Biotechnological tools are being used in malaria, filariasis and dengue research. The main emphasis has been on the production of reagents for immunodiagnosis and research. In this respect monoclonal antibodies (McAbs) against various species and stages of the above pathogens have been produced. It is hoped that these McAbs will be useful not only in immunodiagnosis but also for seroepidemiological applications. A DNA probe against Brugia malayi has been tested in Malaysia and was found to be sensitive and specific.
There are essentially no reports on the use of modern biotechnological methods on the study of cestode parasites in the Philippines, Indonesia or Malaysia. The only recent reports of cestode studies in these countries have been on reports of new species in animals and on prevalence rates of cestode parasites in humans; Taenia solium and cysticercosis, Taenia saginata and Hymenolepis nana, etc. Reports on the use of biotechnology has emanated from outside the area on cestodes of humans and animals, and some of these methods could be used to study cestodes in this part of the world.
Aminoacylase I (E.C.3.5.1.14) was immobilized by entrapment in calcium alginate beads coated with polyethyleneimine for the production of L-phenylalanine by the hydrolysis of a racemic mixture of N-acetyl-DL-phenylalanine. The operational stability in terms of batch operation and continuous reaction in packed-bed bioreactor were studied. Kinetic constants, Km and Vmax values of free and immobilized enzymes were studied. Polyethyleneimine treatment was found to enhance the operational stability of the enzyme though its activity was substantially reduced. When polyethyleneimine-coated calcium alginate beads were packed into packed bed bioreactor, it was stable for at least 25 days under continuous operation without appreciable loss of activity.
The effects of pump speed, cumulative permeate volume and concentration of feed (yeast cells) on the permeate flux have been studied on a batch cross-flow microfiltration process. The experiments were conducted for two different cellulose acetate membrane modules of 0.2 micron and 0.45 micron pore size. A three factor experiment was designed for this purpose and the effect of the operating parameters on the filtration rate was studied by the analysis of variance (ANOVA). It is concluded from the analysis of the experimental data that pump speed has the maximum bearing upon the permeate rate within the operating range of parameters. Fouling conditions were examined in the light of colloids deposition on membranes due to surface interactions. However this paper looks into the relationship and sensitivity of the operating parameters in a cross-flow microfiltration unit rather than exploring the theoretical principles behind the observed phenomena.
Studies were carried out in T-flasks and bioreactor to produce urokinase enzyme using HT 1080 human kidney cell line. While growing the cell line it has been observed that the lag phase is reduced considerably in the bioreactor as compared to T-flask culture. The HT 1080 cell adhesion rate and urokinase production were observed to be the function of serum concentration in the medium. The maximum urokinase activity of 3.1 x 10(-4) unit ml(-1) was achieved in the bioreactor at around 65 h of batch culture. Since HT 1080 is an anchorage dependent cell line, therefore, the hydrodynamic effects on the cell line were investigated.
The objective of this research was to study the kinetics of synthesis of a commercially important ester - Isopropyl Palmitate (IPP) using immobilized lipase (Lipozyme IM). It was studied in a packed bed differential reactor. In order to establish the kinetics of the reaction, parameters such as linear velocity of the fluid through the reactor, particle size, substrate concentration, substrate molar ratio, temperature and water activity were studied. Operational and storage stability of the enzyme were also assessed. The reaction followed Michaelis-Menton kinetics as observed from the relationship of initial rate of the reaction as a function of substrate concentration. It was found that the optimum substrate concentration was 0.15M palmitic acid and isopropyl alcohol in 1:1 stoichiometric ratio. Inhibition by excess of isopropyl alcohol has been identified. The optimum temperature for the esterification reaction was found to be around 50 degrees C. The activation energy of this process was determined to be 43.67 kJ/mol. The optimum water content was 0.50%. The reaction rates were measured in the absence of any significant external diffusional limitations. Since internal diffusional limitations could not be eliminated, the kinetics observed is only apparent.
