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1.
A. Jagannath A. Kalaiselvan S. S. Manjunatha P. S. Raju A. S. Bawa 《World journal of microbiology & biotechnology》2008,24(11):2593-2599
The effect of pH, sucrose and ammonium sulphate concentrations on the production of nata-de-coco, a form of bacterial cellulose, by Acetobacter xylinum was studied. Comparisons for physical properties like thickness, wet weight, water-holding capacity (WHC), moisture content
and hardness, a textural parameter were done on nata-de-coco grown in tender coconut water medium supplemented with varying concentrations of sucrose and ammonium sulphate at different
pH values. The results were analysed by fitting a second-order polynomial regression equation. Response surface methodology
was used to study the effect of the three variables. The study showed that A. xylinum could effectively use sucrose as the sole carbon source in coconut water medium and that cellulose production was more dependent
on pH than either sucrose or ammonium sulphate concentrations. Maximum thickness of nata was obtained at pH 4.0 with 10% sucrose and 0.5% ammonium sulphate concentrations. These conditions also produced good quality
nata-de-coco with a smooth surface and soft chewy texture. The study will enable efficient utilization of coconut water, a hitherto wasted
byproduct of coconut industry and will also provide a new product dimension to the aggrieved coconut farmers who are not getting
the right price for their product. 相似文献
2.
A Blondeaux J-F Hamel P Widehem N Cochet 《Journal of industrial microbiology & biotechnology》1999,23(6):514-519
Pseudomonas syringae is known as a biological ice-nucleating agent. The bacterium has the unusual property of increasing the temperature at which
water freezes by a few degrees. However, the ice-nucleating activity (INA) always remains lower for in vitro cultivated cells, than for cells grown in planta. We examined the effects of the hydrophobic environment and of water availability, on the in vitro growth and INA of P. syringae. The hydrophobic environment was modified by addition of fatty acids, vegetable oils or silicone oil to the culture medium.
Addition of olive oil (1%), or traces of silicone oil in the culture medium had a positive effect upon the expression of INA.
Variations in water activity from 0.990 to 0.988 by addition of sugar beet fibres or sodium chloride in the culture medium
were followed by an increase in INA. This study suggested that control of the medium’s water activity must be considered as
an important parameter for optimization of INA in P. syringae.
Received 16 June 1998/ Accepted in revised form 02 September 1999 相似文献
3.
Cuadra T Fernández FJ Tomasini A Barrios-González J 《Letters in applied microbiology》2008,46(2):216-220
Aims: To investigate the effect of pH regulation and nutrient concentration on cephalosporin C (CPC) production in solid‐state fermentation (SSF), using sugarcane bagasse as inert support, impregnated with liquid medium. Methods and Results: Solid‐state fermentation using different initial pH values, buffer and nutrient concentrations were performed. Results revealed pH as a key parameter in CPC SSF, as it hampered the antibiotic production not only above 7·8, but also under 6·4. Using initial pH lower than 6·8 and PB in the solid medium, it was possible to keep pH within the production range, increase the production period (from 1 to 3 days) and hence the CPC yield from 468 to 3200 μg gdm?1 (g?1 of dry matter). Conclusion: Parameters that help to keep pH in adequate values for CPC production in SSF, such as initial pH, buffering system and nutrient concentration, can greatly increase the production time and CPC yields in this fermentation technique. Significance and Impact of the Study: This is the first work on CPC production on impregnated support, and the only one revealing pH as a key parameter; it is also shown that high nutrient concentration can improve CPC yields in SSF as long as pH is kept under control. 相似文献
4.
A high yielding cell line of Scutellaria baicalensis G. has successfully been developed to produce flavonoids. Major components of the flavonoids were identified as baicalin and wogonin-7-O-glucuronic acid by a series of instrumental analyses using UV, IR, MASS, and NMR. After 12 days in suspension culture, the cell growth reached 14 g
DW/l, and baicalin and wogonin-7-O-glucuronic acid were obtained in concentrations of 2.9 g/l and 1.07 g/l, respectively. The culture temperature was found to be an important parameter for improving production yield of the flavonoids. The yield of baicalin was observed to increase to 4.2 g/l by shifting the temperature from 30 °C to 25 °C after 72 h of suspension culture.Abbreviations DW
cell dry weight
- FW
cell fresh weight
- 2,4-D
2,4-dichlorophenoxyacetic acid
- PSH medium
phytohormone added Schenk and Hildebrandt medium
- FPM
a modified Schenk and Hildebrandt medium for flavonoid production 相似文献
5.
