Papers by Nur Zulaikha Yusof
Microbial pigments due to their better biodegradability and higher compatibility with the environ... more Microbial pigments due to their better biodegradability and higher compatibility with the environment offer promising avenues for various industrial applications like food, cloth, painting, cosmetics, pharmaceuticals, plastics, etc. Nevertheless, the current bacterial pigment productions are not effective to meet their industrial needs. Current research on microbial pigments signify that genetic engineering for strain improvement, optimization of bioprocess modeling and utilizing cheap agro-industrial residues as substrates are key developmental strategies to maximize pigment production. Solid-state fermentation (SSF) has been reassessed as an alternative to submerged fermentation and could be a possible strategy for the cost-effective production of microbial pigments. The investment for SSF is usually lower than that of submerged fermentation, since it uses waste agricultural residues. This chapter summarizes the effective way to produce microbial pigments in agro-industrial waste ...
The effectiveness of water hyacinth (EichhorniaCrassipes) in the remediation of municipal wastewa... more The effectiveness of water hyacinth (EichhorniaCrassipes) in the remediation of municipal wastewater and production of bioethanol was compared with water lettuce (Pistia Stratiotes) and water spinach (Ipomoea Aquatica). Preliminary test using hydroponic system was conducted in order to measure the parameters required at the laboratory scale continuous experimental rig configuration (hydraulic retention time and flowrate). The experiment using the experimental rig was conducted for 18 d for each of the aquatic plant. Water lettuce showed a better removal performance compared with water hyacinth and water spinach. Water lettuce was able to remove 92% of nitrogen and 87% of phosphorus. Besides, water lettuce also showed higher BOD removal of 98.3% followed by water hyacinth 93.9% and then water spinach 89.6%. For COD removal performance, water lettuce treated COD up to 98% followed by water hyacinth 94.2% and water spinach 89.9%. The biomass harvested from water hyacinth, water lettuce...
Batch tests were employed to estimate the optimal conditions for improving the settleability of a... more Batch tests were employed to estimate the optimal conditions for improving the settleability of activated sludge through aggregation under magnetic field. A four – factor central composite design (CCD) was employed to find out the interaction effects of the variables while response surface methodology (RSM) was utilized for process optimization. Four independent variables, viz. magnetic field (15.0 – 88.0 mT), exposure time (0.5 – 48.0 hrs), biomass concentration (2000 – 4000 mg l -1 ) and mixing intensity (200 – 400 rpm) was built to predict the responses. Analysis of variance (ANOVA) was used to evaluate the significance of the independent variables and their interactions. At the optimum conditions of 88.0 mT magnetic field, 16.5 hrs of exposure time, 2800 mg l -1 of biomass concentration and 300 rpm of mixing intensity, the aggregation achieved its maximum value by 99.0%. The element analysis showed that the applied magnetic field is potential to enhance the settling property of ...
Bio-pigmentation and Biotechnological Implementations, 2017
SpringerBriefs in Molecular Science, 2011
Due to the high cost of the technology currently used for pigment production on an industrial sca... more Due to the high cost of the technology currently used for pigment production on an industrial scale, there is a need to develop a low cost process such as the use of agricultural-waste residues as growth medium, instead of the typical expensive synthetic medium. The use of ...
SpringerBriefs in Molecular Science, 2011
Bacteria produce pigments for various reasons and it plays an important role. Some bacteria such ... more Bacteria produce pigments for various reasons and it plays an important role. Some bacteria such as cyanobacteria have phycobilin pigments to carry out photosynthesis. Other example for pigment-producing bacterial strains includes Serratia marcescens that produces prodigiosin, Streptomyces coelicolor (prodigiosin and actinorhodin), Chromobacterium violaceum (violacein) and Thialkalivibrio versutus (natronochrome and chloronatronochrome). These bacteria can be isolated/ cultured/purified from various environmental sources such as water bodies, soil, on plant, in insects and in man or animal. Various growth mediums can be used to isolate different types of bacteria. However, due to the high cost of using synthetic medium, there is a need to develop new low cost process for the production of pigments as well as during the isolation procedure. The use of agro-industrial residues for example, would provide a profitable means of reducing substrate cost. Pigment produced by the bacteria can be isolated using solvent extraction. These pigments can be further purified and characterized for physical and chemical characteristics using various instrumental-based analytical techniques such as TLC, UV-vis Spectroscopy, FTIR, ESI-MS, NMR HPLC and Gel Permeation Chromatography. Keywords Pigment Á Bacteria Á Isolation Á Characterization Á NMR, HPLC Á Extraction Á Medium 2.1 Growth Medium Nutrient broth (8 g L-1 , Merck) and Nutrient agar (20 g L-1 , Merck) were used as growth medium. The mediums were sterilized by autoclaving at 121°C, 103.42 kPa for 15 min where the agar was allowed to harden followed by incubation for 24 h at 30°C to ensure that it was free from contamination.
SpringerBriefs in Molecular Science, 2012
, in its current version, and permission for use must always be obtained from Springer. Violation... more , in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
Applied Biochemistry and Biotechnology, 2012
Biologia, 2016
Natural dyes and pigments are emerged as an important alternative to potentially harmful syntheti... more Natural dyes and pigments are emerged as an important alternative to potentially harmful synthetic dyes. There is a growing demand for eco-friendly/non-toxic colourants specifically for textile dyeing because of its sustainability, green chemistry and improved eco-balances. The present study aimed to evaluate the dyeing potential of violet pigment from
IOP Conference Series: Earth and Environmental Science, 2021
Marine biofouling, the unwanted accumulation of living organisms on man-made structures is worsen... more Marine biofouling, the unwanted accumulation of living organisms on man-made structures is worsening every year. Biofouling in marine environment usually occurs in any wetted surface, submerged for a period of time in the seawater. This phenomenon happens in few stages started with conditioning and followed by attachment and colonization. Marine biofouling is a highly cost problem which requires unnecessary waste of financial source especially in fuel consumption and production time as well as safety problems. The currently used antibiofouling paint is reported to be highly toxic and threatening the marine organisms. The most commonly used antibiofouling agents are biocide-based such as the tributyl-n-tin (TBT), Sea Nine 211, Irgarol 1051, Diuron and the copper-based. The well-developed coating companies such as Hempel USA, SeaCoat Technology, Nippon Paint and many more has started their involvement in making the earths greener by introducing the non-biocide coating that is claimed ...
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Papers by Nur Zulaikha Yusof