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1.
F Aragozzini A Ferrari N Pacini R Gualandris 《Applied and environmental microbiology》1979,38(3):544-546
Fifty-one strains of the genus Bifidobacterium have been found to accumulate indole-3-lactic acid in culture broth. The isolated metabolite was identified through mass and nuclear magnetic resonance spectroscopy. All the microorganisms tested, as resting cells, have been shown to be able to convert L-tryptophan into L-indole-3-lactic acid. 相似文献
2.
Jiayang Qin Bo Zhao Xiuwen Wang Limin Wang Bo Yu Yanhe Ma Cuiqing Ma Hongzhi Tang Jibin Sun Ping Xu 《PloS one》2009,4(2)
Background
The demand for lactic acid has been increasing considerably because of its use as a monomer for the synthesis of polylactic acid (PLA), which is a promising and environment-friendly alternative to plastics derived from petrochemicals. Optically pure l-lactic acid is essential for polymerization of PLA. The high fermentation cost of l-lactic acid is another limitation for PLA polymers to compete with conventional plastics.Methodology/Principal Findings
A Bacillus sp. strain 2–6 for production of l-lactic acid was isolated at 55°C from soil samples. Its thermophilic characteristic made it a good lactic acid producer because optically pure l-lactic acid could be produced by this strain under open condition without sterilization. In 5-liter batch fermentation of Bacillus sp. 2–6, 118.0 g/liter of l-lactic acid with an optical purity of 99.4% was obtained from 121.3 g/liter of glucose. The yield was 97.3% and the average productivity was 4.37 g/liter/h. The maximum l-lactic acid concentration of 182.0 g/liter was obtained from 30-liter fed-batch fermentation with an average productivity of 3.03 g/liter/h and product optical purity of 99.4%.Conclusions/Significance
With the newly isolated Bacillus sp. strain 2–6, high concentration of optically pure l-lactic acid could be produced efficiently in open fermentation without sterilization, which would lead to a new cost-effective method for polymer-grade l-lactic acid production from renewable resources. 相似文献3.
Isolation and characteristics of a skatole-producing Lactobacillus sp. from the bovine rumen. 总被引:4,自引:3,他引:1
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A bacterium that is capable of decarboxylating indoleacetic acid to skatole (3-methylindole) has been isolated from an L-tryptophan enrichment of bovine rumen fluid. The bacterium is a gram-positive, nonmotile, nonsporeforming rod. It is an obligate anaerobe, and strains predominatly produce D-(-)-lactic acid, with smaller amounts of L-(+)-lactic acid and acetic acid, from sugar. All four strains isolated gave a negative reaction to the indole test because they cannot form skatole directly from tryptophan. This is the first report of indoleacetic acid decarboxylation to skatole in pure culture and the demonstration of skatole production by a Lactobacillus species. 相似文献
4.
5.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2326-2332
This report describes the production of highly optically pure D-lactic acid by the continuous fermentation of Sporolactobacillus laevolacticus and S. inulinus, using a membrane-integrated fermentation (MFR) system. The optical purity of D-lactic acid produced by the continuous fermentation system was greater than that produced by batch fermentation; the maximum value for the optical purity of D-lactic acid reached 99.8% enantiomeric excess by continuous fermentation when S. leavolacticus was used. The volumetric productivity of the optically pure D-lactic acid was about 12 g/L/h, this being approximately 11-fold higher than that obtained by batch fermentation. An enzymatic analysis indicated that both S. laevolacticus and S. inulinus could convert L-lactic acid to D-lactic acid by isomerization after the late-log phase. These results provide evidence for an effective bio-process to produce D-lactic acid of greater optical purity than has conventionally been achieved to date. 相似文献
6.
The production of d-lactic acid, a major fermentation product of Scenedesmus obliquus strain D3, is inhibited by light. This inhibition has been observed in the wild type as well as in Bishop's mutant 11. However, in mutant 8, which lacks photophosphorylation, light stimulated the formation of d-lactic acid. 相似文献
7.
