VOLUME 14 NUMBER 2 (July to December 2021)

Eleanor S. Austria*¹, Jette Edcee A. Soto¹, Lisette Ludovice¹, Gil Gabriel S. Villancio^1,4, Christina Y. Loquere², Rey Y. Capangpangan³, Fuh-Kwo Shiah⁵

¹Biology Department, Adamson University, 900 San Marcelino St., Ermita,
     Manila 1000 Philippines
²Department of Chemistry, Caraga State University, Ampayon,
     Butuan City, Philippines
³Department of Physical Sciences and Mathematics, College of Science
     and Environment, Mindanao State University at Naawan,
     Naawan, Misamis Oriental, 9023, Philippines
⁴School of Environmental Science and Management, UP Los Baños,
     Laguna, Philippines
⁵Research Center for Environmental Changes, Academia Sinica, Nangang,
     Taipei, Taiwan

Data on soil bacterial abundances can provide early signs of soil alterations and can be used in the rehabilitation programs of former mining sites. In this study, we used catalyzed reporter deposition-fluorescence in-situ hybridization (CARD-FISH) to assess specific bacterial abundances in soils collected from sites with different levels of mining disturbance. Using specific oligonucleotide probes, more than 70% of the microbial biomass in forest sites belonged to the Domain Bacteria but less than 53% in the mined-out and quarry sites. Phylum Actinobacteria and Classes Gamma- and Delta-Proteobacteria counts were also shown to be three (3) to six (6) times higher in the forest than in the mined-out and quarry site with Phylum Actinobacteria showing higher abundance in the forest sites while Delta-Proteobacteria dominated in the mining-disturbed areas. All bacterial variables are positively correlated with organic matter, nitrogen and phosphorus, suggesting control of bacterial abundance by nutrients; but is negatively correlated with soil pH. Given the large spatial and temporal variations in soil microbial diversity our results provided an insight into the dynamics of soil bacteria in undisturbed and mining-disturbed soil that can be used in the proper design and management of rehabilitation programs for mining-disturbed areas.