RESPON HAMBATAN BAKTERI GRAM POSITIF DAN NEGATIF PADA IKAN NILA (Oreochromis niloticus) YANG DIAWETKAN DENGAN EKSTRAK JAHE (Zingiber officinale)

Abstract

Compared to catfish, tilapia fish is more prospective to be cultivated since it has higher nutritional value. As a type of fish, tilapia is classified perishable, i.e. decay quickly. Due to its high protein and Aw, tilapia decay quickly especially in improper environment, therefore preservation process is important. Several natural substances have ability to preserve fish. Because they contain some component that have antimicrobe activity, for example ginger that contains gingerol, shogaol and zingerone. This experiment aimed to understand influence of ginger extract (Zingiber officinale) to inhibition decaying microbe of tilapia fish (Oreochromis niloticus). This research implemented experimental method with 4 treatments and each treatment is replicated for 2 times. Data were then analysed by classifying inhibition level of each treatment. It was found that of 16 isolate, 10 of them had been inhibited and of those 10, it was revealed that there were 4 types of microorganism, 2 were classified as gram positive while the rest ones gram negative. Based on classifying inhibition level of each treatment, the greatest inhibition zone was found at IB 7 which is a 25 mm and concentration 50% with type of micobe Bacillus alvei. It was gram positive microorganisms were inhibited more effectively and with regard to inhibition level. Based on data, application of ginger extract provided significant difference compared to no extract treatment. Meanwhile, between those three percentages of ginger extract application (50%, 60% and 70%) significant difference was not found in term of inhibition level. Based on result of statistic test, it can be concluded that application of ginger extract provided significant difference compared to no extract treatment. Meanwhile, between those three percentages of ginger extract application (50%, 60% and 70%) significant difference is not found in term of inhibition level.