Qianqian Xu Ying Zang Jie Zhou Peng Liu Xin Li Qiang Yong Jia Ouyang 《Bioprocess and biosystems engineering》2016,39(11):1749-1757
Inulin is a readily available feedstock for cost-effective production of biochemicals. To date, several studies have explored the production of bioethanol, high-fructose syrup and fructooligosaccharide, but there are no studies regarding the production of d-lactic acid using inulin as a carbon source. In the present study, chicory-derived inulin was used for d-lactic acid biosynthesis by Lactobacillus bulgaricus CGMCC 1.6970. Compared with separate hydrolysis and fermentation processes, simultaneous saccharification and fermentation (SSF) has demonstrated the best performance of d-lactic acid production. Because it prevents fructose inhibition and promotes the complete hydrolysis of inulin, the highest d-lactic acid concentration (123.6 ± 0.9 g/L) with a yield of 97.9 % was obtained from 120 g/L inulin by SSF. Moreover, SSF by L. bulgaricus CGMCC 1.6970 offered another distinct advantage with respect to the higher optical purity of d-lactic acid (>99.9 %) and reduced number of residual sugars. The excellent performance of d-lactic acid production from inulin by SSF represents a high-yield method for d-lactic acid production from non-food grains. 相似文献
8.
Xuefeng Wu Shaotong Jiang Mo Liu Lijun Pan Zhi Zheng Shuizhong Luo 《Journal of industrial microbiology & biotechnology》2011,38(4):565-571
Semicontinuous fermentation using pellets of Rhizopus oryzae has been recognized as a promising technology for l-lactic acid production. In this work, semicontinuous fermentation of R. oryzae AS 3.819 for l-lactic acid production has been developed with high l-lactic acid yield and volumetric productivity. The effects of factors such as inoculations, CaCO3 addition time, and temperature on l-lactic acid yield and R. oryzae morphology were researched in detail. The results showed that optimal fermentation conditions for the first cycle were: inoculation
with 4% spore suspension, CaCO3 added to the culture medium at the beginning of culture, and culture temperature of 32–34°C. In orthogonal experiments, high
l-lactic acid yield was achieved when the feeding medium was (g/l): glucose, 100; (NH4)2SO4, 2; KH2PO4, 0.1; ZnSO4·7H2O, 0.33; MgSO4·7H2O, 0.15; CaCO3, 50. Twenty cycles of semicontinuous fermentation were carried out in flask culture. l-lactic acid yield was 78.75% for the first cycle and 80–90% for the repeated cycles; the activities of lactate dehydrogenases
(LDH) were 7.2–9.2 U/mg; fermentation was completed in 24 h for each repeated cycle. In a 7-l magnetically stirred fermentor,
semicontinuous fermentation lasted for 25 cycles using pellets of R. oryzae AS 3.819 under the optimal conditions determined from flask cultures. The final l-lactic acid concentration (LLAC) reached 103.7 g/l, and the volumetric productivity was 2.16 g/(l·h) for the first cycle;
in the following 19 repeated cycles, the final LLAC reached 81–95 g/l, and the volumetric productivities were 3.40–3.85 g/(l·h). 相似文献
9.
Poly-lactic acid (PLA) derived from renewable resources is considered to be a good substitute for petroleum-based plastics. The number of poly l-lactic acid applications is increased by the introduction of a stereocomplex PLA, which consists of both poly-l and d-lactic acid and has a higher melting temperature. To date, several studies have explored the production of l-lactic acid, but information on biosynthesis of d-lactic acid is limited. Pulp and corn stover are abundant, renewable lignocellulosic materials that can be hydrolyzed to sugars and used in biosynthesis of d-lactic acid. In our study, saccharification of pulp and corn stover was done by cellulase CTec2 and sugars generated from hydrolysis were converted to d-lactic acid by a homofermentative strain, L. delbrueckii, through a sequential hydrolysis and fermentation process (SHF) and a simultaneous saccharification and fermentation process (SSF). 36.3 g L?1 of d-lactic acid with 99.8 % optical purity was obtained in the batch fermentation of pulp and attained highest yield and productivity of 0.83 g g?1 and 1.01 g L?1 h?1, respectively. Luedeking–Piret model described the mixed growth-associated production of d-lactic acid with a maximum specific growth rate 0.2 h?1 and product formation rate 0.026 h?1, obtained for this strain. The efficient synthesis of d-lactic acid having high optical purity and melting point will lead to unique stereocomplex PLA with innovative applications in polymer industry. 相似文献
10.
Strain improvement of Rhizopus oryzae for production of l(+)-lactic acid and glucoamylase 总被引:6,自引:0,他引:6
Thirty-eight l(+)-lactic acid-overproducing mutants were isolated by mutagenizing a parent strain of Rhizopus oryzae NRRL 395 with u.v. and/or N -methyl- N '-nitro- N -nitrosoguanidine. Three mutants, 1N1, 3N4 and 3N6, were found to yield significantly more l(+)-lactic acid in a rice medium than the parent strain. Of the mutants examined, only mutant 3N4 produced more glucoamylase than the parent strain. 相似文献
11.
