十字形聚乙烯醇丝固定化米根霉发酵L-乳酸的研究
|
摘要
乳酸是生物医学工程材料聚乳酸的生产原料,而且随着生物可降解材料-聚乳酸研究的迅速发展,乳酸的生产越来越受到人们的高度关注。目前乳酸生产的方法大部分采用微生物发酵法,常用的菌种有米根霉和乳酸菌。米根霉的营养需求低,产出的乳酸光学纯度高。但是由于真菌的菌丝形态难控制,游离发酵易形成凝团和结块,降低了生产效率。采用固定化方法,可以控制菌丝形态,缩短发酵时间,且固定化细胞可重复稳定使用。此外,米根霉可以利用的碳源有葡萄糖和淀粉,但是随着能源和粮食问题的加重,需要找到廉价且易得的原料。目前研究较多的是利用纤维素原料—农业废弃物如玉米秸秆进行发酵,本文对此也进行了探讨。
本文分为两部分进行了研究:采用聚乙烯醇丝作为吸附材料,制成十字形立体载体,研究了该载体的参数、发酵条件及载体的长期稳定性;在此基础上,初步研究了以秸秆酶解液为碳源进行发酵的产乳酸(游离与固定化)。
首先,以葡萄糖作为碳源,确定载体的形状为十字形,载体长度2.5cm、PVA丝质量0.12g/个、孢子浓度0.5×10~6个/ml、1个载体进行发酵,乳酸浓度可达到51.13g/L,转化率为63.90%。与游离发酵相比,摇瓶固定化发酵乳酸浓度提高了25%,发酵时间缩短了33%。
其次,确定了载体的摇瓶发酵条件:在种子培养的开始就加入载体固定化培养24h、转速180 r/min、发酵开始一次性添加20g/L的CaCO3,乳酸浓度54.32g/L。摇瓶和1L的鼓泡式生物反应器的半连续发酵研究表明载体固定化发酵可保持长期稳定性。摇瓶可稳定发酵10批次,平均转化率65.00%,平均产率稳定1.10 g/L·h;1L反应器乳酸浓度最高达到55.68 g/L,转化率69.60%。
最后,以玉米秸秆作的酶解液作为碳源,初步探讨了酶解液的发酵。选择蒸汽爆破和物理化学法相结合对秸秆进行了预处理,降低了木质素的含量,提高了纤维素酶对原料的敏感性。通过均匀设计得到最佳的纤维素酶浓度35FPU/g和底物浓度50g/L,酶解率可达到94.03%。采用酶解液进行发酵的研究中,优化培养基为:MgSO_4·7H_2O 0.35 g/L,ZnSO_4·7H_2O 0.20 g/L,KH_2PO_4 0.15 g/L,尿素1g/L。游离发酵中,48小时乳酸转化率52.36%;采用PVA丝载体固定化发酵,发酵周期缩短为30小时,乳酸转化率30.19%。
Lactic acid is precursor of poly lactic acid which is a kind of biomedical engineering materials.Recently, with the rapid development of biodegradable materials-poly lactic acid, there has been an high interest in lactic acid production. The main lactic acid production method is microorganism fermentation in which lactic acid bacteria and Rhizopus oryzae are commonly used. The nutritional requirement of Rhizopus oryzae is simple and its output is in high optical purity. However, it is difficult to control the fungal cell morphology and the dispersed mycelia would easily form clumps which will impose diffusion limitation and reduce lactic acid production. The immobilized-cell fermentation can easily control the mycelium morphology and shorten fermentation time, besides the immobilized-cell can be reused stably. Glucose and starch are often used as the carbon source of Rhizopus oryzae, but as the energy and food problem becoming more and more serious, it is urgent to find new raw materials which are inexpensive and easy to get. Nowadys, the agriculture waste such as corn straw are extensively studied as cellulosic raw material in lactic acid fermentation which was also investigated in this paper.
This paper was divided into two parts. Firstly, polyving achohol fiber as absorbing material for cruciform matrix production was adopted, and the parameters, fermentation conditions and long-term stability of matrix were researched. At the same time, the fermentation production of lactic acid (free and immobilized cell) by using straw hydrolyzate as carbon source was studied.
Firstly, using glucose as carbon source and determining the shape of matrix to be cruciform in the fermentation, with the matrix inner diameter of 2.5 cm, PVA quality of 0.12g/per matrix, spores concentration of 0.5×10~6/ml and one matrix, as a result, the lactic acid concentration achieved 51.13 g/Lwith the yield of 63.90%. Compared with free fermentation, using immobilized fermentation in shake-flasks, the final lactic acid concentration was increased by 25% and the fermentation time was shortened by 33%.
Secondly, the matrix conditions of shake-flasks fermentation were determined: matrix was put in at the beginning and culturing for 24h, with a rotation speed of 180r/min and adding 20g/L CaCO3 at the beginning of the fermentation at once, lactic acid concentration reached 54.32 g/L. The performance in both of shake-flasks and 1L bubble-column bioreactor operated in a repeated batch mode was indicated the long-term reusability. The overall yield of first 10 cycles in shake-flasks was 65%, corresponding to a volumetric productivity of 1.1g/L·h. Moreover, the highest lactic acid concentration in the bubble-column bioreactor was 55.68% with a yield of 69.60%.
