April - June 2007 - Kasetsart University

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332 et al. (2003) who reported that, carotenoid contents of Thraustochytrium CHN-1 paralleled the biomass and cell growth. The mutant S. limacinum BR2.1.2 could produce both DHA and astaxanthin at moderate amounts. However, DHA production decreased from 224.6 mg/l day 6 to only 29.8 mg/l at day 10. Hence it seemed that we have to sacrifice either DHA or astaxanthin production depending on the degree of necessity. 2. Effect of light intensity on astaxanthin accumulation by S. limacinum BR2.1.2 mutant CDW (g/l); Astaxanthin (ug/ml) 12 10 8 6 4 2 0 Kasetsart J. (Nat. Sci.) 41(2) 2 4 6 8 10 Time (days) Under dark condition, the mutant accumulated 5.6 µg/ml of astaxanthin at 25°C after incubation for 8 days. However, when fluorescent light source of 5 kLux was provided, the culture produced higher pigment yield of 13.1 µg/ml. Further increase of light intensity to 10 kLux had adverse effect on astaxanthin production (10.7 µg/ml) (Figure 8). Therefore, moderate light was an important bioinduction for carotenogenesis as it was also shown by Phycomyces blaksleeanus and several species of Rhodotolula (Goodwin, 1984). Yamaoka et al. (2004) also demonstrated that Thraustochytrium sp. CHN-1 grown under Astaxanthin (ug/ml) DHA production (mg/l) CDW (g/l) Figure 7 Growth, astaxanthin and DHA production by S. limacinum BR2.1.2 mutant strain in GYC broth at 25°C with 2 kLux light intensity and light:dark 16:8 hrs. Astaxanthin (ug/ml) 14 12 10 8 6 4 2 0 0 5 10 Light intensity (kLux) Figure 8 Effect of light intensity for astaxanthin production by S. limacinum BR2.1.2 mutant strain in GYC broth at 25°C, 180 rpm for 8 days. 250 200 150 100 50 0 DHA production ((mg/l)
fluorescent lamp at 1.5 kLux developed orange to red color. CONCLUSIONS A thraustochytrid strain BR2.1.2 was isolated from mangrove forest in Thailand. The strain showed an ability to grow rapidly while accumulating large amounts of DHA. Identification of the strain based on morphological characteristics and 18S rDNA sequence revealed that it belonged to Schizochytrium limacinum species. Under optimal culture conditions, i.e., 5% glucose, combined nitrogen source (0.5% peptone, 0.2% MSG, 0.25% soybean meal and 1% skimmed milk) and C/N ratio at 15:1, the DHA yield was 2,416.7 mg/l from a cell dry weight of 27.6 g/l. Furthermore S. limacinum BR2.1.2 had a unique feature of growing in media having a wide range of salinity equating to 0-200% seawater. When the strain was cultivated in liquid GPY medium the culture appeared creamy white color. But on agar medium with prolong incubation, color of the colony developed into typical orange color of carotenoid pigment which was identified as astaxanthin. Improvement of S. limacinum BR2.1.2 for astaxanthin content by mutation with NTG was carried out and resulted in a colony with intense red color. This mutant produced astaxanthin in liquid medium even without light. Optimization of culture conditions in liquid GYC medium, particularly high light intensity at 5 kLux at 25°C caused the mutant to accumulate the pigment at 13.1 µg/ml. ACKNOWLEDGEMENTS The authors would like to thanks The Graduate School of Kasetsart University, Bangkok, Thailand for providing research grant. Special thank to Dr. C. Norman Scholfield, Queen University, UK, for his English editing was also acknowledged. Kasetsart J. (Nat. Sci.) 41(2) 333 LITERATURE CITED Andrews, A.G., H.J. Phaff and M.P. Starr. 1976. Carotenoids of Phaffia rhodozyma, a redpigmented fermenting yeast. Phytochem. 15: 1003-1007. Bligh, E.G. and W.J. Dyer. 1959. A rapid method for total lipid extraction and purification. Can. J. Biochem. Physiol. 37: 911-917. Barr, D.J.S. 1992. Evolution and kingdom of organisms from the perspective of a mycologist. Mycologia. 84: 1-11. Chaunpit, D., 1993. Mutagenesis in fungi. pp. 5.24-5.25. In Wattanalai Panbanklet and Sroung Udomworabpun (eds.). Biotechnology Laboratory Manual I. Thai Society for Biotechnology. Donkin, P. 1976. Ketocarotenoid biosynthesis by Haematococcus pluvialis. Phytochemistry 15: 711-718. Fan, K.W., L.L.P. Vrijmoed. and E.B.G. Jones. 2002. Physiological studies of subtropical mangrove thraustochytrids. Botanical Marina 45: 50-57. Fang, T.J. and Y.S. Cheng. 1993. Improvement of astaxanthin production by Phaffia rhodozyma through mutation and optimization of culture conditions. J. Ferment. Bioeng. 75: 466-469. Fontana, J.D., B. Czeczuga, T.M.B. Bonfim, M.B. Chociai, B.H. Oliveira, M.F. Guimaraes and M. Baron. 1996. Bioproduction of carotenoids: The comparative use of raw sugarcane juice and depolymerized bagasse by Phaffia rhodozyma. Bioresource Technology 58: 121-125. Goodwin, T.W. 1984. The Biochemistry of the Carotenoids, Vol 1. Plants, 2 nd ed, Chapman and Hall, London. 377 p. Holub, B.J. and C.M. Skeaff. 1987. Nutritional regulation of cellular phosphatidyllinositol. Methods in Enzymology 141: 234-244. Huang, J., T. Aki., K. Hachida., T. Yokochi., S. Kawamoto., S. Shigeta., K. Ono. and O.
