for the CBP biometric entry/exit program and Trump’s 2017 executive order on protecting the nation from foreign terrorist entry called on CBP to “expedite the completion and implementation of a biometric entry exit tracking system.”
In Sept. 2020, the first Trump administration proposed a rule to expand the collection of biometric data from immigrants. This proposal sought to allow the government to collect additional personal data, including DNA and voice prints, from a broader group of individuals, including children. The stated goal was to improve security vetting and reduce fraud within the immigration system.
As DHS expands its use of biometrics, President Biden called on the agency to create accountability measures for the tech.
DHS, in partnership with the Department of Justice (DOJ) and White House Office of Science and Technology Policy (OSTP), released a new biometric technology report at the end of 2024 required under the 2022 executive order on advancing accountable policing and criminal justice practices to enhance public trust and safety. The report outlined the best practices for the use of facial recognition technology (FRT).
“This interagency group focused on the EO’s direction to ensure that ‘law enforcement technologies do not exacerbate disparities,” the report stated. “[It] is critical to the effective administration of justice in the United States and equitable [law enforcement] activity more broadly. Therefore, law enforcement’s use of technology — including FRT and other artificial intelligence (AI)-enabled biometric tools — must always respect these values and adhere to the highest ethical standards and constitutional principles.”
Noem has backed biometric advancements as South Dakota governor. In 2022, Noem’s budget included $3.5 million for the Division of Criminal Investigation (DCI) to update the software that catalogs arrest and fingerprint records that date back to 1937. The proposed funding aimed to modernize the system to integrate and communicate more efficiently with databases used by other agencies like the Unified Judicial System (UJS).
Interim DCI Director Chad Mosteller said in 2022 the system requires manual entry of certain records, so one goal of the funding is to automate and simplify the maintenance process. Noem’s budget also called for a $70 million overhaul of the system to modernize it and back up records in the commercial cloud.
Throughout 2024, DHS has continued to modernize biometrics to increase border security.
“There are reasons for the use of biometrics within the department, but we are also responsible for helping to screen and inspect people crossing the borders, entering secure facilities, traveling and flying, to help make sure that the right person is going through the right process,” Arun Vemury, director of the Biometric and Identity Technology Center at DHS, told GovCIO Media & Research in a 2024 interview.
CBP is also harnessing biometric technology to combat environmental challenges when it comes to identifying people at the border.
“Making these technologies more robust to environmental and use case situations, there’s a lot of interest in potentially new modalities … especially as we start getting to more things like smartphone based or remote applications,” added Vemury.
Tech Security and Drone Management
Mark Cancian, senior adviser with the Defense and Security Department at the Center for Strategic and International Studies (CSIS), told GovCIO Media & Research that he expects there will be both low-tech and high-tech mechanisms to secure the border under Trump’s second administration.
Cancian speculated Trump’s “low-tech” advancements would be physical infrastructure upgrades like extending the border wall, stating “there will be efforts to make the structure as robust as possible.”
“Beyond that, everyone recognizes that a physical wall is not, in itself, enough. Military doctrine holds that barriers must be observed and then have mechanisms for reaction. The same applies to the border wall,” said Cancian. “Physical patrols can provide some of that observation and reaction, but more will be needed. That might include camera surveillance and drones … I expect there to be a major push in the area.”
During Trump’s previous administration, he worked with the Department of Transportation to implement the Unmanned Aircraft Systems (UAS) Integration Pilot Program which allowed drones to be tested for safety. It also helped validate advanced operations for drones in partnership with state and local governments.
DOT officials said the program also addressed the challenges in incorporating drones into the national airspace while reducing safety and security risks to the public.
“This program supports the President’s commitment to foster technological innovation that will be a catalyst for ideas that have the potential to change our day-to-day lives,” said former DOT Secretary Elaine Chao. “Drones are proving to be especially valuable in emergency situations, including assessing damage from natural disasters such as the recent hurricanes and the wildfires in California.”
Increasing Border Patrol
Since Trump made secure borders the centerpiece of his campaign, Cancian believes there will be immediate action taken by Trump and Noem to build more border walls and increase the size of the border patrol.
According to Cancian, over the past several decades the military has provided support services at the border, such as transportation, surveillance and engineering projects.
“Trump has hinted at using the military for deportation efforts away from the border,” said Cancian. “Gov. Noem has strongly supported using the National Guard at the border so I expect that she will expand that role.”
Noem has previously sent National Guard troops to the southern border. In 2024, she deployed 60 soldiers from South Dakota to help secure the area following a request from Texas Governor Gregg Abbott. That was the fifth time that Noem had sent National Guard troops to the area since she was elected Governor.
“The border is a warzone, so we’re sending soldiers,” Noem. “These soldiers’ primary mission will be construction of a wall to stem the flow of illegal immigrants, drug cartels and human trafficking into the United States of America.”
Shortly after one group of National Guard troops returned to South Dakota after securing the border wall and mitigating dozens of breaches in south Texas, Noem announced her intent to deploy more in the fall of 2024.
“Texas is working with South Dakota and other states to pick up the slack. We will continue to do our part,” said Noem. “We have another group of South Dakota National Guard soldiers scheduled to deploy to the Southern Border on a federal activation later this Fall. And we will continue to do everything we can to mitigate the cartels’ influence here at home.”