Finally, the fermentation with hydrolyzate of corn straw as carbon source was primary investigated. The pretreatment of corn straw adopted the method of combined steam explosion and physical-chemical process. The content of lignin was reduced; meanwhile the sensitivity of cellulase enzyme to corn straw was increased. The optimal condition for hydrolyze was developed by using Uniform Design theory. When the concentration of cellulose enzyme was 35FPU/g and substrate was 50g/L, the hydrolysis achieved 94.03%. During the study of hydrolyzate fermentation, an optimal medium of MgSO_4·7H_2O 0.35 g/L, ZnSO_4·7H_2O 0.20 g/L, KH_2PO_4 0.15 g/L and urea 1g/L was used. The lactic acid yield was 52.36% in 48h by using free cell while the lactic acid yield was 30.19% by using immobilized cell and the fermentation time was shortened to 30h.
本文分为两部分进行了研究:采用聚乙烯醇丝作为吸附材料,制成十字形立体载体,研究了该载体的参数、发酵条件及载体的长期稳定性;在此基础上,初步研究了以秸秆酶解液为碳源进行发酵的产乳酸(游离与固定化)。
首先,以葡萄糖作为碳源,确定载体的形状为十字形,载体长度2.5cm、PVA丝质量0.12g/个、孢子浓度0.5×10~6个/ml、1个载体进行发酵,乳酸浓度可达到51.13g/L,转化率为63.90%。与游离发酵相比,摇瓶固定化发酵乳酸浓度提高了25%,发酵时间缩短了33%。
其次,确定了载体的摇瓶发酵条件:在种子培养的开始就加入载体固定化培养24h、转速180 r/min、发酵开始一次性添加20g/L的CaCO3,乳酸浓度54.32g/L。摇瓶和1L的鼓泡式生物反应器的半连续发酵研究表明载体固定化发酵可保持长期稳定性。摇瓶可稳定发酵10批次,平均转化率65.00%,平均产率稳定1.10 g/L·h;1L反应器乳酸浓度最高达到55.68 g/L,转化率69.60%。
最后,以玉米秸秆作的酶解液作为碳源,初步探讨了酶解液的发酵。选择蒸汽爆破和物理化学法相结合对秸秆进行了预处理,降低了木质素的含量,提高了纤维素酶对原料的敏感性。通过均匀设计得到最佳的纤维素酶浓度35FPU/g和底物浓度50g/L,酶解率可达到94.03%。采用酶解液进行发酵的研究中,优化培养基为:MgSO_4·7H_2O 0.35 g/L,ZnSO_4·7H_2O 0.20 g/L,KH_2PO_4 0.15 g/L,尿素1g/L。游离发酵中,48小时乳酸转化率52.36%;采用PVA丝载体固定化发酵,发酵周期缩短为30小时,乳酸转化率30.19%。
Lactic acid is precursor of poly lactic acid which is a kind of biomedical engineering materials.Recently, with the rapid development of biodegradable materials-poly lactic acid, there has been an high interest in lactic acid production. The main lactic acid production method is microorganism fermentation in which lactic acid bacteria and Rhizopus oryzae are commonly used. The nutritional requirement of Rhizopus oryzae is simple and its output is in high optical purity. However, it is difficult to control the fungal cell morphology and the dispersed mycelia would easily form clumps which will impose diffusion limitation and reduce lactic acid production. The immobilized-cell fermentation can easily control the mycelium morphology and shorten fermentation time, besides the immobilized-cell can be reused stably. Glucose and starch are often used as the carbon source of Rhizopus oryzae, but as the energy and food problem becoming more and more serious, it is urgent to find new raw materials which are inexpensive and easy to get. Nowadys, the agriculture waste such as corn straw are extensively studied as cellulosic raw material in lactic acid fermentation which was also investigated in this paper.
This paper was divided into two parts. Firstly, polyving achohol fiber as absorbing material for cruciform matrix production was adopted, and the parameters, fermentation conditions and long-term stability of matrix were researched. At the same time, the fermentation production of lactic acid (free and immobilized cell) by using straw hydrolyzate as carbon source was studied.
Firstly, using glucose as carbon source and determining the shape of matrix to be cruciform in the fermentation, with the matrix inner diameter of 2.5 cm, PVA quality of 0.12g/per matrix, spores concentration of 0.5×10~6/ml and one matrix, as a result, the lactic acid concentration achieved 51.13 g/Lwith the yield of 63.90%. Compared with free fermentation, using immobilized fermentation in shake-flasks, the final lactic acid concentration was increased by 25% and the fermentation time was shortened by 33%.
Secondly, the matrix conditions of shake-flasks fermentation were determined: matrix was put in at the beginning and culturing for 24h, with a rotation speed of 180r/min and adding 20g/L CaCO3 at the beginning of the fermentation at once, lactic acid concentration reached 54.32 g/L. The performance in both of shake-flasks and 1L bubble-column bioreactor operated in a repeated batch mode was indicated the long-term reusability. The overall yield of first 10 cycles in shake-flasks was 65%, corresponding to a volumetric productivity of 1.1g/L·h. Moreover, the highest lactic acid concentration in the bubble-column bioreactor was 55.68% with a yield of 69.60%.
Finally, the fermentation with hydrolyzate of corn straw as carbon source was primary investigated. The pretreatment of corn straw adopted the method of combined steam explosion and physical-chemical process. The content of lignin was reduced; meanwhile the sensitivity of cellulase enzyme to corn straw was increased. The optimal condition for hydrolyze was developed by using Uniform Design theory. When the concentration of cellulose enzyme was 35FPU/g and substrate was 50g/L, the hydrolysis achieved 94.03%. During the study of hydrolyzate fermentation, an optimal medium of MgSO_4·7H_2O 0.35 g/L, ZnSO_4·7H_2O 0.20 g/L, KH_2PO_4 0.15 g/L and urea 1g/L was used. The lactic acid yield was 52.36% in 48h by using free cell while the lactic acid yield was 30.19% by using immobilized cell and the fermentation time was shortened to 30h.
