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การใช้กากเนื้อลำไยอบแห้งปราศจากน้ำตาลโมเลกุลสายสั้นเป็นแหล่งอาหารคาร์บอนในการผลิตเอนไซม์ไพรูเวตดีคาร์-บอกซิเลสและ R-phenylacetylcarbinol (R-PAC)
รศ.ดร. นพพล เล็กสวัสดิ์ - มหาวิทยาลัยเชียงใหม่
ชื่อเรื่อง: การใช้กากเนื้อลำไยอบแห้งปราศจากน้ำตาลโมเลกุลสายสั้นเป็นแหล่งอาหารคาร์บอนในการผลิตเอนไซม์ไพรูเวตดีคาร์-บอกซิเลสและ R-phenylacetylcarbinol (R-PAC)
ชื่อเรื่อง (EN): The Application of Oligosaccharides Depleted Dried Longan Flesh Meal as a Carbon Source in the Production of Pyruvate Decarboxylase and R-phenylacetylcarbinol (R-PAC)
ผู้แต่ง / หัวหน้าโครงการ: รศ.ดร. นพพล เล็กสวัสดิ์
บทคัดย่อ (EN): Longin is a crucial expurted economac crop of Thailand and ranked at the fourth posiliom after pineapple, durian, and young com. Each year, tbe majority of longan produced in tbe Northern region is amount to about S00.000 loas with the expo xoriation values of too less than S billion babt. The proce cessing of fresh longan to dried longan for added value purpuse had encountered a deadstock problem which prevented 67,000 tons of tbe processed longans from being transferred aboard during 2003 - 2004. It toxok more than 6 years to reach the fimal resolution to rectity the problem. Obe altemnalive strategy is to retrieve dried longan with high level of sugars and utlize it for ethanol production as biofuels. The altained biomass can also be used as biocatalyst for the production of a precursur for medicines, namely, epbedrine and pseuxdoepbedrine with the properties of relieving tbe allergic and nasal congesbon symptoens. The previous research report suggested that a microbial strain which belonged to the group of Candida utilis was tbe best biocatalyst. This study was therefore focused on tbe cultivation of six C. atilis strains which incluxded TISTR 5001, 5032, 5043, 5046, 5198, and 5352 to evaluate the growth and ethanol production kinetics in detail. The cultivation level was 150 ml with dried lngan extract as a carbon source under static condition for 192 h at 25.6C and 4 replicates. The concentra rations of sugars such as sucrose, glucose, and fructose as as well as ethanol were ere determir rmined by HPLC. The str rain which was able to generale the higbest level of ethanol and bimass was C. utilis TISTR 5198 at 0.46 0.14 g I and 6.47 t 0.12 g I, respectively. The higbest specific growth rate was 0.044 - 0.011 h which corresponded to the doubling time of 15.7 ? 3.8 b. Growth kinetic of C.wils TISTR 5352 for 1,500 ml scale was level of ethanol and biomass at 0.100 0.011 g I and 0.115 t 0.00s g I, respectively. The higbest specific growth rate was 0.008 t 0.000 h which cotresponded to the doubling timse of of 83.0 t 4.1 h. The cultivation of C. utilis TISTR 5198 and TISTR 5352 in DDLFH medium at TSS levels of 20 and 40Brix indicated tbe growth inhibition. The two-phase PAC biotransformati t C. uilis TISTR 5198 using whole ce. ells harvested at 192 h in DDLFH medium with 6.12 g I of dried biomass equivalent resulted in the overall PAC production level of 1.76 0.06 mM. The implementaton of microorganism such as Saccharomyces cerevisiae TISTR 5606, which was capable of converting sugars in tbe overprxduced fresh longan or deadstock dried longan to fermented broth witb bigh ethanol conceatra ration level, was an example of biocbemical process application in order to replace fossil energy with a new energy source. The development of this biofuel would be beneficial in assisling to rectify not oaly global warming but also devalued longan problems. In current study, the research team investigated the effect of varied inoculum concentration levels (1, 5, and 10% (v/v)) to elucidate a cost reduction strategy for the microbial cultivation in dried longan extract from the conventional level of 10% (v/v). In addition, the detailed growth and ethanol produetion kinetics were also evaluated simultaneously. The cultivation level was 1,500 ml in static condition for 36 h at 25.6C. The results suggested that inoculum level of 1% (v/v) was able to produce the highest levels of ethanol concentration and yield of 53.8 t 0.5 g I and 0.49 t 0.01 g ethanol per g of consumed sugars. Moreover, the achieved dried biomass concentration was also the highest at 7.47 t 0.08 g I which was not significantly different (p > 0.05) in comparisor rison to the cultivation n with inoculum level of 5% (v/v) (7.39 + 0.10 g1). In fact, the inoculum level of 10% (v/v) yielded the lower level of dried biomass concentration (6.31 t0.11 gl). The method of score weighing was introduced later by considering three factors which included costing (20%), microbial growh (30%6), and substrates as well as product (50%). The most appropriate yeast inoculum level was 1% (viv) followed by 5 and 10% (v/v) with the corresponding weighing scores of 91.2, 82.3, and 79.5, respectively. DLE medium was the most suitable carbomn source for batch cultivation in 5,000 ml scale with an initial aeration period of 12 h from tbe overall 36 h cultivation period at 25.6C. The ethanol production of S. cerevtsiae TISTR 560 606 in DLE was the highest in comparison with DDLFH medium with corresponding ethanol concentration and yield of 73.77 + 0.48 g 1 " and 0.53 t 0.01 g ethanol per g of consumed sugars, respectively. The level of dried bionass concentration obtained was also the highest at 10.81 - 0.08 g I which was signifieantly different p s 0.05) from that of DDLFH medium (0.17 ? 