共查询到20条相似文献,搜索用时 31 毫秒
1.
Changhua Hu Yi Zou Wenting Zhao 《World journal of microbiology & biotechnology》2009,25(10):1705-1711
Effect of soybean oil on mycelial biomass and pleuromutilin biosynthesis by Pleurotus mutilis-04 was investigated in shake flask culture. The maximum pleuromutilin production and mycelial biomass were 8.32 ± 0.02 g l−1 and 49.10 ± 1.00 g l−1 when 20 g l−1 soybean oil was fed at 24 and 96 h respectively. A repeated fed-batch fermentation strategy with feeding 3 g l−1 soybean oil from 96 to 144 h at 24 h intervals was developed successfully to maintain mycelial growth and provide abundant
fatty acids for pleuromutilin biosynthesis. Compared with glucose as the sole carbon source, soybean oil was obviously beneficial
for the production of pleuromutilin. The results suggested that manipulation of metabolic regulation by soybean oil was an
effective way to enhance the production pleuromutilin. 相似文献
2.
Morita T Konishi M Fukuoka T Imura T Kitamoto D 《Applied microbiology and biotechnology》2006,73(2):305-313
The search for a novel producer of glycolipid biosurfactants, mannosylerythritol lipids (MEL) was undertaken based on the analysis of ribosomal DNA sequences on the yeast strains of the genus Pseudozyma. Pseudozyma rugulosa NBRC 10877 was found to produce a large amount of glycolipids from soybean oil. Fluorescence microscopic observation also demonstrated that the strain significantly accumulates polar lipids in the cells. The structure of the glycolipids produced by the strain was analyzed by 1H and 13C nuclear magnetic resonance and gas chromatography–mass spectrometry methods, and was determined to be the same as MEL produced by Pseudozyma antarctica, a well-known MEL producer. The major fatty acids of the present MEL consisted of C8 and C10 acids. Based on high performance liquid chromatography, the composition of the produced MEL was as follows: MEL-A (68%), MEL-B (12%), and MEL-C (20%). To enhance the production of MEL by the novel strain, factors affecting the production, such as carbon and nitrogen sources, were further examined. Soybean oil and sodium nitrate were the best carbon and nitrogen sources, respectively. The supplementation of a MEL precursor, such as erythritol, drastically enhanced the production yield from soybean oil at a rate of 70 to 90%. Under the optimal conditions in a shake culture, a maximum yield, productivity, and yield coefficient (on a weight basis to soybean oil supplied) of 142 g l−1, 5.0 g l−1 day−1, and 0.5 g g−1 were achieved by intermittent feeding of soybean oil and erythritol using the yeast. 相似文献
3.
Lakkana Laopaiboon Pornthap Thanonkeo Prasit Jaisil Pattana Laopaiboon 《World journal of microbiology & biotechnology》2007,23(10):1497-1501
Sweet sorghum juice supplemented with 0.5% ammonium sulphate was used as a substrate for ethanol production by Saccharomyces cerevisiae TISTR 5048. In batch fermentation, kinetic parameters for ethanol production depended on initial cell and sugar concentrations.
The optimum initial cell and sugar concentrations in the batch fermentation were 1 × 108 cells ml−1 and 24 °Bx respectively. At these conditions, ethanol concentration produced (P), yield (Y
ps) and productivity (Q
p
) were 100 g l−1, 0.42 g g−1 and 1.67 g l−1 h−1 respectively. In fed-batch fermentation, the optimum substrate feeding strategy for ethanol production at the initial sugar
concentration of 24 °Bx was one-time substrate feeding, where P, Y
ps and Q
p
were 120 g l−1, 0.48 g g−1 and 1.11 g l−1 h−1 respectively. These findings suggest that fed-batch fermentation improves the efficiency of ethanol production in terms of
ethanol concentration and product yield. 相似文献
4.
Haijun Wu Qingbiao Li Rui Lu Yuanpeng Wang Xiaoling Zhuang Ning He 《Journal of industrial microbiology & biotechnology》2010,37(11):1203-1209
The constant-rate fed-batch production of the polygalacturonic acid bioflocculant REA-11 was studied. A controlled sucrose-feeding
strategy resulted in a slight improvement in biomass and a 7% reduction in flocculating activity compared with the batch process.
