Judul: Karakteristik dan Kinetika Enzimatik β-Galaktosidase Isolat Bakteri AV-1 pada Susu Pasteurisasi
Abstrak: Lactose is not found in natural product except from mammary gland. Lactose must be hydrolized into glucose and galactose by β-galaktosidasesenzyme. So that, it is posible to be absorb by intestine. The purpose of this research was determined differences in characteristic and kinetics of β- galaktosidases-enzyme produced by AV-1 selected isolate lactid acid bacteria and Lactobacillus bulgaricus in hydrolyzing pasteurized milk. The optimum condition of AV-1 isolate β-galaktosidase enzyme was on incubation time 25 minute, temperature 43 °C, pH 6.5, with activity 0.182 U/ml, while the optimum condition of Lactobacillus bulgaricus β-galaktosidase enzyme was on incubation time 20 minute, temperature 43 °C, pH 6.5, with activity 0.357 U/ml. The kinetics parameters (Vmaks. and apparent KM) of isolate AV-1 β-galaktosidase enzyme were 0.198 U/ml and 1.314 mM, while the kinetics parameters (Vmaks. and apparent KM) of Lactobacillus bulgaricus’ β-galaktosidase enzyme (as control) were 0.385 U/ml and 1.075 mM. The activity of β-galaktosidase AV-1 isolate statistically was different from Lactobacillus bulgaricus’ (P < 0.05).
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Judul: Purifikasi, amobilisasi, dan karakterisasi β-galaktosidase dari Enterobacter cloacae serta potensinya terhadap susu UHT
Abstrak: Enzymatic hydrolysis of lactose is an important biotechnological process because the hydrolyzed products can be consumed by people with lactose intolerance. The aim of this study was purification, immobilization, and characterization of β-galactosidase from E. cloacae. This research also studied the hydrolysis of lactose in UHT milk. The stages of this research were production and purification β-galactosidase from E. cloacae; characterization of enzyme; optimization of immobilization formula; and hydrolisis of UHT milk. The β- galactosidase from E. cloacae was purified and showed a purification of 30.26- fold, a yield of about 6.18%, and a specific activity of 101.781 U/mg. Free and immobilized enzyme exhibited maximum activity at an optimal pH of 7.0 and an optimum temperature of 40°C. This enzyme was activated by Co2+, Mn2+, and Mg2+; however, was inhibited by Ca2+, Zn2+, Cu2+, and Hg2+. KM for free and immobilized β-galactosidase were 0.434 and 2.068 mM, respectively. Optimal formulation of cell and enzyme immobilization were consist of 10% (w/v) cell with 5% (w/v) sodium alginate and 10% (v/v) purified enzyme with 5% (w/v) sodium alginate, respectively. This researh found that entrapped β-galactosidase was higher in the hydrolysis of lactose present in milk (28.09%) after 6 hours in batch process as compared to entrapped E. cloacae (22.01%) after 18 hours. Free β-galactosidase was higher in the hydrolysis of lactose present in milk (78.20%) after 6 hours as compared to free E. cloacae (55.14%) after 18 hours.
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Judul: Perencanaan Sistem Ruang Terbuka Hijau (RTH) Untuk Mendukung Terciptanya Kenyamanan dan Identitas Lanskap Kotamadya Metro.
Abstrak: Secara umum luas RTH total Kota Metro menurut Inmendagri No. 14 Tahun 1988 masih mencukupi yaitu sebesar 3.639,09 Ha (52,94% dari luas total wilayah). Berdasarkan perhitungan Simonds (1983), kebutuhan RTH dalam skala kota saat ini masih mencukupi yaitu sebesar 951,20 Ha (kebutuhan RTH hanya 760,08 Ha), dan menurut metode Gerarkis kebutuhan RTH berupa tegakan pohon sebesar 940,94 Ha (kebutuhan RTH hanya 558,80 Ha). Meskipun kebutuhan RTH Kota Metro dalam skala kota masih mencukupi, namun dari segi kualitas dalam bentuk RTH untuk kenyamanan lingkungan masih kurang, terutama dengan semakin meningkatnya pembangunan fisik di tahun mendatang. Konsep sistem RTH yang diusulkan adalah sistem jejaring RTH yang berkesinambungan sehingga dapat menyangga sistem ekologi kota, memberikan kenyamanan bagi warga kota serta menampilkan identitas dan keindahan visual melalui pengembangan lanskap kota dan penataan vegetasi sesuai fungsi serta bentuk RTH diharapkan dapat menampilkan identitas kota. Karakter identitas RTH Kota Metro terbentuk melalui pola jejaring RTH yang diusulkan, taman kota di kecamatan Metro Pusat sebagai landmark dan pusat jejaring, serta melalui penataan vegetasi yang adaptif dan disukai oleh masyarakat. Sistem jejaring RTH ini diterapkan dalam perencanaan RTH berdasarkan pendekatan kebutuhan RTH, peningkatan kualitas RTH dan pembangunan RTH melalui konversi bentuk­bentuk RTH yang memungkinkan. Selain itu, untuk menunjang aspek kehyamanan diperoleh dari penerapan sistem jejaring RTH, peningkatan jumlah pohon, penataan secara estetis dan pemeliharaan yang berkelanjutan. Dalam studi ini, konsep dituangkan juga dalam bentuk rencana spasial RTH Kota Metro...dst
Keyword: tataguna lahan, tata ruang kota, identitas kota, RTH, topografi