ISOLASI DAN IDENTIFIKASI BAKTERI ASAM LAKTAT DARI FESES BAYI DAN EVALUASI IN VITRO POTENSI PROBIOTIK

• Main Authors: , Tiyas Tono Taufiq, , Widodo, S.P., M.Sc., Ph.D.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2012
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/100548/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=56469
• Institution: Universitas Gadjah Mada

gene The aims of this experiment was to isolate and identify LAB from infant faeces and subsequent evaluation of its potential probiotics. LAB was isolated from faeces of infants who consumed breast milk as the only source of diet on Lcysteine- supplemented MRS Agar, and incubated on 37 o C for 48 hours. Colonies grew on this media were then identified based on cellular, physiological and molecular approaches. Cellular and physiological identifications based on Gram staining, motility, Catalase, CO2 and NH3 production, and the ability to grow on 10º and 45ºC. Molecular identification relied on the amplification of sequence of 16S rRNA . The potential application of selected isolates for probiotics was evaluated based on the ability to grow on media with low pH and bile salts, the ability to inhibit the growth of pathogenic Bacillus cereus and Escherrichia coli, to utilize inulin as the only carbon source, and in vitro adherence ability. Cellular and physiological identification resulted 17 isolates with lactic acid bacteria characteristic. On the basis of analysis of 16S rRNA gene, the 1AF isolates were classified as Lactobacillus casei. Evaluation of probiotic in vitro showed a growth decreases of 39,56% viability after growing at pH 2.0 for 90 minutes. The growth decline of isolates on the medium with the addition of 0.5% bile salts was 20,71%. The selected isolate showed the ability to inhibit the growth of E. coli and Bacillus cereus with inhibitory zone of 12,00±1,00 mm and 15,33±1,53 mm respectively. Ability of attachment to the solid plate was 9.367±1721,43 colony/mm 2 . Growth analysis of the selected isolates on a member of different carbon sources showed the ability to grow normally on glucose, lactose, and sucrose as the only carbon sources. Meanwhile, the growth of isolates on inulin as the only carbon sources was slower than previously carbon sources. The data obtained had indicate that the selected isolated isolates are of potential candidate as probiotic in vitro and able to ferment inulin as the only carbon source.