Waraporn Apiwatanapiwat

Direct ethanol production from cassava pulp using a surface-engineered yeast strain co-displaying two amylases, two cellulases, and β-glucosidase.

In order to develop a method for producing fuel ethanol from cassava pulp using cell surface engineering (arming) technology, an arming yeast co-displaying α-amylase (α-AM), glucoamylase, endoglucanase, cellobiohydrase, and β-glucosidase on the surface of the yeast cells was constructed. The novel yeast strain, possessing the activities of all enzymes, was able to produce ethanol directly from soluble starch, barley β-glucan, and acid-treated Avicel. Cassava is a major crop in Southeast Asia and used mainly for starch production. In the starch manufacturing process, large amounts of solid wastes, called cassava pulp, are produced. The major components of cassava pulp are starch (approximately 60%) and cellulose fiber (approximately 30%). We attempted simultaneous saccharification and ethanol fermentation of cassava pulp with this arming yeast. During fermentation, ethanol concentration increased as the starch and cellulose fiber substrates contained in the cassava pulp decreased. The results clearly showed that the arming yeast was able to produce ethanol directly from cassava pulp without addition of any hydrolytic enzymes.

Production of Ligninolytic Enzymes by White-Rot Fungus Datronia sp. KAPI0039 and Their Application for Reactive Dye Removal

This study focused on decolorization of 2 reactive dyes; Reactive Blue 19 (RBBR) and Reactive Black 5 (RB5), by selected white-rot fungus Datronia sp. KAPI0039. The effects of reactive dye concentration, fungal inoculum size as well as pH were studied. Samples were periodically collected for the measurement of color unit, Laccase (Lac), Manganese Peroxidase (MnP), and Lignin Peroxidase (LiP) activity. Eighty-six percent of 1,000  RBBR decolorization was achieved by 2% (w/v) Datronia sp. KAPI0039 at pH 5. The highest Lac activity (759.81 ) was detected in the optimal condition. For RB5, Datronia sp. KAPI0039 efficiently performed (88.01% decolorization) at 2% (w/v) fungal inoculum size for the reduction of 600  RB5 under pH 5. The highest Lac activity (178.57 ) was detected, whereas the activity of MnP and LiP was absent during this hour. The result, therefore, indicated that Datronia sp. KAPI0039 was obviously able to breakdown both reactive dyes, and Lac was considered as a major lignin-degradation enzyme in this reaction.

Efficient saccharification for non-treated cassava pulp by supplementation of Clostridium thermocellum cellulosome and Thermoanaerobacter brockii β-glucosidase.

Cassava pulp containing 60% starch and 20% cellulose is a promising renewable source for bioethanol. The starch granule was observed to tightly bind cellulose fiber. To achieve an efficient degradation for cassava pulp, saccharification tests without pre-gelatinization treatment were carried out using combination of commercial α-amylase with cellulosome from Clostridium thermocellum S14 and β-glucosidase (rCglT) from Thermoanaerobacter brockii. The saccharification rate for cassava pulp was shown 59% of dry matter. To obtain maximum saccharification rate, glucoamylase (GA) from C. thermocellum S14 was supplemented to the combination. The result showed gradual increase in the saccharification rate to 74% (dry matter). Supplementation of GA to the combination of commercial α-amylase, cellulosome and rCglT is powerful method for efficient saccharification of cassava pulp without pretreatment.

Evaluation of Fourier transform-near infrared spectroscopic measurements for the quantification of curcumin in turmeric herbal medicines

In this investigation, Fourier transform-near infrared (FT-NIR) spectroscopy was used to determine the curcumin content in commercial turmeric herbal medicines. Two different sample presentations originating from a turmeric capsule and powder were evaluated and compared using an FT-NIR spectrometer equipped with a 30-capsule sample plate in the wavenumber region of 11,500–6000 cm−1 (transmittance mode) and a 6-vial sample plate in the wavenumber region of 10,000–4000cm−1 (reflectance mode), respectively. One hundred and forty samples of turmeric herbal medicines were divided into two sets: a training set with 110 samples and a prediction set with 30 samples. High-quality FT-NIR spectra for the turmeric powder containing the informative regions of curcumin (6850, 6000 and 4600 cm−1) were obtained while collecting FT-NIR data on the powder samples in the glass vials. A successful partial least-squares calibration model for curcumin content in commercial turmeric herbal medicine powders was then obtained by utilising the entire spectral region (10,000–4000 cm−1) as well as a second derivative spectral pretreatment containing seven principal components. The best model for predicting curcumin in 30 test samples returned a coefficient of determination (r2) of 0.98, a root mean squares error of prediction (RMSEP) of 0.13% that was only 1.35 times the standard error of laboratory and a ratio of RMSEP to the standard deviation of curcumin content in the prediction set (RPD) of 7.76. These statistical values confirmed the high predictive performance of this model. All these results confirm that the use of turmeric herbal medicine powder and a wide informative wavenumber range of 10,000–4000 cm−1 can increase the efficacy of FT-NIR spectroscopy for the rapid and non-destructive analysis of curcumin content in commercial turmeric herbal medicines. By contrast, models developed for determining curcumin in turmeric contained in capsules were not suitable for analytical purposes.