引文
[1] Hofvendahl K, Akerberg C,Zacchi G. Simultaneous enzymatic wheat starch saccarification and fermentation to lactic acid by lactococcus lactis[J].Appl Microbiol Biotechnol,1999,52:163-169.
[2] Akerberg C, Hofvendahl K, ZacchiG, et al.Modelling the influence of pH, temperature, glucose and lactic acid concentrations on the kinetics of lactic acid production by Lactoccus lactis ssp lactis ATCC19435 in whole-wheat flour[J]. Appl Microbiol Biotechnol, 1998, 49:682-690.
[3]金其荣,金丰球.玉米原料生产L-乳酸的几个技术问题[J].化工时刊,1998, 11:17-19.
[4]姜邵通,陆香庆,郑志,等.固定化米根霉发酵生产L-乳酸产酸速率的研究[J].合肥工业大学学报, 2007, 30: 384-386.
[5] Wang YJ, Yang XJ, Li HY, et al. Immobilization of Acidithiobacillus ferrooxidans with complex of PVA and sodium alginate[J]. Polym Degrad Stab, 2006, 91(10): 2408-2414.
[6]曹本昌,徐建林,匡群.L-乳酸研究综述[J].食品与发酵工业, 1993,3:56-61.
[7]王博彦,金其荣.发酵有机酸生产与应用手册[M].北京:中国轻工业出版社, 2000, 337-389.
[8]曹本昌,徐建林,匡群.根霉发酵L—乳酸[J].食品与发酵工业, 1994, 1:37-40.
[9]肖阳.米根霉R 1021 L(+)-乳酸发酵工艺研究[D].天津大学, 2003.
[10]王正岩,郝章来.聚乳酸的生产和应用及市场前景[J].化工新型材料, 2003, 3(17):40-41.
[11] Amass W, Amass A, Tighe B. A review of biodegradable polymers:uses, current developments in the synthesis and characterization of biodegradable polymers, blengds of biodegradable polymers and recent advances in biodegradation studies[J].Polym Int, 1998, 47: 89-114.
[12] Tomita K, Nakajima T, Kikuchi Y, et al. Degradation of poly (L-lactic acid) by a newly isolated thermophile[J]. Polym Degrad Stab, 2004, 84: 433-438.
[13]博彦,金其荣.发酵有机酸生产与应用手册[M].中国轻工业出版社, 2000, 337-389.
[14] Akerberg FC, Zacchi G. An economic evaluation of the fermentative production of lactic acid from wheat ?our[J].Bioresour Technol, 2000, 75: 119-126.
[15]陈育如,夏黎明,岑沛霖.利用固定化米根霉在三相流化床中发酵生成L-乳酸[J].微生物学报, 2000, 40(4): 415-419.
[16] Angelova M, Petricheva E. Glucose and nitrogen-dependence of acid proteinase production in semicontinuous culture with immobilized cells of Humicola lutea[J]. J Biotechnol, 1997, 58, 51-55
[17]付永前,黄和,李霜,等.固定化米根霉发酵生产乳酸的现状及发展趋势[J].现代化工, 2008, 12: 88-91.
[18] Efremenko EN, Spiricheva OV, Veremeenko DV, et al. L (+)-lactic acid production using poly(vinyl alcohol)-cryogel-entrapped Rhizopus oryzae fungal cell[J]. J Chem Technol Biotechnol, 2006, 81: 519-522.
[19] Li XM, Lin JP, Liu M. Repeated-batch and continuous production of L-lactic acid by Rhizopus oryzae immobilized in calcium alginate beads: reactor performance and kinetic model[J]. Chin J Chem Eng, 1998a, 6: 330-339.
[20] Hang YD, Hamamci H, Woodams EE. Production of L (+)-lactic acid by Rhizopus oryzae immobilized in calcium alginate gels [J]. Biotechnolo Lett, 1989, 11:119-120.
[21] Tay A, Yang ST. Production of L (+)-lactic acid from glucose and starch by immobilized cells of Rhizopus oryzae in a rotating fibrous bed bioreactor[J]. Biotechnol Bioeng, 2002, 80: 1-12.
[22] Ganguly R, Dwivedi P, Singh RP. Production of lactic acid with loofa sponge immobilized Rhizopus oryzae RBU2-10[J]. Bioresour Technol, 2007, 98: 1246-1251.
[23] Roble ND, Ogbonna JC, TanakaH. L-Lactic acid production from raw cassava starch in a circulating loop bioreactor with cells immobilized in loofa (Luffa cylindrica)[J]. Biotechnol Lett, 2003, 25:1093-1098.
[24] Dong XY, Bai S, Sun Y. Production of L-lactic acid with Rhizopus oryzae immobilized in polyurethane foam cubes[J]. Biotechnol Lett, 1996, 18: 225-228.
[25] Zhang ZY. Production of Lactic acid from renewable materials by Rhizopus fungal[J]. Biochem Engin J, 2007, 35: 251-263.
[26] Chisti MY, Moo-Yong M. Airlift reactors: characteristics, applications and design conside- rations[J]. Chem Eng Commun, 1987, 60: 195-242.
[27] Jin B, Yu Q, Leeuwen J. A bioprocessing mode for fungal biomass protein production and wastewater treatment using external air-lift bioreactor[J]. J Chem Technol Biotechnol, 2001, 76: 1041-1048.
[28] Park EY, Kosakai Y, Okabe M. Efficient Production of L(+)-lactic acid using mycelial cotton-like flocs of Rhizopus oryzae in an air-lift bioreactor[J]. Biotechnol Prog, 1998, 14: 699-704.
[29]蒋明珠,吴芷萍,许孟琴,等. L-乳酸发酵的研究[J].微生物学通报, 1991, 31(1): 41-47.
