Pseudomonas sp. strain SS22 telah dipencilkan daripada kolam oksidasi kilang minyak kelapa sawit di Malaysia. Dalam kajian ini, keupayaaan bakteria ini mentransformasikan asid oleik kepada produk baru telah dikaji. Produk biotransformasi dianalisis dengan kromatografi lapisan nipis (KLN), kromatografi gas (KG), spektroskopi inframerah gandingan fourier (SIGF) dan kromatografi gas-spektrometri jisim (KG-s.1). Analisis KLN menunjukkan bahawa hanya satu produk baru terbentuk selepas 7 hari eraman pada suhu 37°C, goncangan pada 150 ppm. Semakin lama eraman menyebabkan pengurangan titik produk pada 14 harL Analisis KG menunjukkan bahawa 5 puncak produk baru pada masa penahanan 13.1(*A), 15.0 (*C), 15.3 (*D), 16.8 (*E) dan 18.4 (*F) minit telah terbentuk selepas 7 hari eraman. Spektrum inframerah (Im) bagi produk yang terbentuk daripada asid oleik selepas 7 hari, menunjukkan kewujudan regangan OH/NH pada 3417 cm-'. Serapan pada 2673 cm-', kemungkinan regangan CH bersama-sama dengan kumpulan karbonil. Serapan pada 1712 cm-' adalah konstan dengan regangan c=o daripada keton atau asid karboksilik. Regangan CH pada 2932, 2854, 1462 dan 1379 cm-1 merupakan kumpulan alkil, menandakan produk hidrokarbon juga wujud dalam produk campuran. Kehadiran CH/C-C pada serapan 969 dan 725 cm-', menandakan kewujudan alkena trans (C=C). Analisis KG-SJ mengesahkan bahawa produk tersebut merupakan campuran asid 9(E)- heksadekenoik, asid kaprilik, asid miristik dan hidrokarbon. Walaupun produk yang terbentuk bercampur, asid 9(E)-heksadekenoik boleh digunakan sebagai komponen membran lipidnya. Penghasilan produk tersebut boleh dipertingkatkan dengan mengoptimumkan keadaan pertumbuhan.
Lipase from a newly isolated strain of Rhizopus rhizopodifonnis was partially purified and characterized. By acetone fractionation, the enzyme was purified to about 2.8 fold, with 62.5% recovery and with specific activity of 3.2 U/mg. By gel filtration through Sephadex G-100, the enzyme was further purified to 9.7 fold and had a specific activity of 11.1 U/mg. By polyacrylamide gel electrophoresis, five protein bands were observed after acetone fractionation, white two protein bands were observed after the preparation was passed through Sephadex G-100. It has a pH optimum at 6.0 and a temperature optimum at 45°C. The enzyme is most stable at pH 7.0 and temperature of 50°C. The enzyme has a preference for short chain triglycerides and can also hydrolyse some methyl esters. The lipase is specific for 1,3 positions.
Lipase daripada satu stren Rhizopus rhizopodifonnis yang baru dipencilkan telah diseparatulen dan diciri. Melalui fraksi asiton, enzim telah ditulen lebih kurang 2.8 ganda, dengan pengutipan 62.5% dan aktiviti spesifik 3.2 U/mg. Dengan penurasan gel melalui Sephadex G-l00, enzim ditulenkan lagi hingga 9.7 ganda dengan aktiviti spesifik mencapai 11.1 U/mg. Dengan elektroforesis gel poliakritamida, 5 jalur protein didapati selepas fraksi asetone, sementara 2 jalur protein dilihati selepas penurasan gel Sephadex G-10. Enzim ini mempunyai pH optimum pada pH 6.0 dan suhu optimumnya ialah 45°C Enzim ini paling stabit pada pH 7.0 dan suhu 50°C Enzim mempunyai kepilihan pada trigliserida rantai pendek dan dapat menghidrolisiskan beberapa ester metit. Lipase ini spesifik pada posisi 1,3.
The land area of Tanah Putih, Gua Musang, Kelantan (Malaysia) is well-known for its wealth in industrial mineral resources, especially aluminosilicate of feldspar and mica. Natural feldspar and mica were physicochemically characterized with regard to X-ray diffraction (XRD), nitrogen sorption analysis and transmission electron microscopy (TEM) techniques for qualitative and quantitative identification of feldspar and mica. They show a good crystallinity, high surface area and uniformity of mesoporous structures. For the purpose of this experiment, the aluminosilicate of feldspar was modified either by acid treatment, or grafting the silanol groups present with various functional groups including aminopropyl-, octyl-, vinyl-, mercapto- and glycidoxy-triethoxysilanes, or activation of pre-treated support with glutaraldehyde. These support derivatives were used for further utilization in the immobilization of lipase from Candida rugosa and resulted in various interaction mechanisms between enzyme and introduced supports. It seemed that the features of the functionalized feldspar surfaces provide a preferable environmental host to enable the adsorption of lipase via interfacial adsorption method. Lipase immobilization onto feldspar support were further confirmed by scanning electron microscopy (SEM) coupled with energy dispersive X-ray microanalysis (EDX), transmission electron microscopy (TEM) and infra-red spectroscopy (FTIR) techniques. Enhancement of protein loading (up to 8.22 mg protein/g support) and immobilization yield (up to 78%) were shown by modified feldspar-lipase derivatives compared to unmodified feldspar support.