‘Dark Match’ Trailer – ‘WolfCop’ Director’s Pro Wrestling Horror Movie Gets Gory

Arts & Culture, Film & TV

A vague first teaser trailer has paved the way for a much more in-depth official trailer for Companion today, the new horror movie from Warner Bros., New Line Cinema, and producer Zach Cregger (Barbarian). It reveals the sci-fi twist of the upcoming genre movie, which stars Sophie Thatcher (Heretic, The Boogeyman) as a sex bot seeking bloody vengeance.
Watch the official trailer for sci-fi/horror movie Companion below.
Companion will release in theaters on January 31, 2025.
The film marks the directorial debut of Drew Hancock, who also wrote the script. 
“The silver lining of showing the audience [that] this is a movie about a robot is it’s a way to kind of get ahead of anyone dismissing it as another robot movie,” Hancock explains to EW today. “Because it’d be so easy to just be like, ‘This is M3GAN,’ or, ‘This is the Megan Fox movie [Subservience].’ It’s a little different to be like, ‘No, this is a robot movie, but it’s not like any other robot movie that’s out right now.’ It’s not A.I. gone wrong, it’s A.I. gone right.”
Rupert Friend (Separation), Harvey Guillén (“What We Do in the Shadows”), Lukas Gage (“You”), Megan Suri (It Lives Inside), and Jack Quaid (Scream, “The Boys”) also star.
Companion has been rated “R” by the MPA for…
“Strong violence, sexual content, and language throughout.”
BoulderLight’s Raphael Margules and J.D. Lifshitz will also produce, along with Vertigo’s Roy Lee. BoulderLight’s Tracy Rosenblum and Vertigo’s Andrew Childs will exec produce.
New Line Cinema presents A BoulderLight Pictures Production In Association With Vertigo Entertainment/Subconscious. You can purchase your tickets for Companion right now.
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Non-Europeans travelling from Donegal to Derry will need an ETA from January 8