[30]杨虹,林宇野,史美榕.产L-乳酸的丝状真菌的研究[J].微生物学通报, 1994, 21(6): 339- 342.
[31]曹本昌,徐建林,匡群.根霉发酵L-乳酸[J].食品与发酵工业, 1991, 1: 37-40.
[32] Yin P, Yahiro K, Ishigaki T. L(+)-lactic acid production by repeated batch culture of Rhizopus oryzae in air-lift bioreactor[J]. J of Ferment and Bioeng, 1998, 85(1): 96-100.
[33] Kosakai Y, Park YS, Okabe M. Enhancement of L(+)-lactic acid production using mycelialflocs of Rhizopus oryzae[J] Biotechnol Bioeng, 1997, 55: 461-470.
[34] Du JX, Cao NJ, Gong CS. Production of L(+)-lactic acid by Rhizopus oryzae in a bubble column fermentor[J]. Appl Biochem Biotech, 1998, 70/ 71/ 72: 323-329.
[35] Zhou Y, Dominguez JM, Cao NJ. Optimization of L(+)-lactic acid production from glucose by Rhizopus oryzae ATCC52311[J]. Appl Biochem Biotech, 1999, 77/ 78/ 79: 401-407.
[36] Bai DM, Jia MZ, Zhao XM, et al. L(+)-lactic acid production by pellet-form Rhizopus oryzae R1021 in a stirred tank fermentor[J]. Chem Eng Sci, 2003, 58: 785-791.
[37] Liu Y, Liao W, Liu CB,et al. Optimization of L(+)-lactic acid production using pelletized filamentous Rhizopus oryzae NRRL395[J]. Applied Biochem Biotech, 2006, 129/132: 844-853.
[38]宁尚勇,李十中.真菌固定床反应器发酵L(+)-乳酸的初步研究[J].食品与发酵工业, 2006, 32(3): 22-25.
[39]刘娟,刘昊智,陈海晏,等.大米原料根霉发酵制L-乳酸的发酵条件研究[J].南昌大学学报(工科版), 2001, 23(3): 99-104.
[40] Rueng RC, Hang YD. L(+)-Lactic acid Production from corncobs by Rhizopus oryzae NRRL-395[J]. Food Sci Technol Int, 2003, 36: 573-575.
[41]王蓉,王远亮,王珍,等.米根霉发酵生产L-乳酸研究进展[J].重庆大学学报(自然科学版), 2004, 27(12): 95-97.
[42] Yu RC, Hang YD. Kinetic of direct fermentation of agricultural commodities to L-lactic acid by Rhizopus oryzae[J]. Biotechnol Lett, 1989, 11(8): 597-600.
[43]陈育如,夏黎明,岑沛霖.纤维废渣酶水解及L-乳酸发酵的研究[J].高校化学工程学报, 2000, 5(14):437-441.
[44] Park EY, Anh PN, Okuda N. Bioconversion of waste office paper to L(+)-lactic acid by the filamentous fungus Rhizopus oryzae[J]. Bioresour Technol, 2004, 93: 77-83.
[45]樊华,张劢,黄莉,等.稻草秸秆发酵同时糖化酵解产乳酸的初步研究[J].江西化工, 2007, 3:99-102.
[46] Wu ZG,Lee YY. Nonisothermal simultaneous saccharification and fermentation for direct conversion of lignocellulosic biomass to ethanol[J].Appl Biochem Biotechnol, 1998, 70-72: 479-492.
[47] Kádár Z, Szengyel Z, Réczey K. Simultaneous saccharification and fermentation (SSF) of industrial wastes for the production of ethanol[J]. Indust Crops Prod, 2004, 20: 103-110.
[48] Efremenko E, Spiricheva O, Lozinsky V, et al. Rhizopus oryzae fungus cells producing L(+)-lactic acid: kinetic and metabolic parameters of free and PVA-cryogel-entrapped mycelium[J]. Appl Microbiol Biotechnol, 2006, 72: 480-485.
[49] Idris A, Zain NAM, Suhaimi MS. Immobilization of Baker’s yeast invertase in PVA–alginatematrix using innovative immobilization technique[J].Process Biochem, 2008, 43: 331-338.
[50] Ding SF, Tan TW. L-lactic acid production by Lactobacillus casei fermentation using different fed-batch feeding strategies[J]. Process Biochem, 2006, 41: 1451-1454.
[51]贾士儒.生物工艺与工程实验技术[M].北京:轻工业出版社, 2002.
[52] Kourkoutas Y, Bekatorou A, Banat IM, et al. Immobilization technologies and support materials suitable in alcohol beverages production: a review[J]. Food Microb, 2004, 21: 377-397.
[53] Miura S, Arimura T, Hoshino M, et al. Optimization and scale-up of L-lactic acid fermentation by mutant strain Rhizopus sp. MK-96-1196 in airlift bioreactors[J]. J Biosci Eng, 2003, 96: 65-69.
[54] Thibault J, Pouliot K, Agosin E, et al. Reassessment of the estimation of dissolved oxygen concentration profile and KLa in solid-state fermentation[J]. Process Biochem, 2000, 36: 9-18.
[55] Liao W, Liu Y, Chen SL. Studying pellet formation of a filamentous fungus Rhizopus oryzae to enhance organic acid production[J]. Appl Biochem Biotechnol, 2007, 137: 689-701.
[56] Zhou Y, Du JX, Tsao GT. Mycelial pellet formation by Rhizopus oryzae ATCC20344[J]. Appl Biochem Biotechnol, 2000, 84: 779–789.
