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1.
Fabiana R. X. Batista Carlos A. Pereira Ronaldo Z. Mendon?a Angela M. Moraes 《Cytotechnology》2005,49(1):1-9
Animal cells can be cultured both in basal media supplemented with fetal bovine serum (FBS) and in serum-free media. In this
work, the supplementation of Grace’s medium with a set of nutrients to reduce FBS requirements in Spodoptera frugiperda (Sf9) cell culture was evaluated, aiming the production of Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) at a cost lower than those for the production using Sf900 II medium. In Grace’s medium supplemented
with glucose, Pluronic F68 (PF68) and yeast extract (YE), the effects of FBS and milk whey ultrafiltrate (MWU) on cell concentration
and viability during midexponential and stationary growth phase were evaluated. In spite of the fact that FBS presented higher
statistical effects than MWU on all dependent variables in the first cell passage studies, after cell adaptation, AgMNPV polyhedra
production was comparable to that in Sf900 II. Batch cultivation in Grace’s medium with 2.7 g l−1 glucose, 8 g l−1 YE and 0.1% (w/v) PF68 supplemented with 1% (w/v) MWU and 3% (v/v) FBS increased viable cell concentration to about 5-fold
(4.7×106 cells ml−1) when compared to Grace’s containing 10% (v/v) FBS (9.5×105 cells ml−1). AgMNPV polyhedra (PIBs) production was around 3-fold higher in the MWU supplemented medium (1.6×107 PIBs ml−1) than in Grace’s medium with 10% FBS (0.6×107 PIBs ml−1). This study therefore shows a promising achievement to significantly reduce FBS concentration in Sf9 insect cell media,
keeping high productivity in terms of cell concentration and final virus production at a cost almost 50% lower than that observed
for Sf900 II medium.
C.A. Pereira is recipient of a CNPq fellowship. 相似文献
2.
Production of clavulanic acid (CA) by Streptomyces clavuligerus in a shake-flask culture increased from 92 to 180 mg l−1 with an increased O2 transfer efficiency (0.039 → 0.058 s−1), which maintained the redox potential values above −250 mV. Compared with traditional measures, such as dissolved O2 concentration and respiratory activity, the redox potential can easily be determined and correlates closely with CA production.
It can therefore be used to monitor microbial activities during biosyntheses of secondary metabolites.
Revisions requested 5 April 2005 and 19 July 2005; Revisions received 19 July 2005 and 9 September 2005 相似文献
3.
Production of biomass and phycocyanin (PC) were investigated in highly pigmented variants of the unicellular rhodophyte Galdieria sulphuraria, which maintained high specific pigment concentrations when grown heterotrophically in darkness. The parental culture, G. sulphuraria 074G was grown on solidified growth media, and intensely coloured colonies were isolated and grown in high-cell-density fed-batch
and continuous-flow cultures. These cultures contained 80–110 g L−1 biomass and 1.4–2.9 g L−1 PC. The volumetric PC production rates were 0.5–0.9 g L−1 day−1. The PC production rates were 11–21 times higher than previously reported for heterotrophic G. sulphuraria 074G grown on glucose and 20–287 times higher than found in phototrophic cultures of Spirulina platensis, the organism presently used for commercial production of PC. 相似文献
4.
E Parente C Brienza A Ricciardi G Addario 《Journal of industrial microbiology & biotechnology》1997,18(1):62-67
Production of the bacteriocin enterocin 1146 (E1146) by Enterococcus faecium DPC1146 was studied in batch and continuous fermentation. Growth was strongly inhibited by lactic acid. In batch fermentations
maximum E1146 activity (2.8 MBU L−1) was obtained in 9 h with 20 g L−1 glucose. Increase in initial glucose concentration did not lead to a proportional increase in E1146 activity. A simple linear
model was found to be adequate to explain the relationship between specific bacteriocin production rate and specific growth
rate in batch fermentations with initial glucose concentration higher than 20 g L−1. Maximum bacteriocin activity (2.9–3.2 MBU L−1) was obtained in continuous fermentations at dilution rates between 0.12 and 0.17 h−1 and specific bacteriocin production rate increased linearly with dilution rate.
Received 31 July 1996/ Accepted in revised form 01 November 1996 相似文献
5.