In 2000, agriculture contributed 13% to the national gross domestic product of Malaysia. The country of 23 million people has created a competitive program coordinated by the Ministry of Science, Technology and the Environment, research institutions, and universities to undertake biotechnology research in several areas. Intensified research efforts are under way on oil palm, rubber, rice, papaya, and orchids. Although the most progress has been made in rice and papaya, no transgenic crop is ready for field trials. Nonetheless, preliminary steps have been taken to prepare for the trials, and detailed testing protocols are being developed.
The importance and development of industrial biotechnology processing has led to the utilisation of microbial enzymes in various applications. One of the important enzymes is amylase, which hydrolyses starch to glucose. In Malaysia, the use of sago starch has been increasing, and it is presently being used for the production of glucose. Sago starch represents an alternative cheap carbon source for fermentation processes that is attractive out of both economic and geographical considerations. Production of fermentable sugars from the hydrolysis of starches is normally carried out by an enzymatic processes that involves two reaction steps, liquefaction and saccharification, each of which has different temperature and pH optima with respect to the maximum reaction rate. This method of starch hydrolysis requires the use of an expensive temperature control system and a complex mixing device. Our laboratory has investigated the possibility of using amylolytic enzyme-producing microorganisms in the continuous single-step biological hydrolysis of sago flour for the production of a generic fermentation medium. The ability of a novel DNA-recombinated yeast, Saccharomyces cerevisiae strain YKU 107 (expressing alpha-amylase production) to hydrolyse gelatinised sago starch production has been studied with the aim of further utilizing sago starch to obtain value-added products.
In this paper, we investigated the development of a simplified and rapid primary capture step for the recovery of M13 bacteriophage from particulate-containing feedstock. M13 bacteriophage, carrying an insert, was propagated and subsequently purified by the application of both conventional multiple steps and expanded bed anion exchange chromatography. In the conventional method, precipitation was conducted with PEG/NaCl, and centrifugation was also performed. In the single step expanded bed anion exchange adsorption, UpFront FastLine 20 (20 mm i.d.) from UpFront Chromatography was used as the contactor, while 54 ml (Ho = 15 cm) of STREAMLINE DEAE (rho = 1.2 g/cm3) from Amersham Pharmacia Biotechnology was used as the anion exchanger. The performance of the two methods were evaluated, analysed, and compared. It was demonstrated that the purification of the M13 bacteriophage, using expanded bed anion exchange adsorption, yielded the higher recovery percentage, at 82.86%. The conventional multiple step method yielded the lower recovery percentage, 36.07%. The generic application of this integrated technique has also been assessed.
In the present study, the performances of conventional purification methods, packed bed adsorption (PBA), and expanded bed adsorption (EBA) for the purification of the nucleocapsid protein (NP) of Newcastle disease virus (NDV) from Escherichia coli homogenates were evaluated. The conventional methods for the recovery of NP proteins involved multiple steps, such as centrifugation, precipitation, dialysis, and sucrose gradient ultracentrifugation. For the PBA, clarified feedstock was used for column loading, while in EBA, unclarified feedstock was used. Streamline chelating immobilized with Ni2+ ion was used as an affinity ligand for both PBA and EBA. The final protein yield obtained in conventional and PBA methods was 1.26% and 5.56%, respectively. It was demonstrated that EBA achieved the highest final protein yield of 9.6% with a purification factor of 7. Additionally, the total processing time of the EBA process has been shortened by 8 times compared to that of the conventional method.
Chemostat cultures of NS0 cell lines were carried out at dilution rates ranging from 0.8 d(-1) to 0.2 d(-1). Compared with the control, the viable cell density of the Bcl-2 cell line was approximately 10% higher at 0.8 d(-1) and increased to 55% when the dilution rate was reduced to 0.2 d(-1). As the dilution rate was reduced, the viability of the two cultures diverged reaching a difference of 43% at 0.2 d(-1). The specific growth rate of the control cells was the same as the dilution rate down to a value of 0.6 d(-1). By contrast, the specific growth rate of Bcl-2 cells was parallel to the dilution rate down to a value as low as 0.3 d(-1). For both NS0 cell lines, the G1 cell population decreased, while the S and G2/M cell populations increased as the dilution rate was reduced. The antibody titer of the control cells increased from 7 to 21 microg.ml(-1) as the dilution rate was reduced from 0.8 to 0.2 d(-1). With an initial increase from 2 to 15 microg.ml(-1) as the dilution rate was reduced from 0.8 to 0.4 d(-1), the antibody titer of the Bcl-2 cells remained constant as the dilution rate was further reduced to 0.2 d(-1). A good correlation between specific antibody production rate and the percentage of G2/M cells was observed.
