Papers by Kamonchai Cha-aim
International Journal of Biological Macromolecules, 2021
This research aims to develop white bread shelf-life extension sachet with controlled release of ... more This research aims to develop white bread shelf-life extension sachet with controlled release of antimicrobial agent prepared from multicomponent bio-based materials. For the controlled release purpose, structure of an antimicrobial sachet consists of two major parts i.e., controlled release part and active part. The first one produced from a white paper coated with ethylene vinyl alcohol (EVOH). The second one functions as an active part which produced from biodegradable poly(butylene succinate) (PBS) and geraniol essential oil blend. Inhibition clear zone results showed that a suitable geraniol concentration, encapsulated in PBS, was 10 wt%. Based on the water vapor transmission test, coating paper with EVOH for three times (around 450 μm) was an optimum condition for the use as a controlled release part. Release test indicated that geraniol migration concentration increased with increasing the relative humidity in the package which correlated to the moisture liberated from bread. Shelf-life extension study informed that the spoilage of bread stored with antimicrobial sachet was delayed by more than three weeks while maintaining the textural hardness. In summary, this antimicrobial sachet could be used as food shelf-life extension materials which easily placed in any food container. This is an alternative way of food waste minimization.
International Journal of Sustainable Engineering, 2021
ABSTRACT To minimise the food waste, this paper applied the antimicrobial plates produced from po... more ABSTRACT To minimise the food waste, this paper applied the antimicrobial plates produced from poly(butylene succinate) (PBS)/geraniol blend which was processed into two different microstructures. Experimental work was separated into three major parts. The first one was the determination of a suitable geraniol concentration by minimum inhibitory concentration and inhibitory clear zone techniques. After that a selected PBS/geraniol composition was then processed into the solid and porous antimicrobial plates of 15 mm in diameter and 2 mm in thickness. Finally, the solid and porous antimicrobial plates were inserted in bread package and evaluated the shelf-life extension performances. Experimental results indicated that a suitable geraniol composition was 8 wt%. Migration test confirmed that geraniol released from both solid and porous plates by more than 30 days. Shelf-life evaluation by counting the microorganisms indicated that applying antimicrobial plates in bread package was found to extend by around 5 and 10 days with solid and porous antimicrobial plates, respectively. In summary, both antimicrobial plates are possibly applied for bread shelf-life extension which easily inserts inside any food container. This is a practical use for retail and household stages.
Methods in Molecular Biology, 2012
Overlap extension or fusion PCR is thought to be a simple and easy method to produce fusion DNA f... more Overlap extension or fusion PCR is thought to be a simple and easy method to produce fusion DNA fragments without the need for restriction enzyme digestion and DNA ligation. However, this method has not been used frequently, probably as it is not always reliable. When natural sequences are used for overlap sequences, sometimes either no fusion DNA is produced or only faint DNA bands are detected owing to low annealing between the overlap sequences selected. Here, we introduce several artificial overlap sequences, most of which are GC-rich, that can be used for reliable fusion PCR. We describe how these overlap sequences can be used for fusion DNA construction, in-frame gene fusion, and cloning in yeast.
Yeast, 2013
The isolation and application of auxotrophic mutants for gene manipulations, such as genetic tran... more The isolation and application of auxotrophic mutants for gene manipulations, such as genetic transformation, mating selection and tetrad analysis, form the basis of yeast genetics. For the development of these genetic methods in the thermotolerant fermentative yeast Kluyveromyces marxianus, we isolated a series of auxotrophic mutants with defects in amino acid or nucleic acid metabolism. To identify the mutated genes, linear DNA fragments of nutrient biosynthetic pathway genes were amplified from Saccharomyces cerevisiae chromosomal DNA and used to directly transform the K. marxianus auxotrophic mutants by random integration into chromosomes through non-homologous end joining (NHEJ). The appearance of transformant colonies indicated that the specific S. cerevisiae gene complemented the K. marxianus mutant. Using this interspecific complementation approach with linear PCR-amplified DNA, we identified auxotrophic mutations of ADE2,
Yeast, 2013
Recombinant DNAs are traditionally constructed using Escherichia coli plasmids. In the yeast Sacc... more Recombinant DNAs are traditionally constructed using Escherichia coli plasmids. In the yeast Saccharomyces cerevisiae, chromosomal gene targeting is a common technique, implying that the yeast homologous recombination system could be applied for recombinant DNA construction. In an attempt to use a S. cerevisiae chromosome for recombinant DNA construction, we selected the single ura3Δ0 locus as a gene targeting site. By selecting this single locus, repeated recombination using the surrounding URA3 sequences can be performed. The recombination system described here has several advantages over the conventional plasmid system, as it provides a method to confirm the selection of correct recombinants because transformation of the same locus replaces the pre-existing selection marker, resulting in the loss of the marker in successful recombinations. In addition, the constructed strains can serve as both PCR templates and hosts for preparing subsequent recombinant strains. Using this method, several yeast strains that contained selection markers, promoters, terminators and target genes at the ura3Δ0 locus were successfully generated. The system described here can potentially be applied for the construction of any recombinant DNA without the requirement for manipulations in E. coli. Interestingly, we unexpectedly found that several G/C-rich sequences used for fusion PCR lowered gene expression when located adjacent to the start codon.