[57] Wang Z, Wang YL, Yang ST, et al.A novel honeycomb matrix for cell immobilization to enhance lactic acid production by Rhizopus oryzae[J]. Bioresour Technol, 2010, 101(14): 5557-5564.
[58] Thongchul N. Lactic acid production by immobilized Rhizopus oryzae in a rotating fibrous bed bioreactor[M].PhD thesis. Ohio State University. Columbus, Ohio, 2005.
[59] Skory CD, Freer SN, Bothast RJ. Production of L-lactic acid by Rhizopus oryzae under oxygen limiting conditions[J]. Biotechnol Lett, 1998, 20: 191-194.
[60] Taherzadeh MJ, Fox M, Hjorth H, Edebo L. Production of mycelium biomass and ethanol from paper pulp sulfite liquor by Rhizopus oryzae[J]. Bioresour Technol, 2003, 88: 167-177.
[61] Federici F, Petruccioli M. Immobilization of filamentous fungi: a new frontier in the production of organic acids[J]. Ital J Food Sci, 1997, 9: 171-182.
[62]杜晶娜,王新宇.摇床转速对VB12发酵的影响.河北化工, 2009, 32: 47-48.
[63]郑志,姜绍通,罗水忠,等.不同通气条件下米根霉发酵产L-乳酸的代谢调控[J].农业机械学报, 2008, 39: 79-83.
[64]吴清林,郭宝江.玉米淀粉双酶水解糖米根霉L-乳酸发酵的研究[J].华南师范大学学报, 2002, 1: 31-35.
[65] Karin H, Barbel H. Factors affecting the fermentative lactic acid production from renewable resources[J]. Enzyme Microb Technol, 2000, 26: 87-107.
[66] Bai DM, Yan ZH, Wei Q, et al. Ammonium lactate production by Lactobacillus lactisBME5218M in pH-controlled fed-batch fermentations[J]. Biochem Engin J, 2004, 19(1): 47-51.
[67] Lynd R, Paul JW, et al. Microbial cellulose utilization: Fundamentals and biotechnology[J]. Microbiology and molecular biology reviews, 2002, 66(33): 506-577.
[68]陆玲,袁生.真菌顶端生长菌丝内CaM的免疫组化定位[C].中国菌物学会论文摘要, 1993: 176.
[69]徐国谦,储炬,等.不同的中和剂对L(+)-乳酸发酵的影响.工业微生物, 2007, 37: 1-5.
[70] Liu TJ, Miura S, Yaguchi M, et al. Scale-up of L-lactic acid production by mutant strain Rhizopus sp. MK-96-1196 from 0.003 m3 to 5 m3 in airlift bioreactors[J]. J Biosci Bioeng, 2006, 101: 9-12.
[71]叶勤.发酵过程原理[M].北京:化学工业出版社, 2005.
[72] Garbayo C,V?lchez JM,Vega JE, et al. Influence of immobilization parameters on growth and lactic acid production by Streptococcus thermophilus and Lactobacillus bulgaricus co-immobi- lized in calcium alginate gel beads[J]. Biotechnol Lett, 2004, 26: 1825-1827.
[73]张艳哲,李毅.秸秆综合利用技术进展[J].纤维素科学与技术, 2003, 11(2): 58-60.
[74] Ghose TK. Measurement of cellulase activities[J]. Pure Appl Chem, 1987, 59: 257-268.
[75] Liu SC. Analysis and measurement in papermaking industry[J]. Beijing: Chemical Industry Press, 2004: 19-27.
[76] Moniruzzaman M. Saccharification and alcohol fermentation of steamexploded rice straw[J]. Bioresour Technol, 1996, 55: 111-117.
[77]陈洪章,刘丽英.蒸汽爆碎技术原理及应用[M].化学工业出版社,北京: 2007.
[78]丁为民,王洋,阎秀峰,等.均匀设计法优化桦木醇的超临界二氧化碳萃取工艺[J].林产化学与工业, 2007, 27(3): 63-66.
[79] Eriksson T, Borjesson J, Tjerneld F. Mechanism of surfactant effect in enzymatic hydrolysis of lignocellulose [J]. Enzyme Microb Technol, 2002, 31: 353-364.
[80] Yang B, Wyman CE. BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates[J]. Biotechnol Bioeng, 2006, 94: 611-617.
[81] Chen M, Zhao J, Xia LM. Enzymatic hydrolysis of maize straw polysaccharides for the production of reducing sugars[J]. Carbohydr Polym, 2008, 71: 411-415.
[82]姚日生,邓胜松,齐本坤,等. Tween80对稻草水解及同步糖化与发酵产乳酸的影响[J].精细化工, 2008, 25: 155-158.
[83] Rudolf A, Alkasrawi M, Zacchi G, et al.A comparison between batch and fed-batch simultaneous saccharification and fermentation of steam pretreated spruce[J]. Enzyme Microb Technol, 2005, 37: 195-204.
[84] Zhou Y, Dominguez JM, Cao N, et al.Optimization of l-lactic acid production from glucose byRhizopus oryzae ATCC 52311[J]. Appl Biochem Biotechnol, 1999, 77-79: 401-407.
[85]姜绍通,吴学凤,潘丽军,等.米根霉菌丝球半连续发酵产乳酸的工艺研究[J].农业机械学报, 2009, 40: 150-155.
[86] Bulut S, Elibol M, Ozer D. Effect of different carbon sources on L(+)-lactic acid production by Rhizopus oryzae[J]. Biochem Eng J, 2004, 21: 33-37.
[87]周与良,邢来君.真菌学[M].高等教育出版社,北京, 1986: 52-55.
[88] Jin B, Huang LP, Lant P. Rhizopus arrhizus-a producer for simultaneous saccharifition and fermentation of starch waste materials to L(+)-lactic acid[J]. Biotechnol Lett, 2003, 25: 1983-1987.