When fed with a 3 g l−1 urea solution, the flocculating activity was enhanced to 720 U ml−1 in 36 h. High cell density (2.12 g l−1) and flocculating activity (820 U ml−1) were obtained in a 10-l fermentor by feeding with a sucrose-urea solution, with values of nearly two times and 50% higher
than those of the batch process, respectively. Moreover, the residual sucrose declined to 2.4 g l−1, and residual urea decreased to 0.03 g l−1. Even higher flocculating activity of 920 U ml−1 and biomass of 3.26 g l−1 were obtained by feeding with a sucrose-urea solution in a pilot scale fermentation process, indicating the potential industrial
utility of this constant-rate feeding strategy in bioflocculant production by Corynebacterium glutamicum. 相似文献
5.
Kim JH Han KC Koh YH Ryu YW Seo JH 《Journal of industrial microbiology & biotechnology》2002,29(1):16-19
Xylitol, a functional sweetener, was produced from xylose by biological conversion using Candida tropicalis ATCC 13803. Based on a two-substrate fermentation using glucose for cell growth and xylose for xylitol production, fed-batch
fermentations were undertaken to increase the final xylitol concentration. The effects of xylose and xylitol on xylitol production
rate were studied to determine the optimum concentrations for fed-batch fermentation. Xylose concentration in the medium (100
g l−1) and less than 200 g l−1 total xylose plus xylitol concentration were determined as optimum for maximum xylitol production rate and xylitol yield.
Increasing the concentrations of xylose and xylitol decreased the rate and yield of xylitol production and the specific cell
growth rate, probably because of an increase in osmotic stress that would interfere with xylose transport, xylitol flux to
secretion to cell metabolism. The feeding rate of xylose solution during the fed-batch mode of operation was determined by
using the mass balance equations and kinetic parameters involved in the equations in order to increase final xylitol concentration
without affecting xylitol and productivity. The optimized fed-batch fermentation resulted in 187 g l−1 xylitol concentration, 0.75 g xylitol g xylose−1 xylitol yield and 3.9 g xylitol l−1 h−1 volumetric productivity. Journal of Industrial Microbiology & Biotechnology (2002) 29, 16–19 doi:10.1038/sj.jim.7000257
Received 15 October 2001/ Accepted in revised form 30 March 2002 相似文献
6.
Constant medium feeding rate and intermittent fed-batch fermentation strategies were investigated aiming to increase the yields
of γ-decalactone production by Yarrowia lipolytica, using methyl ricinoleate as substrate and ricinoleic acid source. The accumulation of another compound, 3-hydroxy-γ-decalactone,
was also analyzed since it derives from the direct precursor of γ-decalactone thereby providing information about the enzymatic
activities of the pathway. Both strategies were compared with the traditional batch mode in terms of overall productivity
and yield in respect to the substrate. Although the productivity of γ-decalactone was considerably higher in the batch mode
(168 mg l−1 h−1), substrate conversion to lactone (73 mg γ-decalactone g−1) was greater in the intermittent fed-batch giving 6.8 g γ-decalactone l−1. This last strategy therefore has potential for γ-decalactone production at an industrial level. 相似文献
7.
Ezeji TC Qureshi N Blaschek HP 《Journal of industrial microbiology & biotechnology》2007,34(12):771-777
A potential industrial substrate (liquefied corn starch; LCS) has been employed for successful acetone butanol ethanol (ABE)
production. Fermentation of LCS (60 g l−1) in a batch process resulted in the production of 18.4 g l−1 ABE, comparable to glucose: yeast extract based medium (control experiment, 18.6 g l−1 ABE). A batch fermentation of LCS integrated with product recovery resulted in 92% utilization of sugars present in the feed.
When ABE was recovered by gas stripping (to relieve inhibition) from the fed-batch reactor fed with saccharified liquefied
cornstarch (SLCS), 81.3 g l−1 ABE was produced compared to 18.6 g l−1 (control). In this integrated system, 225.8 g l−1 SLCS sugar (487 % of control) was consumed. In the absence of product removal, it is not possible for C. beijerinckii BA101 to utilize more than 46 g l−1 glucose. A combination of fermentation of this novel substrate (LCS) to butanol together with product recovery by gas stripping
may economically benefit this fermentation.
Mention of trade names of commercial products in this article/publication is solely for the purpose of providing scientific
information and does not imply recommendation or endorsement by the United States Department of Agriculture. 相似文献
8.
