共查询到20条相似文献,搜索用时 31 毫秒
1.
R. C. Agu T. U. Anyanwu A. H. Onwumelu 《World journal of microbiology & biotechnology》1993,9(6):660-661
High-ethanol-resistant yeasts, characterized as Saccharomyces sp., were isolated from Nigerian palm wine with added sucrose for high gravity brewing. The yeast isolates that survived the highest ethanol production were used to ferment brewery wort and produced 8.2 to 8.5% (v/v) ethanol; values almost double that of the control yeast from a local brewery. 相似文献
2.
《Critical reviews in biotechnology》2013,33(3):273-288
AbstractThe bacterium Zymomonas mobilis, which is used in the tropics to make pulque and alcoholic palm wines, appears to have considerable potential for industrial alcohol fermentations. Some of the advantages of the Zymomonas process reported in studies from our laboratory1-24 are1. There are significantly higher specific rates of sugar uptake and ethanol production compared to those found for yeasts.2. Considerably higher volumetric ethanol productivities found in continuous cell recycle systems (up to 120 to 200 g/hr).3. There are higher ethanol yields and lower biomass production than for yeasts. The lower biomass concentrations would seem to be a consequence of the lower metabolic energy available for growth. Zymomonas metabolize glucose via the Entner-Doudoroff pathway while yeasts convert glucose to ethanol via glycolysis.4. Zymomonas cultures grow anaerobically and, unlike yeasts, do not require the controlled addition of oxygen to maintain viability at high cell concentrations.5. The ethanol tolerance of some selected strains of Zymomonas is comparable if not higher than strains of Saccharomyces cerevisiae. Ethanol concentrations of 85 g/(up to 11% v/v) have been achieved in continuous culture and up to 130 g/(16% v/v) in batch culture. 相似文献
3.
Summary Induction of ascospore formation in hydrocarbon utilizing ascosporogenous yeasts was observed during the growth of the yeasts on gas oil, diesel oil, white kerosene and n-alkanes. Studies of relationships between cell morphology and cell growth showed that ascospores were formed during the active growth phase on gas oil but not on glucose. Contact of yeast cells with hydrocarbons may be the possible reason for sporogenesis on hydrocarbons. 相似文献
4.
Jeong-Sam Koh Takashi Yamakawa Tohru Kodama Yasuji Minoda 《Bioscience, biotechnology, and biochemistry》2013,77(5):1411-1416
A soil microorganism, identified as Acinetobacter calcoaceticus KB-2, was cultivated on palm oil as a carbon source for cell production. This organism grew with a specific growth rate of l.lOh?1. The pH optimum for growth was between 6.5 and 7.0, and the temperature optimum was 39°C. Compared with other strains on water-insoluble substrates such as hydrocarbons and natural oils and fats so far reported, the cultivation time for this strain was short and the cell mass productivity was relatively high. More than 90% of the palm oil was assimilated by this strain, and the overall cell yield was 1.02 (g of cells/g of palm oil) after 8 hr cultivation with the concentration of 3% palm oil. 相似文献
5.
《Journal of Fermentation Technology》1987,65(2):229-232
Chemostat culture of Acinetobacter calcoaceticus KB-2 was done under palm oil-limiting conditions for cell production, and variation of cell compositions and yield coefficients were investigated in connection with the specific growth rates. At the concentration of 0.6% palm oil, the productivity of cells and yield coefficient were 4.76 g cells/l/h and 1.18 g cells/g palm oil, respectively, at a practical dilution rate of 0.85 h−1. About 80% of the palm oil was assimilated by the strain, and the maintenance coefficient was 0.035 g palm oil/g cells/h. Although the carbohydrate content remained essentially constant when the growth rate was varied, the lipid, protein, and nucleic acid contents were increased slightly at higher growth rates. Although the protein content increased only 3%, the protein yield coefficient (Yp) increased about 1.5 times over the range of specific growth rates between 0.1 and 0.7 h−1. The increase in Yp was due to the higher protein content of the biomass and to higher values of the cell yield coefficient. 相似文献
6.