During the cheese-making process, water activity (aw) is one of the essential environmental parameters acting on bacterial growth and metabolic pathways. The influence of aw on Streptococcus diacetylactis growth and lactic acid production was studied. The specific growth rate was linearly related to water availability in the milk medium. The cell behaviour was quite different above and below aw=0.95, which can be considered a limiting value. Below this value, the lactic acid production reached 1.4–6.1 mg·g–1, whereas the specific productivity was 2.0–2.6 mg·10–10 cells·h–1. Changes in the consumption of lactose and amino acids during the different growth phases was completely modified by decreasing the water availability in the medium.
Correspondence to: N. Cochet 相似文献
6.
Summary The growth and the sporulation of Trichoderma viride TS in relation to water activity (a
w) of sugar-beet pulp medium was studied. It was found that the maximum growth, monitored by protein production, substrate
utilization and pH alteration, appeared at a
w=0.990–0.992. Optimal water activity of the medium for sporogenesis was 0.980. It was observed that both physiological phenomena
appeared in narrow ranges of water activity which caused the rigorous a
w control in solid-state fermentation to be postulated. 相似文献
7.
In this study, a N-deregulated mutant (der8-5) of Phanerochaete chrysosporium was used as a tool to investigate the interrelationships between N, C, and Mn(II) regulation of LIP and MNP production in this organism. The results showed that LIP and MNP production by der8-5 was blocked in excess C medium but not in excess N medium. Furthermore, LIP and MNP production in this organism was subject to Mn(II) regulation regardless of the fact whether it is grown in low N medium or in high N medium. These and other results indicate that N regulation of LIP and MNP production in P. chrysosporium is independent of C and Mn(II) regulation.Abbreviations LIP
lignin peroxidase
- MNP
manganese-dependent peroxidase
- WT
wild-type
-
der8-5
nitrogen-deregulated mutant 相似文献
8.
Christian Larroche Chantal Desfarges Jean-Bernard Gros 《Applied microbiology and biotechnology》1988,28(1):85-92
Summary The effect of substrate (buckwheat seeds) pretreatment on the growth and the sporulation behaviour of Penicillium roqueforti is presented. When a saccharifying enzyme (-amylase) is added to a medium which exhibits a low water content (0.46 g water/g initial dry matter, IDM), a more rapid internal colonization of the seeds occurs, but the final spore production does not increase and remains close to 8.109 spores/g dry matter (DM) at 500 h. No carbon source limitation is then observed. The addition of casein hydrolysate to this medium gives rise to a great increase of the sporulation, since 14.5 109 spores/g DM are obtained after 600 h. This result is attained by a better spore yield from the mycelium, the substrate colonization being unchanged. High water content (0.60 g water/g IDM) of buckwheat seeds induces a shorter cultivation time along with a higher biomass production. However, the spore content of the medium remains close to the low water content one, but 60% total spores are external against 30% to 35% in the other media. 相似文献
9.
Ryo Yamauchi Masahiro Kojima Masatoshi Isogai Koji Kato Yoshimitsu Ueno 《Bioscience, biotechnology, and biochemistry》2013,77(11):2847-2849
The NaCl concentration of the growth medium affected hydrogen production by Lyngbya sp. (No. 108) strain. Cells grown in medium containing 3% NaCl produced the most hydrogen. The carbohydrate content of this strain also increased with increasing NaCl concentration of the growth medium up to 720 fig/mg cells at 5 % NaCl. In the presence of 20 finlol/ml MFA (monofluoroacetic acid), inhibition of hydrogen production was observed. We extracted the glycogen from this nonheterocystous filamentous cyanobacterium, Lyngbya sp. (No. 108), and observed that glycogen and carbohydrate consumption of this strain is coincident with hydrogen production.These results led us to the conclusion that the reserve glycogen or other carbohydrate were used as sources of electron donors for hydrogen production, and that the NaCl concentration of the medium affected the hydrogen production by this strain. 相似文献
10.
《Bioscience, biotechnology, and biochemistry》2013,77(9):1474-1475
A novel marine ice-nucleating bacterium, KUIN-5, was isolated from a marine algae, Monostroma latissum. Strain KUIN-5 was identified as a Pseudomonas sp. from its characteristics and taxonomies; the optimum temperature and pH for its growth were 25°C and 6.0, respectively. When strain KUIN-5 was aerobically cultured in Carlucci-Pramer medium (pH 6.0) for 50 h at 25°C, the highest ice-nucleating activity of the cells among the media for marine bacteria was obtained, and the ice-nucleating temperature, T50, was indicated to be ? 3.2°C. Also, the optimum concentration of NaCl for the growth in this medium, which was prepared with distilled water instead of seawater, was 2.0% (w/v) and then the ice-nucleating activity was inversely proportional to the NaCl concentration. Moreover, when strain KUIN-5 was cultured in Davis medium under optimum conditions, it produced insoluble polysaccharide (IPS) in the culture. The maximum amount of IPS production by strain KUIN-5 was 84.5 mg/ml of medium under optimum conditions. Therefore, this IPS was isolated and could be identified as cellulose, based on TLC or HPLC of the acid hydrolysate, and GC-MS of the acetylated polyalcohol prepared by periodate oxidation and Smith degradation of this polysaccharide. This is the first report of cellulose production by a marine ice-nucleating bacterium. 相似文献
11.
