Growth rate and molecular identification of two Chlorella sp. from Balai Besar Perikanan Budidaya Air Payau (BBPBAP) Jepara

Chlorella is one of the important photosynthetic microalgae from the phylum Chlorophyta which is rich in pigments, lipid, amino acid, carbohydrates, pigments, and vitamins. The need to obtain growth characteristics and pure isolates of Chlorella is necessary for further development of its potential. The Center for Brackish Water Cultivation Fisheries (BBPBAP) is a large center for several types of microalgae cultivation located in Jepara, Indonesia. Therefore, the purpose of this study was to determine the growth characteristics of two samples of Chlorella spp. from BBPBAP and to identify its molecular characteristics based on the Internal Transcribed Spacer (ITS) gene. The method used is the calculation of the number and density of microalgae cells using a haemocytometer in each growth phase. Molecular characterization was carried out using DNA isolation and amplification of the ITS region followed by sequencing and similarity analysis. The results of DNA sequencing were analyzed using ChromasPro software and the sequences were aligned in the National Center for Biotechnology Information (NCBI) database. The growth of the two Chlorella samples on a laboratory scale lasted for 9 days. The highest cell number of C. vulgaris was achieved on the 7th and 8th days with a cell count of 2.75 x 106 cells/mL and C. sorokiriana occurred on the 8th day was 4.4 x 106 cells/mL. The molecular identification results showed that the two Chlorella cells had the highest similarity with Chlorella vulgaris and Chlorella sorokiniana. The results of molecular identification also indicate that the species that is predicted to be Chlorella pyrenoidosa as Chlorella sorokiriana.