Summary
Candida albicans, a dimorphic yeast, has the abililty to switch its growth form between budding growth and hyphal growth. Since fungal growth involves secretory processes, spatial control of secretion should play a crucial role in such a morphogenetic transition. Brefeldin A (BFA), an inhibitor of the membrane trafficking system of eukaryotes, increases the occurrence of Golgi-like cisternae in the yeast. In the present study, BFA was used to obtain further insights into the spatial organization of secretory processes in hyphal growth ofC. albicans. BFA completely inhibited the formation and growth of germ tubes at a concentration of 35 M or higher. Electron microscopy of BFA-untreated germinated cells revealed many vesicles in the apical region and Golgi-like cisternae in the cytoplasm. In cells treated with 35 M BFA, the vesicles disappeared from the apical region, and, instead, stacked membrane cisternae and membrane-enclosed spherical dense bodies accumulated in the subapical region. These accumulated structures were positive for both polysaccharide staining and immunocytochemical staining with antibodies raised against cell surface antigens ofC. albicans, as were Golgi cisternae in BFA-untreated cells. In cells treated with a higher concentration of BFA (140 M), the structures that appeared in cells treated with 35 M BFA were no longer observed and the endoplasmic reticulum was extended and positive for polysaccharide staining. These results suggested that BFA affects different steps of membrane trafficking in a concentration-dependent manner. The accumulated structures induced by 35 M BFA seemed to be the altered forms of Golgi cisternae. Their accumulation in the subapical region of the germ tube might indicate that the step(s) in membrane trafficking that are associated with the Golgi pathway are vectorially organized in hyphal growth ofC. albicans.Abbrevations BFA
brefeldin A
- BSA
bovine serum albumin
- CBB
Coomassie brilliant blue
- Con A
concanavalin A
- HRP
horseradish peroxidase 相似文献
7.
Tipparat Hongpattarakere Aran H-Kittikun 《World journal of microbiology & biotechnology》1995,11(6):607-609
Schwanniomyces castellii B5285 grew faster and produced greater biomass and higher protein yield than either S. alluvius ATCC 26074 or S. alluvius 81Y when these amylolytic yeasts were grown with 2% (w/v) cassava starch as sole C source. With 0.5% (w/v) glutamate as N source, S. castellii reached 7.12 g cell dry mass/l, with a protein yield of 6.4 g/100 g starch. The optimal agitation speed, aeration rate and pH for growth of this yeast in a fermenter were 400 rev/min, 1.67 vol./vol.min. and 5.0, respectively. Tween 80 at 0.1% increased cell dry mass to 8.90 g/l, cell yield to 44 g/100 g starch and protein yield to 7.4 g/100 g starch.The authors are with the Department of industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai 90110, Thailand 相似文献
8.
G Zayed 《Journal of industrial microbiology & biotechnology》1997,19(1):39-42
Among three esters of p-hydroxybenzoate, n-butyl p-hydroxybenzoate was selected as the best antimicrobial substance. Molasses medium sterilized by this ester was used as
a substrate for ethanol production. n-Butyl p-hydroxybenzoate (0.15% w/v) completely inhibited the growth of free yeast cell inoculum, Ca-alginate immobilized yeast
inoculum and bacterial contaminants. Immobilization of the yeast cell inoculum in Ca-alginate with castor oil (6% v/v) offered
a yeast cell protection against the inhibitory effect of n-butyl p-hydroxybenzoate. The presence of castor oil in this immobilization system did not affect the metabolic activity of the yeast
in beads compared to the cells immobilized without castor oil. The yeast cell beads in this system completely utilized up
to 25% molasses sugar with an ethanol yield of 10.58%, equal to 83% of its theoretical value. The beads were stable and
could be used successfully for seven cycles of batch fermentation. The optimum fermentation temperature using this system
was 35°C.
Received 21 January 1997/ Accepted in revised form 05 May 1997 相似文献
9.
Effects of acetic acid and lactic acid on the growth of Saccharomyces cerevisiae in a minimal medium 总被引:1,自引:0,他引:1
N V Narendranath K C Thomas W M Ingledew 《Journal of industrial microbiology & biotechnology》2001,26(3):171-177
Specific growth rates (μ) of two strains of Saccharomyces cerevisiae decreased exponentially (R
2>0.9) as the concentrations of acetic acid or lactic acid were increased in minimal media at 30°C. Moreover, the length of
the lag phase of each growth curve (h) increased exponentially as increasing concentrations of acetic or lactic acid were
added to the media. The minimum inhibitory concentration (MIC) of acetic acid for yeast growth was 0.6% w/v (100 mM) and that
of lactic acid was 2.5% w/v (278 mM) for both strains of yeast. However, acetic acid at concentrations as low as 0.05–0.1%
w/v and lactic acid at concentrations of 0.2–0.8% w/v begin to stress the yeasts as seen by reduced growth rates and decreased
rates of glucose consumption and ethanol production as the concentration of acetic or lactic acid in the media was raised.