Natalia P. Kosykh Natalia G. Koronatova Natalia B. Naumova Argenta A. Titlyanova 《Wetlands Ecology and Management》2008,16(2):139-153
We measured phytomass stock and production in Western Siberian mire ecosystems (palsa, ridge, oligotrophic and mesotrophic
hollows, fen). To determine the contribution of different phytomass fractions into total production, we developed a method
to estimate below-ground production (BNP). Standing crop of living above-ground phytomass on treeless plots varied from 300
to 660 g m−2, reaching maximum on palsa, where 81% of phytomass consisted of Sphagnum mosses and lichens. In the hollows and the fen, Sphagnum percentage varied from 70 to 95%. Standing crop of living below-ground phytomass varied from 325 to 1,210 g m−2. It consisted of woody stems, stem bases, rhizomes and roots, with the latter contributing from 30 to 60%. Total production
of mire ecosystems in northern taiga of Western Siberia ranged from 350 to 960 g m−2 year−1 and depended on microtopography of the ecosystem (the presence of permafrost and water table depth). Production of treeless
plant communities located on the elevated sites depended on the presence of permafrost: in comparison with the ridge, palsa
production was lower. Production on the low sites increased with increase pH and reached maximum (960 g m−2 year−1) in poor fens. Bryophytes were the major producers above ground. Their production varied from 100 to 272 g m−2 year−1 and reached maximum on ridges. BNP contributed 37–66%, increasing due to increased contribution of sedges. 相似文献
6.
Responses of sawgrass and spikerush to variation in hydrologic drivers and salinity in Southern Everglades marshes 总被引:3,自引:3,他引:0
Daniel L. Childers David Iwaniec Damon Rondeau Gustavo Rubio Emilie Verdon Christopher J. Madden 《Hydrobiologia》2006,569(1):273-292
Aboveground net primary production (ANPP) by the dominant macrophyte and plant community composition are related to the changing
hydrologic environment and to salinity in the southern Everglades, FL, USA. We present a new non-destructive ANPP technique
that is applicable to any continuously growing herbaceous system. Data from 16 sites, collected from 1998 to 2004, were used
to investigate how hydrology and salinity controlled sawgrass (Cladium jamaicense Crantz.) ANPP. Sawgrass live biomass showed little seasonal variation and annual means ranged from 89 to 639 gdw m−2. Mortality rates were 20–35% of live biomass per 2 month sampling interval, for biomass turnover rates of 1.3–2.5 per year.
Production by C. jamaicense was manifest primarily as biomass turnover, not as biomass accumulation. Rates typically ranged from 300 to 750 gdw m−2 year−1, but exceeded 1000 gdw m−2 year−1 at one site and were as high as 750 gdw m−2 year−1 at estuarine ecotone sites. Production was negatively related to mean annual water depth, hydroperiod, and to a variable
combining the two (depth-days). As water depths and hydroperiods increased in our southern Everglades study area, sawgrass
ANPP declined. Because a primary restoration goal is to increase water depths and hydroperiods for some regions of the Everglades,
we investigated how the plant community responded to this decline in sawgrass ANPP. Spikerush (Eleocharis sp.) was the next most prominent component of this community at our sites, and 39% of the variability in sawgrass ANPP was
explained by a negative relationship with mean annual water depth, hydroperiod, and Eleocharis sp. density the following year. Sawgrass ANPP at estuarine ecotone sites responded negatively to salinity, and rates of production
were slow to recover after high salinity years. Our results suggest that ecologists, managers, and the public should not necessarily
interpret a decline in sawgrass that may result from hydrologic restoration as a negative phenomenon. 相似文献
7.
Rose C. Kaggwa Anne A. van Dam John S. Balirwa Frank Kansiime Patrick Denny 《Wetlands Ecology and Management》2009,17(3):257-277
The processes driving primary productivity and its impacts on fish production were investigated in field trials in eight seasonal
earthen wetland ponds ‘Fingerponds’ (192 m2) in Uganda between 2003 and 2005. The ponds were stocked by the seasonal flood with predominantly Oreochromis spp. at densities ranging from 0.1 to 0.5 fish m−2. Chicken manure (521, 833 or 1,563 kg ha−1) was applied fortnightly. Results showed that primary productivity was enhanced with maximum average net primary productivity
(±Standard Error) of 11.7 (±2.5) g O2 m−2 day−1 at the Gaba site and 8.3 (±1.5) g O2 m−2 day−1 at the Walukuba site. Net fish yields were higher in manured ponds with up to 2,670 kg ha−1 yield for a 310 day growth period compared to less than 700 kg ha−1 in unmanured ponds. Fish production was limited mainly by high recruitment, falling water levels, light limitation from high
suspended solids and turbidity, and low zooplankton biomass. It was concluded that Fingerponds have a high potential for sustainable
fish production and can contribute to the alleviation of protein shortages amongst the riparian communities around Lake Victoria.
