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1.
Nancib N Nancib A Boudjelal A Benslimane C Blanchard F Boudrant J 《Bioresource technology》2001,78(2):149-153
Production of lactic acid from date juice by fermentation has been studied using Lactobacillus casei subsp. rhamnosus as the producer organism. The optimum substrate concentration, expressed in its glucose content, was 60 g l(-1). Various nitrogen sources were compared with yeast extract in terms of their efficiency for lactic acid production. None of these nitrogen sources gave lactic acid concentrations as high as that obtained with yeast extract. As yeast extract supplementation was not economically attractive, different proportions of (NH4)2SO4 and yeast extract were used. When the elemental nitrogen ratio of(NH4)2SO4 to yeast extract was 4:1, the substrate use and efficiency of lactic acid production were the same as in date juice supplemented with 20 g l(-1) yeast extract (0:5). 相似文献
2.
Kohei Nishino Misaki Kushima Tomohiro Kaino Yasuhiro Matsuo 《Bioscience, biotechnology, and biochemistry》2017,81(7):1444-1451
Cell lysis is induced in Schizosaccharomyces pombe ?ura4 cells grown in YPD medium, which contains yeast extract, polypeptone, and glucose. To identify the medium components that induce cell lysis, we first tested various kinds of yeast extracts from different suppliers. Cell lysis of ?ura4 cells on YE medium was observed when yeast extracts from OXOID, BD, Oriental, and Difco were used, but not when using yeast extract from Kyokuto. To determine which compounds induced cell lysis, we subjected yeast extract and polypeptone to GC-MS analysis. Ten kinds of compounds were detected in OXOID and BD yeast extracts, but not in Kyokuto yeast extract. Among them was urea, which was also present in polypeptone, and it clearly induced cell lysis. Deletion of the ure2 gene, which is responsible for utilizing urea, abolished the lytic effect of urea. The effect of urea was suppressed by deletion of pub1, and a similar phenotype was observed in the presence of polypeptone. Thus, urea is an inducer of cell lysis in S. pombe ?ura4 cells. 相似文献
3.
Vlada B. Veljković Miodrag L. Lazić Mihajlo Z. Stanković 《World journal of microbiology & biotechnology》2006,22(5):519-523
Summary The object of this study was to establish the possibility of using the yeast biomass separated from the fermentation broth
at the end of ethanol fermentation of juniper berry sugars as an inoculum in successive batch fermentation processes. A part
of the fermentation broth (10% v/v) and a suspension of yeast biomass (separated from the same broth) into the water extract
of juniper berries (2 g of wet yeast biomass per liter of water extract) were used as inocula. It was shown that the suspension
of yeast biomass could be used as inoculum in successive batch processes without negative effects on the kinetics and ethanol
yield, but with positive effects on the capacity and economy of the bioprocess. The addition of ammonium salts at optimum
levels did not affect the final ethanol concentrations (4.3–4.4% v/v), but enhanced the specific rate of ethanol production,
thus reducing the process duration by about five times. 相似文献
4.
Nucleosome stability at the yeast PHO5 and PHO8 promoters correlates with differential cofactor requirements for chromatin opening
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The coregulated PHO5 and PHO8 genes in Saccharomyces cerevisiae provide typical examples for the role of chromatin in promoter regulation. It has been a long-standing question why the cofactors Snf2 and Gcn5 are essential for full induction of PHO8 but dispensable for opening of the PHO5 promoter. We show that this discrepancy may result from different stabilities of the two promoter chromatin structures. To test this hypothesis, we used our recently established yeast extract in vitro chromatin assembly system, which generates the characteristic PHO5 promoter chromatin. Here we show that this system also assembles the native PHO8 promoter nucleosome pattern. Remarkably, the positioning information for both native patterns is specific to the yeast extract. Salt gradient dialysis or Drosophila embryo extract does not support proper nucleosome positioning unless supplemented with yeast extract. By competitive assemblies in the yeast extract system we show that the PHO8 promoter has greater nucleosome positioning power and that the properly positioned nucleosomes are more stable than those at the PHO5 promoter. Thus we provide evidence for the correlation of inherently more stable chromatin with stricter cofactor requirements. 相似文献
5.
