School of Bioprocess Engineering (Theses)http://dspace.unimap.edu.my:80/xmlui/handle/123456789/192962024-03-05T07:29:24Z2024-03-05T07:29:24ZCharacterization of different types of spent mushroom substrate (SMS) for African catfish (Clarias Gariepinus) diet suitabilityhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/802592024-03-05T01:13:25ZCharacterization of different types of spent mushroom substrate (SMS) for African catfish (Clarias Gariepinus) diet suitability
Spent Mushroom substrate (SMS) is one of agricultural wastes produced by thever expending mushroom industries in Malaysia. Chemically, it is rich in organic matter which potentially can be utilized for aquaculture. Utilization of SMS as fish feed has
never been conducted before as very limited information on SMS biochemical composition is available. Regarding to this matter, new formulation of fish feed was developed by incorporating SMS and other ingredients namely soybean waste, fish meal,
topioca flour and rice bran. Commanly, different types of SMS that being cultivated at six to seven cycles were collected which identified as white oyster (Pleuratos ostreatus), grey oyster (Pleuratos sajor-caju), abalone (Pleuratos cystidiosus), ganoderma
(Ganoderma lucidium) and black jelly (Auricularia polytricha). Those SMS were tested on their biochemical composition which involving the analysis of crude protein, carbohydrate, fat, lignin and ash. Overall trend showed an increment in crude protein
and fat content, whereas carbohydrate and lignin showed a reduction in the content. Ganoderma attained the highest protein value, 36.6 g, followed by black jelly, white oyster, grey oyster and abalone. Contradictory, lowest carbohydrate reduction was
observed in ganoderma at 70.42 g and the most was in black jelly. Increment in fat and reduction in lignin showed almost similar value for each SMS. The highest (ganoderma), medium (white oyster) and lowest (abalone) protein content were the basis of SMS types selection to be incorporated in pellet formulation using Pearson square method which emphasized on the protein and energy. The ingredients were mixed and a pelletalization was carried out after 40 minutes of steaming process at 80° C. A series of physical properties test of SMS pellets were conducted to confirm the applicability of the formulated pellet for fish consumption by comparing with commercial fish feed.
Master of Science in Bioprocess Engineering
Evaluation of a novel halophilic lipase secrection by Marinobacter litoratis SW-45 for butyl esters synthesis from palm-based oilshttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/802522024-03-05T00:56:27ZEvaluation of a novel halophilic lipase secrection by Marinobacter litoratis SW-45 for butyl esters synthesis from palm-based oils
Fatty acid esters are currently synthesized by esterification via chemical technologies involving the use of toxic mineral acids as catalysts, and requiring high energy consumption. The alternative enzyme technology which is a greener process involves the
use of microbial lipase as catalysts, and holds enormous advantages of moderate reaction conditions, process simplification, and product quality over the conventional chemical process. The current trend of adopting a greener approach towards the synthesis of high value oleochemicals has prompted the need to consistently explore and improve extremozymes with novel qualities as a stable biocatalyst to function in biotechnological processes. Hence, in this study, a total of 56 halophilic bacteria and 9 halophilic fungal strains were isolated from various saline environments and screened for lipase secretion on tributyrin solid agar. The halophilic bacterial strain SW-45 which secreted the highest lipase (0.603 U/mL) in SMF under agitation condition was chosen for further optimization studies. This highest lipase-secreting strain was outsourced for molecular identification and was designated as Marinobacter litoralis SW-45. A combinatorial nonstatistical one-factor-at-a-time (OFAT) method and statistical optimization of Plackett-Burman (PB) and face-centered central composite design (FCCCD) approaches were adopted to improve halophilic lipase production by the strain. The optimum level halophilic lipase production was obtained with 3.0 g/L maltose, 1% (v/v) olive oil, 30 °C growth temperature, and 4% inoculum volume (v/v), and the optimization by FCCCD revealed 1.7-fold improvement in the halophilic lipase production from 0.603 U/mL to 1.0307 U/mL.