Production can be enhanced further with improved stock management. 相似文献
8.
He Jun Yu Bing Zhang Keying Ding Xuemei Chen Daiwen 《Indian journal of microbiology》2009,49(2):188-195
The strain of Trichoderma reesei Rut C-30 was subjected to mutation after treatment with N-methyl-N′-nitro-N-nitrosoguanidine (NG) for 6 h followed by UV irradiation for 15 min. Successive mutants showed enhanced cellulase production,
clear hydrolysis zone and rapid growth on Avicel-containing plate. Particularly, the mutant NU-6 showed approximately two-fold
increases in activity of both FPA and CMCase in shake flask culture when grown on basal medium containing peptone (1%) and
wheat bran (1%). The enzyme production was further optimized using eight different media. When a mixture of lactose and yeast
cream was used as cellulase inducer, the mutant NU-6 yielded the highest enzyme and cell production with a FPase activity
of 6.2 U ml−1, a CMCase activity of 54.2 U ml−1, a β-glucosidase activity of 0.39 U ml−1, and a fungal biomass of 12.6 mg ml−1. It deserved noting that the mutant NU-6 also secreted large amounts of xylanases (291.3 U ml−1). These results suggested that NU-6 should be an attractive producer for both cellulose and xylanase production. 相似文献
9.
Synopsis The age structures of brook charr (Salvelinus fontinalis) and ouananiche (Salmo salar) stocks inhabiting a large rapid the river Méo, tributary to the Caniapiscau River were used to compare population stability
and production of these species in north central Quebec. The brook chart stock was stable whereas ouananiche showed considerable
variation in year class strength. Stock estimates were not significantly different for the two species although the brook
charr estimate was 1.5 that of the ouananiche. Production estimates differed by a greater margin because of different growth
patterns. Brook chair production was estimated at 19.4 kg ha−1 yr−1. Above age 2+ it was 11.4 kg ha−1 yr−1 which compares with 4.8 kg ha−1 yr−1 for the same age groups of ouananiche. 相似文献
10.
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
11.
Candida cylindracea NRRL Y-17506 was grown to produce extracellular lipase from oleic acid as a carbon source. Through flask cultures, it was found that the optimum initial oleic acid concentration for cell growth was 20 g l−1. However, high initial concentrations of oleic acid up to 50 g l−1 were not inhibitory. The highest extracellular lipase activity obtained in flask culture was 3.0 U ml−1 after 48 h with 5 g l−1 of initial oleic acid concentration. Fed-batch cultures (intermittent and stepwise feeding) were carried out to improve cell concentration and lipase activity. For the intermittent feeding fed-batch culture, the final cell concentration was 52 g l−1 and the extracellular lipase activity was 6.3 U ml−1 at 138.5 h. Stepwise feeding fed-batch cultures were carried out to simulate an exponential feeding and to investigate the effects of specific growth rate (0.02, 0.04 and 0.08 h−1) on cell growth and lipase production. The highest final cell concentration obtained was 90 g l−1 when the set point of specific growth rate (μset) was 0.02 h−1. High specific growth rate (0.04 and 0.08 h−1) decreased extracellular lipase production in the later part of fed-batch cultures due to build-up of the oleic acid oversupplied. The highest extracellular lipase activity was 23.7 U ml−1 when μset was 0.02 h−1, while the highest lipase productivity was 0.31 U ml−1 h−1 at μset of 0.08 h−1. 相似文献
12.
H-J Son K-K Kim H-S Kim Y-K Kim S-J Lee 《Journal of industrial microbiology & biotechnology》2000,24(1):36-40
Pseudomonas sp EL-2 was cultivated to produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] from a structurally unrelated
carbon source, glucose, by a fed-batch culture technique. Variation of the carbon to nitrogen (C/N) ratio of the medium produced
optimal P(3HB-co-3HV) production at a C/N ratio of 95. Production of P(3HB-co-3HV) was favored by a dissolved oxygen tension
of 40%. A maximum biomass concentration of 38 g L−1 containing 53% P(3HB-co-3HV) was achieved after 45 h of cultivation. This corresponds to a volumetric productivity of 0.84 g
L−1 h−1. The copolymer contained 7.5 mol% 3-hydroxyvalerate. Journal of Industrial Microbiology & Biotechnology (2000) 24, 36–40.
Received 28 January 1999/ Accepted in revised form 11 September 1999 相似文献
13.
