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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Production and Partial Characterization of Chitosanases from a Newly Isolated Bacillus cereus) ผู้เขียน: Sutee Wangtueai,  ดร.วันชัย วรวัฒนเมธีกุล, รองศาสตราจารย์ , นางมัทนา แสงจินดาวงษ์, รองศาสตราจารย์ , นางสาวนวลพรรณ ณ ระนอง, ดร.สาโรจน์ ศิริศันสนียกุล, ศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThe production of chitosanases by a newly isolated Bacillus cereus TP12.24 was studied both in shake flask and fermenter cultures. The M9-chitosan medium was found most suitable with 0.5% chitosan as a sole carbon source optimized under aerobic growth conditions at pH 6.0 and 30?C. The specific rates of growth, substrate consumption, and enzyme production were improved using controlled completely aerobic conditions in 2-l fermenter. While the yield of biomass was considerably increased, the enzyme yield was on the contrary decreased. As a result, the volumetric chitosanases productivity was 43.55 U/l h, which was 1.2 times that obtained from shake flask culture due to higher specific rates of chitosan consumption and chitosanases production. In this work, the crude chitosanases from Bacillus cereus TP12.24 showed their optimal pH and temperature at 6.5 and 55?C, while the stabilities to pH and temperature were found at 3.0-8.0 and 30-50?C, respectively. The Bacillus cereus chitosanases could be used for preparing the chitosano-oligosaccharides under mild temperature. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Production of L-Lactic Acid from Raw Cassava Starch by Rhizopus oryzae NRRL 395) ผู้เขียน:นางสาวนวลพรรณ ณ ระนอง, Duangduan Poocharoen สื่อสิ่งพิมพ์:pdf AbstractLactic acid, which is commonly used in food, chemical and pharmaceutical industries, has recently received much attention for the production of biodegradable plastic. L-lactic acid production by Rhizopus oryzae NRRL 395 from raw cassava starch as a sole carbon source was studied. The optimum production medium was as follows (g/l) : raw cassava starch, 120; (NH4) 2 SO4, 3.0; KH2PO4, 1.0; MgSO4.7H2O, 0.25; ZnSO4.7H2O, 0.04; pH 6.0. The maximum L-lactic acid production in shake flasks was 68.32 g/l on day 5 with the shaking speed of 200 rpm at 30?C. L – lactic acid yield and productivity were 0.59 g/g substrate and 0.57 g/lh, respectively. In a jar fermentor, the maximum L-lactic acid production was 54.62 g/l on day 4 of cultivation at the agitation speed of 400 rpm and the aeration rate of 1.5 vvm. The L – lactic acid yield was 0.49 g/g substrate with the productivity of 0.56 g/lh. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Isolation and Screening of Chitosanase Producing Microorganisms) ผู้เขียน:Sutee Wangtueai, ดร.วันชัย วรวัฒนเมธีกุล, รองศาสตราจารย์, นางมัทนา แสงจินดาวงษ์, รองศาสตราจารย์, นางสาวนวลพรรณ ณ ระนอง, ดร.สาโรจน์ ศิริศันสนียกุล, ศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractA total of 183 isolates of microorganisms were collected from forest soil with the shrimp wastes deposited. The selected four bacterial isolates with high activity of chitosanolytic enzymes on chitosanase detected agar plates (CDA-plates) were TP11.03, TP11.22, TP12.24 and KU22.13. Among them, the potential isolate TP12.24 was identified as Bacillus cereus which produced the highest amount of chitosanase on M9-Chitosan medium. |
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