Pengaruh Jenis Sumber Nitrogen Pada Pembuatan Olyhydroxybutyrate Dari Glukosa Menggunakan Bakteri Bacillus Cereus

Polyhydroxybutyrate (PHB) adalah salah satu bahan baku plastik biodegradabel. Bakteri memproduksi PHB di dalam selnya, sebagai cadangan sumber carbon dan energi untuk pertumbuhannya, pada saat pasokan nutrisi tidak seimbang. Sifat PHB mirip dengan sifat polypropylene (PP) yang merupakan bahan baku plastik berbasis petrokimia. Selain itu PHB juga bersifat renewable, ramah lingkungan dan biokompatibel. Salah satu nutrisi untuk pertumbuhan bakteri adalah Nitrogen. Penelitian ini dilakukan untuk mengetahui pengaruh jenis sumber Nitrogen terhadap pertumbuhan sel bakteri dan kadar PHB yang diperoleh.Pembuatan PHB dilakukan secara proses fermentasi. Mula-mula glukosa sebagai sumber karbon dan larutan Mineral Salt Medium (MSM), ditambah dengan sejumlah sumber nitrogen (Tripton, Pepton, Ammonium Sulfat, Ammonium Chlorida). Larutan selanjutnya disterilisasi menggunakan autocalve. Setelah medium dingin ditambahkan sejumlah 10% vol bakteri Bacillus cereus. Selanjutnya medium dilakukan proses fermentasi selama 96 jam. Setelah fermentasi selesai dilakukan pemanenan untuk pemisahan sel biomass dari filtratnya dengan cara centrifugasi. Filtrat yang diperoleh dianalisa kandungan gula reduksi, sedangkan sel biomass dianalisa kadar PHB. Hasil penelitian menunjukkan fermentasi oleh bakteri Bacillus cereus menggunakan sumber nitrogen Tripton, menghasilkan berat sel kering yang banyak, yaitu 5,391 g/L, dan produksi PHB sedikit, yaitu 11,2%. Sedangkan pada fermentasi menggunakan sumber nitrogen Pepton, menghasilkan berat sel kering sedikit (3,031g/L), tetapi produksi PHB banyak (19,6%)

Technique for Immobilization of Lipase Within Membrane Pores as Nanoreactor

The objective of this study was to design of nanoscale biocatalyst system by utilizing the membrane as nanoporous media. The nanostructure was modified by two step methods: simple adsorption and continue with pressure driven filtration. Two types of polymeric membranes Mixed Cellulose Ester (MCE) and Polyethersulfone (PES) were used asmatrices for immobilization of lipase from Pseudomonas fluorescens. The lipase solution was allowed to permeate through the membrane and lipase molecule adsorbed on the inner wall of pores. The porosity and membrane matrices influenced the enzyme loading. The best result for enzyme loading inmembrane matric is 3.75 g.m-2 using PES membrane with incubation time of 18 hours. PES membrane was selected for further continuous transesterification studies. We evaluated the transesterification activity by converting triolein and methanol to methyl oleate and glycerol. The reaction was carried out in situ within the pores of membrane matric, so that its pores act kind of nanoreactor during formation of product material. The degree of triolein conversion using this kind of nanoreactor was about 80% with 30 minutes of residence time. The productivity of immobilized lipase within the pores were 40 fold higher than that of native free lipase

Biomass Production Chlorella Vulgaris Buitenzorg Using Series of Bubble Column Photo Bioreactor with a Periodic Illumination

Chlorella vulgaris Buitenzorg cultivation using three bubble column photo bioreactors arranged in series with a volume of 200 mL for 130 hours shows an increase of biomass production of Chlorella vulgaris Buitenzorg up to 1.20 times and a decrease of the ability of CO2 fixation compared to single reactor at a periodic sun illumination cycle. The operation conditions on cultivation are as following: T, 29.0oC; P,1 atm.; UG, 2.40 m/h; CO2, 10%; Benneck medium; and illumination source by Phillip Halogen Lamp 20W /12V/ 50Hz. Other research parameters such as microbial carbon dioxide transferred rate (qco2), CO2 transferred rate (CTR), energy consumption for cellular formation (Ex), and cultural bicarbonate species concentration [HCO3] also give better results on series of reactor