Sources and Quantities of Yeast Extract for Growth of Rhizobia 总被引:2,自引:2,他引:0
R. A. Date 《Journal of applied microbiology》1972,35(3):379-387
S ummary : The growth of 4 strains of rhizobia representing 4 inoculation groups (clover, medic, cowpea-type and lupin) in liquid medium containing one of 4 commercially available sources of yeast extract (Vegemite, Oxoid powder, Oxoid paste and BBL yeast) was compared at 4 levels of each extract (1, 2, 4 and 8 g/l). Total cell numbers increased with increasing levels of yeast extract, but viable cell numbers were significantly depressed by some yeast sources. For the clover, cowpea-type and lupin strains strong depressive effects of BBL yeast were recorded at the highest levels, but satisfactory growth was obtained at the lower levels. Oxoid powder depressed viable numbers slightly but Vegemite did not. All yeast sources increased viable cell numbers of the medic strain with increasing levels in the medium. Reasons for these depressive effects and their practical implication are discussed in relation to legume inoculant preparation. 相似文献
6.
The responses of anthocyanin-producing (violet) and non-producing (white) cells of Glehnia littoralis to radical generators were compared. Cell growth, anthocyanin content, phenylalanine ammonia-lyase (PAL) activity and furanocoumarin production were determined after treatment with H(2)O(2), 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH), X-ray and yeast extract, independently. AAPH and H(2)O(2) repressed the growth of both violet and white cells, but violet cells grew better than white cells. On the other hand, the anthocyanin content in violet cells decreased. Neither X-ray nor yeast extract affected cell growth or pigment production. Treatment with H(2)O(2), yeast extract, and X-ray, but not AAPH, induced PAL activity and furanocoumarin production in white cell cultures, whereas violet cell cultures did not produce furanocoumarin following any of the treatment employed. 相似文献
7.
Maria M. BayliakVolodymyr I. Lushchak 《Phytomedicine》2011,18(14):1262-1268
The effect of aqueous extract from R. rosea root on lifespan and the activity of antioxidant enzymes in budding yeast Saccharomyces cerevisiae have been studied. The supplementation of the growth medium with R. rosea extract decreased survival of exponentially growing S. cerevisiae cells under H2O2-induced oxidative stress, but increased viability and reproduction success of yeast cells in stationary phase. The extract did not significantly affect catalase activity and decreased SOD activity in chronologically aged yeast population. These results suggest that R. rosea acts as a stressor for S. cerevisiae cells, what sensitizes yeast cells to oxidative stress at exponential phase, but induces adaptation in stationary phase cells demonstrating the positive effect on yeast survival without activation of major antioxidant enzymes. 相似文献
8.
To improve dextransucrase production from Leuconostocmesenteroides NRRL B-640 culture medium was screened and optimized using the statistical design techniques of Plackett-Burman and response surface methodology (RSM). Plackett-Burman design with six variables viz. sucrose, yeast extract, K2HPO4, peptone, beef extract and Tween 80 was performed to screen the nutrients that were significantly affecting dextransucrase production. The variables sucrose, K2HPO4, yeast extract and beef extract showed above 90% confidence levels for dextransucrase production and were considered as significant factors for optimization using response surface methodology. 2(4)-central composite design was used for RSM optimization. The experimental results were fitted to a second-order polynomial model which gave a coefficient of determination R2=0.95. The optimized composition of 30g/l sucrose, 18.9g/l yeast extract, 19.4g/l K2HPO4 and 15g/l beef extract gave an experimental value of dextransucrase activity of 10.7U/ml which corresponded well with the predicted value of 10.9U/ml by the model. 相似文献
9.