Some white rot fungi, including Ganoderma lucidum and Schizophyllum commune, were collected from ... more Some white rot fungi, including Ganoderma lucidum and Schizophyllum commune, were collected from several provinces around Thailand. All fungi were positive for phenoloxidase activity. S. commune PT1 was found to be the more thermotolerant by being able to grow and survived up to 45 oC. Laccase was produced from G. lucidum BT (0.507 U/ml) and S. commune (0.014 U/ml) and the enzyme was partially purified by using ultrafiltration. The partial purified enzymes were used for Polycyclic Aromatic Hydrocarbons (PAHs) degradation and pulp bleaching. The results showed that some of PAHs (such as fluorene, Benzo(a)pyrene and Benzo(a)anthracene) were degraded. The ceriporic acid B was also cooperated in the PAHs degradation and showed slightly induction for fluorene degradation. The pre-bleaching of eucalyptus paper helped decrease in Kappa number and inversely increased in brightness of the pre-treated paper pulp.
Gene, 2009
Recombinant DNA technology largely depends upon Escherichia coli plasmid construction via restric... more Recombinant DNA technology largely depends upon Escherichia coli plasmid construction via restriction enzyme digestion and DNA ligation. Overlap extension PCR is another simple technique for constructing recombinant DNA but is not commonly used. This is likely due to the inefficiency of fusion after the annealing of overlaps that are generally designed from authentic sequences in the DNA fragments. In our current study, we describe the development of novel overlap sequences that can be used for the construction of fusion DNA fragments, including the one-step fusion of three fragments in a single PCR and also for in-frame fusions. Novel poly G or C stretches showed strong and also specific annealing to the complementary sequences in the fusion PCR. This DNA fusion method is thus both a simple and versatile recombinant DNA technique.
Bioscience, Biotechnology, and Biochemistry, 2009
Applied Microbiology and Biotechnology, 2013
Expression of foreign enzymes in yeast is a traditional genetic engineering approach; however, us... more Expression of foreign enzymes in yeast is a traditional genetic engineering approach; however, useful secretory enzymes are not produced in every case. The hyperthermostable α-amylase encoded by the AmyL gene of Bacillus licheniformis was expressed in Saccharomyces cerevisiae; however, it was only weakly produced and was degraded by the proteasome. To determine the cause of low α-amylase production, AmyL was expressed in a panel of yeast mutants harboring knockouts in non-essential genes. Elevated AmyL production was observed in 44 mutants. The knockout genes were classified into six functional categories. Remarkably, all non-essential genes required for N-linked oligosaccharide synthesis and a gene encoding an oligosaccharyl transferase subunit were identified. Immunoblotting demonstrated that differently underglycosylated forms of AmyL were secreted from oligosaccharide synthesis-deficient mutants, while a fully glycosylated form was produced by wild-type yeast, suggesting that N-linked glycosylation of AmyL inhibited its secretion in yeast. Mutational analysis of six potential N-glycosylation sites in AmyL revealed that the N33Q and N309Q mutations remarkably affected AmyL production. To achieve higher AmyL production in yeast, all six N-glycosylation sites of AmyL were mutated. In wild-type yeast, production of the resulting non-glycosylated form of AmyL was threefold higher than that of the glycosylated form.
Applied and Environmental Microbiology, 2008
We demonstrate herein the ability of Kluyveromyces marxianus to be an efficient ethanol producer ... more We demonstrate herein the ability of Kluyveromyces marxianus to be an efficient ethanol producer and host for expressing heterologous proteins as an alternative to Saccharomyces cerevisiae . Growth and ethanol production by strains of K. marxianus and S. cerevisiae were compared under the same conditions. K. marxianus DMKU3-1042 was found to be the most suitable strain for high-temperature growth and ethanol production at 45°C. This strain, but not S. cerevisiae , utilized cellobiose, xylose, xylitol, arabinose, glycerol, and lactose. To develop a K. marxianus DMKU3-1042 derivative strain suitable for genetic engineering, a uracil auxotroph was isolated and transformed with a linear DNA of the S. cerevisiae Sc URA3 gene. Surprisingly, Ura + transformants were easily obtained. By Southern blot hybridization, the linear Sc URA3 DNA was found to have inserted randomly into the K. marxianus genome. Sequencing of one Lys − transformant confirmed the disruption of the Km LYS1 gene by the ...
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Papers by Kamonchai Cha-aim