In the presence of increasing acetic acid, all the glucose in the medium was eventually consumed even though the rates of
consumption differed. However, this was not observed in the presence of increasing lactic acid where glucose consumption was
extremely protracted even at a concentration of 0.6% w/v (66 mM). A response surface central composite design was used to
evaluate the interaction between acetic and lactic acids on the specific growth rate of both yeast strains at 30C. The data
were analysed using the General Linear Models (GLM) procedure. From the analysis, the interaction between acetic acid and
lactic acid was statistically significant (P≤0.001), i.e., the inhibitory effect of the two acids present together in a medium is highly synergistic. Journal of Industrial Microbiology & Biotechnology (2001) 26, 171–177.
Received 06 June 2000/ Accepted in revised form 21 September 2000 相似文献
10.
The kinetics of cell inactivation in the presence of ethanol at 20, 22.5% and 25% (v/v), was measured by progressive sampling and viable counting, and used as an inference of the ethanol resistance status of five non-Saccharomyces strains and one strain of Saccharomyces cerevisiae. The capacity of standard inocula of the same strains to establish growth at increasing initial ethanol concentrations was employed as a comparison. The effect of various different pre-culture conditions on the ethanol resistance of the 6 strains was analysed by the cell inactivation method and by the cell growth method. Exposing cells to 25% (v/v) ethanol for 4 min enabled the differentiation of the yeasts in terms of their resistance to ethanol. The results suggest that the two methods are generally concordant and that the cell inactivation method can, thus, be used to infer ethanol resistance of yeast strains. 相似文献
11.
Akhilesh Kumar Singh Nirupama Mallick 《Journal of industrial microbiology & biotechnology》2009,36(3):347-354
Studies conducted with various inexpensive carbon sources such as whey, vegetable oils (palm, mustard, soybean and coconut),
a low-cost source of glucose-D, rice and wheat bran, and mustard and palm oil cakes demonstrated palm oil as the best substrate
for accumulation of a novel short-chain-length–long-chain-length polyhydroxyalkanoate (SCL–LCL-PHA) co-polymer containing
SCL 3HAs [3-hydroxybutyric acid (3HB) and 3-hydroxyvaleric acid (3HV)] and LCL 3HAs of 3-hydroxyhexadecanoic acid (3HHD) and
3-hydroxyoctadecanoic acid (3HOD) units as constituents by a sludge-isolated Pseudomonas aeruginosa MTCC 7925. The co-polymer content reached up to 60% of dry cell weight (dcw) at 48 h of incubation in 0.5% (v/v) palm oil
and the extract of 0.5% (v/v) palm oil cake supplemented vessels. The PHAs pool was further enhanced up to 69 and 75% (dcw),
when the above culture was subjected to P- and N-limitation, respectively. The mol fraction of 3HB:3HV:3HHD:3HOD units were,
respectively, 83.1:7.7:3.8:5.4 and 87.3:5.1:3.6:4.0 in P- and N-limited cultures. Consequently, a co-polymer yield of 5 g l−1 (approx.) was achieved, which was about 80-fold higher as compared to 69 mg l−1 of the control culture. On substrate basis, the accumulation reached up to 0.62 g PHAs per g substrate, which was significantly
higher as compared to the yield obtained from starch by Haloferax mediterranei and Azotobacter
chroococum, from molasses by A. vinelandii UWD, and from lactose and xylose by Pseudomonas cepacia. This novel P(3HB-co-3HV-co-3HHD-co-3HOD) co-polymer exhibited better thermal and mechanical properties as revealed from the differential scanning calorimetry
and mechanical property studies, thus opens up new possibilities for various industrial applications. 相似文献
12.
Ainon Hamzah Chia-Wei Phan Pek-Hoon Yong Nurul Hayati Mohd Ridzuan 《Soil & Sediment Contamination》2014,23(7):751-762
Contamination of soil by petroleum hydrocarbons is becoming prevalent in Malaysia. Infiltration of soil contamination into groundwater poses a great threat to the ecosystem and human health. Bioremediation can occur naturally or can be enhanced with supplementation of microorganisms and fertilizers. However, fertilizers are expensive and therefore alternative nutrient-rich biomaterials are required. In this study, two organic wastes from agricultural industry (i.e., sugarcane bagasse and oil palm empty fruit bunch) were investigated for possible enhanced bioremediation of soil contaminated with Tapis crude oil. Two bacterial strains isolated and characterized previously (i.e., Pseudomonas aeruginosa UKMP-14T and Acinetobacter baumannii UKMP-12T) were used in this study. Sugarcane bagasse (5% and 15%, w/w) and oil palm empty fruit bunch (20%, w/w) were mixed with soil (500 g) spiked with Tapis crude oil (3%, v/w). The treated soils as well as controls were incubated for 20 days under controlled conditions. Sampling was carried out every four days to measure the number of bacterial colonies (CFU/g) and to determine the percentage of oil degradation by gas chromatography. The two biostimulating agents were able to maintain the soil moisture holding capacity, pH, and temperature at 38-40% volumetric moisture content (VMC), 7.0, and 29–30°C; respectively. The growth of bacteria consortium after 20 days in the treatment with sugarcane bagasse and oil palm empty fruit bunch had increased to 10.3 CFU/g and 9.5 CFU/g, respectively. The percentage of hydrocarbon degradation was higher in the soil amended with sugarcane bagasse (100%) when compared to that of oil palm empty fruit bunch (97%) after 20 days. Our results demonstrated the potential of sugarcane bagasse and oil palm empty fruit bunch as good substrates for enhanced bioremediation of soil contaminated with petroleum crude oil. 相似文献
13.
