Judul: Pengaruh Nilai Dan Kelompok Acuan Terhadap Pembelian Hedonis Konsumen Muda
Abstrak: Pembelian hedonis merupakan suatu pembelian yang berdasarkan pada aspek kesenangan, melibatkan sensori dan diluar kebutuhan. Tujuan dari penelitian ini adalah menganalisis pengaruh nilai dan kelompok acuan terhadap pembelian hedonis konsumen muda. Desain penelitian ini menggunakan cross sectional study dengan metode survei secara self report menggunakan kuisioner. Hasil penelitian didukung dengan wawancara mendalam terhadap beberapa contoh. Penelitian ini melibatkan 205 orang mahasiswa Strata-1 (S1) Institut Pertanian Bogor yang dipilih secara proportional random sampling. Analisis statistik yang digunakan adalah uji beda independent t-test dan analisis linear berganda. Terdapat perbedaan signifikan pada dimensi nilai kegembiraan dan pembelian hedonis antara laki-laki dan perempuan. Nilai berpengaruh secara signifikan dan positif terhadap pembelian hedonis, sedangkan kelompok acuan tidak berpengaruh signifikan terhadap pembelian hedonis.
Keyword: kelompok acuan, nilai, pembelian hedonis

Judul: Pengaruh Promosi Pemasaran, Kelompok Acuan dan Konsep Diri terhadap Perilaku Pembelian Hedonis pada Generasi Z.
Abstrak: Perilaku pembelian hedonis merupakan suatu tingkah laku yang lebih mengutamakan keinginan pada saat melakukan pembelian terhadap barang. Tujuan dari penelitian ini adalah menganalisis pengaruh dari promosi pemasaran, kelompok acuan dan konsep diri terhadap perilaku pembelian hedonis. Penelitian dilakukan melalui survei online. Analisis data yang digunakan adalah analisis deskriptif, faktor analisis, structural equation modelling (SEM) dan independent sampel t-test. Dua ratus dua puluh dua orang responden dipilih secara stratified proportionate random sampling. Hasil dari penelitian menunjukkan bahwa konsep diri berpengaruh signifikan terhadap perilaku pembelian hedonis pada kelompok sains, promosi pemasaran dan kelompok acuan berpengaruh signifikan terhadap perilaku pembelian hedonis. Penelitian juga menemukan perbedaan signifikan pada variabel promosi pemasaran, kelompok acuan, konsep diri dan perilaku pembelian hedonis antara kelompok sains dengan kelompok sosial.
Keyword: kelompok acuan, konsep diri, perilaku pembelian hedonis, promosi pemasaran, SEM

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