Biotransformation of various carbon sources to kojic acid by cell-bound enzyme system of A. flavus Link 44-1

The ability of cell-bound enzyme of Aspergillus flavus Link 44-1 for production of kojic acid was studied in resuspended cell system. Cell material was produced in batch fermentation using 2 L stirred tank fermenter. The cell mycelia were then resuspended into 250 mL shake flask containing various carbon sources solution. Among the carbon sources tested, glucose gave the highest kojic acid yield based on carbon consumed (0.365 g/g) followed by sucrose (0.279 g/g), starch hydrolysate (0.212 g/g) and fructose (0.195 g/g). The rate of biotransformation was increased with increasing mycelial cell. Kojic acid production was also varied with different glucose and sucrose concentrations. The highest production was obtained at 100 g/L glucose and 100 g/L sucrose with a final kojic acid concentration of 45.3 and 33.4 g/L, respectively. The rate of biotransformation of glucose and sucrose to kojic acid followed the Michaelis–Menten equation, suggesting that the biotransformation rate vary with substrate concentration similar to the behaviour of many enzymes reaction

The Assessment of Plastic Materials for Monitoring the Moisture, Colour, Pungency and Rancidity of 'Chili Boh'

'Chili Boh', which is a slurry of Capsicum annum was prepared in the laboratory and then packaged in heat sealed pouches of polypropylene (PP), low density polyethylene (LDPE), a laminate of polypropylene, cellophane and polyethylene (PPICPPILDPE) and a laminate of oriented polypropylene- polyethylene (OPPIPE). The package samples were stored at ambient temperature and analysed periodically to assess any changes in its moisture, colour, pungency and flavour. Colour was found to be the limiting factor in the shelf-life of the product. The pungency and the flavour (related to degree of rancidity) of the samples were relatively stable up to six weeks. Slight loss of moisture was observed upon storage. PPICPPILDPE and OPPIPE proved to be equally acceptable in maintaining the studied qualities of 'Chili Boh' for up to four weeks. However, OPPIPE is recommended for commercial use due to its low unit cost

The morphology and structure of red pigment producing fungus: monascus purpureus

Thered pigment producing, ascospore forming fungus Monascus purpureuswas obtained by monospore isolation and maintained on potato dextrose agar at 32°C for 7 days. M. purpureusproduces compact colonies of mycelia and accumulates large quantities of red pigment. Here we aimed to describe this newly isolated red pigment producing fungus using biochemical and microscopy technique. A newly isolated red pigment producing fungus from local red fermented rice was identified using Microbial Identification System based on fatty acids profiles.The growth, morphology, and structure of M. purpureuswere characterized by Scanning Electron Microscopy (SME). We found that M. purpureusreproduces sexually (by the formation of cleistothecium with ascospores) and asexual (by the formation of conidia). In Monascusspecies, the formation of either asexual or sexual spores appears to be an effective growth strategy. On the basis of biochemical and all morphological investigations it could be concluded that the new strain isolated from red fermented rice belongs to species M. purpureus, labeled as M. purpureus FTCC 5391

Comparison of expression systems for the production of human interferon-a2b.

The production of human interferon alpha2b (IFN-α2b) in two expression systems, tobacco (Nicotiana tabaccum) and Escherichia coli, was compared in various aspects such as safety, yield, quality of product and productivity. In the E. coli system, IFN-α2b was expressed under a pelB signal sequence and a T7lac promoter in a pET 26b(+) vector. The same gene was also cloned in expression plant vector (pCAMBIA1304) between cauliflower mosaic virus promoter (CaMV35S) and poly A termination region (Nos) and expressed in transgenic tobacco plants. The expression of protein in both systems was confirmed by western immunoblotting and the quantity of the protein was determined by immunoassay. The amount of periplasmic expression in E. coli was 60 µg/L of culture, while the amount of nuclear expression in the plant was 4.46 µg/kg of fresh leaves. The result of this study demonstrated that IFN-α2b was successfully expressed in periplasm of bacterial and plant systems. The limitations on the production of IFN-α2b by both systems are addressed and discussed to form the basis for the selection of the appropriate expression platform

