ANALYSIS OF BACTERIAL COMMUNITY LEVEL PHYSIOLOGICAL PROFILING ON THE FERMENTATION OF TRADITIONAL PLIEK U USING BIOLOGTM ECOPLATE

• Main Author: Edwar, Suji
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49390
• Institution: Institut Teknologi Bandung

Pliek u is Acehnese traditional food produced from the process of coconut endosperm fermentation. The process typically involves fermenting coconut endosperm in an open environment and afterward pressing the endosperm to separate the coconut oil from its pulp, futher called Pliek u. During the process of Pliek u fermentation, it is believed that the coconut endosperm is undergoing a number of changes due to the activities of a diverse microbial community. The dynamic of these activities, however, is still under explored. The profile of the microbial community diversity can be investigated with Community Level Physiological Profiling (CLPP) analysis. This method is based on the different uses of carbon substrate by the microbial community. The profiling of the functional structure of the microbial community becomes a basis for controlling the microorganism involved in the fermentation process. This research began with sample collection of the traditional fermented Pliek u in Desa Siron of Aceh Besar regency in the province of Aceh, Indonesia. The sample was collected every 12 hours during a 72-hour fermentation. The changes in the pH of the sample were examined with proximate analysis. Then, CLPP analysis using Biolog EcoPlateTM was conducted on the sample in four stages: at 0 hour (I), 24 hour (II), 48 hour (III) and 72 hour (IV). Bacterial isolation was done when the BIOLOGTM EcoPlate well indicated positive result (the solution colour became purple). The isolated bacteria were then selected based on their ability to produce cellulase, lipase, and protease enzymes. The selected isolated bacteria were sequenced with primers of the 16s rRNA gene and examined with phylogenetic analysis using neighbor-joining (NJ) method with bootstraps 1000 times. During the Pliek u fermentation, there was a reduction in the value of pH from 4.43 in the beginning of the fermentation to 3.96 at the end of the fermentation process. Result from the proximate analysis indicated a reduction in water level of 7.5%, ash level of 0.17%, and carbohydrate level of 1.35%, while there was an increase in protein and fat levels of 8.55% and 0.48% respectively at the end of the fermentation process. Analysis of the physiology of the bacterial community with EcoPlate showed the value of Average Well color Development (AWCD) increased during the EcoPlate incubation period, where the highest value of AWCD occurred at the 72 hour fermentation. PCA analysis indicated the use of substrate by the bacterial community in the beginning of the fermentation correlated with the substrate groups of carbohydrate, carboxylate acid and polymer; and at the end of the fermentation with the substrate groups of carbohydrate, carboxylate acid and amino acid. Of the 5 isolated bacteria, isolate EC1 and EC3 had the ability to produce good cellulase, lipase and protease enzymes. The phylogenetic analysis showed that EC1 had a close relation with Pseudomonas azotoformans NBRC strain and EC3 had a close relation with Psedomonas lundensis ATCC 49968 strain. Based on the results from the analyses, it can be concluded that there was a change in the use of substrate and in the activities of the bacterial community during the process of Pliek u fermentation.