PRODUKSI DAN OPTIMASI ENZIM PROTEASE DARI Bacillus cereus STRAIN TD5B, TD5K, LS2B DAN POTENSINYA SEBAGAI AGEN PENGEMPUK DAGING

VINI OKTAVIA, Yuny Erwanto, S.Pt, MP., Ph.D.

2015 | Tesis | S2 Ilmu Peternakan

Penelitian bertujuan untuk mengetahui isolat bakteri penghasil enzim protease dari tanah sekitar peternakan ayam petelur, Indeks Proteolitik, aktivitas proteolitik dan pengaruhnya terhadap keempukan daging sapi. Aktivitas protease dilihat dengan mengamati zona bening di sekeliling isolat. Uji kuantitatif dengan mengukur pertumbuhan sel bakteri pada masing-masing isolat. Dari pengukuran OD diperoleh OD tertinggi pada strain LS2B yaitu 0,339 dan aktivitas enzim tertinggi yaitu 0,8986 U/ml. Berdasarkan karakterisasi suhu isolat Bacillus cereus strain TD5B, TD5K dan LS2B sampai suhu 90ºC masih menunjukkan aktivitas yang terus meningkat dengan nilai aktivitas 1,772 U/ml 1,624 U/ml dan 1,760 U/ml seiring bertambahnya suhu yang diberikan. Hal ini menunjukkan bahwa ketiga isolat tergolong thermofilik yaitu mampu bertahan pada suhu tinggi. Kondisi pH tertinggi terdapat pada pH 11 strain TD5B yaitu 1,1657 U/ml sedangkan strain TD5K dan LS2B pada pH 9 yaitu 1,0354 U/ml dan 1,0887 U/ml. Kadar protein yang terkandung pada masing-masing isolat Bacillus cereus yaitu TD5B=0,026 mg/ml TD5K=0,031 mg/ml LS2B=0,031 mg/ml dan aktivitas spesifik pada masing-masing strain adalah TD5B=28,584 unit/mg TD5K=26,806 unit/mg LS2B=28,770 unit/mg. Ekstrak enzim yang telah diuji aktivitasnya ini diaplikasikan untuk pengempuk daging. Nilai daya putus WB menunjukkan adanya persamaan antara enzim TD5K dengan TD5B, yaitu kedua enzim tersebut mampu bekerja optimal dengan lama inkubasi 30 menit dan 60 menit, tetapi nilai daya putus WB enzim TD5K berbeda nyata (P<0,05) lebih rendah dibandingkan dengan nilai daya putus WB enzim LS2B. Hal ini dikarenakan analilsis statistik menunjukkan nilai daya putus WB pada waktu inkubasi 60 menit secara nyata (P<0,05) lebih rendah dibandingkan waktu inkubasi 30 menit. Kesimpulan penelitian ini adalah bakteri Bacillus cereus strain TD5B, TD5K dan LS2B mampu menghasilkan enzim protease, tetapi belum mampu memberikan efek maksimal terhadap keempukan daging. Kata kunci : Bacillus cereus, enzim protease, aktivitas enzim, pengempuk daging

The aim of this study was to determine the enzyme producing bacterial isolates from poultry farm soil around, proteolytic index, proteolytic activity and to determine the effect of bacterial proteases on beef tenderness. Protease activity was seen by observing the clear zone around the isolates. The test has been done by measuring the growth of bacterial cells in each isolate. Through optical density measurements, obtained the highest optical density on LS2B strain at 0,339 and the highest enzyme activity at 0,8986 units/ml. Based on temperature characterization of Bacillus cereus isolate strain TD5B, TD5K and LS2B, until reaching 90ºC temperature, those isolates still showed continously increasing activity with values of 1,772 units/ml, 1,624 units/ml and 1,760 units/ml as given temperature increased. This suggests that the three isolates belong to thermophilic are able to withstand high temperature. In the direction of pH characterization, the highest enzyme activity was at pH 11 for strains TD5B with a value of 1,1657 U/ml, while for strains TD5K and LS2B at pH 9 with values of 1,0354 units/ml and 1,0887 units/ml. To obtain the specific activity of the enzyme, protein content contained therein was measured. Levels of the protein contained in each isolates of Bacillus cereus are TD5B=0,026 mg/ml, TD5K=0,031 mg/ml, LS2B=0,031 mg/ml and the specific activity of each strain was TD5B=28,584 units/mg, TD5K=26,806 units/mg, LS2B=28,770 units/mg. Extracted enzyme activity which has been tested is applied to meat tenderizer. Warner-Bratzler shear force (WBSF) values indicates between the enzyme TD5K breaking with TD5B, that these enzymes are able to work optimally with the incubation time of 30 minutes and 60 minutes, but the WBSF values TD5K significantly different (P<0,05) lower than WBSF values of LS2B enzyme. This is because analilsis statistics show the WBSF values the 60 minutes incubation time significantly (P<0,05) lower than the incubation time of 30 minutes. The conclusion of this study is the bacterium Bacillus cereus strain TD5B, TD5K and LS2B are able to produce protease enzymes, but have not been able to give the maximum effect on meat tenderness. Keywords : Bacillus cereus, protease, enzyme activity, meat terderness

Kata Kunci : Bacillus cereus, enzim protease, aktivitas enzim, pengempuk daging; Bacillus cereus, protease, enzyme activity, meat terderness