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Fermented Food Microbiology Researcher in Mohali, India Receives 2024 Gregor Reid Award for Outstanding Scholars in Developing Nations

/in News /by KC

ISAPP’s board of directors is happy to announce the 2024 winner of the Gregor Reid Award for Outstanding Scholars in Developing Nations: Dr. Rounak Chourasia PhD, a research associate at the National Agri-food Biotechnology Institute in Mohali, Punjab (India).

Dr. Chourasia’s work focuses on discovering microorganisms with specific properties that contribute to the enhanced health benefits of a traditional cheese called chhurpi from Sikkim Himalaya (a state in Northeast India). He has developed a process for the production of milk cheese using selected strains of lactic acid bacteria, resulting in the release of novel bioactive peptides with potential nutraceutical applications. Furthermore, he has applied selected microbial strains to develop bioactive peptide-enriched novel soybean cheese suitable for those with lactose intolerance. The research has not only contributed to knowledge about the functional properties of chhurpi, but has also provided a foundation for helping local farmers expand their entrepreneurial opportunities.

Dr. Chourasia received both a Bachelor and Master of Science in microbiology from the University of North Bengal, India, followed by a PhD in biotechnology in 2023 from the Institute of Bioresources and Sustainable Development (DBT-IBSD), regional centre, Sikkim, and Kalinga Institute of Industrial Technology (KIIT) University under the guidance of Dr. Amit Kumar Rai and Prof. Dinabandhu Sahoo.

The 2024 committee selected Dr. Chourasia from among the many qualified candidates for the Gregor Reid Award for Outstanding Scholars in Developing Nations in this inaugural year. ISAPP established the award in honor of Dr. Gregor Reid PhD, for the purpose of recognizing and supporting early career researchers within low and middle income countries (LMICs). Dr. Reid is a founding board member of ISAPP, former President of ISAPP, and founder of the ISAPP Students and Fellows Association (SFA), whose work in LMICs throughout his career showed his commitment to scientific excellence, innovation, and community development.

Dr. Chourasia will receive an award plaque and will speak about his work at the ISAPP annual meeting in July, 2024.

Bacterial genes lead researchers to discover a new way that lactic acid bacteria can make energy and thrive in their environments

/in ISAPP Science Blog /by KC

Lactic acid bacteria are an important group of bacteria associated with the human microbiome. Notably, they are also responsible for creating fermented foods such as sauerkraut, yogurt, and kefir. In the past two decades, culture-independent techniques have allowed scientists to sequence the genomes of these bacteria and discover more about their capabilities.

Researchers studying a type of lactic acid bacteria called Lactiplantibacillus plantarum found something unexpected: they contained genes for making energy in a way that had not been previously documented. Generally, living organisms obtain energy from their surroundings either by fermentation or respiration. L. plantarum have long been understood to obtain energy using fermentation, but the new genetic analysis found they had additional genes that were suited to respiration. Could they be using both fermentation and respiration?

ISAPP board member Prof. Maria Marco is a leading expert on lactic acid bacteria and their role in fermented foods and in human health. In her lab at University of California Davis, she decided to investigate why L. plantarum had genes equipping it for respiration. Her group recently published findings that show a new type of “hybrid” metabolism used by these lactobacilli.

Here is a Q&A with Prof. Marco about these exciting new findings.

What indicated to you that some of the genes in L. plantarum didn’t ‘belong’?

Organisms that use respiration normally require an external molecule that can accept electrons, such as oxygen. Interestingly, some microorganisms can also use solid electron acceptors located outside the cell, such as iron. This ability, called extracellular electron transfer, has been linked to proteins encoded by specific genes. L. plantarum had these genes, even though this species is known to use fermentation. We first learned about their potential function from Dr. Sam Light, now at the University of Chicago. Sam discovered a related pathway in the foodborne pathogen Listeria monocytogenes. Sam came across our research on L. plantarum because we previously published a paper showing that a couple of genes in this pathway are switched on in the mammalian digestive tract. We wondered what the proteins encoded by these genes were doing.

How did you set out to investigate the metabolism of these bacteria?

We investigated this hybrid metabolism in a variety of ways. Using genetic and biochemical approaches we studied the extent to which L. plantarum and other lactic acid bacteria are able to use terminal electron acceptors like iron. Our collaborators at Lawrence Berkeley National Lab and Rice University contributed vital expertise with their electrochemistry experiments, including making fermented kale juice in a bioelectrochemical reactor.

What did you find out?

We discovered a previously unknown method of energy metabolism in Lactiplantibacillus plantarum. This hybrid strategy blends features of respiration (a high NAD+/NADH ratio and use of a respiratory protein) with features of fermentation (use of endogenous electron acceptors and substrate-level phosphorylation).

