UP researchers identify new Mayon bacteria with antibiotic potential

Found in volcanic soil in Albay, the newly classified organism belongs to a bacterial group responsible for producing many of today’s antibiotics, underscoring the Philippines’ potential role in the global search for new treatments against drug-resistant infections.

MANILA, Philippines — University of the Philippines researchers have officially identified a new bacterial species from the slopes of Mayon Volcano, a discovery that adds a Philippine organism to the global scientific record as the World Health Organization warns of a worsening shortage of innovative antibiotics to combat drug-resistant infections.

The newly classified species, named Streptomyces mayonensis, belongs to a bacterial genus responsible for producing many antibiotics used worldwide. Researchers said the discovery also reinforces the value of exploring the country’s biodiversity as scientists search for new compounds that could eventually contribute to future drug development.

The research was conducted by Gerald M. Aguilar, Kristel Mae P. Oliveros, Albert Remus R. Rosana, Rina B. Opulencia and Asuncion K. Raymundo of the University of the Philippines Los Baños. Rosana is also affiliated with the Department of Science and Technology, while Raymundo is affiliated with the National Academy of Science and Technology.

Their study, titled “Streptomyces mayonensis sp. nov., isolated from the volcanic soils of Mt. Mayon, Philippines,” was published in the International Journal of Systematic and Evolutionary Microbiology in 2025. The project was supported by the University of the Philippines Office of the Vice President for Research and Innovation’s Enhanced Creative Work and Research Grant.

The discovery builds on previous work by the same research team, which showed that the bacterial strain possesses antibacterial and anticancer properties. The latest study formally establishes it as a genetically distinct species through comprehensive laboratory and genomic analyses.

From Mayon soil to science record

The bacterium was isolated from volcanic soil collected about 500 meters above sea level in Malilipot, Albay, on the slopes of Mayon Volcano, one of the Philippines’ most active volcanoes.

The discovery traces back to a broader 2021 effort by UPLB researchers to explore one of the country’s least-studied environments. The team initially isolated 30 bacteria from Mayon’s volcanic soil, with 13 showing varying degrees of antimicrobial activity against organisms known to cause diseases in humans or plants, according to a Department of Science and Technology article published at the time.

READ: Mayon soil hosts bacteria with potential anticancer properties – UPLB researchers

Researchers collect soil samples on the slopes of Mayon Volcano in Malilipot, Albay, in this 2021 photo featured in a Department of Science and Technology article. The sampling formed part of earlier research that eventually led to the identification of Streptomyces mayonensis, a newly confirmed bacterial species by University of the Philippines Los Baños researchers. (Photo courtesy of the researchers via DOST)

Initially designated as strain A1-08T, the organism drew scientists’ attention because of its biological activity against several disease-causing microorganisms.

According to the study, the strain previously demonstrated activity against Salmonella enterica, Klebsiella pneumoniae, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus or MRSA, Candida albicans, Aspergillus niger, and Fusarium species. It also showed anticancer properties against human colorectal cancer cells.

In 2021, the researchers said they deliberately selected a broad range of bacteria, yeasts, and molds for testing.

“One of the objectives of the study is to screen actinomycete isolates for antimicrobial activity. Therefore, we ensured that our selected test organisms would represent some of the major groups of microorganisms, including bacteria, yeasts, and molds to capture a broader antimicrobial spectrum result,” Oliveros said in a DOST article.

The latest research focused on determining whether the organism represented an entirely new species.

To answer that question, the researchers used what scientists describe as a polyphasic taxonomic approach, combining physical observations, biochemical testing, phylogenetic analysis, and whole-genome sequencing.

The findings confirmed that the organism was genetically distinct enough to warrant classification as a new species, named Streptomyces mayonensis, derived from Mayon Volcano.

The whole-genome analysis found that it shared only 57.8 percent digital DNA-DNA hybridization and 93.03 percent average nucleotide identity with its closest known relative, Streptomyces olivaceus, values that fall below internationally accepted thresholds for species classification.

GRAPHIC: Ed Lustan/INQUIRER.net

This means that while the organism shares ancestry with known Streptomyces bacteria, it is genetically distinct enough to stand on its own. The study noted that scientists typically use minimum thresholds of 70 percent for digital DNA-DNA hybridization and 95 percent for average nucleotide identity when determining whether bacteria belong to the same species. The newly identified organism fell below both benchmarks, confirming that it is a separate species.

The researchers said that formally establishing the organism’s taxonomic identity provides a stronger foundation for future studies of its potential applications.

“By resolving the taxonomic status of this strain – previously shown to possess antibacterial and cytotoxic activities – the study lays the groundwork for its potential development in pharmaceutical and biotechnological applications,” the researchers wrote in the paper’s impact statement.

Why scientists study Streptomyces

The discovery carries significance because of the bacterial group to which the organism belongs.

Streptomyces is among the most extensively studied bacterial genera in medicine because of its role in producing antibiotics and other biologically active compounds.

According to the study, Streptomyces species account for 80 percent of the world’s antibiotics. Researchers also noted that 5 percent to 10 percent of the genome of many Streptomyces species are dedicated to producing bioactive compounds with antibacterial, anticancer, antifungal, antiparasitic, and immunosuppressive properties.

GRAPHIC: Ed Lustan/INQUIRER.net

The organisms are found in a wide range of environments, including ordinary soils, plant roots, marine ecosystems, and extreme environments such as deep-sea habitats and arid regions.

However, the researchers said that volcanic environments in the Philippines remained largely unexplored until recently.