0.03 g 1). The toxicity of DDLFH medium in comparison to DLE medium was elucidated in the fed batch experiment. The ethanol production from the system with DLE medium feeding was 24.93 - 1.13 g I, which was significantly different (p S 0.05) from DDLFH medium feeding at 8.61 - 0.56 g L. Dried biomass concentration obtained from DLE medium feeding was also higher at 5.72 0.13 g I which was signifcantly different (p S 0.05) from DDLFH medium feeding at 3.00 t 0.17g I. The two-phase separated PAC biotransfornation using whole cells cultivated in 5,000 ml scale with DLE and DDLFH media did not result in PAC production.The problems of longan overproduction and dried longan deadstock that spanned over 6 Norhem provincial area of Thailand gave rise to the research endeavour which concentrated on finding the solution for these issues. Previous research results suggested that Saccharomyces cerevsiae TISTR 5606 was the microbial strain with the highest capability in producing ethanol from three types of sugars commonly found in dried longan extract, namely, glucose, fructose and sucrose. The development of matbematical model for ethanol production kinetics in batch system for S. cerevistae TISTR 5606 w 6 was essential in the further optimization of final ethanol concentration level and productivity based on fed batch and continuous production systems. The research team carried out the detailed investigation of growth and ethanol production kinetics in batch system for this microbi ial strain in 1,500 ml scale. The utilized carbon source was pure analytical grade sugar with an initial concentration of 40 g I under static condition for 36 h, 25.6C, and five replicates. The analyses of sugars and ethanol concentrations were done with HPLC. The developed mathematical model included the constants such as ethanol concentration threshold (P.) and maximum ethanol concentration (P ). The numerical integration w was applied in the simulation of microbial cultivation kinetics with an individual pure sugar. The simulated curves predicted the experimental profiles relatively well (average RSS of 58.9, R > 0.98). The parameter values such as maximums specific growth rate constant (H...), maximum specifie substrate consumption rate constant (q....), and maximum specific ethanol production rate constant (q....) for each sugar were obtained. The subsequent mathematical moxdel development and simulation for static batch cultivation using triple pure sugars (glucose/fructose/sucrose at 20/20/20, 30/30/30, 40/40/40, and 60(60/60) and dried longan extract (60, 120, and 180 g I) resulted in the good agreement of model fiting to experimental data with the corresponding total RSS and average R of(1,033, 0.97) and (1,894, 0.96), respectively. Pyruvate decarboxylasel (PDCI) converts benzaldehyde and pyruvate into (R) phenylacetylcarbinol (R - PAC) in enzymatic biotransformation. R-PAC is the preeursor for the production of ephedrine and pseudoephedrine, used as anti-asthmatic and nasal decongestants, respectively. In this study the PDCI gene was amplified from Saccharomyces cerevisiae e 5606. The amplicon was ligated into pPICZA. The resulting pPICZA-PDCI was transformed into Pichia pastoris X-33. Three clones of recombinant P. pastoris found on selective media containing 500 ug mI zeocin were cultured and induced with methanol. The activities of PDCI expressed from P. pastoris were similar to S. cerevisiae TISTR5606 and C. utils TISTR5198. Further studies are needed in order to optimize the PDCI expression.
บทคัดย่อ: ไม่พบข้อมูลจากหน่วยงานต้นทาง
ภาษา (EN): th
เผยแพร่โดย: มหาวิทยาลัยเชียงใหม่
คำสำคัญ: ไพรูเวตดีคาร์บอกซิเลส
เจ้าของลิขสิทธิ์: สำนักงานคณะกรรมการวิจัยแห่งชาติ
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การใช้กากเนื้อลำไยอบแห้งปราศจากน้ำตาลโมเลกุลสายสั้นเป็นแหล่งอาหารคาร์บอนในการผลิตเอนไซม์ไพรูเวตดีคาร์-บอกซิเลสและ R-phenylacetylcarbinol (R-PAC)
มหาวิทยาลัยเชียงใหม่
30 กันยายน 2552
การผลิต Inulin และ Oligofructose จากกล้วยเพื่อใช้เป็นสารเสริมอาหาร วิถีชีวิตแบบสโลว์ฟูดส์… เพื่อคุณภาพชีวิตที่ดี การศึกษาการผลิตอาหารสุนัข การศึกษาเพื่อผลิตเอ็นไซม์ผสมกลุ่มเซลลูเลสโดยการเพาะเลี้ยงเชื้อราร่วมกัน อาหารบำรุงสมอง การพัฒนาอาหารนกกระจอกเทศ กระบวนการผลิตน้ำเชื่อมเข้มข้นจากลำไยและการประยุกต์ใช้ในผลิตภัณฑ์อาหาร อนาคตของอาหารโลกอยู่ในมือของคุณ การตลาดยุคดิจิทัลของผลิตภัณฑ์ลำไยอบแห้งเนื้อสีทอง การโคลนยีนไฟเตสทนร้อนจากแอคติโนไมซีท Thermomonospora sp. RC7 เพื่อพัฒนาการผลิตเอนไซม์ไฟเตสทดแทนการนำเข้าจากต่างประเทศ
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