The yeast extract (of unknown origin) present in the commercially available serum-free medium ‘Express Five’ contains factors
(‘yeast extract factors’) up to 35 kDa which are essential for growth of Trichoplusia ni insect cells. A yeast extract brand lacking these components could not support growth of T. ni cells. However, cell proliferation was restored by adding chromatographic fractions containing the yeast extract factors.
The yeast extract factors were not solely responsible for the growth enhancing effect of yeast extract but some other components,
which seem to be generally present in yeast extracts, are also required for T. ni proliferation. 相似文献
10.
发酵产丁二酸过程中废弃细胞的循环利用 总被引:1,自引:0,他引:1
对厌氧发酵产丁二酸后的废弃细胞进行破壁处理,考察了以细胞水解液作为有机氮源重新用于丁二酸发酵的可行性。比较了超声破碎、盐溶、酶解3种方法破碎细胞获得的水解液作为氮源发酵产丁二酸的效果,结果表明酶解制得的细胞水解液效果最佳。以总氮含量为1.11g/L的酶解液(相当于10g/L酵母膏)作为氮源发酵,丁二酸产量可达42.0g/L,继续增大酶解液用量对耗糖、产酸能力没有显著提高。将细胞酶解液与5g/L酵母膏联用发酵36h后,丁二酸产量达75.5g/L,且丁二酸生产强度为2.10g/(L·h),比使用10g/L酵母膏时提高了66.7%。因此,厌氧发酵产丁二酸结束后的废弃细胞酶解液可以替代原培养基中50%的酵母膏用于发酵。 相似文献
11.
Peighamy-Ashnaei S Sharifi-Tehrani A Ahmadzadeh M Behboudi K 《Communications in agricultural and applied biological sciences》2007,72(4):951-956
One of the most important environmental factors that regulate the growth and antagonistic efficacy of biocontrol agents is the medium. The aim of this paper was to find the nitrogen and carbon sources that provide maximum biomass production of strains P-5 and P-6 (Pseudomonas fluorescens), B-3 and B-16 (Bacillus subtilis) and minimum cost of media, whilst maintaining biocontrol efficacy. All of the strains were grown in seven liquid media (pH=6.9) including: sucrose + yeast extract, molasses of sugar beet + yeast extract in 2:1 and 1:1 w/w ratios, molasses of sugar beet + urea, nutrient broth, molasses and malt extract, at an initial inoculation of 1 x 10(5) CFU ml(-1). Cells from over night cultures used to inoculate soil at 1 x 10(9) CFU cm(-3) soil. At the same time, fungal inoculum (infected millet seed with Rhizoctonia solani) was added to soil at the rate of 2 g kg(-1) soil. Results indicated that growth of P-6, B-3 and B-16 in molasses + yeast extract (1:1 w/w) medium was significantly higher than in the other media. Molasses + yeast extract (1:1 and 2:1 w/w) media supported rapid growth and high cell yields in P-5. In greenhouse condition, results indicated that the influence of the media on the biocontrol efficacy of P-5, P-6, B-3 and B-16 was the same and Pseudomonas fluorescens P-5 in molasses and malt extract media reduced the severity of disease up to 72.8 percent. On the other hand, there were observed significant differences on bean growth after one month in greenhouse. P-5 in molasses + yeast extract (1:1 w/w) medium had the most effects on bean growth promotion. In this study molasses media showed good yield efficacy in all of the strains. The high sucrose concentration in molasses justifies the high biomass in all of the strains. Also, the low cost of molasses allows its concentration to be increased in media. On the other hand, yeast extract was the best organic nitrogen source for antagonist bacteria but it is expensive for an industrial process. So it should be replaced by another industrial product instead of yeast extract, which confirm by an economic and technological study. The results obtained in this study could be used to provide a reliable basis to increase the population of biocontrol agents in fermentation process. 相似文献
12.