Direct production of L+-lactic acid from starch and food wastes using Lactobacillus manihotivorans LMG18011 总被引:3,自引:0,他引:3
This study describes several essential factors for direct and effective lactic acid production from food wastes by Lactobacillus manihotivorans LMG18011, and optimum conditions for simultaneous saccharification and fermentation using soluble starch and food wastes as substrates. The productivity was found to be affected by three factors: (1) initial pH, which influenced amylase production for saccharification of starch, (2) culture pH control which influenced selective production of L(+)-lactic acid, and (3) manganese concentration in medium which improved in production rate and yield of lactic acid. The optimum initial pH was 5.0-5.5, and the fermentation pH for the direct and effective fermentation from starchy substrate was 5.0 based on the yield of L(+)-lactic acid. Under these conditions, 19.5 g L(+)-lactic acid was produced from 200 g food wastes by L. manihotivorans LMG18011. Furthermore, the addition of manganese stimulated the direct fermentation significantly, and enabled complete bioconversion within 100 h. 相似文献
12.
Potential of solid state fermentation for production of L(+)-lactic acid by Rhizopus oryzae 总被引:2,自引:0,他引:2
C. R. Soccol B. Marin M. Raimbault J. -M. Lebeault 《Applied microbiology and biotechnology》1994,41(3):286-290
Production of l(+)-lactic acid by Rhizopus oryzae NRRL 395 was studied in solid medium on sugar-cane bagasse impregnated with a nutrient solution containing glucose and CaCO3. A comparative study was undertaken in submerged and solid-state cultures. The optimal concentrations in glucose were 120 g/l in liquid culture and 180 g/l in solid-state fermentation corresponding to production of l(+)-lactic acid of 93.8 and 137.0 g/l, respectively. The productivity was 1.38 g/l per hour in liquid medium and 1.43 g/l per hour in solid medium. However, the fermentation yield was about 77% whatever the medium. These figures are significant for l(+)-lactic acid production. 相似文献
13.
Summary Fermentation of L-(+)-lactic acid from soluble starch by Lactobacillus amylophilus was studied. The bacterium produced about 30 g of L-(+)-lactic acid from 50 g of soluble starch when the pH of the culture was ranging from pH 5 to pH 6.8 at 28°C. 53.4 g of L-(+)-lactic acid was produced when 100 g of starch was added in the medium. The fermentation procedures will reduce the cost of complete hydrolysis of starch to glucose prior to fermentation. 相似文献
14.
Tiejun Liu Shigenobu Miura Tomohiro Arimura Min-Yi Tei Enoch Y. Park Mitsuyasu Okabe 《Biotechnology and Bioprocess Engineering》2005,10(6):522-527
Various processes which producel-lactic acid using ammonia-tolerant mutant strain,Rhizopus sp. MK-96-1196, in a 3 L airlift bioreactor were evaluated. When the fed-batch culture was carried out by keeping the glucose
concentration at 30 g/l, more than 140 g/l ofl-lactic acid was produced with a product yield of 83%. In the case of the batch culture with 200 g/l of initial glucose concentration, 121 g/L ofl-lactic acid was obtained but the low product yield based on the amount of glucose consumed. In the case of a continuous culture,
1.5 g/l/h of the volumetric productivity with a product yield of 71% was achieved at dilution rate of 0.024 h−1. Basis on these results three processes were evaluated by simple variable cost estimation including carbon source, steam,
and waste treatment costs. The total variable costs of the fed-batch and continuous cultures were 88% and 140%, respectively,
compared to that of batch culture. The fed-batch culture with highl-lactic acid concentration and high product yield decreased variable costs, and was the best-suited for the industrial production
ofl-lactic acid. 相似文献
15.
Silvia Klotz Norman Kaufmann Anja Kuenz Ulf Prüße 《Applied microbiology and biotechnology》2016,100(22):9423-9437
The fermentation process of l-lactic acid is well known. Little importance was attached to d-lactic acid, but in the past 10 years, d-lactic acid gained significantly in importance. d-Lactic acid is an interesting precursor for manufacturing heat-resistant polylactic acid (PLA) bioplastics which can be widely used, for example as packaging material, coatings, for textiles or in the automotive industry.This review provides a comprehensive overview of the most recent developments, including a spectrum of studied microorganisms and their capabilities for the production of d-lactic acid. Additionally, the technological achievements in biotechnological d-lactic acid production including fermentation techniques like fed batch, simultaneous saccharification, and fermentation and continuous techniques are presented. Attention is also turned to suitable alternative substrates and their applicability in fermentation processes. Furthermore, advantages and disadvantages of product recovery and purification are discussed. Economic aspects of PLA are pointed out, and the present industrial producers of lactic acid are briefly introduced. 相似文献
16.
