Kinetics of Lactic Acid Fermentation by Lactobacillus delbrueckii Grown on Beet Molasses

The fermentation kinetics for the conversion of beet molasses, a valuable and economical fermentation substrate, to lactic acid by the homofermentative organism Lactobacillus delbrueckii C.E.C.T. 286 have been studied at controlled pH and temperature under anaerobic batch conditions. An inhibitory effect of lactic acid on fermentation of beet molasses has been found. The bacterium was able to produce lactic acid even after growth ceased. A kinetic model for the fermentation is proposed. From this model, the maximum allowable lactic acid concentration above which growth stops and the lactic acid level above which bacteria stop producing lactic acid were found to be 45 g dm⁻³ and 57 g dm⁻³, respectively. © 1997 SCI.     

Production of lactic acid from beet molasses by calcium alginate immobilized Lactobacillus delbrueckii IFO 3202

Lactic acid was produced from pretreated beet molasses by the homofermentative organism Lactobacillus delbrueckii subsp delbrueckii IFO 3202 entrapped in calcium alginate gel using batch, repeated batch and continuous fermentation systems. In batch fermentation studies successful results were obtained with 2.0–2.4 mm diameter beads prepared from 2% sodium alginate solution. The highest effective yield (82.0%) and conversion yield (90.0%) were obtained from substrate concentrations of 52.1 and 78.2 g dm⁻³ respectively. The gel beads produced lactic acid for 14 consecutive batch fermentations without marked activity loss and deformation. In the continuous fermentation, the highest lactic acid (4.22%) was obtained at a dilution rate of 0.1 h⁻¹ while the highest productivity (13.92 g dm⁻³ h⁻¹) was obtained at a dilution rate of 0.4 h⁻¹. © 1999 Society of Chemical Industry     

Improved Ethanol Production by Saccharomyces cerevisiae with EDTA,Ferrocyanide and Zeolite X Addition to Sugar Beet Molasses

The influence of ethylenediaminetetra acetic acid (EDTA), potassium ferrocyanide and zeolite X on ethanol production from sugar beet molasses by Saccharomyces cerevisiae was studied. For all of the three substances used, the effect was more pronounced when added to the fermentation medium rather than to the growth medium; 1·9 mmol dm⁻³ potassium ferrocyanide caused an increase in the final ethanol concentration of about 16·4% and 47·5% with respect to control culture on addition to growth and fermentation media respectively. The greatest stimulation in product yield was obtained with zeolite X introduced during the fermentation stage; 8·0 g dm⁻³ zeolite X increased ethanol concentration by 53·3%. © 1997 SCI.     

Production of L‐lactic acid by Lactobacillus delbrueckii in chemostat culture using an ion exchange resins system

L ‐Lactic acid production from beet molasses by Lactobacillus delbrueckii CECT 286 in a continuous fermenter‐ion exchange resins system has been investigated and compared with that observed in a conventional chemostat. The principle of this method is to remove the lactate during the course of fermentation as it is formed by adsorption to an anion exchange resin (Amberlite IRA‐420) in the carbonate form and to overcome its inhibitory effects on lactic acid bacteria by maintaining low lactate concentrations in the medium. Ammonium lactate was formed by percolating ammonium carbonate solution through this resin and it was converted to lactic acid by treatment with a cation exchange resin (Amberlite IR‐120) in hydrogen form. Compared with a conventional chemostat, this fermentation–ion exchange resins system enhanced the fermentation, controlled the pH, and showed the remarkable effect of increasing the yields of lactic acid from sucrose and biomass from sucrose due to the complete utilization of sucrose. © 1999 Society of Chemical Industry     

Batch production of L(+) lactic acid from whey by Lactobacillus casei (NRRL B‐441)

The effects of temperature, pH, and medium composition on lactic acid production by Lactobacillus casei were investigated. The highest lactic acid productivity values were obtained at 37 °C and pH 5.5. The productivity was 1.87 g dm^?3 h^?1 at 37 °C in shake flasks. In the fermenter, a productivity of 3.97 g dm^?3 h^?1 was obtained at pH 5.5. The most appropriate yeast extract concentration was 5.0 g dm^?3. Whey yielded a higher productivity value than the analytical lactose and glucose. Initial whey lactose concentration did not affect lactic acid productivity. MnSO₄ ·H₂O was necessary for lactic acid production by L casei from whey. Product yields were approximately 0.93 g lactic acid g lactose^?1. Copyright © 2004 Society of Chemical Industry     

