Electronic Theses and Dissertation

Limbah industri tahu merupakan salah satu sumber bakteri asam laktat (bal) yang berpotensi dimanfaatkan sebagai agen antibakteri dan kandidat probiotik. penelitian ini bertujuan membandingkan aktivitas antibakteri bal yang diisolasi dari limbah padat tahu (lpt) dan limbah cair tahu (lct) terhadap pseudomonas aeruginosa, serta mengevaluasi keamanan isolat berdasarkan uji hemolitik. penelitian menggunakan tujuh isolat bal, yaitu lpt 1, lpt 2, lpt 3, lct 1, lct 2, lct 3, dan lct 5. uji aktivitas antibakteri dilakukan dengan metode agar plug diffusion pada media mueller-hinton agar (mha), sedangkan uji hemolitik menggunakan media blood agar (ba). data aktivitas antibakteri dianalisis menggunakan uji kruskal–wallis yang dilanjutkan dengan uji mann–whitney, sedangkan data uji hemolitik dianalisis secara deskriptif. hasil penelitian menunjukkan bahwa terdapat perbedaan aktivitas antibakteri yang signifikan antar isolat (p

Tofu industry waste is a potential source of lactic acid bacteria (LAB) that can be utilized as antibacterial agents and probiotic candidates. This study aimed to compare the antibacterial activity of LAB isolated from tofu solid waste (LPT) and tofu wastewater (LCT) against Pseudomonas aeruginosa and to evaluate the safety of the isolates based on hemolytic activity. Seven LAB isolates (LPT 1, LPT 2, LPT 3, LCT 1, LCT 2, LCT 3, and LCT 5) were used in this study. Antibacterial activity was evaluated using the agar plug diffusion method on Mueller–Hinton Agar (MHA), while hemolytic activity was determined on Blood Agar (BA). Antibacterial activity data were analyzed using the Kruskal–Wallis test followed by the Mann–Whitney test, whereas hemolytic activity was analyzed descriptively. The results showed significant differences in antibacterial activity among the LAB isolates (p < 0.05). Isolate LCT 5 exhibited the highest inhibition zone diameter (10.81 ± 1.23 mm), classified as strong antibacterial activity, followed by LCT 2 (9.76 ± 0.41 mm) and LCT 3 (6.01 ± 0.77 mm), both categorized as moderate activity. All LCT isolates exhibited γ-hemolysis (non-hemolytic), whereas all LPT isolates exhibited α-hemolysis. These findings indicate that LAB isolated from tofu wastewater, particularly isolate LCT 5, have promising potential as probiotic candidates and natural antibacterial agents against Pseudomonas aeruginosa. Keywords: antibacterial activity, hemolytic, lactic acid bacteria, tofu industry waste, probiotic, Pseudomonas aeruginosa