[2] Akerberg C, Hofvendahl K, ZacchiG, et al.Modelling the influence of pH, temperature, glucose and lactic acid concentrations on the kinetics of lactic acid production by Lactoccus lactis ssp lactis ATCC19435 in whole-wheat flour[J]. Appl Microbiol Biotechnol, 1998, 49:682-690.
[3]金其荣,金丰球.玉米原料生产L-乳酸的几个技术问题[J].化工时刊,1998, 11:17-19.
[4]姜邵通,陆香庆,郑志,等.固定化米根霉发酵生产L-乳酸产酸速率的研究[J].合肥工业大学学报, 2007, 30: 384-386.
[5] Wang YJ, Yang XJ, Li HY, et al. Immobilization of Acidithiobacillus ferrooxidans with complex of PVA and sodium alginate[J]. Polym Degrad Stab, 2006, 91(10): 2408-2414.
[6]曹本昌,徐建林,匡群.L-乳酸研究综述[J].食品与发酵工业, 1993,3:56-61.
[7]王博彦,金其荣.发酵有机酸生产与应用手册[M].北京:中国轻工业出版社, 2000, 337-389.
[8]曹本昌,徐建林,匡群.根霉发酵L—乳酸[J].食品与发酵工业, 1994, 1:37-40.
[9]肖阳.米根霉R 1021 L(+)-乳酸发酵工艺研究[D].天津大学, 2003.
[10]王正岩,郝章来.聚乳酸的生产和应用及市场前景[J].化工新型材料, 2003, 3(17):40-41.
[11] Amass W, Amass A, Tighe B. A review of biodegradable polymers:uses, current developments in the synthesis and characterization of biodegradable polymers, blengds of biodegradable polymers and recent advances in biodegradation studies[J].Polym Int, 1998, 47: 89-114.
[12] Tomita K, Nakajima T, Kikuchi Y, et al. Degradation of poly (L-lactic acid) by a newly isolated thermophile[J]. Polym Degrad Stab, 2004, 84: 433-438.
[13]博彦,金其荣.发酵有机酸生产与应用手册[M].中国轻工业出版社, 2000, 337-389.
[14] Akerberg FC, Zacchi G. An economic evaluation of the fermentative production of lactic acid from wheat ?our[J].Bioresour Technol, 2000, 75: 119-126.
[15]陈育如,夏黎明,岑沛霖.利用固定化米根霉在三相流化床中发酵生成L-乳酸[J].微生物学报, 2000, 40(4): 415-419.
[16] Angelova M, Petricheva E. Glucose and nitrogen-dependence of acid proteinase production in semicontinuous culture with immobilized cells of Humicola lutea[J]. J Biotechnol, 1997, 58, 51-55
[17]付永前,黄和,李霜,等.固定化米根霉发酵生产乳酸的现状及发展趋势[J].现代化工, 2008, 12: 88-91.
[18] Efremenko EN, Spiricheva OV, Veremeenko DV, et al. L (+)-lactic acid production using poly(vinyl alcohol)-cryogel-entrapped Rhizopus oryzae fungal cell[J]. J Chem Technol Biotechnol, 2006, 81: 519-522.
[19] Li XM, Lin JP, Liu M. Repeated-batch and continuous production of L-lactic acid by Rhizopus oryzae immobilized in calcium alginate beads: reactor performance and kinetic model[J]. Chin J Chem Eng, 1998a, 6: 330-339.
[20] Hang YD, Hamamci H, Woodams EE. Production of L (+)-lactic acid by Rhizopus oryzae immobilized in calcium alginate gels [J]. Biotechnolo Lett, 1989, 11:119-120.
[21] Tay A, Yang ST. Production of L (+)-lactic acid from glucose and starch by immobilized cells of Rhizopus oryzae in a rotating fibrous bed bioreactor[J]. Biotechnol Bioeng, 2002, 80: 1-12.
[22] Ganguly R, Dwivedi P, Singh RP. Production of lactic acid with loofa sponge immobilized Rhizopus oryzae RBU2-10[J]. Bioresour Technol, 2007, 98: 1246-1251.
[23] Roble ND, Ogbonna JC, TanakaH. L-Lactic acid production from raw cassava starch in a circulating loop bioreactor with cells immobilized in loofa (Luffa cylindrica)[J]. Biotechnol Lett, 2003, 25:1093-1098.
[24] Dong XY, Bai S, Sun Y. Production of L-lactic acid with Rhizopus oryzae immobilized in polyurethane foam cubes[J]. Biotechnol Lett, 1996, 18: 225-228.
[25] Zhang ZY. Production of Lactic acid from renewable materials by Rhizopus fungal[J]. Biochem Engin J, 2007, 35: 251-263.
[26] Chisti MY, Moo-Yong M. Airlift reactors: characteristics, applications and design conside- rations[J]. Chem Eng Commun, 1987, 60: 195-242.
[27] Jin B, Yu Q, Leeuwen J. A bioprocessing mode for fungal biomass protein production and wastewater treatment using external air-lift bioreactor[J]. J Chem Technol Biotechnol, 2001, 76: 1041-1048.
[28] Park EY, Kosakai Y, Okabe M. Efficient Production of L(+)-lactic acid using mycelial cotton-like flocs of Rhizopus oryzae in an air-lift bioreactor[J]. Biotechnol Prog, 1998, 14: 699-704.
[29]蒋明珠,吴芷萍,许孟琴,等. L-乳酸发酵的研究[J].微生物学通报, 1991, 31(1): 41-47.