PERILAKU HOMOSEKSUAL: MENCARI AKAR PADA FAKTOR GENETIK

The study based on literatures on this article presents data that is critical discourses of homosexuality and genetics. This article does not disclose the direction of Islam in terms of homosexuality because it is so obvious expressed in the Koran and explained by the righteous mufassir, muslim clerics and scholars. There is no strong data linking specific genetic factors with the emergence of homosexual behavior. Research conducted by the proponents of homosexual showed no single gene that govern human behavior which is a very complex phenomena. In other words, the genes do not determine behavior of homosexuality in particular. Expressed genes responsible for the nature of homosexuality is also interpreted as genes responsible for other mental problems. The experts further revealed that homosexual orientation is strongly affected by the events and stimuli experienced by either of the environment with a growing degree of openness to homosexual behavior as well as due to the availability of information, especially in cyberspace. Some chemicals are suspected of causing physical changes and influence on sexual orientation. Efforts of healing through action or medical intervention are not  impossible. Some researches suggest that homosexual behavior is more aggressive than men hetersexual both in individual and family scale. The author sees the belief that genetic factors are the reason for accepting homosexual behavior has no strong scientific roots. Behavior of homosexuality thus can actually be, or should be, repaired and healed.The study based on literatures on this article presents data that is critical discourses of homosexuality and genetics. This article does not disclose the direction of Islam in terms of homosexuality because it is so obvious expressed in the Koran and explained by the righteous mufassir, muslim clerics and scholars. There is no strong data linking specific genetic factors with the emergence of homosexual behavior. Research conducted by the proponents of homosexual showed no single gene that govern human behavior which is a very complex phenomena. In other words, the genes do not determine behavior of homosexuality in particular. Expressed genes responsible for the nature of homosexuality is also interpreted as genes responsible for other mental problems. The experts further revealed that homosexual orientation is strongly affected by the events and stimuli experienced by either of the environment with a growing degree of openness to homosexual behavior as well as due to the availability of information, especially in cyberspace. Some chemicals are suspected of causing physical changes and influence on sexual orientation. Efforts of healing through action or medical intervention are not  impossible. Some researches suggest that homosexual behavior is more aggressive than men hetersexual both in individual and family scale. The author sees the belief that genetic factors are the reason for accepting homosexual behavior has no strong scientific roots. Behavior of homosexuality thus can actually be, or should be, repaired and healed

How Indonesians Cope with Chronic Pain: Does Seeking Help and Comfort from God Work?

Chronic pain is a significant health problem in many countries including Indonesia, with high prevalence and the possibility to increase in the future. Individuals experiencing chronic pain elicit cognitive and behavioral responses, including pain catastrophizing which can cause high pain interference. Effective coping ability can help reduce the impact of pain catastrophizing on pain interference. Previous research focused on emotion-focused and problem-focused coping in dealing with chronic pain. However, Indonesia as a country with a strong influence from religious values and practices encourages the exploration of positive religious coping. A part of a longitudinal study on psychological factors in chronic pain development, this study aimed to examine the moderating role of three coping styles on pain catastrophizing and pain interference associations. Results from 368 participants male and female with chronic pain showed that positive religious coping and problem-focused coping significantly moderated the effects of pain catastrophizing on pain interference. Seeking help from God helped individuals deal with chronic pain problems, as well as actively resolving difficulties. The use of these two coping styles in the Indonesian population can be useful for managing chronic pain

A response surface methodology for the use of MIL‐101 as a catalyst for the one‐step synthesis of lactide

Lactide is a vital monomer for producing high molecular weight polylactic acid (PLA) through ring‐opening polymerization. This study synthesized crude lactide from L‐lactic acid with MIL‐101 as the catalyst. MIL‐101 is a metal‐based catalyst with organic ligands (MOF) that was prepared by reacting Cr(NO3)3.9H2O with terephthalic acid (BDC). The formation of MIL‐101 was confirmed from Fourier‐transform infrared (FTIR) analysis. The role of MIL‐101 and the effect of temperature, time, and MIL‐101 loading, as well as their interactions in the conversion of lactic acid to crude lactide, were then investigated using the response surface method (RSM). Crude lactide was analyzed using 1H‐nuclear magnetic resonance (NMR) spectroscopy to confirm the presence of lactide. The RSM results indicated that the highest conversion of 22.84% can be obtained using a temperature of 175 °C, 1.5% w/w MIL‐101 loading, and a reaction time of 5 h. The RSM model showed that the interaction of MIL‐101 loading and reaction time strongly affected the conversion of lactic acid to lactide, with a P‐value of 0.0021 and an F‐value of 50.45. In contrast, the interaction of catalyst loading and temperature did not significantly affect the conversion of lactic acid to lactide, with a P‐value of 0.2565 and an F‐value of 1.75

Student Perspectives of the Value of a Drop-In Room and its Influence on their School Experience

In the United States, the prevalence of poor mental health among middle and high school kids has amplified quickly (CDC, 2023). Schools are looking for different initiatives to combat this epidemic (Department of Education, n.d.). A local school district has an initiative where students have access to a room where they can come to relax and destress during the day. The purpose of this study is to determine the value and usefulness of such a room. We used a non-experimental questionnaire, as well as informal interviews with students, to understand student perspectives on the drop-in room. From our initial data, it seems that most students think the drop-in room improves their school experience and would like to see it continued. Based on our results, we recommend that other schools consider implementing a drop-in room based on the positive impacts it could potentially have on students’ mental health and school experience.https://orb.binghamton.edu/research_days_posters_2023/1032/thumbnail.jp