“Volcanic habitats in the Philippines remain uninvestigated until 2021 when Oliveros et al. explored Mt. Mayon, one of the most active volcanoes in the Philippines, for actinomycetes,” the study said.

That earlier investigation ultimately led to the isolation of Streptomyces mayonensis.

Built to survive change

The researchers also examined how the organism may have adapted to survive in volcanic conditions.

Their genomic analysis found genes associated with managing environmental stress, including mechanisms that help the bacterium regulate water balance, protect itself from oxidative damage, and acquire nutrients from its surroundings.

The organism also possessed genes associated with the breakdown of complex organic compounds and the production of molecules linked to plant growth promotion.

A closer look at Streptomyces mayonensis. These scanning electron microscope images show the microscopic structures of the newly identified bacterial species discovered in Mayon Volcano soil, including its chains of spores. The images were taken at 10,000× (left) and 80,000× (right) magnification. (Image from Aguilar et al., 2025/International Journal of Systematic and Evolutionary Microbiology)

The study said these characteristics demonstrate the adaptability of Streptomyces species to environments that remain understudied.

“Moreover, the genetic adaptability of the strain to environmental stresses showed remarkable evidence that Streptomyces species can thrive and survive in one of the least explored and dynamic environments, such as Mayon Volcano,” the researchers wrote in the impact statement.

Discovery amid antibiotic crisis

The findings also come amid growing international concern over antimicrobial resistance.

Antimicrobial resistance, or AMR, occurs when bacteria evolve and become resistant to medicines designed to kill them, making infections harder and more expensive to treat.

READ: AMR: When infections fight back, kill

The antimicrobial resistance issue had also influenced some of the researchers’ earlier decisions. In 2021, Rosana said the team partly selected its test organisms based on global health priorities.

“The choice of test organisms was also associated with the World Health Organization’s (WHO) list of human pathogens that pose imminent danger to human health by 2050, mainly due to antibiotic resistance,” he said.

In 2021, the WHO warned that the world was still failing to develop urgently needed antibacterial treatments despite increasing awareness of the problem.

At the time, the agency reported that none of the 43 antibiotics then in clinical development sufficiently addressed drug resistance among the world’s most dangerous bacteria.

“The persistent failure to develop, manufacture, and distribute effective new antibiotics is further fueling the impact of antimicrobial resistance (AMR) and threatens our ability to successfully treat bacterial infections,” said Dr. Hanan Balkhy, WHO assistant director-general on AMR.

WHO also noted that almost all antibiotics introduced in recent decades have been variations of existing antibiotic classes discovered before the 1980s.

The impact of antimicrobial resistance is especially severe in resource-constrained settings.

The agency cited evidence showing that approximately 30 percent of newborns with sepsis die because of bacterial infections resistant to multiple first-line antibiotics.

GRAPHIC: Ed Lustan/INQUIRER.net

A year later, WHO said progress remained insufficient.

Its 2022 annual assessment described the antibacterial development pipeline as “stagnant and far from meeting global needs.” According to the report, only 27 new antibiotics were in clinical development against priority pathogens in 2021, down from 31 in 2017.

The economic barriers are also substantial. WHO said it currently takes 10 to 15 years to move an antibiotic candidate from preclinical development to clinical stages. For antibiotics belonging to existing drug classes, only one out of every 15 candidates eventually reaches patients, while entirely new classes have even lower success rates, with only one out of every 30 making it through the process.

“There is a major gap in the discovery of antibacterial treatments, and more so in the discovery of innovative treatments,” Balkhy said in WHO’s 2022 report.

“This presents a serious challenge to overcoming the escalating pandemic of antimicrobial resistance and leaves every one of us increasingly vulnerable to bacterial infections, including the simplest infections.”

WHO Director of AMR Global Coordination Dr. Haileyesus Getahun also warned that innovation is not keeping pace with the threat.

“Time is running out to get ahead of antimicrobial resistance, the pace and success of innovation is far below what we need to secure the gains of modern medicine against age-old but devastating conditions like neonatal sepsis,” he said.

RELATED STORY: UP chemists develop AI tool to help fight antimicrobial resistance

Boosting biodiversity research

The researchers did not make direct claims about future medical applications of Streptomyces mayonensis. Instead, they said formally establishing the organism’s taxonomic identity creates a stronger foundation for future scientific work involving its pharmaceutical and biotechnological potential.

The researchers themselves have previously stressed that more work remains before any practical applications can be explored.

“Way forward, further studies should be made for us to establish that this novel species can likewise produce novel bioactive compounds,” Oliveros said in 2021.

“Future rigorous research in drug chemistry combined with metabolomics are vital to claim that the secondary metabolites produced by our isolate is totally new and hopefully effective as a chemotherapy drug,” she added.

Meanwhile, the study said validating the species “enhances the understanding of Streptomyces diversity and supports future research into the discovery and exploitation of novel microbial metabolites.”

The researchers also noted that the bacterium’s ability to survive in volcanic conditions expands scientific knowledge of microorganisms inhabiting dynamic, understudied environments in the Philippines. According to the study, the findings provide “remarkable evidence that Streptomyces species can thrive and survive in one of the least explored and dynamic environments, such as Mayon Volcano.”

The discovery adds to a growing body of Philippine research examining local microbial biodiversity, an area scientists continue to explore for compounds that may eventually have applications in medicine, biotechnology, and other fields.

The UP Office of the Vice President for Research and Innovation described the discovery as proof that “scientific capacity exists at home” and called for stronger support for research that explores the country’s biodiversity and potential solutions to global challenges. /dm

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