NSTU Researchers Discover New Bacterium Responsible for Rice Disease

Researchers at Noakhali Science and Technology University (NSTU) have identified an entirely new bacterial species responsible for grain discoloration in rice. Named Pantoea bangladeshensis sp. nov. NSTU24 after Bangladesh, the bacterium was identified as a new species through whole-genome analysis.

The discovery opens new opportunities for investigating rice diseases, developing effective disease-management strategies and potentially breeding disease-resistant rice varieties.

The research has been accepted for publication in Scientific Reports, a journal under the Nature Portfolio, and is awaiting publication. A separate research paper by the team on the prevention and management of the disease has also been published in the same journal.

Research Began with a Facebook Post from Farmers

The research journey began in February 2023, when Arnab Goswami, then a final-year undergraduate student in NSTU's Department of Agriculture, was searching for a suitable thesis topic under the supervision of Professor Dr Mehedi Hasan Rubel.

He came across a Facebook post by farmers from Tanore upazila in Rajshahi district. Photographs shared by the farmers showed rice panicles and grains gradually turning black.

The discoloration was damaging the rice husks and grain quality, causing substantial financial losses for marginal farmers.

Concerned about the problem, Arnab decided to investigate its scientific cause. Following Professor Rubel's advice, he began collecting diseased rice samples from affected fields in Tanore, Rajshahi, and other parts of northern Bangladesh.

Assistant Professor Dr Piyush Kanti Jha of the Department of Agriculture also joined the research.

Initial Findings Pointed Beyond Known Bacteria

Initially, the research team suspected that the disease was caused by bacteria belonging to the familiar genus Burkholderia.

The researchers successfully isolated bacteria from the collected samples and identified seven suspected colonies.

However, isolation and characterisation revealed that their genetic characteristics did not match those of commonly known bacteria.

Pathogenicity tests identified two bacterial isolates capable of reproducing symptoms similar to those observed in the field samples.

The researchers subsequently conducted partial genome sequencing of the two isolates. The results showed that they did not belong to the genus Burkholderia, but rather to Pantoea, a genus containing opportunistic bacteria.

During this phase, Arnab received extensive assistance from Ankon Dutta, a lecturer in the Department of Microbiology at Primeasia University.

Whole-Genome Sequencing Confirms a New Species

Arnab continued the research even after completing his undergraduate studies, encouraged by Professor Mehedi Hasan Rubel.

The research team was later joined by Maksudur Rahman Nayem of DNA Solution Limited and A B Z Naimur Rahman of NSTU's Department of Microbiology.

Under their direct guidance, the researchers completed whole-genome sequencing of the bacterium. The analysis established that it represented an entirely new bacterial species.

Professor Dr Toffazzal Islam, founding chairman of the Institute of Biotechnology and Genetic Engineering (IBGE) at Gazipur Agricultural University, subsequently provided advanced genomic guidance that helped bring the research to completion.

Mahmudul Hasan Shanto, a student of NSTU's Department of Microbiology, also assisted in preparing the research paper.

International Recognition Required Strict Scientific Procedures

Getting the discovery published in an international scientific journal proved challenging.

The research paper was initially submitted to several renowned journals but was rejected.

Reviewers pointed out that, under the International Code of Nomenclature of Prokaryotes (ICNP), researchers claiming a new bacterial species must deposit the bacterium in at least two internationally recognised culture collection centres.

After a lengthy process, the team obtained the necessary government permissions with special assistance from Dr Fahmida Khanam, then Additional Secretary, and Amirul Kaisar, Deputy Secretary, at the Ministry of Environment, Forest and Climate Change.

Following further verification, the bacterium was successfully deposited as a type strain in two international culture collections: ICMP in New Zealand and BCCM/LMG in Belgium.

The deposits fulfilled a key requirement for establishing the bacterium's scientific identity and recognition.

Research Cost More Than Tk 300,000 Without Funding

Professor Dr Mehedi Hasan Rubel expressed satisfaction with the achievement, highlighting its significance for Bangladesh's international scientific profile.

“The greatest achievement is that through this research, Bangladesh and our university are gaining recognition on the global stage. When researchers or students read our work through paper citations, they will come to know our country,” he said.

However, he expressed disappointment over the lack of research funding.

According to Rubel, the team submitted research proposals to the University Grants Commission (UGC) twice but received no funding.

He said he personally spent more than Tk 300,000 to complete the research. The high costs of gene sequencing and DHL transportation were also covered from personal funds.

Despite the lack of adequate financial support from research funding sources, he said the satisfaction of bringing international recognition to Bangladesh had outweighed much of the hardship.

Arnab Describes Discovery as a Scientific Milestone

Arnab Goswami, who was involved in the research from the beginning, described the discovery as both a personal achievement and a significant scientific milestone.

“This discovery brings me immense joy and is also a major scientific milestone. When we started working in the laboratory entirely through our own funding, without any research grant, our primary objective was to identify the unknown pathogen behind rice grain discoloration. The moment we confirmed through genomic analysis that it was an entirely new species with no previous record in global databases was extraordinary,” he said.

He added, “Being able to introduce the species Pantoea bangladeshensis, named after our country, to the international scientific community is a tremendous source of pride for me. I am deeply grateful to my supervisor, Dr Mehedi Hasan Rubel, all my lab mates and co-authors for their continuous guidance and support throughout this long journey. I believe our genomic data and pathological findings will make important contributions to developing disease-resistant rice varieties and strengthening global food security in the future.”

Researchers Plan to Extend Study to Field Conditions

After overcoming prolonged research challenges, financial constraints and strict international publication requirements, Pantoea bangladeshensis NSTU24 has achieved an important step towards international scientific recognition.

The research, initiated by young researcher Arnab Goswami, was conducted with the guidance of Professor Dr Mehedi Hasan Rubel and Professor Dr Toffazzal Islam, alongside contributions from other researchers.

The team believes the discovery could create new opportunities for protecting rice production across South Asia and developing disease-resistant varieties.

Following successful laboratory investigations, the researchers now plan to extend the study to field-level applications.

However, they emphasised that adequate financial assistance and government support would be essential for the next phase.

They expect that effective management of the bacterial disease could help increase rice production while reducing financial losses for farmers.

//DBTech/Samea Hossan Munea/SMP/MIST//