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Title:	Bioprocessing of oil palm trunk for succinic acid production
Authors:	Nurul Adela Bukhari (P94480)
Supervisor:	Peer Mohamed, Dr.
Keywords:	Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia Bioprocessing Oil palm trunk Succinic acid production Oil palm
Issue Date:	22-Sep-2022
Description:	Oil palm trunk (OPT) is a promising biomass for bioconversion due to its abundant availability, low-cost and high carbohydrates content. Exploitation of agro-industrial lignocellulose, such as OPT as a raw material for the production of succinic acid (SA) may serve as an effective strategy to propel the bio-based industry. SA, a dicarboxylic acid, is used in many fields such as food, agriculture, pharmaceutical and polymer industries. This study aimed to investigate the potential of the whole OPT utilisation for SA production by Actinobacillus succinogenes 130Z. In order to utilise the raw materials efficiently, OPT was separated into sap and residual fibre (bagasse). The sap was used as it is while the bagasse was hydrolysed into fermentable sugars before being used as fermentation substrate. OPT sap was then characterised and its fermentability were investigated, with addition of yeast extract and mineral salts in the OPT sap. Furthermore, parameters optimisation for the pretreatment of OPT bagasse prior to enzymatic hydrolysis were also conducted using dilute organic acids. Three types of organic acids namely the citric acid, formic acid and oxalic acid were investigated to find a suitable catalyst for hydrolysing the OPT bagasse as an alternative to conventional sulphuric acid pretreatment. The effectiveness of these acid pretreatments were evaluated based on xylose recovery (for hemicellulose hydrolysis), enzymatic digestibility (based on theoretical glucose yield of cellulose in the pretreated biomass) and fermentability. The results demonstrated that the use of raw OPT sap has performed as a sole supplier of nutrients, which resulted comparable SA titer, yield and productivity (13.16 g/L, 0.54 g/g and 0.35 g/L.h) as to those supplemented with yeast extract (12.96 g/L, 0.50 g/g and 0.36 g/L.h) and mineral salts (15.17 g/L, 0.55 g/g and 0.40 g/L.h), respectively. These findings indicate that the sugary sap might be the best carbon source since no additional treatment was required to promote the fermentation. The results have shown that the oxalic acid was the most effective in solubilising hemicellulose of OPT bagasse, by maximum recovery of xylose at approximately 61.2%. When fermentation was performed using the bagasse hydrolysate from 1% (w/v) oxalic acid pretreatment, the results showed that total sugar concentration of 43.2 g/L, the highest SA titer of 17.5 g/L and yield of 0.44 g/g were achieved. Further optimisation study of the fermentation conditions with minimal addition of yeast extract has improved the SA titer value to 21.1 g/L and yield at 0.58 g/g. The study also showed that A. succinogenes 130Z was capable to utilise all types of sugars with carbon-5 and carbon-6 which available in both OPT sap and bagasse hydrolysates to produce SA. The findings suggest that the OPT is a suitable substrate for SA production thus could offer a great potential for development of SA bioresource industry.,Ph.D
Pages:	208
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

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