TANGGAPAN FISIOLOGIS RHIZOBAKTERI OSMOTOLERAN (Enterococcus flavescens) TERHADAP CEKAMAN OSMOTIK (GLUKOSA) DAN KEASAMAN (ALUMINIUM SULFAT)

SUMITRI, Prof.Ir.Triwibowo Yuwono, Ph.D.

2014 | Skripsi | MIKROBIOLOGI PERTANIAN

Rhizobakteri osmotoleran yang diduga sebagai Enterococcus flavescensdiperlakukan dalam kondisi cekaman glukosa dan asam untuk mengetahui tanggapan fisiologis. Sel ditumbuhkan dalam dua medium yang berbeda yaitu medium LB (Luria Bertani) dan medium M63 (minimal medium)yang ditambah dengan glukosa dan aluminium sulfat untuk menghasilkan cekaman ganda. Tanggapan fisiologis mikrobia terhadap cekaman lingkungan diamati melalui pola pertumbuhan dan metabolit yang terbentuk. Hasil penelitian ini menunjukkan bahwa kerapatan sel pada medium LB lebih tinggi daripada medium M63. Di sisi lain, pada medium M63, semakin tinggi konsentrasi glukosa menghasilkan kerapatan sel yang lebih tinggi, meskipun sebenarnya kepadatan sel dalam medium M63 jauh lebih rendah daripada di medium LB. Analisis GC-MS (Gas Chromatography Mass Spectrophotometer) dilakukan pada sel dengan media LB tanpa perlakuan (kontrol) dan pada sel-sel yang tumbuh di medium LB dengan perlakuan glukosa 5% dan Al2(SO4)3 500 ppm menghasilkan beberapa metabolit. Pada medium kontrol teridentifikasi 2 senyawa metabolit, yaitu oxirane dan phenol. Pada medium LB dengan perlakuan glukosa 5%+Al2(SO4)3 500ppm teridentifikasi 9 senyawa metabolit, yaitu phenol, Butanoic acid; 1,5- Anhydro-6- deoxyhexo-2,3-diulose; Fenoprofen+TMAH; Eicosanoic acid; 9-Octadecenoic acid; Octadecenoic acid; Hexadecanoic acid dan 9-Octadecen-1-ol

Osmotolerant Rhizobacteria designated as Enterococcus flavescens has been subjected to glucose and acid stress condition to study its physiological response. Cells were cultured in 2 different media : LB (Luria Bertani) and M63 (minimal medium), supplemented with glucose and aluminium sulphate to imposedouble stress condition. Physiological responses of the rhizobacteriaunder environmental stress were observed by measuring its growthandthemetabolitessynthesised. The results of thisstudydemonstrated that the higher glucose concentration, the lower thecell density in M63 medium. On the other hand, in M63 medium, elevated concentration of glucose resulted in higher cell density, despite the fact that the actual cell density in M63 medium was much lower than in LB medium.GC-MS (Gas Chromatography Mass Spectrophotometer) analysis conductedon cells cultivated using LB medium without any treatment (control) and on cells grown under LB medium supplemented with glucose 5% and Al2(SO4)3 500 ppm resulted in several metabolites detected.Two metabolite compounds were identified in control medium, i.e.oxirane andphenol, whilein LB medium supplemented with glucose 5% and Al2(SO4)3 500 ppm, nine metabolite compounds were identified, i.e.phenol, Butanoic acid; 1,5- Anhydro-6- deoxyhexo-2,3-diulose; Fenoprofen+TMAH; Eicosanoic acid; 9-Octadecenoic acid; Octadecenoic acid; Hexadecanoic acid dan 9-Octadecen-1-ol.

Kata Kunci : rhizobakteri, cekaman glukosa, cekaman aluminium sulfat, metabolit total