Environmental DNA Approach to Identify Protists Community in Sediment of Balekambang Lake, Indonesia, Using 18S rRNA Gene

Balekambang is one of the lakes in the Dieng plateau, Indonesia, which has various problems. This is influenced by several things, including polluted lake waters due to the accumulation of garbage in the waterways that lead to the lake and the use of agricultural fertilizers around the lake. Meanwhile, protists are basically eukaryotic with high diversity and wide distribution which are commonly found in aquatic ecosystems. Environmental DNA (eDNA) is a new method for population monitoring that is superior to conventional methods and is starting to be widely used. With this in mind, a study was conducted on the use of eDNA as a fast and efficient method to identify protists communities in this area. Samples of ±10 g were collected using a sterile spatula on the sediment surface layer (0–2 cm). The extraction process followed the protocol in the Zymo Quick-DNA™ Fecal/Soil Microbe MiniPrep kit. Sequencing using amplicon-based method with Next Generation Sequencing (NGS) approach using 18S rRNA primers. Data analysis was carried out with the GALAXY program and R-STUDIO software to obtain 43 ASVs (Amplicon Sequences Variants) of total Eukaryotes and 16 ASVs belonged to the protists family that could be identified. The five families are Cyrtolophosididae, Gregarinidae, Isotrichidae, Ophryoscolecidae, and Tritrichomonadidae with the dominance of the Tritrichomonadidae family totaling 11 ASVs (25.6%) and Ophryoscolecidae with 2 ASVs (4.7%) indicating that the lake has small diversity and low community stability. Therefore, the analysis revealed that eDNA is an efficient method to identify protists communities in the lake.