乳酸菌发酵甘蔗糖蜜产乳酸的培养条件优化

乳酸是有广泛应用的有机酸,廉价原料是降低乳酸生产成本的重要因素。以实验室前期筛选的植物乳杆菌sy4为出发菌株研究了利用甘蔗糖蜜生产乳酸的培养条件。在确定发酵温度和初始pH后,通过Plackett-Burman实验和中心复合实验优化乳酸发酵条件。结果表明：植物乳杆菌sy4乳酸发酵的最适条件为温度32℃、60h、初始pH 6.5;Plackett-Burman实验表明酵母提取物、糖蜜和碳酸钙是影响乳酸产量的主要因素;中心复合实验得到三因素的最优组合为：酵母提取物13.19g/L、糖蜜476.63g/L和碳酸钙134.82g/L,确定了最适发酵培养基。在此条件下乳酸产量为（145.53±1.24） g/L,与模型预测值147.23g/L接近。本研究为以甘蔗糖蜜为原料生产乳酸提供了技术支持。     

-乳酸的研究

从所选取的产l-乳酸的4株菌中筛选出一株性能优良、糖利用率和乳酸产量较高的菌种作为试验用菌种。对影响乳酸菌发酵大豆秸秆酶解物制备l-乳酸的因素进行了研究,影响大豆秸秆酶解液发酵的主要因素是菌种类型、底物糖浓度、接种量、温度及pH值。结果表明:干酪乳酸菌是较适宜的发酵菌种,较适宜的发酵条件为:发酵温度30℃,接种量10%,pH值5.5。随着底物糖含量的增加,乳酸产率相应增大,在实验范围内,乳酸菌发酵所产乳酸的产率达到80%。     

我国乳酸的生产技术及研发状况

介绍了我国乳酸行业目前的生产技术和研发状况,综述了乳酸的主要生产方法(化学合成法、酶法合成、发酵法),对各种方法的特点进行了点评,详细点评了乳酸发酵法生产,并对乳酸发酵技术的前景进行了展望。     

乳酸菌微生物燃料电池产电性能及产电机理研究

采用双室微生物燃料电池（MFC）,以乳酸菌为产电微生物,并以葡萄糖为唯一的电子供体,研究MFC的产电性能以及乳酸菌MFC产电机理。在30 ℃下,底物浓度为1.5 g/L时,该MFC的开路电压稳定在500 mV。实验条件下测得该MFC的最大功率密度为393.23 mW/m²,内阻约为500 Ω。利用气相色谱分析乳酸菌MFC产电过程中代谢产物的含量变化,实验数据表明无论是不参与产电的正常代谢途径还是产电过程中,都涉及到乳酸菌的同型乳酸发酵途径、异型乳酸发酵的经典途径和双歧杆菌发酵途径。在乳酸菌MFC运行过程中人为添加乙醇,该实验结果显示乙醇不利于乳酸菌产电,表明乳酸菌的异型乳酸发酵途径是乳酸菌进行产电的关键代谢途径。     

发酵液中乳酸的盐析萃取

研究了一种利用盐析萃取法分离发酵液中乳酸的新方法. 通过系统考察乳酸在不同盐析萃取体系中的分配规律,发现K2HPO4-甲醇和K2HPO4-乙醇体系适合分离发酵液中的乳酸. 发酵液中乳酸浓度为167 g/L时,采用25%(w) K2HPO4-26%(w)甲醇盐析萃取体系,乳酸的分配系数和回收率分别为4.01和86.0%;采用14%(w) K2HPO4-30%(w)乙醇盐析萃取体系,乳酸的分配系数和回收率分别为3.23和90.6%. 此时上相中残余葡萄糖、菌体和可溶性蛋白的去除率分别达67.3%, 100%和85.9%.     