Doctor of Philosophy in Bioprocess Engineering
Potential applications of exposure to magnetic field in changing water properties and improving growth performance of selected aquaculture organismshttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/790102023-08-03T07:22:32ZPotential applications of exposure to magnetic field in changing water properties and improving growth performance of selected aquaculture organisms
This study intends to understand the effect of magnetic field on water properties and on aquaculture organisms. Magnetic water is produced when water is passed through a magnetic field which alters the state of the macromolecules of the water. Changes to the physico-chemical properties of magnetised water affect the biological properties of the organisms that consume or are exposed to it. This study is based on previous works reporting the positive effects of exposure to magnetic field on water properties, plant growth, plant germination, livestock-drinking water, fish fertilisation and against the backdrop of issues pertaining to water quality in recirculating aquaculture systems (RAS), which negatively impacted fish growth and hatchability rate of aquaculture species. First, this work evaluated the effect of exposure to magnetic field intensities of 0.10, 0.15, 0.20, 0.10+0.15, 0.10+0.20, 0.15+0.20, and 0.10+0.15+0.20 T on water qualities. The results showed significant (p < 0.05) increase in dissolved oxygen, pH, and conductivity by 17.3, 1.6, 3.0%, respectively, and a significant decrease of the ammonium level, specific conductivity, total dissolved solids, oxygen reduction potential, and chlorides by 25.3, 1.1, 1.4, 1.0, 16.9, 3.4%, respectively. A study on the effect of magnetically charged water on Artemia (Artemia salina) showed an increase of hatchability rate, from 49.3% for the normal water to 89.1, 88.4, and 69.5% for magnetised water of 0.10, 0.15, and 0.20 T, respectively. However, a decline in Artemia hatchability rate to 48.6, 42.3, 43.7, and 42.0% occurred when water was magnetised to 0.10+0.15, 0.10+0.20, 0.15+0.20, and 0.10+0.15+0.20T respectively. An increase of 64.7% in Artemia hatchability (H%) was attained in the water exposed to a magnetic field of 0.15 T for 20 hours compared with the control treatment at 41.7%. The increase of 86.3, 86.7 and 86.3% in red hybrid tilapia’s (Oreochromis sp.) hatchability rate (H%) were attained in water exposed to magnetic field intensities of 0.10, 0.15, and 0.20 T for 5 hours, compared to the control treatment at 78.8%. Increases of 55.0, 59.2, and 66.8% in catfish’s (Clarius gariepinus) hatchability rate (H%) were attained in water exposed to magnetic fields of 0.10, 0.15 and 0.20 T, compared to the control treatment at 51.7%. Significant decrease (p < 0.05) in feed conversion ratio by 14.9% and increase in body weight by 5.2% for jade perch (Scortum barcoo) and significant decrease in FCR by 30.7% and increased weight gain by 17.0% for red hybrid tilapia juveniles in RAS. The best results were obtained when using water exposed to magnetic field intensities of 0.10 and 0.15 T, respectively. The liver cells of the fishes grown in the control treatment and those in 0.10 T magnetic water exhibited a normal sinusoid organisation with no indications of lesions or abnormalities of the hepatocytes. In summary, the study demonstrated the benefits of using magnetically charged water for aquaculture due to increased hatchability of artemia, red tilapia, and catfish, and a better growth performance for jade perch and red hybrid tilapia culture in waters exposed to magnetic fields demonstrated significantly lower FCR, hence improve in fish productivity in RAS. Since the installation of the device is simple, low cost, and can be retro-fitted into existing systems, fish farmers can increase their aquaculture productivity.
Doctor of Philosophy in Biosystem Engineering
The novel green extraction of essential oil for quality pharmaceutical productshttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/790092023-08-03T07:15:15ZThe novel green extraction of essential oil for quality pharmaceutical products
Essential oils are secondary metabolites produced by aromatic plants which have various applications in the industries. The conventional method to extract essential oil from plants such as steam distillation, hydro distillation and solvent extraction have many drawbacks that lead to the research on the new technique to overcome the flaws. This research was conducted to introduce a new method to extract essential oils where in this new method, the extraction process has been done in a closed vacuum system without the addition of any solvents or water. The novelty of this method is the closed system extraction process where all the compounds of the essential oil were trapped inside the system to prevent the loss of valuable components. The extraction studies for this solvent free method was conducted for both laboratory scale and pilot scale. For the laboratory scale, extraction process using solvent free method and hydro distillation method was conducted for comparison. The peels from Citrus sinensis and the leaves from Chromolaena odorata, Cymbopogon nardus and Baeckea frutescens have been extracted for their essential oils. The essential oils collected from both methods were measured for their yield and physical characterizations. From the results obtained, it showed that the essential oil yield for all the four plants used was significantly higher by using solvent free method compared to hydro distillation method. The yield for solvent free method has been increased by 100% for Chromolaena odorata, 76% for Cymbopogon nardus, 92% for Baeckea frutescens and 174% for Citrus sinensis. Baeckea frutescens essential oil was selected for further analysis. The morphology image of Baeckea frutescens essential oil glands before and after extraction using both methods were determined using Scanning Electron Microscope (SEM). The essential oil was then being analyzed using Gas Chromatography (GC) and Gas Chromatography - Mass Spectrometry/Mass Spectrometry (GC-MS/MS) for their chemical constituents. As expected from the compound elucidations, solvent free method has more compounds compared to hydro distillation method. One new compound which is 3-carene has been obtained by using solvent free method. The existence of 3-carene in this essential oil was not been reported before. It was also discovered that the compounds obtained from solvent free method contained lighter molecular mass compared to the compounds from hydro distillation method which have mostly heavier molecular mass fractions. This is in alignment with the prediction that the new method can preserve lower boiling point compounds which would have lighter molecular mass. With the convincing results from the laboratory scale, the pilot scale for the solvent free method has been designed and developed. The pilot scale essential oil extractor has a maximum of 30-liter capacity for the plant material. As the new method of extraction were more convenient, less processing steps, zero solvent waste and less time consumptions, hence, it is suitable for industrial application such production of pharmaceutical products as active components in medicines or as fragrance ingredients in aromatherapy and perfumery.
Doctor of Philosophy in Bioprocess Engineering