Travel

Watch more of our videos on ShotsTV.com and on Freeview 262 or Freely 565Visit Shots! nowNon-Europeans travelling from Donegal to Derry will from Wednesday need to hold the British Government’s controversial Electronic Travel Authorisation (ETA) with tourism representatives warning of a potentially significant impact on visitor numbers.From January 8, non-European travellers must obtain an ETA for entry into the UK.Judith Owens, Chair of the NI Tourism Alliance (NITA), said: “The introduction of the ETA scheme poses a substantial threat to Northern Ireland’s tourism sector.”With approximately 70 per cent of our international visitors entering via the Republic of Ireland and crossing the land border, the additional requirement of obtaining an ETA could deter many from including Northern Ireland in their travel plans.Non-Europeans travelling from Donegal to Derry will from Wednesday need to hold the British Government’s controversial Electronic Travel Authorisation (ETA) with tourism representatives warning of a potentially significant impact on visitor numbers.”This not only jeopardises an estimated £210 million in annual revenue but also risks diminishing our global tourism appeal.”These visitors represent approximately 1 per cent of total international visitors to the UK and we urgently call on the UK Government to agree to an exemption to mitigate these adverse impacts and safeguard the future of our tourism industry.”The scheme has already been rolled out for people from Qatar, Bahrain, Jordan, Kuwait, Oman, United Arab Emirates and Saudi Arabia while eligible European visitors will need one from April 2025.Economy Minister Murphy recently met with Seema Malhotra MP, Home Office Minister for Migration and Citizenship to outline his concerns about the anticipated impacts of the ETA scheme on our tourism economy and to seek a solution.Mr. Murphy said: “I have made it clear to Minister Malhotra that solutions to the ETA Scheme are needed to protect the north’s tourism sector. Ideally a complete exemption should be introduced for those crossing into the north but not travelling on to Britain. At the very least a time-limited exemption for people visiting up to 7 days would cover most of our international visitors.“The existing exemption for French school groups shows that a solution is perfectly possible. A similar, pragmatic, and flexible approach could be taken by the Home Office to avoid damaging tourism growth in the north.”Key findings from recent Tourism Ireland Sentiment Research across international markets found that due to the introduction of the ETA requirements 1 in 4 people in Europe, and 1 in 5 people in North America say they would make the decision not to travel.Mr. Murphy said: “Our all-island economy is vital, and seamless all-island travel is key to building on the growth we have seen in our tourism sector.”I share the strong concerns expressed by the tourism and travel industry here and will continue to press the British Government for a solution to this challenging issue.”In 2023, the previous UK Government introduced the ETA scheme under the Nationality and Borders Act 2022. It is a requirement (at a cost of £10 per person) for all non-visa national visitors to the UK.For visitors coming here, the requirement to obtain and hold an ETA will apply whether they arrive direct at a UK port of entry (Airport/Ferry Terminal) or via the land border with the south.Continue Reading

Breakthrough Discovery: Scientists Reveal Crucial Mechanism in Nitrogen Fixation by Diazotrophs