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April - June 2007 Volume 41 Number
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KASETSART JOURNAL NATURAL SCIENCE T
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Kasetsart J. (Nat. Sci.) 41 : 205 -
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harvesting time which started from
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y Chen and Paull (2000). Figure 1 a
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pineapple fruit allowed the accumul
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Kasetsart J. (Nat. Sci.) 41(2) 215
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Cluster analysis Cluster analysis u
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Table 3 (Continued) 1 2 3 4 5 6 7 8
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CONCLUSION AFLP markers classified
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difference of soil texture used in
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under wet soil condition planting.
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tropics. Following the expansion, w
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sealed in a plastic box with 1 cm w
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moisture content increment after so
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Frequency Frequency 30 20 10 0 20.0
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School, Kasetsart University. The a
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for combining ability of lines (Lam
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selective mass sibbing within indiv
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Although most of S 2-interfamily hy
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composite sets as used in this stud
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days. The numbers of calli producin
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the report of Ching (1982) showing
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clearly amplified bands generated b
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caused by either the recombination
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Kuhlmann, V. and B. Foroughi-Wehr.
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Xanthomonas fuscans subsp. aurantif
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was collected and washed with 70% e
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expected size was amplified with 35
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eaction technique has been used for
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Schaad, N.W., D. Opgenorth and P. G
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MATERIALS AND METHODS Model descrip
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calculated TF value calculated TF v
Page 81 and 82: sincere gratitude and deep apprecia
Page 83 and 84: 1989). In monogastrics, the inclusi
Page 85 and 86: of all LLS samples in this study we
Page 87 and 88: Melbourne, Parkville, Victoria. Goe
Page 89 and 90: considered responsible for low prod
Page 91 and 92: Kasetsart J. (Nat. Sci.) 41(2) 291
Page 93 and 94: mineral supplementation suggested b
Page 95 and 96: Body weight chane (kg/head) 32 30 2
Page 97 and 98: CONCLUSION AND RECOMMENDATION With
Page 99 and 100: SAS. (Statistical Analysis System).
Page 101 and 102: genes covering a variety of desirab
Page 103 and 104: mg/l NAA and 0.5 mg/l zeatin) incub
Page 105 and 106: 5. Purification by various sucrose
Page 107 and 108: as the culture period increased. So
Page 109 and 110: culture, pp. 1-20. In L.C. Fowke an
Page 111 and 112: Kasetsart J. (Nat. Sci.) 41 : 311 -
Page 113 and 114: GC. Analytical methods Total carboh
Page 115 and 116: ash. The crude hot water polysaccha
Page 117 and 118: spirulan (H-SP), and a desulfated c
Page 121 and 122: cells often displayed an increased
Page 123 and 124: LITERATURE CITED Bell, T.A. and D.V
Page 125 and 126: for alternative sources of supply.
Page 127 and 128: BR2.1.2 formed the same clade with
Page 129 and 130: supplement with glutamate (Iida et
Page 131: optimal for S. limacinum BR2.1.2 fo
Page 137 and 138: Wisconsin, USA). Total extracted RN
Page 139 and 140: RESULTS Cloning and sequencing of m
Page 141 and 142: Expression of rmIL-2 and purificati
Page 143 and 144: other strains of mice have differen
Page 145 and 146: dose interleukin-2 therapy promotes
Page 147 and 148: The chitosano-oligosaccharides are
Page 149 and 150: enzyme and cells were maximized by
Page 151 and 152: of crude chitosanases. Fortunately,
Page 153 and 154: Relative activity (%) 100 80 60 40
Page 155 and 156: Uchida, K. Tateishi, O. Shida and K
Page 157 and 158: MATERIALS AND METHODS 1. Materials
Page 159 and 160: without coating and coated with pec
Page 161 and 162: in Table 5-7. It was found that the
Page 165 and 166: the cultures at 10,200 × g for 15
Page 167 and 168: incubation and reached the final pH
Page 169 and 170: y lysine- and tyrosine-decarboxylas
Page 171 and 172: during the stages of ripening as su
Page 175 and 176: As the 25 companies were divided in
Page 177 and 178: All the data comes up with informat
Page 179 and 180: as piece “A” or straight as pie
Page 181 and 182: et al. (1998); Zeng (2000); and Tal
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p 1, i * Kasetsart J. (Nat. Sci.) 4
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c ≤ c2 jq2 j n q p k p * 2, j , ,
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algorithm would consider RM 5, prio
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the maximum deviation of about 10%.
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Stock Quantities Using Heuristic Op
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which dynamically and automatically
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2. Framework architecture and compo
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Risk (VaR) calculation which was im
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Throughput (job/sec) 7 6 5 4 3 2 1
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Speed up 40 35 30 25 20 15 10 5 0 F
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and discovery, resource selection a
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April - June 2007 - Kasetsart University

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