UTILIZATION OF OIL PALM EMPTY FRUIT BUNCHES FOR XYLANASE PRODUCTION VIA SOLID STATE FERMENTATION

• Main Author: Meilany, Diah
• Format: Dissertations
• Language: Indonesia
• Subjects: Teknik kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/52104
• Institution: Institut Teknologi Bandung

Xylanase is an industrial enzyme that is widely used in the pulp and paper industry in Indonesia. Besides, xylanase is used in bakery, beverages, and animal feed industries. The high market demand is still met by importing, so the opportunity to produce it is wide open. Like other enzymes, xylanase is a product of submerged fermentation, but solid-state fermentation can provide a higher yield and thus more beneficial. This dissertation research focused on utilizing Oil Palm's Empty Bunches (OPEFB) because it is a waste from the palm oil industry, and it is available in abundance for xylanase production. The selection of OPEFB as the medium for xylanase production provides an added value to OPEFB and is the novelty of this dissertation research. Aspergillus fumigatus was used in this research to produce xylanase. Despite its well-known capability as a cellulase-producing fungus, A. fumigatus can produce xylanase enzymes by xylan or xylose induction. OPEFB hemicellulose contains xylan, which can be used as an inducer for A. fumigatus to produce xylanase, which can hydrolyze OPEFB. The problem is that xylan is chemically bonded with cellulose and lignin. To separate OPEFB xylan from its bonds with cellulose and lignin, it requires proper process conditions and pre-treatment methods, and this is another novelty of this dissertation research The solid-state fermentation method has problems in heat dissipation and bed homogeneity. Alternative methods for removing heat accumulation are by introducing humid air as well as by mixing the beds. The bed environment also requires considerable attention because it affects the performance of A. fumigatus. The bed's moisture content and the production medium's nutrient content are among the many essential variables. The research was initiated by evaluating the performance of hydrothermal and organosolv pretreatment processes in obtaining xylose. Based on the results obtained, the study was continued to verify the OPEFB hydrothermal pre-treatment process conditions, namely temperature and time, to obtain a high xylanolytic activity from the crude xylanase produced. The next step was to produce xylanase in a tray fermentor using 250 g of OPEFB. The variables studied were aeration using saturated air, humidity, mixing, xylan availability from the pre-treatment process, spore homogenization, media enrichment with the addition of xylose, and fermentation time. The best process conditions were then applied in the scale-up of production capacity to 1 kg EFB. Seven variables were evaluated in three sections, and the xylanolytic activities of the crude xylanase were measured at the end of each section. The final stage was developing and simulating a mathematical model to evaluate the distribution of air and heat in the tray fermentor used in the production of xylanase enzymes. For this reason, modeling was carried out with variations in the arrangement of fermenters in series using two chambers and parallel using four chambers. The results obtained showed that temperature was more significant than time and SL on the hydrothermal pre-treatment process. The pre-treatment process, either hydrothermal or organosolv, caused more released xylan in the pretreated solids. However, the hydrothermal pre-treatment process resulted in a much higher xylose recovery than the organosolv pretreatment process. The optimal hydrothermal pre-treatment process condition to obtain maximum xylose was at a temperature of 165°C for 7 minutes with 7% of SL. Under these conditions, 35% of EFB xylan can be enzymatically converted to xylose. The verification of the hydrothermal pre-treatment process conditions suitable for xylanase production was at 130°C for 60 minutes, which could increase the xylanolytic activity of the produced crude xylanase, with the lowest cellulolytic activity. Furthermore, xylanase production with 250 g of OPEFB in a tray fermenter is significantly influenced by the fermentor humidity, followed by aeration using saturated air. An increase in production capacity requires improving air distribution in the tray fermenter. The evaluation of model simulation results showed that the serial fermentor arrangement resulted in an inhomogeneous system, which agreed with the experimental results. Meanwhile, the parallel fermentor arrangement provided a homogeneous fermenter condition that gave higher productivity than the serial fermentor arrangement. This finding, however, requires further validation. In general, the results showed that OPEFB has great potential to be used as the raw material for producing xylanase. Considering that OPEFB is an industrial waste, it increases the opportunity to produce xylanase at a lower cost. Tray fermentation has the potential to be used in scale-up of production capacity, although there are several aspects and process parameters that require further attention and research. This potential makes xylanase production from TKKS quite promising.