Isolation of three genera of microorganisms in lahar-laden soils of Sta. Rita, Pampanga, Philippines through the 16s rRNA gene sequence analysis

ABSTRACT

A lahar-laden soil is described as marginal soil due to its poor physicochemical and biological properties and is hypothesised to have low biodiversity of soil microbes that would help support plant growth. Thus, the study aimed to assess the presence of soil microorganisms in lahar-laden soils in Sta. Rita, Pampanga, with their ability as beneficial microbes for crop production. Vigna radiata was used as the trap crop and grown for a maximum of 35 days in a microcosm experiment where all variables were similar except for the location of the sampling site. Through the sequence analysis of the 16S rRNA gene, five representative isolates revealed close resemblance to the genus Bradyrhizobium and Rhizobium, while the others were classified as non-rhizobial endophytes, namely, Pseudomonas, Agrobacterium, and Leifsonia. These results indicate that the lahar-laden soils in the sampling site harbour some agronomically-important genera of microorganisms. Surprisingly, this is the first time that the species Leifsonia xyli was identified and isolated in acidic lahar-laden soil. In contrast, it is hypothesised that the presence of L.xyli in this study might be attributed to the acidic soil pH, leading to the suppression of rhizobia in root nodules.

KEYWORDS:

• Acid soil
• Bradyrhizobium
• Leifsonia xyli
• life on land
• Vigna radiata

Acknowledgment

The Department of Science and Technology- Science Education Institute funded the study under the Accelerated Science and Technology Human Resource Development Programme (ASTHRDP). The author would like to thank also the Plant Disease Diagnostic and Biocontrol Laboratory, Pampanga State Agricultural University, for providing the facilities for completing the research work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The data supporting this study's findings are available upon reasonable request.

Additional information

Funding

This work was supported by DEPARTMENT OF SCIENCE AND TECHNOLOGY - SCIENCE EDUCATION INSTITUTE (DOST-SEI), Republic of the Philippines.

Notes on contributors

Israel M. Guanzon

Israel Guanzon is currently a faculty in Dept. of Crop Science, College of Agriculture Systems and Technology at Pampanga State Agricultural University, Pampanga, Philippines, He holds an MS in Soil Science (Soil biology) with a cognate of Crop Seed physiology and is a scholar.

Maria Luisa T. Mason

Dr. Maria Luisa T. Mason is currently holding a position as an Associate professor in the Department of Soil Science, College of Agriculture at Central Luzon State University, Nueva Ecija, Philippines. She obtained her graduate degree (MS/Ph.D) from the University of Miyazaki, Japan, under the Japanese Government (MEXT) Scholarship program in 2019. She has published several articles in international journals since 2017 and served as a reviewer in some National & International journals.

Purisima P. Juico

Dr. Purisima P. Juico is also a Associate professor in Department of Soil Science in College of Agriculture at Central Luzon State University. She took her graduate degree in Soil Science with specialization on Soil Chemistry and Mineralogy at the University of the Philippines, Los Banos in Laguna Philippines she also published several articles both national and abroad.

Fernan T. Fiegalan

Dr. Fernan T. Fiegalan- have an in depth knowledge on soil geomorphology, soil conservation and environmental soil science. He is a MS /Ph. D holder in Environmental Science at the University of the Philippines, he also published numerous journal both national and international. Dr. FIEGALAN is currently associate professor at the Department of Soil Science, College of Agriculture at Central Luzon State university, Nueva Ecija, Philippines.