Chou-Chiang Kuo Ching-An Lin Jing-Yi Chen Ming-Tse Lin Kow-Jen Duan 《Biotechnology letters》2009,31(11):1723-1727
Batch and fed-batch fermentation processes were employed to culture an alkalophilic Bacillus sp. for the production of cyclodextrin glucanotransferase (CGTase). CGTase production was repressed by glucose and induced
by soluble starch. By fed-batch fermentation, a CGTase activity up to 56 unit ml−1 with 65 g dry cells l−1 were achieved. The CGTase activity and cell density were increased 360 and 510%, respectively, from those values achieved
with batch fermentation. 相似文献
9.
Hee-Sik Kim Jong-Woon Jeon Hong-Won Lee Yong-Il Park Weon-Taek Seo Hee-Mock Oh Tohoru Katsuragi Yoshiki Tani Byung-Dae Yoon 《Biotechnology letters》2002,24(3):225-229
Candida antarctica (sp. SY16) required avegetable oil as the carbon source to produce a biosurfactant, mannosylerythritol lipid (MEL-SY16). Biosurfactant production was 31 g l–1 after 7 days in a batch culture and was not growth associated. In a two-stage culture, glycerol and oleic acid were used as an initial and a feeding carbon source, respectively, and 41 g l–1 biosurfactant was produced after 8 days. 相似文献
10.
Biosynthesis of guanosine 5′-diphosphate-l-fucose (GDP-l-fucose) requires NADPH as a reducing cofactor. In this study, endogenous NADPH regenerating enzymes such as glucose-6-phosphate
dehydrogenase (G6PDH), isocitrate dehydrogenase (Icd), and NADP+-dependent malate dehydrogenase (MaeB) were overexpressed to increase GDP-l-fucose production in recombinant Escherichia coli. The effects of overexpression of each NADPH regenerating enzyme on GDP-l-fucose production were investigated in a series of batch and fed-batch fermentations. Batch fermentations showed that overexpression
of G6PDH was the most effective for GDP-l-fucose production. However, GDP-l-fucose production was not enhanced by overexpression of G6PDH in the glucose-limited fed-batch fermentation. Hence, a glucose
feeding strategy was optimized to enhance GDP-l-fucose production. Fed-batch fermentation with a pH-stat feeding mode for sufficient supply of glucose significantly enhanced
GDP-l-fucose production compared with glucose-limited fed-batch fermentation. A maximum GDP-l-fucose concentration of 235.2 ± 3.3 mg l−1, corresponding to a 21% enhancement in the GDP-l-fucose production compared with the control strain overexpressing GDP-l-fucose biosynthetic enzymes only, was achieved in the pH-stat fed-batch fermentation of the recombinant E. coli overexpressing G6PDH. It was concluded that sufficient glucose supply and efficient NADPH regeneration are crucial for NADPH-dependent
GDP-l-fucose production in recombinant E. coli. 相似文献
11.
Beauvericin (BEA) is a cyclic hexadepsipeptide mycotoxin with notable phytotoxic and insecticidal activities. Fusarium redolens Dzf2 is a highly BEA-producing fungus isolated from a medicinal plant. The aim of the current study was to develop a simple
and valid kinetic model for F. redolens Dzf2 mycelial growth and the optimal fed-batch operation for efficient BEA production. A modified Monod model with substrate
(glucose) and product (BEA) inhibition was constructed based on the culture characteristics of F. redolens Dzf2 mycelia in a liquid medium. Model parameters were derived by simulation of the experimental data from batch culture.
The model fitted closely with the experimental data over 20–50 g l−1 glucose concentration range in batch fermentation. The kinetic model together with the stoichiometric relationships for biomass,
substrate and product was applied to predict the optimal feeding scheme for fed-batch fermentation, leading to 54% higher
BEA yield (299 mg l−1) than in the batch culture (194 mg l−1). The modified Monod model incorporating substrate and product inhibition was proven adequate for describing the growth kinetics
of F. redolens Dzf2 mycelial culture at suitable but not excessive initial glucose levels in batch and fed-batch cultures. 相似文献
12.