The aim of this work was to determine the effect of yeast extract and of its vitamin contents on autotrophic and heterotrophic
growth and metabolism of four acetogenic bacteria from the human colon. Yeast extract exerted a stimulatory effect on autotrophic
growth of the colonic acetogens, but concentration of this compound above 1–2 g. L−1 in the medium did not enhance utilization of H2/CO2. Vitamins provided by yeast extract were shown to be essential cofactors of the reductive pathway of acetate synthesis except
for one Clostridium strain. Yeast extract was also necessary to maintain heterotrophic growth and acetate synthesis from glucose in acetogenic
species, except in the Streptococcus strain. In the absence of yeast extract, vitamins could efficiently restore glucose fermentation via acetate. The reductive
and oxidative pathways of acetate synthesis might, therefore, depend on vitamin cofactors supplied by yeast extract in most
of the human acetogenic bacteria. Non-vitaminic factors appeared also to be involved in the metabolism of some of these acetogenic
species.
Received: 6 March 1998 / Accepted: 3 April 1998 相似文献
13.
T A Oleinikova A N Shkidchenko N M Verbina 《Prikladnaia biokhimiia i mikrobiologiia》1975,11(6):857-861
The effect of an aqueous extract from malt sprouts on the growth and development of fodder yeast was investigated during their continuous cultivation. The extract can be used as a nitrogen source during continuous cultivation of fodder yeast. It is supposed that the extract contains compounds capable to inhibit yeast growth. The extract should be added to the nutrient medium in the amount of 4 g/l of dry weight. 相似文献
14.
Mycelium ofBeauveria bassiana can be grown in liquid culture, filtered, and the mycelium dried. After rehydration the mycelium sporulates.
Two carbohydrate sources (sucrose and maltose), and one nitrogen/vitamin source (yeast extract) were tested for mycelium growth
and subsequent conidial production. Maximum mycelium growth (12.31 mg/ml), in liquid culture, was in the sucrose (3.5%)/yeast
extract (3.5%) medium, but mycelium from a maltose (2%)/yeast extract (0.75%) medium produced the maximum of 4.62×106 conidia/mg dry mycelium after incubation in moist Petri dishes.
Using the data on mycelium yield (in liquid culture) and conidial production (by dry mycelium) it is calculated that the sucrose
(3.5%)/yeast extract (3.5%) and the maltose (2%)/yeast extract (0.75%) media produce most conidia per media volume (an equivalent
of 3.52–3.72×107 conidia/ml).
相似文献
15.
The nutritional requirements of Brettanomyces bruxellensis have been investigated. Batch culture and chemostat pulse techniques were used to identify growth-limiting nutrients. The study included determination of the essential components of the culture medium and quantification of the effects of the components. Among the components tested, ammonium sulfate and yeast extract had a significant effect on glucose consumption, growth, and ethanol production. However, if the ammonium sulfate concentration is above 2 g/L, an inhibitory effect on B. bruxellensis growth is observed. The yeast extract appears to be the most important and significant component for growth. The maximum amount of synthesized biomass is proportional to the concentration of yeast extract added to the culture broth (in the tested range). Magnesium and phosphate ions are probably not essential for B. bruxellensis. These ions appear to be supplied in sufficient amounts by the yeast extract in the culture medium. Brettanomyces bruxellensis appears to have very low nutritional requirements for growth. 相似文献
16.