Peng Wang Juan Li Li Wang Ming-li Tang Zeng-liang Yu Zhi-ming Zheng 《Journal of industrial microbiology & biotechnology》2009,36(11):1363-1368
Low-energy ion beam irradiation (10–200 keV) has been proved to have a wide range of biological effects in recent years. When
Rhizopus oryzae PW352 was irradiated with a 15-keV low-energy ion beam an l(+)-lactic acid high-yield mutant, RQ4015, was obtained. When 150 g/l glucose was used as the sole carbon source, l(+)-lactic acid of RQ4015 reached 121 g/l after 36 h shake-flask cultivation. However, the highest lactic acid concentration
74 g/l was obtained when 100 g/l xylose was present in the medium as the sole carbon source. When mixed xylose (25 g/l) and
glucose (75 g/l) were present in a bubble column, l(+)-lactic acid production of RQ4015 reached 83 g. A high mutation rate and a wide mutation spectrum of low-energy ion implantation
were observed in the experiment, suggesting that ion implantation can be a highly efficient mutagenic means for microorganism
breeding in many commercial applications. 相似文献
17.
Chiaki Inaba Kenjiro Maekawa Hironobu Morisaka Kouichi Kuroda Mitsuyoshi Ueda 《Applied microbiology and biotechnology》2009,83(5):859-864
The whole-cell biocatalyst displaying Candida antarctica lipase B (CALB) on the yeast cell surface with α-agglutinin as the anchor protein was easy to handle and possessed high stability.
The lyophilized CALB-displaying yeasts showed their original hydrolytic activity and were applied to an ester synthesis using
ethanol and l-lactic acid as substrates. In water-saturated heptane, CALB-displaying yeasts catalyzed ethyl lactate synthesis. The synthesis
efficiency increased depending on temperature and reached approximately 74% at 50°C. The amount of l-ethyl lactate increased gradually. l-Ethyl lactate synthesis stopped at 200 h and restarted after adding of l-lactic acid at 253 h. It indicated that CALB-displaying yeasts retained their synthetic activity under such reaction conditions.
In addition, CALB-displaying yeasts were able to recognize l-lactic acid and d-lactic acid as substrates. l-Ethyl lactate was prepared from l-lactic acid and d-ethyl lactate was prepared from d-lactic acid using the same CALB-displaying whole-cell biocatalyst. These findings suggest that CALB-displaying yeasts can
supply the enantiomeric lactic esters for preparation of useful and improved biopolymers of lactic acid. 相似文献
18.
Optically pure d-lactic acid was produced by fermentation of lactose with Lactobacillus bulgaricus Lb-12, and purified by crystallisation as magnesium d-lactate followed by extraction with butanol. The yield of d-lactate and contaminations with nitrogen and phosphorus were mapped during the purification procedure. The overall yield of d-lactic acid was 72% and the purity was more than 99%. Contaminations in the final d-lactic acid with nitrogen, phosphorus and l-lactic acid were only 0.032% w/w, 0.018% w/w and 0.04% w/w respectively. 相似文献
19.
Three mutants, isolated by repeated UV mutagenesis of Lactobacillus lactis NCIM 2368, produced increased d-lactic acid concentrations. These mutants were compared with the wild type using 100 g hydrolyzed cane sugar/l in the fermentation
medium. One mutant, RM2-24, produced 81 g lactic acid/l which was over three times that of the wild type. The highest d-lactic acid (110 g/l) in batch fermentation was obtained with 150 g cane sugar/l with a 73% lactic acid yield. The mutant
utilizes cellobiose efficiently, converting it into d-lactic acid suggesting the presence of cellobiase. Thus, this strain could be used to obtain d-lactic acid from cellulosic materials that are pre-hydrolyzed with cellulase. 相似文献
20.
d-lactic acid is a versatile and important industrial chemical that can be applied in the synthesis of thermal-resistant poly-lactic acid. Biosynthesis of d-lactic acid can be achieved by a variety of microorganisms, including lactic acid bacteria, yeast, and fungi; however, the final product yield, optical purity, and the utilization of both glucose and xylose are restricted. Consequently, engineered microbial systems are essential to attain high titer, productivity, and complete utilization of sugars. Herein, we critically evaluate the promising wild-type microorganisms, as well as genetically modified microorganisms to produce enantiomerically pure d-lactic acid, particularly from renewable lignocellulosic biomass. In addition, innovative bioreactor operation, metabolic flux analysis, and recent genetic engineering methods for targeted microbial d-lactic acid synthesis will be discussed. 相似文献