Y-W Ryu C Y Park J B Park S-Y Kim J-H Seo 《Journal of industrial microbiology & biotechnology》2000,25(2):100-103
A two-stage fed-batch process was designed to enhance erythritol productivity by the mutant strain of Candida magnoliae. The first stage (or growth stage) was performed in the fed-batch mode where the growth medium was fed when the pH of the
culture broth dropped below 4.5. The second stage (or production stage) was started with addition of glucose powder into the
culture broth when the cell mass reached about 75 g dry cell weight l−1. When the initial glucose concentration was adjusted to 400 g l−1 in the production stage, 2.8 g l−1 h−1 of overall erythritol productivity and 41% of erythritol conversion yield were achieved, which represented a fivefold increase
in erythritol productivity compared with the simple batch fermentation process. A high glucose concentration in the production
phase resulted in formation of organic acids including citrate and butyrate. An increase in dissolved oxygen level caused
formation of gluconic acid instead of citric acid. Journal of Industrial Microbiology & Biotechnology (2000) 25, 100–103.
Received 25 February 2000/ Accepted in revised form 08 June 2000 相似文献
13.
Morita T Konishi M Fukuoka T Imura T Kitamoto D 《Applied microbiology and biotechnology》2007,74(2):307-315
Vegetable oil is the usual carbon source for the production of biosurfactants (BS), mannosylerythritol lipids (MEL). To simplify
the procedures of BS production and recovery, we investigated the extracellular production of MEL from water-soluble carbon
sources instead of vegetable oils by using two representative yeast strains. The formation of extracellular MEL from glucose
was confirmed by thin layer chromatography (TLC) and HPLC analysis. On glucose cultivation, pure MEL were easily prepared
by only solvent extraction of the culture medium, different from the case of soybean oil cultivation. The fatty acid profile
of the major MEL produced from glucose was similar to that produced from soybean oil based on GC–MS analysis. The resting
cells of Pseudozyma antarctica T-34 produced MEL by feeding of glucose only and gave a yield of 12 g l−1. In contrast, Pseudozyma aphidis ATCC 32657 gave no MEL from glucose. Moreover, the extracellular lipase activities were detected at high levels during the
cultivation regardless of the carbon sources. These results indicate that all the biosynthesis pathways for MEL in P. antarctica T-34 should constitutively function. In conclusion, P. antarctica T-34 thus has potential for BS production from glucose. 相似文献
14.
A biofilm reactor not only shortens the lag phase of nisin production, but also enhances nisin production when combined with an appropriate pH profile. Due to the substrate inhibition that takes place at high levels of carbon source, fed-batch fermentation was proposed as a better alternative for nisin production. In this study, the combined effects of fed-batch fermentation and various pH profiles on nisin production in a biofilm reactor were evaluated. The tested pH profiles include 1) a constant pH profile at 6.8 (profile 1), 2) a constant pH profile with an autoacidification after 4 h (profile 2), and 3) a step-wise pH profile with pH adjustment every 2 h (profile 3). When profile 1 was applied, fed-batch fermentation enhanced nisin production for both suspended-cell (4,188 IU ml−1) and biofilm (4,314 IU ml−1) reactors, yielded 1.8- and 2.3-fold higher nisin titer than their respective batch fermentation. On the other hand, pH profiles that include periods of autoacidification (profiles 2 and 3) resulted in a significantly lower nisin production in fed-batch fermentation (2,494 and 1,861 IU ml−1 for biofilm reactor using profile 2 and 3, respectively) due to toxicity of excess lactic acid produced during the fermentation. Overall, this study suggested that fed-batch fermentation can be successfully used to enhance nisin production for both suspended-cell and biofilm reactors. 相似文献
15.
Liang Qu Lu-Jing Ren Guan-Nan Sun Xiao-Jun Ji Zhi-Kui Nie He Huang 《Bioprocess and biosystems engineering》2013,36(12):1905-1912
Different fermentation processes, including batch, fed-batch and repeated fed-batch processes by Schizochytrium sp., were studied and compared for the effective DHA-rich microbial lipids production. The comparison between different fermentation processes showed that fed-batch process was a more efficient cultivation strategy than the batch process. Among the four different feeding strategies, the glucose concentration feed-back feeding strategy had achieved the highest fermentation results of final cell dry weight, total lipids content, DHA content and DHA productivity of 72.37, 48.86, 18.38 g l?1 and 138.8 mg l?1 h?1, respectively. The repeated fed-batch process had the advantages of reducing the time and cost for seed culture and inoculation between each fermentation cycles. The results of fermentation characteristics and lipid characterization of the repeated fed-batch process indicated that this repeated fed-batch process had promising industrialization prospect for the production of DHA-rich microbial lipids. 相似文献
16.
Two strains of Pseudozyma aphidis, DSM 70725 and DSM 14930, were used for the bioreactor production of mannosylerythritol lipids (MELs). Foam formation interfered
substantially with the cultivation process. Soybean oil was simultaneously employed as both carbon source and anti-foam agent.