2′-Fucosyllactose (2′-FL), a human milk oligosaccharide with confirmed benefits for infant health, is a promising infant formula ingredient. Although Escherichia coli, Saccharomyces cerevisiae, Corynebacterium glutamicum, and Bacillus subtilis have been engineered to produce 2′-FL, their titers and productivities need be improved for economic production. Glucose along with lactose have been used as substrates for producing 2′-FL, but accumulation of by-products due to overflow metabolism of glucose hampered efficient production of 2′-FL regardless of a host strain. To circumvent this problem, we used xylose, which is the second most abundant sugar in plant cell wall hydrolysates and is metabolized through oxidative metabolism, for the production of 2′-FL by engineered yeast. Specifically, we modified an engineered S. cerevisiae strain capable of assimilating xylose to produce 2′-FL from a mixture of xylose and lactose. First, a lactose transporter (Lac12) from Kluyveromyces lactis was introduced. Second, a heterologous 2′-FL biosynthetic pathway consisting of enzymes Gmd, WcaG, and WbgL from Escherichia coli was introduced. Third, we adjusted expression levels of the heterologous genes to maximize 2′-FL production. The resulting engineered yeast produced 25.5 g/L of 2′-FL with a volumetric productivity of 0.35 g/L∙h in a fed-batch fermentation with lactose and xylose feeding to mitigate the glucose repression. Interestingly, the major location of produced 2′-FL by the engineered yeast can be changed using different culture media. While 72% of the produced 2′-FL was secreted when a complex medium was used, 82% of the produced 2′-FL remained inside the cells when a minimal medium was used. As yeast extract is already used as food and animal feed ingredients, 2′-FL enriched yeast extract can be produced cost-effectively using the 2′-FL-accumulating yeast cells. 相似文献
17.
在重组枯草芽孢杆菌24/pMX45核黄素发酵中,酵母粉促进核黄素合成,酵母抽提物抑制核黄素合成。分析显示,酵母抽提物的无机离子和游离氨基酸含量均高于酵母粉。在酵母粉基础发酵培养基中,添加各种无机离子和游离氨基酸,使其含量与酵母抽提物相同。摇瓶发酵结果表明:过量的无机离子和谷氨酸对核黄素合成有显著的抑制作用。酵母抽提物含有较高浓度的谷氨酸,是其抑制核黄素合成的主要原因。 相似文献
18.
The enantioselectivity of the enzymes responsible for reduction of prochiral compound 3-phenylthiopropan-2-one was dependent on the concentration of yeast extract and glucose in the growth medium. Low concentrations of yeast extract (0.1-0.9% w/v) favored the formation of S-enantiomer (62% ee at 0.1% w/v yeast extract) of 3-phenylthiopropan-2-ol. However, R-enantiomer of the reduced product was formed when MSM was supplemented with yeast extract at a concentration of 1% (w/v) or more with a maximum ee of 85% at 2.0% (w/v) yeast extract supplement in the growth medium. 相似文献
19.
Germ tube and subsequent mycelial development from yeast-like and swollen cells ofAureobasidium pullulans (IMI 45533) was induced by yeast extract in defined liquid medium. This morphogenetic transition was dependent on inoculum
size; pH effects were not involved and once mycelial development was induced in the cells it continued even in the absence
of yeast extract. The progeny of mycelium and future generations were unaffected by yeast extract. Cessation of germination
was not due to any obvious medium changes but appeared to be partly due to the production of a germination inhibitor, which
could also be produced by control cells grown in the absence of yeast extract. 相似文献
20.
Two low-salt complex media, bactopeptone and desalted yeast extract, were used for high density cultivation of the hyperthermophilic
archaeonSulfolobus solfataricus (DSM 1617). Bactopeptone, which has low mineral ion content among various complex media, was good for cell growth in batch
cultures; the maximal cell density in bactopeptone was comparable to that in yeast extract. Howver, cell growth was rather
poor when bactopeptone was added by the fed-batch procedure. Since several vitamins are deficient in bactopeptone, the effect
of vitamins on cell growth was examined. Among the vitamins tested, pyridoxine was found to improve the growth rate ofS. solfataricus. To reduce the growth inhibition caused by mineral ions, yeast extract was dialyzed against distilled water and then fed-batch
cultures were carried out using a feed medium containing desalted yeast extract. Although the concentrations of mineral ions
in yeast extract were significantly lowered by the dialysis procedure, fed-batch cultivation with desalted yeast extract was
unsatisfactory. To examine whether low molecular weight solutes in yeast extract are crucial for cell growth, we investigated
the effect of trehalose, a most abundant compatible solute in yeast extract, on the growth pattern. Cell densities were increased
and the length of the lag phase was markedly shortened by the presence of trehalose, indicating that trehalose plays an important
role in the growth ofS. solfataricus. 相似文献