Location-Related Differences in Weathering Behaviors and Populations of Culturable Rock-Weathering Bacteria Along a Hillside of a Rock Mountain

Abstract

Bacteria play important roles in rock weathering, elemental cycling, and soil formation. However, little is known about the weathering potential and population of bacteria inhabiting surfaces of rocks. In this study, we isolated bacteria from the top, middle, and bottom rock samples along a hillside of a rock (trachyte) mountain as well as adjacent soils and characterized rock-weathering behaviors and populations of the bacteria. Per gram of rock or surface soil, 10-10 colony forming units were obtained and total 192 bacteria were isolated. Laboratory rock dissolution experiments indicated that the proportions of the highly effective Fe (ranging from 67 to 92 %), Al (ranging from 40 to 48 %), and Cu (ranging from 54 to 81 %) solubilizers were significantly higher in the top rock and soil samples, while the proportion of the highly effective Si (56 %) solubilizers was significantly higher in the middle rock samples. Furthermore, 78, 96, and 6 % of bacteria from the top rocks, soils, and middle rocks, respectively, significantly acidified the culture medium (pH < 4.0) in the rock dissolution process. Most rock-weathering bacteria (79 %) from the rocks were different to those from the soils and most of them (species level) have not been previously reported. Furthermore, location-specific rock-weathering bacterial populations were found and Bacillus species were the most (66 %) frequently isolated rock-weathering bacteria in the rocks based on cultivation methods. Notably, the top rocks and soils had the highest and lowest diversity of rock-weathering bacterial populations, respectively. The results suggested location-related differences in element (Si, Al, Fe, and Cu) releasing effectiveness and communities of rock-weathering bacteria along the hillside of the rock mountain.

Bio-Organic Mineral Fertilizer for Sustainable Agriculture: Current Trends and Future Perspectives

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Use of Mineral Weathering Bacteria to Enhance Nutrient Availability in Crops: A Review

“…Most of the studies discussed in the previous topics deal with a single bacterial inoculant or a combination of few microorganisms. However, the weathering process in soil occurs by integrative metabolism of plenty of microorganisms distributed on soil, each one possibly displaying particular weathering abilities (Wang et al, 2017). A better understanding of microbial weathering requires an integrative investigation of microbial communities and their complex interaction with different abiotic factors.…”

Distinct biotite‐weathering activities of Arthrobacter pascens F74 under different contact conditions

“…Biotite is a common mineral in the earth's crust and is an important source for nutrients in terrestrial ecosystems, while Arthrobacter strains have been reported to weather minerals on rock surfaces and in soils . However, little is known regarding the geomicrobial contribution of Arthrobacter strains to the processes of mineral weathering and soil formation under low‐nutrient conditions.…”