Industrializing biotechnology: roles of fermentation and bioprocess technology

iotechnology is defined by the tools used to practice it. By programming DNA and directing cellular machinery, the products that were unimaginable even 10 years ago could be produced. With biotechnology, the nanoscale machinery of living cells to produce self-contained factories that perform on a characteristic scale of one micron could be established. For industrialization of biotechnology, however, bioproducts and bioenergy must be produced in immense or large quantities to meet market demand. Genetic engineering, for example, is carried out at a molecular scale but is amplified through fermentation and bioprocess technology to transfer the process from the test tube to the bottle through a sequence of integrated steps that generate, recover, purify, formulate and package the product. The challenge facing the fermentation and bioprocess technology discipline is in redirecting the genetic and cellular machinery to make commercially and economically important biomolecules when the cells are placed in controlled environments. Fermentation and bioprocess technology knowledge and skills are applied to design, build and operate hardware and integrated systems that can be used to culture the cells and produce the required products efficiently, as well as to recover, purify and formulate the products in a cost-effective manner to enable the products to be commercialized. In addition, the design and operation of the biomanufacturing process must also follow the regulations set by the authorized bodies prior to commercialization. For example, the current Good Manufacturing Practice (cGMP) regulation set by the Food Drug Authority (FDA) must be adhered to in the production of biopharmaceuticals, while GMP requirements must be applied in food and food ingredient production. The demand for knowledge and skills in fermentation and bioprocess technology continues to grow. This discipline provides a bridge between the research laboratory and the economic, large-scale implementation of biomanufacturing systems. With the rapid growth of biologically based technologies, fermentation and bioprocess technology is needed to solve the problems of today and tomorrow. This lecture describes the basic concept of biomanufacturing processes for the production of various biotechnology products and also the roles of fermentation and bioprocess technology to “Bring Technology To Life” through the conversion of biological materials into other forms needed by mankind. Examples of approaches that have been applied by our research group in the development and improvement of various biomanufacturing processes, such as production of kojic acid, solvents, probiotic microorganisms, metabolites and biopharmaceuticals, using microbials, plant cells and microalgae are highlighted

Properties of kojic acid and curcumin: assay on cell B16-F1

Ultra violet (UV) exposure and oxidative stress are casually linked to skin disorders. They can increase melanin synthesis, proliferation of melanocytes, and hyperpigmentation. It is possible that antioxidants or inhibitors may have a beneficial effect on skin health to reduce hyperpigmentation. In the last few years, a huge number of natural herbal extracts have been tested to reduce hyperpigmentation. The objective of this study was to determine and to compare of kojic acid and curcumin properties to viability cell B16-F1. In this study, our data showed that the viability of cell B16-F1 was 63.91% for kojic acid and 64.12% for curcumin at concentration 100 µg/ml. Further investigation assay of antioxidant activities, indicated that IC50 for kojic acid is 63.8 µg/ml and curcumin is 16.05 µg/ml. Based on the data, kojic acid and curcumin have potential antioxidant properties to reduce hyperpigmentation with low toxicity effect in cell B16-F1

Effect of precursors on flavonoid production by Hydrocotyle bonariensis callus tissues

Callus tissue of Hydrocotyle bonariensis was initiated from the leaf of H. bonariensis treated with 2 mg/l of 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 mg/l kinetin. The culture was kept at 25°C, under light (cool white fluorescent tubes, 1200 lux). To optimize the precursors to increase the production of flavonoid, different precursors were used. The data showed that 4 mg/l proline produced the highest flavonoid yield (10.77 ± 0.25 mg/g DW). The increase in proline concentration did not significantly increase the production of flavonoid. The highest flavonoid yield (10.59 ± 0.18 mg/g DW) was produced in 1 mg/l of glutamine. No significant increase was attained in the flavonoid yield in callus treated with 2, 3 mg/l compared with the control. Phenylalanine at the concentration of 3 mg/l, successfully triggered the production of flavonoid (11.43 ± 0.12 mg/g DW), which was 23% higher than the control. The highest flavonoid production was attained in calluses treated with 4 mg/l of naringenin; and it was 19.72% higher compared with the control.Key words: Flavonoids, cell culture, amino acid, precursor

Enzymatic saccharification of pretreated solid palm oil mill effluent and oil palm fruit fiber.

The effectiveness of various chemicals pretreatment (NaOH, HCl, NH3, HNO3 and EDTA) on the enzymatic saccharification of solid palm oil mill effluent (POME) and oil palm fruit fibre (OPFF) was investigated. The results showed that NaOH seem to be the most suitable chemical pretreatment for enhancing sugar production and the degree of hydrolysis from saccharification of OPFF. NaOH at a concentration of 2% (w/v) appears to be optimal for alkaline pretreatment of OPFF. However, chemical pretreatment of solid POME using NaOH, NH3, HNO3, HCl and EDTA was found to be ineffective in enhancing the degree of hydrolysis and sugar production as compared to chemically untreated solid POME. Autoclaving OPFF at 121°C, 15 psi for 5 minutes improved the degree of hydrolysis up to 2.4 times. However, the degree of hydrolysis was not significantly affected for solid POME under the same conditions

The performance of a glass bead shaking technique for the disruption of Escherichia coli cells

The efficacy of a simple laboratory method for cell disruption based on the shaking of glass beads on a rotary shaker was assessed in this study, via measurements of the release of total protein and interferon-α2b from E.coli. The optimum conditions for cell disruption were detected after 30 min of shaking in Tris-HCl buffer (pH 8) at 300 rpm with 1.5g of glass beads (diameter: 0.5 mm) per mL of cell suspension volume. Three test runs were conducted under the above conditions and the maximum average protein release values were determined as 3.048, 3.564, and 3.015 mg/mL, respectively. The amount of protein release was comparable to the amount of protein release in ultrasonication and glass bead vortexing procedures. The amount of interferon-α2b release in the ultrasonication, glass bead vortexing, and glass bead shaking trials were 240, 172, and 201 ng/mL, respectively. This method was shown to process between 1 and 10 mL of sample volume in a 50 mL Falcon tube without a great deal of deviation, and was able to handle in excess of 60 samples simultaneously