[30]杨虹,林宇野,史美榕.产L-乳酸的丝状真菌的研究[J].微生物学通报, 1994, 21(6): 339- 342.
[31]曹本昌,徐建林,匡群.根霉发酵L-乳酸[J].食品与发酵工业, 1991, 1: 37-40.
[32] Yin P, Yahiro K, Ishigaki T. L(+)-lactic acid production by repeated batch culture of Rhizopus oryzae in air-lift bioreactor[J]. J of Ferment and Bioeng, 1998, 85(1): 96-100.
[33] Kosakai Y, Park YS, Okabe M. Enhancement of L(+)-lactic acid production using mycelialflocs of Rhizopus oryzae[J] Biotechnol Bioeng, 1997, 55: 461-470.
[34] Du JX, Cao NJ, Gong CS. Production of L(+)-lactic acid by Rhizopus oryzae in a bubble column fermentor[J]. Appl Biochem Biotech, 1998, 70/ 71/ 72: 323-329.
[35] Zhou Y, Dominguez JM, Cao NJ. Optimization of L(+)-lactic acid production from glucose by Rhizopus oryzae ATCC52311[J]. Appl Biochem Biotech, 1999, 77/ 78/ 79: 401-407.
[36] Bai DM, Jia MZ, Zhao XM, et al. L(+)-lactic acid production by pellet-form Rhizopus oryzae R1021 in a stirred tank fermentor[J]. Chem Eng Sci, 2003, 58: 785-791.
[37] Liu Y, Liao W, Liu CB,et al. Optimization of L(+)-lactic acid production using pelletized filamentous Rhizopus oryzae NRRL395[J]. Applied Biochem Biotech, 2006, 129/132: 844-853.
[38]宁尚勇,李十中.真菌固定床反应器发酵L(+)-乳酸的初步研究[J].食品与发酵工业, 2006, 32(3): 22-25.
[39]刘娟,刘昊智,陈海晏,等.大米原料根霉发酵制L-乳酸的发酵条件研究[J].南昌大学学报(工科版), 2001, 23(3): 99-104.
[40] Rueng RC, Hang YD. L(+)-Lactic acid Production from corncobs by Rhizopus oryzae NRRL-395[J]. Food Sci Technol Int, 2003, 36: 573-575.
[41]王蓉,王远亮,王珍,等.米根霉发酵生产L-乳酸研究进展[J].重庆大学学报(自然科学版), 2004, 27(12): 95-97.
[42] Yu RC, Hang YD. Kinetic of direct fermentation of agricultural commodities to L-lactic acid by Rhizopus oryzae[J]. Biotechnol Lett, 1989, 11(8): 597-600.
[43]陈育如,夏黎明,岑沛霖.纤维废渣酶水解及L-乳酸发酵的研究[J].高校化学工程学报, 2000, 5(14):437-441.
[44] Park EY, Anh PN, Okuda N. Bioconversion of waste office paper to L(+)-lactic acid by the filamentous fungus Rhizopus oryzae[J]. Bioresour Technol, 2004, 93: 77-83.
[45]樊华,张劢,黄莉,等.稻草秸秆发酵同时糖化酵解产乳酸的初步研究[J].江西化工, 2007, 3:99-102.
[46] Wu ZG,Lee YY. Nonisothermal simultaneous saccharification and fermentation for direct conversion of lignocellulosic biomass to ethanol[J].Appl Biochem Biotechnol, 1998, 70-72: 479-492.
[47] Kádár Z, Szengyel Z, Réczey K. Simultaneous saccharification and fermentation (SSF) of industrial wastes for the production of ethanol[J]. Indust Crops Prod, 2004, 20: 103-110.
[48] Efremenko E, Spiricheva O, Lozinsky V, et al. Rhizopus oryzae fungus cells producing L(+)-lactic acid: kinetic and metabolic parameters of free and PVA-cryogel-entrapped mycelium[J]. Appl Microbiol Biotechnol, 2006, 72: 480-485.
[49] Idris A, Zain NAM, Suhaimi MS. Immobilization of Baker’s yeast invertase in PVA–alginatematrix using innovative immobilization technique[J].Process Biochem, 2008, 43: 331-338.
[50] Ding SF, Tan TW. L-lactic acid production by Lactobacillus casei fermentation using different fed-batch feeding strategies[J]. Process Biochem, 2006, 41: 1451-1454.
[51]贾士儒.生物工艺与工程实验技术[M].北京:轻工业出版社, 2002.
[52] Kourkoutas Y, Bekatorou A, Banat IM, et al. Immobilization technologies and support materials suitable in alcohol beverages production: a review[J]. Food Microb, 2004, 21: 377-397.
[53] Miura S, Arimura T, Hoshino M, et al. Optimization and scale-up of L-lactic acid fermentation by mutant strain Rhizopus sp. MK-96-1196 in airlift bioreactors[J]. J Biosci Eng, 2003, 96: 65-69.
[54] Thibault J, Pouliot K, Agosin E, et al. Reassessment of the estimation of dissolved oxygen concentration profile and KLa in solid-state fermentation[J]. Process Biochem, 2000, 36: 9-18.
[55] Liao W, Liu Y, Chen SL. Studying pellet formation of a filamentous fungus Rhizopus oryzae to enhance organic acid production[J]. Appl Biochem Biotechnol, 2007, 137: 689-701.
[56] Zhou Y, Du JX, Tsao GT. Mycelial pellet formation by Rhizopus oryzae ATCC20344[J]. Appl Biochem Biotechnol, 2000, 84: 779–789.
[57] Wang Z, Wang YL, Yang ST, et al.A novel honeycomb matrix for cell immobilization to enhance lactic acid production by Rhizopus oryzae[J]. Bioresour Technol, 2010, 101(14): 5557-5564.