Lactic acid production from dining‐hall food waste by Lactobacillus plantarum using response surface methodology

BACKGROUND: Food waste generally has a high starch content and is rich in nutritional compounds, including lipids and proteins. It therefore represents a potential renewable resource. In this study, dining‐hall food waste was used as a substrate for lactic acid production, and response surface methodology was employed to optimise the fermentation conditions. RESULTS: Lactic acid biosynthesis was significantly affected by the interaction of protease and temperature. Protease, temperature and CaCO₃ had significant linear effects on lactic acid production, while α‐amylase and yeast extract had insignificant effects. The optimal conditions were found to be an α‐amylase activity of 13.86 U g^?1 dried food waste, a protease activity of 2.12 U g^?1 dried food waste, a temperature of 29.31 °C and a CaCO₃ concentration of 62.67 g L^?1, which resulted in a maximum lactic acid concentration of 98.51 g L^?1 (88.75% yield). An increase in inoculum size would be appropriate for accelerating the depletion of initial soluble carbohydrate to enhance the efficiency of α‐amylase in dining‐hall food waste fermentation. CONCLUSION: A suitable regression model for lactic acid production was developed based on the experimental results. Dining‐hall food waste was found to be a good substrate for lactic acid fermentation with high product yield and without nutrient supplementation. Copyright © 2008 Society of Chemical Industry     

乳酸生产的现状及未来的发展方向

乳酸作为一种非常具有市场发展潜质的有机酸之一,现虽已被广泛推广,但限于生产技术与不同市场的需求,仍需有很远的路要走。预测其未来的发展方向与规模是十分有必要的。     

发酵生产L-乳酸的现状与展望

L-乳酸是一种有多种用途的重要的有机酸。概述了生产制备L-乳酸的方法及其优缺点,着重综述了微生物发酵法生产L-乳酸的研究现状,并展望了其发展前景。     

甜菜糖蜜发酵废液中提取甜菜碱新工艺研究

研究了采用三段离子交换法从甜菜糖蜜发酵废液中提取甜菜碱的工艺条件和影响因素。三段交换分别使用D31 4、D0 0 1及 0 0 1× 7等苯乙烯型离子交换树脂。第一段交换使脱色、脱盐和除杂同时进行 ,免除了活性炭脱色过程。确定了第二段脱盐交换以pH =3为终点 ,使甜菜碱与金属离子彻底分离。第三段为吸附纯化甜菜碱 ,使用 c(HCl) =1 4mol/L为洗脱剂 ,直接制取了盐酸甜菜碱 ,并使洗脱与树脂再生同时进行 ,简化了工艺操作。所得产品纯度达 98%以上 ,收率(对甜菜 )达 90 %以上。     

从甜菜糖蜜发酵废液中提取色素及甘油的工艺研究

研究了用离子交换法从甜菜糖蜜发酵废液中提取焦糖色素和甘油的新工艺 ,探讨了工艺条件及影响因素。结果表明 ,色素的产率 (对废液 )达 1 %～ 1 .5 % ,得到的精制甘油 ,其纯度可达 98%以上。通过实验找出了色素在吸附和洗脱过程中的体积、p H值及相应的色素含量之间的变化关系。与前文制取甜菜碱工艺相结合并与糖蜜发酵工业相配套 ,将形成一套彻底综合利用糖蜜生产多种产品的新工艺方案     

乳酸／聚乳酸生产技术进展

介绍乳酸／聚乳酸的主要生产技术及其研究、开发动向。     

玉米代替大米发酵生产乳酸新工艺的改进

介绍了用玉米为原料发酵生产乳酸的新工艺。它与大米法相比较，需在粉碎、配方、发酵、脱色等工艺进行改进，并提出可行的改进方法。     

Kinetics of growth and lactic acid production from whey permeate by Lactobacillus helveticus

Batch fermentation kinetics of Lactobacillus helveticus were examined in detail. The nature of the culture medium had a significant effect on the product synthesis mechanism. In a glucose synthetic medium, lactic acid produced by the non-growth-associated mechanism was less than that by the growth-associated mechanism. In a lactose synthetic medium, the contribution of both mechanisms was approximately equal at the end of fermentation. In the whey-yeast extract permeate medium, the contribution by the non-growth-associated mechanism was superior to that of the growth-associated mechanism. Temperature and pH also influenced the relative contribution of the two mechanisms on the total production of lactic acid in whey-yeast extract permeate medium. Under optimal conditions for temperature and pH, the contribution of non-growth-associated product formation was the highest among all temperatures, and the lowest among all pH's. The ATP concentration-biomass concentration relationship in the batch fermentation process could be roughly approximated by a Luedeking-Piret-like equation.