10:45 AM - 12:15 PM
[AHW18-P17] Analysis of microbial communities formed by lighting inside the show cave Ryugado
Keywords:Microbial communities, Show cave, Amplicon sequencing
Ryugado, a national natural monument in Kochi Prefecture, Japan, is a cave formed in a limestone layer. A part of it is opened to the public as a tourism resource. In 1952, fluorescent lighting was introduced for visitors. When the lighting was switched to LED in 2013, the illuminance increased due to the smaller light-receiving area, which was thought to have promoted the growth of mosses and algae. Attempts were made to limit light wavelength for photosynthetic organism suppression to control coloring organisms to preserve the cave walls. As a result, it was shown that the occurrence of mosses and other organisms could be reduced in some cases. However, the causative microorganisms that cause the coloration and degradation of the cave walls are still unclear. In this study, we investigated the microbial communities in the areas illuminated by lighting in Ryugado.
Microbes, walls and floor surfaces discolored by lighting at 13 locations along an almost 1 km sightseeing course, were collected using sterile swabs. DNA was extracted from the swabs, and microbial, and plant diversity was examined using DNA barcodes that detect bacteria, fungi, and plant species. Microorganisms were isolated from the swabs and identified using DNA barcoding. Mosses, fungi, and algae were detected inside Ryugado. Among them, a group of photosynthetic bacteria was detected in the blue light receiving area, and bacteria producing blue pigments were detected in the white light receiving area. These pigmented organisms are thought to be one of the primary causes of the wall coloration in Ryugado. It is assumed that these pigmented organisms were introduced by water entering and exiting the cave and by visitors.
Microbes, walls and floor surfaces discolored by lighting at 13 locations along an almost 1 km sightseeing course, were collected using sterile swabs. DNA was extracted from the swabs, and microbial, and plant diversity was examined using DNA barcodes that detect bacteria, fungi, and plant species. Microorganisms were isolated from the swabs and identified using DNA barcoding. Mosses, fungi, and algae were detected inside Ryugado. Among them, a group of photosynthetic bacteria was detected in the blue light receiving area, and bacteria producing blue pigments were detected in the white light receiving area. These pigmented organisms are thought to be one of the primary causes of the wall coloration in Ryugado. It is assumed that these pigmented organisms were introduced by water entering and exiting the cave and by visitors.