Arun M. Khurad Min-Juan Zhang Chanchal G. Deshmukh Ravindra S. Bahekar Ashish D. Tiple Chuan-Xi Zhang 《In vitro cellular & developmental biology. Animal》2009,45(8):414-419
A new continuous cell line from ovarian tissue of commercial variety “Kolar Gold” of silkworm, Bombyx mori, was established and designated as DZNU-Bm-12. The tissue was grown in MGM-448 insect cell culture medium supplemented with
10% fetal bovine serum (FBS) and 3% heat-inactivated B. mori hemolymph at 25 ± 1°C. The migration of partially attached small round refractive cells from the fragments of ovarioles began
from the beginning of explantation. The cells multiplied partially attached in the primary culture initially, and some of
them become freely suspended after 20 passages. The cells were adapted to MGM-448 and TNM-FH media each with 10% FBS and the
population doubling time of cell line was about 36 and 24 hr, respectively. The chromosome number was near diploid at initial
passages and slightly increased at 176th passage, but a few tetraploids and hexaploids were also observed. DNA profiles using
simple sequence repeat loci established the differences between DZNU-Bm-12 and DZNU-Bm-1 and most widely used Bm-5 and BmN
cell lines. The cell line was found susceptible to B. mori nucleopolyhedrovirus (BmNPV) with 85–90% of the cells harboring BmNPV and having an average of 3–17 OBs/infected cell. We
suggest the usefulness of this cell line in BmNPV-based baculoviral expression system and also for studying in vitro virus
replication. 相似文献
14.
Peter von Feiten Hans Zürrer Reinhard Bachofen 《Applied microbiology and biotechnology》1985,23(1):15-20
Summary Cells ofRhodospirillum rubrum have been immobilized in various gels and tested for photobiological hydrogen production. Agar proved to be the best immobilizing
agent with respect to production rates as well as stability. Agar immobilized cells were also superior compared to liquid
suspension cultures. Growth conditions of the cells prior to immobilization, e.g. cell age, light intensity or nutrient composition,
were of primary importance for the activity in the later immobilized state. A reactor with agar immobilized cells has been
operated successfully over 3000 h with a loss of the activity of about 60%. Mean rates for hydrogen production for immobilized
cells in this work during the first 60 to 70 hours after immobilization were in the range of 18 to 34 μl H2 mg−1 d.w. h−1 and thus by a factor of up to 2 higher than liquid cultures under the same conditions. Maximal rates of hydrogen production
(57 μl H2 ml−1 immobilized cell suspension) were reached in agar gel beads with cells immobilized after 70 h growth in liquid culture in
the light and a cell density of 1.0 mg ml−1, 70 h after immobilization. 相似文献
15.
Secondary production and diet of an invasive snail in freshwater wetlands: implications for resource utilization and competition 总被引:1,自引:0,他引:1
Invasive species can monopolize resources and thus dominate ecosystem production. In this study we estimated secondary production
and diet of four populations of Pomacea canaliculata, a freshwater invasive snail, in wetlands (abandoned paddy, oxbow pond, drainage channel, and river meander) in monsoonal
Hong Kong (lat. 22°N). Apple snail secondary production (ash-free dry mass [AFDM]) ranged from 165.9 to 233.3 g m−2 year−1, and varied between seasons. Production was lower during the cool dry northeast monsoon, when water temperatures might have
limited growth, but fast growth and recruitment of multiple cohorts were possible throughout much (7–10 months) of the year
and especially during the warm, wet southwest monsoon. The diet, as revealed by stomach-content analysis, consisted mainly
of detritus and macrophytes, and was broadly consistent among habitats despite considerable variation in the composition and
cover of aquatic plants. Apple snail annual production was >10 times greater than production estimates for other benthic macroinvertebrates
in Hong Kong (range 0.004–15 g AFDM m−2 year−1, n = 29). Furthermore, annual production estimates for three apple snail populations (i.e. >230 g AFDM m−2 year−1) were greater than published estimates for any other freshwater snails (range 0.002–194 g AFDM m−2 year−1, n = 33), regardless of climatic regime or habitat type. High production by P. canaliculata in Hong Kong was attributable to the topical climate (annual mean ~24°C), permitting rapid growth and repeated reproduction,
together with dietary flexibility including an ability to consume a range of macrophytes. If invasive P. canaliculata can monopolize food resources, its high productivity indicates potential for competition with other macroinvertebrate primary
consumers. Manipulative experiments will be needed to quantify these impacts on biodiversity and ecosystem function in wetlands,
combined with management strategies to prevent further range extension by P. canaliculata. 相似文献
16.