We verified that this hybrid metabolism happens in different laboratory media and in kale juice fermentations. We also found that, in the complex nutritive environment of a kale juice fermentation, this hybrid metabolism increases the rate and extent of fermentation and increases acidification. Within the ecological context of the fermented food, this could give L. plantarum a fitness advantage in outcompeting other microorganisms. This could potentially be used to change the flavor and texture of fermented foods.

This discovery gives us a new understanding of the physiology and ecology of lactic acid bacteria.

Are there any indications about whether this energy-making strategy is shared by other lactic acid bacteria?

Some other fermentative lactic acid bacteria also contain the same genetic pathway. It is likely that we are just at the tip of the iceberg learning about the extent of this hybrid metabolism in lactobacilli and related bacteria.

Your finding means there is electron transfer during lactic acid bacteria metabolism. What does this add to previous knowledge about bacterially-produced ‘electricity’?

Certain soil and aquatic microbes have been the focus of research on bacterially-produced electricity. We found that by giving L. plantarum the right nutritive environment, it can produce current to the same level as some of those microbes. We believe there is potential to apply the findings from our studies to better inform food fermentation processes and to guide fermentations to generate new or improved products. Because strains of L. plantarum and related bacteria are also used as probiotics, this information may also be useful for understanding their molecular mechanisms of action in the human digestive tract.

How might this knowledge be applied in practice?

Our findings can lead to new technologies which use lactic acid bacteria to produce healthier and tastier fermented foods and beverages. Because this hybrid metabolism leads to efficient fermentation and a larger yield, it could also help minimize food waste. We plan to continue studying the diversity, expression, and regulation of this hybrid metabolism in the environments in which these bacteria are found.

In Memoriam: Todd Klaenhammer

/in ISAPP Science Blog, News /by KC

By Mary Ellen Sanders and Colin Hill

We all suffered a devastating loss this past Saturday with the death of Prof. Todd Klaenhammer, aged 69.

Todd was a larger-than-life figure in the scientific field of genetics of lactic acid bacteria. Todd’s 38-year career started at the age of 26, when he joined North Carolina State University as an assistant professor in 1978. His research and teaching awards are too numerous to count, as the phrase goes, but of special note was his election in 2001 to the U.S. National Academy of Sciences. Later he also received the O. Max Gardner award, given to one researcher in the North Carolina University system “who has made the greatest contribution to the welfare of the human race.”

Gregor Reid, Todd Klaenhammer, Colin Hill and Paul Ross in Tromso, Norway.

For those of us fortunate enough to work closely with him, it was a privilege to witness his mind at work, making those leaps in understanding in real time as he furiously forged ahead of the data while designing strategies to test his theories. He saw the potential for probiotics when few others were interested. He led the field in phage resistance, in bacteriocin research, and in basic lactic acid bacterial genetics. When many preferred to study the more genetically accessible lactococci he went with the much more recalcitrant lactobacilli. The discoveries he made were all the more notable because he always maintained a relatively small laboratory group, not moving to the large team-based approaches that are more common today. He was a fierce competitor, but was warm and generous when his friends and rivals made scientific advances. His willingness to take on challenges was truly inspirational, and his scientific intellect was the rock-solid foundation for everything he achieved in a legendary career.

As a founding board member for ISAPP, serving on the board from 2002 to 2016, Todd helped shape ISAPP’s development. He had a great influence on ISAPP leadership, nudging Prof. Colin Hill to serve as president and nominating Prof. Sarah Lebeer to the board. He, along with Prof. Jeff Gordon, organized the National Academy of Sciences Sackler Symposium “Microbes & Health” in conjunction with the 2009 ISAPP annual meeting at the Beckman Center in Irvine CA. Later, one of ISAPP’s finest moments was the gala dinner during the 2015 ISAPP meeting in Washington DC, which Todd hosted at the National Academy of Sciences Great Hall.

Colin Hill, Todd Klaenhammer, Dymphna Hill and Mary Ellen Sanders at dinner after the 2012 ISAPP annual meeting in Cork, Ireland.

Todd seemed especially happy when he was able to help young scientists succeed in science. His “work hard, play hard” ethic and his fierce dedication made positions in his lab coveted. Competition for a space in his lab became steeper as the years went by. The best and the brightest students and postdocs found their way to his lab over the years, and he was extremely proud of all that those in his lab accomplished.

Todd always welcomed the opportunity to connect with his many colleagues and friends. He was rarely without a story to share – watching his Ford Bronco start to sink into the lake with his cherished golden retriever paddling in the back was a favorite. The listening throng always radiated congeniality. He could work a crowd.

Saying goodbye to Todd will be hard for so many of us across the globe. We will miss his good humor, his friendship, his constant encouragement of others to excel, and his hustle to make sure they did.