When the barley endosperm flinders are incubated with the gibberellin solution under aerobic condition, α-amylase is produced. But it is not clear whether this aerobic condition is necessary for the biosynthesis of α-amylase or for the absoption of gibberellin into the endosperm tissue. The authors found that the rate of the α-amylase production did not decrease when the incubation medium containing gibberellin was flung away after 48 hours incubation and then this incubation was continued with the fresh medium free from gibberellin. When, at the begining of this second incubation, DNP, KCN or chloramphenicol was added to the fresh medium or anaerobic condition was made, this α-amylase production was found to be inhibited to a considerable extent. As at this period (i.e. the first 48 hours incubation) gibberellin seems to be fully absorbed into the tissue, the authors estimated that the aerobic condition is necessary for this α-amylase production. 相似文献
12.
In this report the biokinetic parameter μmax, m and Ymax for the denitrification of a medium containing acetat as C-source and a soft coal gasification water containing volatile fatty acids as main components have been compared. An expression for a true maximum specific growth rate is proposed (μmaxw = μmax + mYmax) and it could be shown that despite different values for μmax the values for μmaxw correspond fairly well. 相似文献
13.
Large‐scale screening and characterisation of Lemna aequinoctialis and Spirodela polyrhiza strains for starch production
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C. J. Yu Y. Wang Y. Liu M. L. Li Y. D. Sun J. S. Zhao G. K. Zhou 《Plant biology (Stuttgart, Germany)》2018,20(2):357-364
- Duckweed is considered a promising feedstock for bioethanol production due to its high biomass and starch production. Selection of duckweed strains with high starch accumulation is essential for application of duckweeds to bioethanol production. Geographic differentiation had a large influence on genetic diversity of duckweeds.
- Biomass production, starch content and starch amount in geographically isolated strains of 20 Lemna aequinoctialis and Spirodela polyrhiza were calculated to evaluate their potential for bioethanol production. The influence of different collection time, culture medium and NaCl concentration on starch accumulation of the best strains were analysed.
- The results showed that biomass production, starch content and starch production of duckweeds demonstrated clonal dependency. The best strain was L. aequinoctialis 6000, with biomass production of 15.38 ± 1.47 g m?2, starch content of 28.68 ± 1.10% and starch production of 4.39 ± 0.25 g m?2. Furthermore, starch content of L. aequinoctialis 6000 was highest after 8 h of light, tap water was the best medium for starch induction, and NaCl did not induce starch accumulation.
- This study suggests duckweed biomass production and starch production demonstrate clonal dependency, indicating that extensive clonal comparisons will be required to identify the most suitable isolates for duckweed selective breeding for bioethanol.
14.
Takeji Mizunuma 《Bioscience, biotechnology, and biochemistry》2013,77(8):742-749
Studies were made on the effect of water level of culture medium on the mycelial compositions and enzyme production in Aspergillus sojae K. S. The mold was grown on the media of various water levels made of powder of defatted soybean and wheat granule. The mycelia grown on the medium of low water level produced more protease and α-amylase, consumed more oxygen, formed less ammonia, and were richer in 2 n H2SO4-soluble glycogen, 60% H2SO4-soluble carbohydrates, protein and RNA per mg dry weight than the mycelia grown on the medium of high water level. Chromatographic analyses were carried out for nucleotides, sugar phosphates and free carbohydrates in cold TCA-soluble fraction of the mycelia. 相似文献
15.
Aims: This study sought to develop a less expensive medium for growth of the polyhydroxyalkanoate-producing bacterium Rhodospirillum rubrum from the ethanol production coproduct, condensed corn solubles (CCS). Methods and Results: Small-scale trials using R. rubrum were performed in aerated or anaerobic stoppered serum bottles filled with media. The CCS (240 g l−1) achieved a maximum cell density and growth rate comparable with the defined supplemented malate-ammonium medium (mSMN) or tryptic soy broth. Microaerophilic solubles medium cultures exhibited significantly higher maximum cell densities and growth rates than did strictly anaerobic cultures; while illumination, nickel or biotin addition had no effect. Growth of R. rubrum in a pH controlled bioreactor was significantly better in CCS (240 g l−1) than in mSMN medium and supported production of 0·36% (cell dry weight) poly-(3-hydroxybutyrate-Co-3-hydroxyvalerate) after 24 h. Conclusions: A CCS medium was devised that supported R. rubrum growth for biopolymer production as effective as the defined medium. Significance and Impact of the Study: This study demonstrates that a more economical medium can be developed for biopolymer production using a low value coproduct from ethanol production. The impact is that this inexpensive solubles medium may make it more economical to produce the biopolymer on a commercial scale. 相似文献
16.
