ABSTRAKAspergillus flavus UICC 360 telah diketahui mampu menghasilkan lovastatinpada fermentasi menggunakan sumber nitrogen NaNO3. Penelitian bertujuanuntuk mengetahui pengaruh variasi konsentrasi NH4NO3 terhadap kemampuankapang tersebut dalam menghasilkan lovastatin. Fermentasi menggunakanmedium Czapek’s Dox Broth modifikasi dengan variasi konsentrasi NH4NO3 (0mM; 25,00 mM; 31,25 mM; 37,50 mM; 43,75 mM; dan 50,00 mM). Aspergillusflavus UICC 360 dengan konsentrasi inokulum sebesar 1,96% (v/v)diinokulasikan ke dalam medium, kemudian diagitasi 90 rpm, pada suhu ruang(27o--30oC) selama 7 hari untuk mendapatkan ekstrak hasil fermentasi. Pengujianekstrak lovastatin di dalam etil asetat dilakukan terhadap Candida albicans UICCY-29 dengan metode difusi agar cara cakram. Ekstrak hasil fermentasi denganperlakuan 37,50 mM NH4NO3 menunjukkan indeks penghambatan tertinggi, yaitusebesar 0,84 ± 0,07. Hasil Kromatografi Lapis Tipis (KLT) ekstrak hasilfermentasi perlakuan 25,00 mM NH4NO3 dan 37,50 mM NH4NO3 memiliki Rf(0,45), perlakuan 31,25 mM NH4NO3 dan 43,75 mM NH4NO3 memiliki Rf (0,47),sedangkan nilai Rf perlakuan 50 mM NH4NO3 (0,48). Nilai Rf ekstrak hasilfermentasi tersebut hampir sama dengan Rf lovastatin standar, yaitu (0,46),sehingga mengindikasikan adanya senyawa lovastatin di dalam ekstrak. Hasil ujiperbandingan berganda Least Significant Differences (LSD) (P < 0,05)menunjukkan adanya pengaruh nyata pemberian variasi konsentrasi NH4NO3terhadap kemampuan A. flavus UICC 360 dalam menghasilkan lovastatin.

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ABSTRACTAspergillus flavus UICC 360 has been reported to produce lovastatin infermentation by using nitrogen source such as NaNO3. The research aims todetermine the effect of variations of NH4NO3 concentration on the ability of A.flavus UICC 360 to produce lovastatin. Fermentation was carried out by usingCzapek's Dox Broth modified with variations of NH4NO3 concentration (0 mM;25.00 mM; 31.25 mM; 37.50 mM; 43.75 mM; and 50.00 mM). Aspergillus flavusUICC 360 with inoculum concentration of 1.96% (v/v) was inoculated into themedium and then agitated 90 rpm, at room temperature (27o--30oC) for 7 days toobtain the fermentation extract. Extract in ethyl acetate was tested with a discdiffusion method against Candida albicans UICC Y-29. The extract from thefermentation using 37.50 mM NH4NO3 showed the highest inhibition index 0.84± 0.07. The results of Thin Layer Chromatography (TLC) of extract from thefermentation of using 25.00 mM NH4NO3 and 37.50 mM NH4NO3 have Rf (0.45),31.25 mM NH4NO3 and 43.75 mM NH4NO3 have Rf (0.47), and 50 mM NH4NO3have Rf (0.48). The Rf value of extracts have nearly similiar with a lovastatinstandard 0.46 which indicated there was lovastatin in the extract. The results ofLeast Significant Differences (LSD) (P <0.05) showed there was a significanteffect of NH4NO3 concentration variation in the ability of A. flavus UICC 360 toproduce lovastatin.