The production of chitinases and hydrophobins from Lecanicillium lecanii was influenced by the cultivation method and type of carbon source. Crude enzyme obtained from solid-substrate culture presented
activities of exochitinases (32 and 51 kDa), endochitinases (26 kDa), β-N-acetylhexosaminidases (61, 80, 96 and 111 kDa). Additionally, submerged cultures produced exochitinases (32 and 45 kDa),
endochitinases (10 and 26 kDa) and β-N-acetylhexosaminidases (61, 96 and 111 kDa). β-N-acetylhexosaminidases activity determined in solid-substrate culture with added chitin was ca. threefold (7.58 ± 0.57 U mg−1) higher than submerged culture (2.73 + 0.57 U mg−1). Similarly, hydrophobins displayed higher activities in solid-substrate culture (627.3 ± 2 μg protein mL−1) than the submerged one (57.4 ± 4.7 μg protein mL−1). Molecular weight of hydrophobins produced in solid-substrate culture was 7.6 kDa and they displayed surface activity on
Teflon. 相似文献
17.
Yasuhiro Satoh Toshiya Katano Takeshi Satoh Osamu Mitamura Kaori Anbutsu Shin-ichi Nakano Hiroyuki Ueno Masaki Kihira Valentin Drucker Yuji Tanaka Tetsuro Mimura Yasunori Watanabe Masahito Sugiyama 《Limnology》2006,7(3):225-229
Nutrient limitation of the primary production of phytoplankton at some stations in southern and central Lake Baikal was studied
by nutrient enrichment experiments in August 2002. Chlorophyll (Chl.) a concentrations ranged from 0.7 to 5.8μgl−1. Inorganic nutrient concentrations were low: soluble reactive phosphorus ranged from 0.05 to 0.20μmoll−1, ammonia from 0.21 to 0.41μmoll−1, and nitrite plus nitrate from 0.33 to 0.37μmoll−1. In the five enrichment experiments, phosphate spikes and phosphate plus nitrate spikes always stimulated primary production.
Nitrate spikes also stimulated primary production in four of the experiments. Significant differences were detected between
the controls and phosphate spikes and between the controls and phosphate plus nitrate spikes. Thus, the first limiting nutrient
is thought to be phosphorus, but once phosphorus is supplied to the surface water, the limiting nutrient will quickly shift
from phosphorus to nitrogen. 相似文献
18.
Survase SA Jurgens G van Heiningen A Granström T 《Applied microbiology and biotechnology》2011,91(5):1305-1313
Clostridium beijerinckii DSM 6423 was studied using different continuous production methods to give maximum and stable production of isopropanol and
n-butanol. In a single-stage continuous culture, when wood pulp was added as a cell holding material, we could increase the
solvent productivity from 0.47 to 5.52 g L−1 h−1 with the yield of 54% from glucose. The overall solvent concentration of 7.51 g L−1 (39.4% isopropanol and 60.6% n-butanol) with the maximum solvent productivity of 0.84 g L−1 h−1 was obtained with two-stage continuous culture. We were able to run the process for more than 48 overall retention times
without losing the ability to produce solvents. 相似文献
19.
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
20.
Claucia Fernanda Volken de Souza Júlio Xandro Heck Marco Antônio Záchia Ayub 《Journal of industrial microbiology & biotechnology》2008,35(12):1677-1685
In this work, we investigated the production of transglutaminase (TGase) by an Amazonian isolated strain of Bacillus circulans by solid-state cultivation (SSC). Several agro-industrial residues, such as untreated corn grits, milled brewers rice, industrial
fibrous soy residue, soy hull, and malt bagasse, were used as substrates for microbial growth and enzyme production. Growth
on industrial fibrous soy residue, which is rich in protein and hemicellulose, produced the highest TGase activity (0.74 U g−1 of dried substrate after 48 h of incubation). A 23 central composite design was applied to determine the optimal conditions of aeration, cultivation temperature and inoculum
cell concentration to TGase production. The best culture conditions were determined as being 0.6 L air min−1, 33 °C and 10 log 10 CFU g−1 of dried substrate, respectively. Under the proposed optimized conditions, the model predicted an enzyme production of 1.16 U g−1 of dried substrate, closely matching the experimental activity of 1.25 U g−1. Results presented in this work point to the use of this newly isolated B. circulans strain as a potential alternative of microbial source for TGase production by SSC, using inexpensive culture media. 相似文献