Leonora Sánchez Fausto Sánchez Pierre Christen Sergio Revah 《World journal of microbiology & biotechnology》2004,20(2):151-160
Ceratocystis fimbriata was grown in a standard liquid medium to determine the production of aroma compounds as affected by thiamine addition to the inoculum, thiamine or leucine addition to the medium, and the effect of water availability. Ethanol constituted more than half of the total volatiles production in the headspace, followed by ethyl acetate (22.6%), ethyl butyrate (10.8%), isobutanol (7.6%), amyl alcohol (1.6%), isoamyl acetate (1.5%), acetaldehyde (1.2%), ethyl propionate (0.9%), isobutyl acetate (0.4%), diacetyl (0.6%) and isoamyl alcohol (0.3%). Although significant two-way interactions were observed (P < 0.05), production of volatile compounds tended to be higher in inocula prepared with thiamine (T+) than in inocula without thiamine (T–), and in the standard medium with thiamine (SMT) as compared to the standard medium alone (SM) and the SM with leucine (SML). Also, the reduction of water activity (a
w) resulted in lower quantities of volatiles being produced. 相似文献
17.
The ability of Bacillus licheniformis strain VKM B-511 to grow and synthesize biosurfactants under both aerobic and anaerobic conditions has been demonstrated.
Yields of biosurfactants, emulsion indices and surface tension were considerably higher in culture liquor and preparations
derived from cultures grown anaerobically at a C/N ratio of 1: 24, pH 7.0, and temperature of 30°C. Biosurfactant production
by B. lichenformis also depended on concentrations of NaCl and Na2S in the medium and on water characteristics, reaching 4.58 g/l for bacteria grown anaerobically on a medium containing anolyte
fraction of water. 相似文献
18.
Although Bacillus thuringiensis and Bacillus sphaericus are being used extensively for mosquito control, the recent reports of development of resistance in insects against them prompted many workers to search for new microbial agents or their metabolites for mosquito control. This has resulted in the isolation of a new bacterial isolate Pseudomonas fluorescens Migula which is known to be toxic against larval and pupal stages of mosquitos and could be considered for further development as a biocontrol agent. But the large-scale production of this bacterium is expensive because the high cost of the medium restricts this bacterium is used in mosquito control programs. In this study, we attempted to develop a cost-effective medium, based on inexpensive, locally available raw material Soya bean (Glycine max) by using 100-L bioreactor. Biomass and pupicidal metabolite production were satisfactory after P. fluorescens was produced on both media. Results showed that the Biomass in dry weight of Soya medium was 12.7 g/L and GPS medium (conventional medium) was 11.23 g/L. The maximum pupicidal metabolite production in Soya medium was (LC50 0.24 μL/mL) and in GPS medium was (LC50 0.44 μL/mL). 相似文献
19.
Phormidium J-1, a benthic filamentous cyanobacterium, isolated from a drainage channel, was found to produce a high molecular weight polymer. This substance can flocculate bentonite particles from suspensions. At the stationary phase of growth the cells excreted this bioflocculant into the surrounding medium. Production was enhanced by reduction of the calcium content in the growth medium or by increasing its EDTA content. Above the isoelectric point (pH 3.5) the bioflocculant is negatively charged. The presence of minimal concentrations of divalent cations in the reaction mixture is required for its flocculating activity. The production of bioflocculant could be of great importance in clarification of turbid water bodies, thus allowing light penetration to the sediment/water interface. Bioflocculant production and excretion was not found in several other benthic cyanobacteria.Dedicated to Prof. Dr. H.-G. Schlegel on the occasion of his 60th birthday 相似文献
20.
An attempt was made to use cyanobacterial biomass of water bloom, groundnut shell (GNS) and dye effluent as culture medium for laccase enzyme production by Coriolus versicolor. Laccase production was found to be 10.15 ± 2.21 U/ml in the medium containing groundnut shell and cyanobacterial bloom in a ratio of 9:1 (dry weight basis) in submerged fermentation at initial pH 5.0 and 28 ± 2 °C temperature. Half life of enzyme was found to be 74 min at 60 °C. Kinetic analysis of laccase when made with substrate ABTS, Km and Vmax were found to be 0.29 mM and 9.49 μmol/min respectively. Azide and hydroxylamine were found to exert significant inhibition on thermostable laccase. Inhibitor constant (ki) for azide and hydroxylamine were 1.33 and 0.18 mM respectively. This study forms the first report on the potential application of waste water cyanobacterial bloom and dyeing effluent as a medium for laccase production by C. versicolor MTCC138. 相似文献