Streptomyces fradiae (NRRL 2702) produced tylosin when cultured on a synthetic defined medium M3. Palm oil, palm kernel oil and their fractions,
as well as fatty acids and glycerol were investigated to serve as the major carbon source in shake flask culture. The lipids,
glycerol and fatty acids, particularly palmitic acid but not oleic or lauric acid, were suitable for growth and tylosin production.
For palmitic acid, at 168 h, the dry cell yield and tylosin production were 8.9 mg/ml and 0.84 mg/g cell mass respectively. 相似文献
14.
Srimhan P Kongnum K Taweerodjanakarn S Hongpattarakere T 《Enzyme and microbial technology》2011,48(3):293-298
Methanol-tolerant lipase producing yeast was successfully isolated and selected thorough ecological screening using palm oil-rhodamine B agar as one step-approach. All 49 lipase-producing yeasts exhibited the ability to catalyze esterification reaction of oleic acid and methanol at 3 molar equivalents. However, only 16 isolates catalyzed transesterification reaction of refined palm oil and methanol. Rhodotorula mucilagenosa P11I89 isolated from oil contaminated soil showed the strongest hydrolytic lipase activity of 1.2U/ml against palm oil. The production of oleic methyl ester and fatty acid methyl ester (FAME) of 64.123 and 51.260% was obtained from esterification and transesterification reaction catalyzed by whole cell of R. mucilagenosa P11I89 in the presence of methanol at 3 molar equivalents against the substrates, respectively. FAME content increased dramatically to 83.29% when 6 molar equivalents of methanol were added. Application of the methanol-tolerant-lipase producing yeast as a whole cell biocatalyst was effectively resolved major technical obstacles in term of enzyme stability and high cost of lipase, leading to the feasibility of green biodiesel industrialization. 相似文献
15.
The heavy metal resistance of yeasts isolated from sugary substrates such as orange, palm wine and pineapple and identified
asSaccharomyces carlsbergensis andS. cerevisiae was studied. The yeast isolates were tested against different concentrations of cadmium, copper, manganese, silver and zinc
salts ranging from 1 to 20 mmol/L. Local yeasts showed resistance to 3–15 mmol/L cadmium, 18–20 copper, 16–20 manganese, 1–9
silver and 16–19 for zinc. The significance of the results is discussed in relation to the effects of heavy metals on growth
of microorganisms and selection of yeasts for the brewing industry in Nigeria. 相似文献
16.
The kinetics of cell inactivation in the presence of ethanol at 20, 22.5% and 25% (v/v), was measured by progressive sampling and viable counting, and used as an inference of the ethanol resistance status of five non-Saccharomyces strains and one strain of Saccharomyces cerevisiae. The capacity of standard inocula of the same strains to establish growth at increasing initial ethanol concentrations was employed as a comparison. The effect of various different pre-culture conditions on the ethanol resistance of the 6 strains was analysed by the cell inactivation method and by the cell growth method. Exposing cells to 25% (v/v) ethanol for 4 min enabled the differentiation of the yeasts in terms of their resistance to ethanol. The results suggest that the two methods are generally concordant and that the cell inactivation method can, thus, be used to infer ethanol resistance of yeast strains. 相似文献
17.