Biotechnology-derived food crops are currently being developed in Malaysia mainly for disease resistance and improved post harvest quality. The modern biotechnology approach is adopted because of its potential to overcome constraints faced by conventional breeding techniques. Research on the development of biotechnology-derived papaya, pineapple, chili, passion fruit, and citrus is currently under way. Biotechnology-derived papaya developed for resistance to papaya ringspot virus (PRSV) and improved postharvest qualities is at the field evaluation stage. Pineapple developed for resistance to fruit black heart disorder is also being evaluated for proof-of-concept. Other biotechnology-derived food crops are at early stages of gene cloning and transformation. Activities and products involving biotechnology-derived crops will be fully regulated in the near future under the Malaysian Biosafety Law. At present they are governed only by guidelines formulated by the Genetic Modification Advisory Committee (GMAC), Malaysia. Commercialization of biotechnology-derived crops involves steps that require GMAC approval for all field evaluations and food-safety assessments before the products are placed on the market. Public acceptance of the biotechnology product is another important factor for successful commercialization. Understanding of biotechnology is generally low among Malaysians, which may lead to low acceptance of biotechnology-derived products. Initiatives are being taken by local organizations to improve public awareness and acceptance of biotechnology. Future research on plant biotechnology will focus on the development of nutritionally enhanced biotechnology-derived food crops that can provide more benefits to consumers.
Heralded by the revelation of the double helical structure of the DNA molecule in 1953, the 21st century is aptly designated the biotechnology century. The 20th century of physics, which saw the transformation of silicon into computing magic, was embraced with enthusiasm by virtually every household. However, unlike her predecessor, the same cannot be said about the advancements in biomedicine.
This study examined the capacity of immobilized bacteria to degrade petroleum hydrocarbons. A mixture of hydrocarbon-degrading bacterial strains was immobilized in alginate and incubated in crude oil-contaminated artificial seawater (ASW). Analysis of hydrocarbon residues following a 30-day incubation period demonstrated that the biodegradation capacity of the microorganisms was not compromised by the immobilization. Removal of n-alkanes was similar in immobilized cells and control cells. To test reusability, the immobilized bacteria were incubated for sequential increments of 30 days. No decline in biodegradation capacity of the immobilized consortium of bacterial cells was noted over its repeated use. We conclude that immobilized hydrocarbon-degrading bacteria represent a promising application in the bioremediation of hydrocarbon-contaminated areas.
Public perceptions, understanding and acceptance of modern biotechnology can both promote and hamper their commercial introduction and adoption. Various studies have shown that consumer acceptance of modern biotechnology tend to be conditional and dependent on several factors. Public perceptions of biotechnology have received extensive attention in recent years in most Western countries such as Europe, USA and Canada but there have been limited similar surveys in developing countries. Most of the earlier studies used uni-dimensional or bi-dimensional instrument with multi-items or the most is four dimensions with single item. In this study, public attitude towards genetically modified (GM) soybean that is already available in the Malaysian market. A survey was carried out on 577 general public respondents in the Klang Valley region. In order to detect the structure of attitude amongst the expert group in the Klang Valley region, structural equation modeling (SEM) using AMOS version 5.1 was carried out. Result of the survey has confirmed that attitude towards complex issues such as biotechnology should be seen as multi-faceted/ multidimensional process. The most important factors predicting encouragement of GM soybean are the specific application-linked perceptions about the benefits and acceptance of risk while moral concern, risk and familiarity are significant predictors of intermediate factors. Researchers, policy makers and industries interested in developing and marketing GM products in Malaysia should consider the various factors mentioned in this in order to gain public approval.