Primary MEL formation occurred after nitrate limitation. After a first short time-period of nitrate limitation and further
nitrate addition, MELs were secreted in spite of nitrate excess. The sedimentation of MEL-enriched beads indicated enhanced
product formation. Maximum yield, productivity and yield coefficient of 165 g l−1, 13.9 g l−1 day−1 and 0.92 g g−1 were achieved using strain DSM 14930 with additional substrate-feeding (glucose, sodium nitrate, yeast extract) and a foam-controlled
soybean oil supply. 相似文献
17.
Using the recombinant flocculating Angel yeast F6, long-term repeated batch fermentation for ethanol production was performed
and a high volumetric productivity resulted from half cells not washed and the optimum opportunity of residual glucose 20
g l−1 of last medium. The obtained highest productivity was 2.07 g l−1 h−1, which was improved by 75.4% compared with that of 1.18 g l−1 h−1 in the first batch fermentation. The ethanol concentration reached 8.4% corresponding to the yield of 0.46 g g−1. These results will contribute greatly to the industrial production of fuel ethanol using the commercial method with the
flocculating yeast. 相似文献
18.
Effects of methanol on expression of an anticoagulant hirudin in recombinant Hansenula polymorpha 总被引:1,自引:0,他引:1
A series of batch, fed-batch, and continuous cultures was carried out to analyze the effects of methanol on the fermentation
characteristics of recombinant Hansenula polymorpha for the production of hirudin, an anticoagulant. Hirudin expression efficiencies were greatly influenced by the methanol
concentrations in continuous and fed-batch culture modes. At a steady state of continuous culture, an optimum methanol concentration
of 1.7 g l−1 was determined at a dilution rate of 0.18 h−1 with 1.8 mg l−1 h−1 hirudin productivity. Journal of Industrial Microbiology & Biotechnology (2001) 27, 58–61.
Received 21 September 2000/ Accepted in revised form 10 June 2001 相似文献
19.
Increased erythritol production in fed-batch cultures of Torula sp. by controlling glucose concentration 总被引:2,自引:0,他引:2
D-K Oh C-H Cho J-K Lee S-Y Kim 《Journal of industrial microbiology & biotechnology》2001,26(4):248-252
The effect of glucose concentration on erythritol production by Torula sp. was investigated. The maximum volumetric productivity of erythritol was obtained at an initial glucose concentration
of 300 g l−1 in batch culture. The volumetric productivity was maximal at a controlled glucose concentration of 225 g l−1, reducing the lag time of the erythritol production. A fed-batch culture was established with an initial glucose concentration
of 300 g l−1 and with a controlled glucose concentration of 225 g l−1 in medium containing phytic acid as a phosphate source. In this fed-batch culture, a final erythritol production of 192 g
l−1 was obtained from 400 g l−1 glucose in 88 h. This corresponded to a volumetric productivity of 2.26 g l−1 h−1 and a 48% yield. Journal of Industrial Microbiology & Biotechnology (2001) 26, 248–252.
Received 26 September 2000/ Accepted in revised form 16 January 2001 相似文献
20.
Lang YJ Bai L Ren YN Zhang LH Nagata S 《Extremophiles : life under extreme conditions》2011,15(2):303-310
Using ectoine-excreting strain Halomonas salina DSM 5928T, we developed a new process for high-efficiency production of ectoine, which involved a combined process of batch fermentation
by growing cells and production by resting cells. In the first stage, batch fermentation was carried out using growing cells
under optimal fermentation conditions. The second stage was the production phase, in which ectoine was synthesized and excreted
by phosphate-limited resting cells. Optimal conditions for synthesis and excretion of ectoine during batch fermentation in
a 10 l fermentor were 0.5 mol l−1 NaCl and an initial monosodium glutamate concentration of 80 g l−1 respectively. The pH was adjusted to 7.0 and the temperature was maintained at 33°C. In phosphate-limited resting cells medium,
monosodium glutamate and NaCl concentration was 200 g l−1 and 0.5 mol l−1, respectively, as well as pH was 7.0. The total concentration of ectoine produced was 14.86 g l−1, the productivity and yield of ectoine was 7.75 g l−1 day−1 and 0.14 g g−1, respectively, and the percentage of ectoine excreted was 79%. These levels of ectoine production and excretion are the highest
reported to date. 相似文献