RBCL GENETIC MARKER FOR MICROALGAE IDENTIFICATION

• Main Author: Reinaldi Hermawan, Okto
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/52270
• Institution: Institut Teknologi Bandung

Microalgae have various benefits such as like a source of nutrition, utilization of biosilica, raw materials for biodiesel, biopigments for commercial applications, besides microalgae is a parameter of the water fertility level. Indonesia is an archipelagic country and located in the tropics, so Indonesia has a very large diversity of marine microalgae species (biodiversity). Various types of microalgae have different potential. Microalgae are known as a cryptic species, so the detection by morphology alone is not accurate enough because of the high similarities between species. Genetic detection is more promising for differentiating microalgae diversity down to species level. SNP (Single Nucleotide Polymorphism) is a variation of a single base between individuals resulting from a point mutation in the genome. These variations differ between species or genus level, so they can be used as genetic markers. The purposes of this study were: (i) to grow samples of marine microalgae obtained from the waters of the bay of Lampung, Indonesia. And (ii) to develop SNP-based genetic markers for microalgae identification using rbcL gene data stored in international databases. Single cell microalgae samples were grown in f/2 medium and the cell morphology was observed under light microscopy for identification. The sample of marine microalgae with code A1 has similarities with Skeletonema sp. While code A6 with Cyclotella sp. The development of genetic markers was carried out by: (i) downloading microalgae rbcL gene data form various databases (NCBI, EMB-EBI, and DDBJ), (ii) organizing rbcL gene data based on genus, species, and fragment length, (iii) carrying out gene-aligment rbcL gene with the Clustal W program, (iv) found diagnostic SNPs as species and genus markers. The results of data download obtained rbcL gene sequences from 246 species belonging to 94 genus of microalgae. Analysis of the rbcL gene data provides potential diagnostic SNPs to identify 61 genus of microalgae and identify species within one genus. The A6 microalgae samples can be further identified to the species level using Cyclotella intra-genus SNP diagnostics (between species: bodanica, atomus, cryptica, chctawhatcheena, costei, cf. ocellata, and cf. comensis) at base positions 750, 768, 780, 792, 816, 828, 831, 840, 877, and 885. While the A1 sample used the Skeletonema intra-genus diagnostic SNP (between species : potamous, pseudocostatum, japonicum, menzelllii, subsalsum, grethae, costatum, tropicum, marinoi, grevillea, dohrnii, and ardens) at base positions 399, 423, 465, 478, 480, 486, 492, 507, 528, 531, 540, 582, 687, and 930.