[58] Thongchul N. Lactic acid production by immobilized Rhizopus oryzae in a rotating fibrous bed bioreactor[M].PhD thesis. Ohio State University. Columbus, Ohio, 2005.
[59] Skory CD, Freer SN, Bothast RJ. Production of L-lactic acid by Rhizopus oryzae under oxygen limiting conditions[J]. Biotechnol Lett, 1998, 20: 191-194.
[60] Taherzadeh MJ, Fox M, Hjorth H, Edebo L. Production of mycelium biomass and ethanol from paper pulp sulfite liquor by Rhizopus oryzae[J]. Bioresour Technol, 2003, 88: 167-177.
[61] Federici F, Petruccioli M. Immobilization of filamentous fungi: a new frontier in the production of organic acids[J]. Ital J Food Sci, 1997, 9: 171-182.
[62]杜晶娜,王新宇.摇床转速对VB12发酵的影响.河北化工, 2009, 32: 47-48.
[63]郑志,姜绍通,罗水忠,等.不同通气条件下米根霉发酵产L-乳酸的代谢调控[J].农业机械学报, 2008, 39: 79-83.
[64]吴清林,郭宝江.玉米淀粉双酶水解糖米根霉L-乳酸发酵的研究[J].华南师范大学学报, 2002, 1: 31-35.
[65] Karin H, Barbel H. Factors affecting the fermentative lactic acid production from renewable resources[J]. Enzyme Microb Technol, 2000, 26: 87-107.
[66] Bai DM, Yan ZH, Wei Q, et al. Ammonium lactate production by Lactobacillus lactisBME5218M in pH-controlled fed-batch fermentations[J]. Biochem Engin J, 2004, 19(1): 47-51.
[67] Lynd R, Paul JW, et al. Microbial cellulose utilization: Fundamentals and biotechnology[J]. Microbiology and molecular biology reviews, 2002, 66(33): 506-577.
[68]陆玲,袁生.真菌顶端生长菌丝内CaM的免疫组化定位[C].中国菌物学会论文摘要, 1993: 176.
[69]徐国谦,储炬,等.不同的中和剂对L(+)-乳酸发酵的影响.工业微生物, 2007, 37: 1-5.
[70] Liu TJ, Miura S, Yaguchi M, et al. Scale-up of L-lactic acid production by mutant strain Rhizopus sp. MK-96-1196 from 0.003 m3 to 5 m3 in airlift bioreactors[J]. J Biosci Bioeng, 2006, 101: 9-12.
[71]叶勤.发酵过程原理[M].北京:化学工业出版社, 2005.
[72] Garbayo C,V?lchez JM,Vega JE, et al. Influence of immobilization parameters on growth and lactic acid production by Streptococcus thermophilus and Lactobacillus bulgaricus co-immobi- lized in calcium alginate gel beads[J]. Biotechnol Lett, 2004, 26: 1825-1827.
[73]张艳哲,李毅.秸秆综合利用技术进展[J].纤维素科学与技术, 2003, 11(2): 58-60.
[74] Ghose TK. Measurement of cellulase activities[J]. Pure Appl Chem, 1987, 59: 257-268.
[75] Liu SC. Analysis and measurement in papermaking industry[J]. Beijing: Chemical Industry Press, 2004: 19-27.
[76] Moniruzzaman M. Saccharification and alcohol fermentation of steamexploded rice straw[J]. Bioresour Technol, 1996, 55: 111-117.
[77]陈洪章,刘丽英.蒸汽爆碎技术原理及应用[M].化学工业出版社,北京: 2007.
[78]丁为民,王洋,阎秀峰,等.均匀设计法优化桦木醇的超临界二氧化碳萃取工艺[J].林产化学与工业, 2007, 27(3): 63-66.
[79] Eriksson T, Borjesson J, Tjerneld F. Mechanism of surfactant effect in enzymatic hydrolysis of lignocellulose [J]. Enzyme Microb Technol, 2002, 31: 353-364.
[80] Yang B, Wyman CE. BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates[J]. Biotechnol Bioeng, 2006, 94: 611-617.
[81] Chen M, Zhao J, Xia LM. Enzymatic hydrolysis of maize straw polysaccharides for the production of reducing sugars[J]. Carbohydr Polym, 2008, 71: 411-415.
[82]姚日生,邓胜松,齐本坤,等. Tween80对稻草水解及同步糖化与发酵产乳酸的影响[J].精细化工, 2008, 25: 155-158.
[83] Rudolf A, Alkasrawi M, Zacchi G, et al.A comparison between batch and fed-batch simultaneous saccharification and fermentation of steam pretreated spruce[J]. Enzyme Microb Technol, 2005, 37: 195-204.
[84] Zhou Y, Dominguez JM, Cao N, et al.Optimization of l-lactic acid production from glucose byRhizopus oryzae ATCC 52311[J]. Appl Biochem Biotechnol, 1999, 77-79: 401-407.
[85]姜绍通,吴学凤,潘丽军,等.米根霉菌丝球半连续发酵产乳酸的工艺研究[J].农业机械学报, 2009, 40: 150-155.
[86] Bulut S, Elibol M, Ozer D. Effect of different carbon sources on L(+)-lactic acid production by Rhizopus oryzae[J]. Biochem Eng J, 2004, 21: 33-37.
[87]周与良,邢来君.真菌学[M].高等教育出版社,北京, 1986: 52-55.
[88] Jin B, Huang LP, Lant P. Rhizopus arrhizus-a producer for simultaneous saccharifition and fermentation of starch waste materials to L(+)-lactic acid[J]. Biotechnol Lett, 2003, 25: 1983-1987.