Rest in peace, Todd. We will try to continue to make you proud.

Mary Ellen Sanders was a graduate student in the Klaenhnammer lab from 1978-1983. Colin Hill was a postdoc in the Klaenhammer lab from 1988-1990.

Todd Klaenhammer (second from left) with other participants in the 2010 ISAPP meeting in Barcelona.

Read more about Todd Klaenhammer’s life and career:

The Passing of Todd Klaenhammer. Annual Review of Food Science and Technology

Beloved Dairy Researcher Klaenhammer Dies

OBITUARY. Todd Robert Klaenhammer

Biography of Todd R. Klaenhammer

A Lasting Legacy: Probiotics Pioneer Todd Klaenhammer Retires

New endowments created honoring Klaenhammer’s legacy in probiotics research

From the Japan Society of Lactic Acid Bacteria: Memory of Prof. Todd R. Klaenhammer (Prof. Todd R. Klaenhammerを偲ぶ), Dr. Mariko Shimizu-Kadota and A legend of LAB is gone (Todd R. Klaenhammer先生を偲んで), Dr. Akinobu Kajikawa. Japan Society of Lactic Acid Bacteria Journal.

Highlighting the importance of lactic acid bacteria: An interview with Prof. Seppo Salminen

/in Consumer Blog, ISAPP Science Blog /by KC

By Kristina Campbell, M.Sc., science & medical writer

 

In a 2009 book called What on Earth Evolved?, British author Christopher Lloyd takes on the task of ranking the top 100 species that have influenced the planet throughout its evolutionary history.

What comes in at number 5, just slightly more influential than Homo sapiens? Lactobacilli, a diverse group of lactic-acid-producing bacteria.

The influential status of these bacteria on a global scale comes as no surprise to Prof. Seppo Salminen, ISAPP president and Professor at University of Turku (Finland), who has spent most of his career studying these microbes. He is the co-editor of the best-selling textbook Lactic Acid Bacteria: Microbiological and Functional Aspects, the fifth edition of which was released earlier this year. Salminen says the scientific community has come a long way in its understanding of lactic acid bacteria (LAB)—and in particular, lactobacilli.

Seppo Salminen at ISAPP annual meeting 2019

“If you think about the history of humankind, earlier on, more than 60% of the food supply was fermented,” explains Salminen. “On a daily basis, humans would have consumed many, many lactic acid bacteria.”

Yet 30 years ago when Salminen and his colleagues published the first edition of the textbook on lactic acid bacteria, they were working against perceptions that bacteria were universally harmful. The science on using live microorganisms to achieve health benefits was still emerging.

“Most people in food technology, they had learned how to kill bacteria but not how to keep them alive,” he explains. “They didn’t yet know how to add them to different formulations in foods and what sort of carrier they need. At that time, the safety and efficacy of probiotics was not well understood.”

Around ten years later, scientists came together to develop a definition of probiotics on behalf of the Food and Agriculture Organization of the United Nations and the WHO (FAO/WHO)—in a report that formed the basis of ISAPP Consensus meeting and today’s international consensus definition: “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”.

With probiotics having been more precisely defined, the following years were a time of rapid scientific progress in the field. Lactobacilli became the stars of the show, as research emerged on the benefits of various strains and combinations of strains in food science and medicine.

Fast forward to today, when rapidly expanding gut microbiome research adds another dimension to what we know about these bacteria. While lactic acid bacteria are still primarily of interest for the health benefits they impart, scientists can now also study their interactions with other microorganisms in the intestinal microbiome. In some cases, this kind of research may help uncover new mechanisms of action.

After everything Salminen and his textbook co-editors (Vinderola, Ouwehand, and von Wright) have learned about lactic acid bacteria over the past few decades, Salminen says there are two main reasons for the perennial importance of the bugs. “One is their importance in food fermentation, extending the shelf life of foods, making a kind of food processing or ‘agricultural processing’ possible. To make sauerkraut shelf-stable for weeks, or to make yogurt or cheese.”

The second reason, he says, relates to their benefits for the host. “Lactic acid bacteria, especially lactobacilli, reinforce intestinal integrity. So they protect us against pathogens; and sometimes against toxins and heavy metals by binding them away.”

He continues, “The more we know, the more we understand that LAB are needed. There are very specific strains that are helpful in different conditions for animal feeds or for clinical nutrition for infants, for example.” He says the knowledge is expanding at such a rapid pace that it may only be a few more years before the textbook he co-edited will need another edition.

Salminen is currently one of the world’s most cited probiotic researchers, and has diverse ongoing research projects related to digestive health, eczema, early life, and nutrition economics—but lactic acid bacteria are the thread that weaves everything together.

“I’m proud to be working on the fifth most important factor in human evolution,” he says.