BAKTERI PROBIOTIK DALAM BUDIDAYA UDANG: SELEKSI, MEKANISME AKSI, KARAKTERISASI, DAN APLIKASINYA SEBAGAI AGEN BIOKONTROL
ABSTRACT: Bacterial disease
attack occurs at the hatchery stage, which is considered to be the most serious
threat, and often results in mass mortality of shrimp larvae by vibrosis which
is that caused by a luminous bacterium identified as Vibrio harveyi. This research
was carried out to obtain local isolates of probiotic bacteria that were able
to inhibit the growth of V. harveyi and effectively apply it as a biocontrol of
vibriosis in shrimp cultures. The research was carried out as follows: (1) In
vitro and in vivo selection of probiotic bacteria candidates, (2) Study of the
action mechanism and characterization of the selected pro biotic bacteria, (3)
Study on application of the selected probiotic bacteria as a biocontrol agent
in shrimp cultures. Results of in vitro and in vivo selection provided the best
three isolates, which were 1Ub, SKT-b and Ua. The survival rate of shrimp
larvae which were not only inoculated by V. harveyi but also with 1Ub, SKT-b
and Ua probiotic bacteria were 88.33, 83.33, and 81.67% respectively; where as
the positive control treatment (merely inoculated with V. harveyi) gave a
41.67% survival rate and the negative control (without bacterial addition) was
68.33%. Studies using a rifampicin resistant marker (RfR) demonstrated that the
number of V. harveyi MR5339 RfR cells in treatments without probiotic addition
were higher than the treatment with the probiotic bacteria, in dead larvae,
living larvae, as well as in the culture media. Partial sequencing of the
I6S-rRNA gene showed that the I Ub isolate was similar to Pseudoalteromonas
piscicida, whereas the SKT -b and Ua isolates were similar to Vibrio
alginolyticus. Selected probiotic bacteria could be applied directly to shrimp
larva culture media, or orally through enrichment of both natural and
artificial food.
Penulis: Widanarni, Sukenda,
Mia Setiawati
Kode Jurnal: jppertaniandd080114