Ana Mendes Pedro Guerra Vânia Madeira Francisco Ruano Teresa Lopes da Silva Alberto Reis 《World journal of microbiology & biotechnology》2007,23(9):1209-1215
In this work, carob pulp syrup was used as carbon source in C. cohnii fermentations for docosahexaenoic acid production. In preliminary experiments different carob pulp dilutions supplemented
with sea salt were tested. The highest biomass productivity (4 mg/lh) and specific growth rate (0.04/h) were observed at the
highest carob pulp dilution (1:10.5 (v/v), corresponding to 8.8 g/l glucose). Ammonium chloride and yeast extract were tested
as nitrogen sources using different carob pulp syrup dilutions, supplemented with sea salt as growth medium. The best results
were observed for yeast extract as nitrogen source. A C. cohnii fed-batch fermentation was carried out using diluted carob pulp syrup (1:10.5 v/v) supplemented with yeast extract and sea
salt. The biomass productivity was 420 mg/lh, and the specific growth rate 0.05/h. Under these conditions the DHA concentration
and DHA production volumetric rate attained 1.9 g/l and 18.5 mg/lh respectively after 100.4 h. The easy, clean and safe handling
of carob pulp syrup makes this feedstock a promising carbon source for large-scale DHA production from C. cohnii. In this way, this carob industry by-product could be usefully disposed of through microbial production of a high value fermentation
product. 相似文献
18.
T. Andlid C. Larsson C. Liljenberg I. Marison L. Gustafsson 《Applied microbiology and biotechnology》1995,42(6):818-825
Microcalorimetry has been demonstrated to be a suitable on-line method for monitoring the lipid production phase of oleaginous yeasts. The choice of lipid extraction method for the oil accumulated by oleaginous yeasts is highly important both for accuracy when quantifying the lipid level and determining the fatty acid composition. The energy content of Rhodotorula glutinis increased from 23.0 kJ/g to 30.6 kJ/g dry biomass during the lipid-accumulating phase and was directly correlated to the analysed level of lipids, when an alkaline hydrolysis extraction method was used. Consequently, bomb-calorimetric measurements of the energy content were shown to be an indirect method of quantifying the lipid content in oleaginous yeasts. The fatty acid composition remained rather constant during the batch growth of Rh. glutinis with approximately 70% unsaturated C18 fatty acids. The high energy content as well as the fatty acid composition of Rh. glutinis makes this yeast a better candidate for use as aquaculture feed compared with the commonly used Saccharomyces cerevisiae. 相似文献
19.
The optimization of culture conditions for the bacteriumPseudomonas aeruginosa BYK-2 KCTC 18012P, was performed to increase its rhamnolipid production. The optimum level for carbon, nitrogen sources,
temperature and pH, for rhamnolipid production in a flask, were identified as 25 g/L fish oil, 0.01% (w/v) urea, 25 and pH
7.0, respectively. Optimum conditions for batch culture, using a 7-L jar fermentor, were 200 rpm of agitation speed and a
2.0 L/min aeration rate. Under the optimum conditions, on fish oil for 216 h, the final cell and rhamnolipid concentrations
were 5.3 g/L and 17.0 g/L respectively. Fed-batch fermentation, with different feeding conditions, was carried out in order
to increase, cell growth and rhamnolipid production by thePseudomonas aeruginosa, BYK-2 KCTC 18012P. When 2.5 g of fish oil and 100 mL basal salts medium, containing 0.01% (w/v) urea, were fed intermittently
during the fermentation, the final cell and rhamnolipid concentrations at 264 h, were 6.1 and 22.7 g/L respectively. The fed-batch
culture resulted in a 1.2-fold increase in the dry cell mass and a 1.3-fold increase in rhamnolipid production, compared to
the production of the batch culture. The rhamnolipid production-substrate conversion factor (0.75 g/g) was higher than that
of the batch culture (0.68 g/g). 相似文献
20.
Ryosuke Yamada Tsutomu Tanaka Chiaki Ogino Hideki Fukuda Akihiko Kondo 《Applied microbiology and biotechnology》2010,85(5):1491-1498
We developed a novel strategy for constructing yeast to improve levels of amylase gene expression and the practical potential
of yeast by combining δ-integration and polyploidization through cell fusion. Streptococcus bovis α-amylase and Rhizopus oryzae glucoamylase/α-agglutinin fusion protein genes were integrated into haploid yeast strains. Diploid strains were constructed
from these haploid strains by mating, and then a tetraploid strain was constructed by cell fusion. The α-amylase and glucoamylase
activities of the tetraploid strain were increased up to 1.5- and tenfold, respectively, compared with the parental strain.
The diploid and tetraploid strains proliferated faster, yielded more cells, and fermented glucose more effectively than the
haploid strain. Ethanol productivity from raw starch was improved with increased ploidy; the tetraploid strain consumed 150 g/l
of raw starch and produced 70 g/l of ethanol after 72 h of fermentation. Our strategy for constructing yeasts resulted in
the simultaneous overexpression of genes integrated into the genome and improvements in the practical potential of yeasts. 相似文献