penghambatan angiotensin converting enzyme (ace

PENGHAMBATAN ANGIOTENSIN CONVERTING ENZYME (ACE),
SALAH SATU PARAMETER HIPERTENSI, OLEH DADIH SOYA HASIL
FERMENTASI SPONTAN BAKTERI ASAM LAKTAT (BAL)
Titian Suryawati Agustina
12/337816/PBI/1043
Program Pasca Sarjana, Fakultas Biologi, Universitas Gadjah Mada
INTISARI
Pengukuran aktivitas penghambatan ACE oleh dadih soya hasil fermentasi susu
kedelai oleh bakteri asam laktat telah dilakukan sebagai upaya mencari alternatif
penurun tekanan darah. Dadih soya dibuat dari biji kedelai varietas Anjasmoro
(BPPTPH Gunung Kidul) dengan mengadaptasi metode pembuatan dadih,
makanan khas Minangkabau. Uji aktivitas penghambatan ACE dilakukan dengan
metode spektrofotometri dan hasilnya menunjukkan bahwa dadih soya hasil
fermentasi spontan memiliki aktivitas penghambatan ACE sebesar 92,15%, yaitu
16% lebih tinggi daripada aktivitas penghambatan ACE oleh susu kedelai nonfermentasi. Sebanyak 32 isolat bakteri penghasil asam diperoleh melalui isolasi
selektif dengan media MRSA-bromcressol purple. Screening BAL yang berperan
dalam fermentasi dadih soya berdasarkan morfologi koloni, pengecatan Gram,
aktivitas katalase, ada tidaknya spora, dan motilitas menghasilkan 16 isolat BAL.
Pengujian dengan media skim milk agar terhadap 16 isolat BAL menghasilkan 10
isolat BAL proteolitik yang diduga sebagai strain anggota genus Lactobacillus
(ds15, ds16, ds18, ds23, ds26, dan ds27), Leuconostoc (ds04, ds05, dan ds21),
dan Streptococcus (ds02) berdasarkan karakteristik morfologis dan fisiologisnya.
Berdasarkan konfirmasi data base kit API 50 CH/L (bioMerieux), isolat BAL
proteolitik terpilih ds15 merupakan Lactobacillus delbrueckii subsp. delbrueckii
dengan nilai probabilistik 94,4% dan digunakan sebagai kultur starter untuk
menghasilkan dadih soya secara monokultur. Penambahan starter monokultur
ds15 tidak meningkatkan aktivitas penghambatan ACE secara signifikan namun
memberikan cita rasa yang berbeda dibandingkan dengan susu kedelai nonfermentasi. Berdasarkan metode SDS-PAGE diketahui bahwa dadih soya hasil
fermentasi spontan, dadih soya monokultur, dan susu kedelai non-fermentasi
memiliki pita protein dengan berat molekul ≤18,6 kD yang diduga mengandung
peptida bioaktif penghambat ACE. Dengan demikian dapat disimpulkan bahwa
dadih soya berpotensi sebagai alternatif penurun tekanan darah.
Kata kunci: dadih soya, bakteri asam laktat, Angiotensin Converting Enzyme,
peptida bioaktif, SDS-PAGE
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INHIBITION OF ANGIOTENSIN CONVERTING ENZYME (ACE), ONE
OF THE HYPERTENSION PARAMETERS, BY DADIH SOYA
PRODUCED BY SPONTANEOUS LACTIC ACID BACTERIA (LAB)
FERMENTATION
Titian Suryawati Agustina
12/337816 / PBI / 1043
Graduate Program, Faculty of Biology, Gadjah Mada University
ABSTRACT
Measurement of ACE inhibitory activity by dadih soya fermented by lactic acid
bacteria was carried out as an attempt to find an alternative in lowering blood
pressure. Dadih soya from soybean varieties Anjasmoro (BPPTPH Gunung Kidul)
made by adapting the method of making dadih, typical Minangkabau’s food. ACE
inhibitory activity was determined spectrophotometrically and the results showed
that spontaneous fermented dadih soya had ACE inhibitory activity of 92.15%,
which was 16% higher than the ACE inhibitory activity of non-fermented soy
milk. As many as 32 acid-producing bacteria were obtained by selective isolation
method with MRSA-bromcressol purple media and 16 isolates were obtained to
be LAB based on colonial morphology, Gram stain, catalase activity, presence or
absence of spores, and motility. Ten isolates among the 16 LAB isolates were
obtained to be proteolytic strains which were identified to be member of three
different genera namely Lactobacillus (ds15, ds16, ds18, ds23, ds26, and ds27),
Leuconostoc (ds04, ds05, and ds21) and Streptococcus (ds02) based on
morphological and physiological characteristics. Selected LAB with high
proteolytic activity, ds15, identified as Lactobacillus delbrueckii subsp.
delbrueckii by 94.4% probabilistic value based on confirmation of database API
50 CH/L kit (bioMerieux) and used as a starter culture to produce dadih soya in
monoculture. The addition of starter culture ds15 did not significantly increase
ACE inhibitory activity but gave a different taste compared to non-fermented
soymilk. SDS-PAGE result showed that spontaneous fermented dadih soya, dadih
soya fermented in monoculture method, and non-fermented soy milk have protein
bands with a molecular weight ≤18.6 kD wich were suspected to contain bioactive
peptides as ACE inhibitors. It can be concluded that dadih soya is potential as an
alternative in lowering blood pressure.
Keywords: dadih soya, lactic acid bacteria, Angiotensin Converting Enzyme,
bioactive peptides, SDS-PAGE
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