Judul: Pengaruh Persepsi dan Pengetahuan terhadap Perilaku Pembelian Perhiasan Emas pada Keluarga Petani
Abstrak: Gold is a precious metal and include to pure metal groups which has a high value. Generally, gold jewelry is a form of savings deposits and have the high liquidity. The aim of this study is to know the influence of consumer perception and knowledge towards purchase behavior on gold. This research used 65 samples. All samples in this research are 65 people. Data were collected through interviews using questionnaires. The results showed that sample’s age included in the category of middle adulthood with educational range of each sample less than six years, and due to family size those family include to small family category. According to analysis data (93.8%) have a good perception of the gold jewelery and (55.4%) have a good perceptions of gold jewelry. There are (72.3%) samples have a good knowledge about gold and jewelry (55%) instances ever made a purchase of gold jewelry. Due to regression test results show that the perception of a savings and total assets possess significant influence on purchase frequence of buying gold as saving, and the total assets of the family had an influence on the weight of gold jewelry is purchased by them.
Keyword: perception, knowledge, gold purchase behavior

Judul: Pengaruh Persepsi Risiko dan Financial Self-Efficacy terhadap Minat Investasi Emas pada Generasi Z
Abstrak: Emas dipandang sebagai produk investasi dengan risiko rendah, namun setiap individu tentu memiliki perbedaan persepsi yang dapat mempengaruhi pilihan investasi. Selain itu, dalam berinvestasi juga dapat dipengaruhi oleh financial self efficacy. Penelitian ini dilakukan dengan tujuan menganalisis pengaruh persepsi risiko dan financial self-efficacy terhadap minat investasi emas. Penelitian menggunakan desain cross sectional study dengan 188 responden generasi Z berusia 17-26 tahun di Indonesia. Data dikumpulkan secara online menggunakan Google Form. Hasil menunjukkan adanya hubungan positif signifikan antara jumlah tanggungan dengan financial self-efficacy dan minat investasi emas serta usia dengan minat investasi emas. Hubungan negatif ditemukan antara persepsi risiko dengan minat investasi emas. Hasil uji regresi menunjukkan jumlah tanggungan, usia, berpengaruh positif terhadap minat investasi emas, sementara pengaruh negatif ditemukan pada variabel persepsi risiko., Gold as an investment is categorised as low risk product, however each individual have their own risk perception, and it is projected that financial self efficacy could also affect the intention to buy gold as investment. The aims of this research is to analyze the influence of risk perception and financial self-efficacy towards intention to invest in gold. This quantitative study was conducted in Indonesia. Using a cross-sectional study design about 188 generation Z aged 17-26 years were involved as the respondents. Data was collected online using Google Form. The results show that the number of dependents has a significant positive relationship with financial self-efficacy and intention to invest in gold. Similarly, age has a positive correlation with intention to invest in gold, while a negative relationship was found. In addition, there is a positive influence on the number of dependents and age towards the intention to invest in gold, while the effect of perceived risk is negative.
Keyword: financial self-efficacy, gold investment intention, risk perception, generation Z

Judul: Extracellular Expression of thermostable Geobacillus stearothermophilus T1.2RQ Lipase for Biodiesel Production
Abstrak: The extracellular expression of enzymes in an excellent secretion host such as Bacillus subtilis is a useful strategy for making enzymes of industrial significance more affordable by lowering the cost of its downstream processing. Lipases are a category of hydrolases that catalyze the hydrolysis of triglycerides to glycerol and free fatty acids. Also, lipases catalyze the hydrolysis and transesterification of other esters as well as the synthesis of esters. They can perform very specific biotransformation reactions and are widely used in food, organic synthesis, detergents, cosmetic, and pharmaceutical industries. Geobacillus stearothermophilus T1.2RQ lipase is an industrially-desired thermostable lipolytic enzyme with an excellent hydrolytic and transesterification activity. This study aimed to express T1.2RQ lipase, in B. subtilis WB800 and ensure its secretion into the extracellular medium. Three signal peptides (AmyQ, Epr, LipA) and two promoters (Pgrac01 and Pgrac100) were used in the secretory-expression of T1.2RQ lipase, based on five constructed expression vectors constructed by restriction cloning and PCR mutagenesis. Sangers sequencing was used to verify constructs to ensure they are in the correct reading frame. Recombinants vectors, pHT43 (plasmid control), pHT43-T1.2RQ, pHT43- T1.2RQ_AmyQ, pHT43-T1.2RQ_Epr, and pHT43-T1.2RQ_LipA, were transformed by electroporation into Bacillus subtilis WB800. The electroporation was successful with the optimum condition of 2500V, 200 ohms, 25µF, and 5milliseconds. Recombinant B. subtilis pHT43 (negative control) and pHT43-T1.2RQlip + signal peptides were streaked on the lipidic agar, LA+TBN. All four recombinants, including the negative control (B. subtilis WB800-pHT43), produced clear zones on the TBN agar plate after overnight incubation (fig 2), indicating the presence of a lipolytic enzyme in all of the recombinant B. subtilis cells. pHT43-T1.2RQlip + signal peptides (AmyQ, Epr, and LipA) have clear zones with significantly higher diameters than B. subtilis WB800-pHT43 (negative control). This phenomenon suggests that the recombinant thermostable lipase T1.2RQ introduced into these cells was successfully expressed, thereby increasing the lipolytic capability of its host cells T1.2RQ lipase was expressed in 50ml terrific broth medium (TB) and the expression induced with 1mM IPTG. Lipase activity assay using p-nitrophenyl esters showed that all three signal peptides directed the secretion of T1.2RQ lipase into the extracellular medium. Signal peptide, LipA, resulted in the highest extracellular activity of 5.6 U/mL, which corresponds to a 6-fold increase over the parent B. subtilis WB800 strain. Meanwhile, signal peptides, AmyQ and Epr produced 4.2 U/mL and 3.4 U/mL activity respectively. SDS-Zymogram analysis confirmed that T1.2RQ lipase was correctly processed and secreted in its original size of 44 kDa. An attempt to further increase lipase expression level by promoter optimization showed that, contrary to expectation, promoter Pgrac100 exhibited similar expression levels as the original Pgrac01. Nevertheless, the demonstration of the successful secretion of T1.2RQ lipase in this work confirms the latter as a promising approach for the industrial production of the enzyme
Keyword: Bacillus subtilis, Expression, Extracellular, Heterologous, Lipase, Thermostable