Judul: Expression Analysis of Lipid Biosynthesis-Related bZIP1 and LEC1 Ortholog Genes in Chlorella vulgaris Cultures Under Nitrogen Deficiency Conditions, Expression Analysis of Lipid Biosynthesis-Related bZIP1 and LEC1 Ortholog Genes in Chlorella vulgaris Cultures Under Nitrogen Deficiency Conditions
Abstrak: Microalgae can produce energy-rich compounds, especially triacylglycerol, for biofuel production. This study aims to analyze the expression of lipid biosynthesis-related bZIP1 and LEC1 ortholog genes in the culture of Chlorella vulgaris under optimum and nitrogen-deficiency conditions and to identify the microalgae isolates through molecular approach. The C. vulgaris samples were cultured and subjected to nitrogen-deficiency treatment in NaNO3 compound with a control-to-treatment ratio 4:1 and final concentrations of 100 and 25 mg/L. Cell harvesting was performed on exponential phase based on the cell growth curve calculated using haemacytometer. Sequencing techniques confirmed the taxonomic status of microalgae isolates on 18S rRNA gene fragments. The orthologous genes were analyzed in the GeneBank database using the BLAST algorithm based on the similarity of protein sequences (BLASTp and tBLASTn). Total RNA isolation, cDNA synthesis, and qRT-PCR performed the gene expression analysis. Cell density calculation results showed that nitrogen-deficiency decreased the C. vulgaris growth. Sequence analysis of the 18S rRNA gene fragment revealed similarity with Chlorella. The qRT-PCR analysis results indicate a significant upregulation of the LEC1 ortholog gene by 2-fold compared to the control. Differently, the upregulation of the bZIP1 ortholog gene is not statistically significant, showing a 1.5-fold increase compared to the control.
Keyword: nitrogen-deficiency, bZIP1, LEC1, qRT-PCR

Judul: Expression of bZIP1 and LEC1 Genes and Lipid Content in  Microalgae Nannochloropsis sp. Cultures Under Salinity Stress
Abstrak: Mikroalga Nannochloropsis sp. merupakan kandidat penghasil bahan bakar berupa biofuel. Hal ini disebabkan, kemampuannya mengakumulasi lipid dalam jumlah tinggi, terutama pada kondisi cekaman. Pembentukan lipid dipengaruhi oleh faktor transkripsi berupa gen Basic Leucine Zipper 1 (bZIP1) dan Leafy Cotyledon 1 (LEC1). Penelitian ini bertujuan menganalisis ekspresi gen bZIP1 dan LEC1 dalam kultur mikroalga Nannochloropsis sp. pada kondisi cekaman salinitas dan hubungannya dengan biosintesis lipid. Isolat Nannochloropsis sp. dikultur pada kultur peralihan, kemudian pada kultur kontrol dan perlakuan cekaman salinitas tinggi dan rendah. Analisis ekspresi gen dilakukan dengan isolasi RNA, sintesis cDNA, dan analisis qRT-PCR. Pengukuran lainnya adalah densitas sel, bobot biomassa, dan kandungan lipid. Hasil qRT-PCR menunjukkan peningkatan secara signifikan ekspresi gen relatif bZIP1 sebesar 340 kali dan LEC1 sebesar 18.000 kali pada kultur Nannochloropsis sp. yang mengalami cekaman salinitas tinggi, dan sebaliknya hampir tidak terdeteksi pada kultur yang mengalami cekaman salinitas rendah dibandingkan kontrol. Densitas sel kultur mikroalga menurun pada perlakuan cekaman salinitas tinggi dan rendah berturut-turut sebesar 38,3% dan 16,3% saat fase stasioner, serta penurunan bobot biomassa berturut-turut sebesar 45,9% dan 40,8%. Kandungan lipid pada kultur mikroalga cekaman salinitas tinggi mengalami peningkatan sebesar 35,3% dan kandungan lipid pada kultur mikroalga cekaman salinitas rendah mengalami penurunan sebesar 34,4%., Nannochloropsis sp. is a promising candidate for producing biofuel, a substitute for fossil fuels. This is due to its ability to accumulate high levels of lipids, especially under stress conditions. Lipid formation is influenced by transcription factors such as Basic Leucine Zipper 1 (bZIP1) and Leafy Cotyledon 1 (LEC1). This study aims to analyze the expression of bZIP1 and LEC1 genes in Nannochloropsis sp. cultures under salinity stress conditions and their relationship with lipid biosynthesis. Nannochloropsis sp. isolates were initially cultured in transition culture, then subcultured in control and salinity stress conditions. Gene expression analysis involved RNA isolation, cDNA synthesis, and qRT-PCR. Cell density, biomass weight, and lipid content were assessed. qRT-PCR showed a significant increase in the relative gene expression of bZIP1 by 340 times and LEC1 by 18.000 times in Nannochloropsis sp. cultures under high salinity stress, while expression was almost undetectable under low salinity stress compared to the control. Cell density of Nannochloropsis sp. cultures decreased by 38,3% and 16,3% respectively, during the stationary phase, with biomass weight reductions of 45,9% and 40,8%, respectively. Lipid content in high salinity stress culture increased by 35.3%, while lipid content in low salinity stress cultures decreased by 34,4%.
Keyword: bZIP1, LEC1, salinity stress, transcription factor, triacylglycerol

Judul: Pola Pernikahan Masyarakat Batak Karo di Perantauan
Abstrak: Pernikahan adalah budaya yang tidak akan pernah berhenti, pernikahan akan terjadi secara berkelanjutan Dasarnya, karena pernikahan merupakan kebutuhan biologis manusia. Indonesia adalah negara yang kaya akan budaya dan etnis. Setiap suku di Indonesia mempunyai tata cara/adat istiadat dalam pelaksanaan pernikahan itu sendiri. Begitupun dengan suku Batak karo yang mempunyai sendiri tata cara pelaksanaan pernikahan. Seiring dengan perkembangan zaman Karo Banyak masyarakat yang merantau ke berbagai daerah di Indonesia, salah satunya Bogor berjalan-jalan. Masyarakat Karo yang merantau ke wilayah Bogor pada umumnya akan berusaha melakukan adaptasi ke negara tempat tinggal baru. Keadaan ini juga terjadi pada perkawinan Karo dalam pola adaptasi di Bogor. Namun adaptasi pernikahan masyarakat Karo di Bogor berupaya menjaga nilai-nilai budaya Karo dan sakralisme perkawinan. Mereka do Karo Dimodifikasi pada pola perkawinan, dengan tetap menjaga nilai budaya pernikahan.
Keyword: Weddings Karo, Adaptation marriage patterns, Attitudes