Science and Health

Nitrogen is a fundamental element necessary for the synthesis of amino acids and nucleic acids, which are vital for the growth and functioning of living cells. Predominantly present in the atmosphere as dinitrogen (N₂), this inert form of nitrogen poses a significant challenge for most organisms, as it is not readily usable. To harness nitrogen from the atmosphere, it must first undergo a process called nitrogen fixation, whereby it is transformed into a more accessible form, most commonly ammonia. Through this bioconversion, plants and other organisms can utilize nitrogen for their metabolic needs. Despite the plentiful availability of nitrogen in the air, the biological fixation of this element occurs primarily through two well-defined pathways: one is industrial, exemplified by the Haber-Bosch process, and the other is biological, executed by specialized microorganisms known as diazotrophs. Aiming to unravel a crucial aspect of the biological fixation pathway, researchers from the University of California San Diego, led by Professor Akif Tezcan and Assistant Professor Mark Herzik, have published their findings in the esteemed journal Nature. The Haber-Bosch process, widely adopted in the early 20th century, revolutionized agriculture by facilitating the large-scale synthesis of fertilizers. Not only did this innovation drive agricultural productivity to unprecedented heights, but it also contributed significantly to the rapid increase in the global population. However, the process is labor-intensive and energy-consuming, typically requiring extreme temperatures and pressures, alongside copious amounts of hydrogen derived from fossil fuels. As a consequence, it has raised substantial environmental concerns due to the greenhouse gas emissions it generates. Conversely, nitrogen fixation in nature is accomplished by diazotrophs, a group of nitrogen-fixing bacteria that harbor an enzyme known as nitrogenase. This remarkable enzyme operates efficiently at ambient conditions, freeing it from the energy restraints imposed by high pressures and temperatures characteristic of industrial methods. More importantly, nitrogenase does not produce greenhouse gases, rendering it a far more sustainable alternative for nitrogen fixation in ecosystems. Nonetheless, while nitrogenase has evolved to facilitate the conversion of nitrogen, it is notably sensitive to oxygen, posing a challenge for diazotrophs that require oxygen for the ATP production necessary to fuel their metabolic processes. The conundrum lies in the requirement for diazotrophs to produce energy while simultaneously safeguarding nitrogenase from oxidative damage. This paradox has intrigued scientists for years, raising questions about the protective mechanisms employed by these microorganisms to shield nitrogenase from oxygen. Diazotrophs have developed various protective strategies to counteract the detrimental impacts of oxygen, although some oxygen infiltration into their cells is inevitable during their metabolic activities. In moments of heightened oxygen presence, certain diazotrophs activate a unique strategy dubbed the “conformational protection mechanism.” This innovative mechanism employs an iron-sulfur protein named FeSII, which plays a crucial role in sensing oxygen levels within the cell. When oxygen concentrations rise, FeSII binds to the nitrogenase enzyme complex, effectively shielding it from damage. This binding not only protects nitrogenase but also halts ammonia production until oxygen levels decrease again, at which point FeSII disengages, reactivating nitrogenase and resuming ammonia synthesis. While previous studies recognized the existence of FeSII, the precise molecular interactions governing its protective role remained a mystery until now. The collaborative research initiative led by Tezcan and Herzik employed an array of advanced techniques to elucidate the underlying mechanism of FeSII’s protective action. First author Sarah Narehood characterized the complex interplay of nitrogenase dynamics while simultaneously leveraging advancements in cryogenic electron microscopy (cryoEM). Through a sophisticated method known as single-particle reconstruction, the team achieved near-atomic resolution imaging of the nitrogenase-FeSII complex. This novel approach allowed them to visualize how FeSII effectively “sandwiches” nitrogenase proteins, forming filamentous structures that obstruct oxygen from accessing the reactive metal cofactors essential for nitrogenase’s catalytic function. This structural insight brought clarity to the manner in which FeSII provides conformational protection, yet questions lingered about its sensing capabilities. To address this, the researchers turned to small-angle X-ray scattering (SAXS), a technique that provides insights into protein dynamics in solution. SAXS experiments revealed that FeSII exhibits significant conformational changes in response to oxygen levels; in an oxygen-rich environment, FeSII adopts a compact shape, intimately fitting between nitrogenase proteins and facilitating their assembly into protective filaments. Conversely, under reduced oxygen conditions, FeSII reverts to a more relaxed structure, leading to the disassembly of these filaments and the restoration of nitrogenase function. Further validation of their findings was achieved through the use of an analytical ultracentrifuge—a high-velocity spinning device that enables the precise measurement of protein sedimentation based on mass. This analysis confirmed that under increased oxygen exposure, FeSII effectively facilitates the aggregation of nitrogenase proteins into larger filamentous assemblies, thereby providing insights into the mechanisms of oxygen sensing and protection. Having successfully deciphered the mechanism by which FeSII protects nitrogenase from oxidative damage, the research team is now poised to explore this protective activity in living bacterial cells. Their goal is to utilize cryoEM tomography to visualize the complete 3D architecture of diazotrophic cells actively facilitating nitrogen fixation in real time. This ambitious goal aims to elucidate the in vivo operation of FeSII and its protective functions, potentially unveiling even more intricate details about nitrogenase biology. Despite nitrogenase’s crucial role in the biosphere and its continuing importance in agricultural contexts, a comprehensive understanding of its operational mechanics remains elusive. The insights garnered regarding the conformational protection mechanism have unveiled a pivotal aspect of the nitrogen fixation puzzle. Moreover, the implications of this research extend beyond theoretical interest; harnessing the nitrogenase pathway within plant systems could reduce humanity’s reliance on synthetic fertilizers, mitigating environmental impacts while sustaining agricultural productivity in a world grappling with population growth and ecological challenges. In summary, the collaboration between chemists and biochemists at UC San Diego has brought forth a remarkable scientific breakthrough. By determining the structural and functional dynamics of the conformational protection mechanism involving FeSII and nitrogenase, they have unveiled an essential protein interaction that not only enhances our understanding of nitrogen fixation but also has the potential to significantly contribute to sustainable agricultural practices. Subject of Research: The mechanism of nitrogenase protection from oxygen damage by FeSII proteinsArticle Title: Structural basis for the conformational protection of nitrogenase from O2News Publication Date: 8-Jan-2025Web References: Nature ArticleReferences: doi:10.1038/s41586-024-08311-1Image Credits: Credit: Brian Cook and Sarah Narehood / UC San Diego Keywords Nitrogen fixation, nitrogenase, FeSII protein, cryogenic electron microscopy, oxygen protection, diazotrophs, amino acids, sustainable agriculture, environmental impact, biochemical pathways, enzymatic mechanisms, protein interactions.