Effect of certain substances on the biosynthesis of cellulase by the thermotolerant fungus, Aspergillus terreus I7P]

Different substrates which activate the enzyme synthesis were added to the natural medium for Asp. terreus 17P cultivation where wheat straw was used as the carbon source. Tween-80, oleic acid, sodium salts of ascorbic and acetic acid, potassium salt of indolyl acetic acid, sunflower seed oil, coreander seed oil, soapstock and sugars--glucose, sucrose, fructose and lactose were tested. An addition of Tween-80 at a concentration of 0.1% to the cultivation medium showed the most favourable effect on the synthesis of cellulolytic enzymes. Milk serum and cheese serum, malt shoots and protein-vitamin complex were examined as a substitute for corn extract. Dry malt shoots added at a concentration of 1.5% was a good substitute for corn extract.     

Effect of various factors on the biosynthesis of piscarinines,secondary metabolites of the fungus <Emphasis Type="Italic">Penicillium piscarium</Emphasis> Westling

Piscarinines A and B were synthesized most actively during the surface cultivation of the fungus Penicillium piscarium in a complex medium (5.5 mg/l). Under conditions of submerged cultivation in a mineral medium, the yield of piscarinines was two times lower. An increase in the inoculum quantity of conidia treated with Tween-80 increased the culture productivity. The biosynthesis of the alkaloid was completely suppressed when mannitol was replaced with glucose or when zinc, iron, or copper ions were added to the culture medium. The metabolites were active against the prostate cancer cell line LNCAP (IC₅₀ were 2.195 and 1.914 μg/ml for piscarinines A and B, respectively).     

Microthrix parvicella, a filamentous bacterium from activated sludge: growth on Tween 80 as carbon and energy source

Microthrix parvicella, cultivated in a medium with Tween 80 and Casamino acids, utilized only the oleic acid moiety of Tween 80 as carbon and energy source. The cell yield from Tween 80 was about 0.32 g dry weight of cells per g of Tween 80 consumed. As only the oleic acid moiety of Tween 80 was utilized, the cell yield from oleic acid was 1.3 g dry weight of cells per g oleic acid consumed. The amount of carbon produced as CO2 was less than 30% of the oleic acid-carbon and this low value was in agreement with the high cell yield. In batch culture M. parvicella stored large amounts of lipid material during the early growth phase. The fatty acids of the lipid globules were similar to the fatty acids supplied as carbon source. The percentage composition of the biomass changed to give C/N percentage ratios of about 15 during the early growth phase due to the high concentration of internal lipids and the low concentration of protein. The growth rate in batch culture was about 0.016 h-1 but was affected by the concentration of Casamino acids in the medium.     

Production of Tricarboxylic Acid Anhydrides from Fatty Acids by a Lipase-producing Strain of Pseudomonas cepacia

A lipase-producing strain of Pseudomonas cepacia isolated from a soil sample was found to produce five compounds when oleic acid was added to the culture medium as lipase inducer. The five compounds were isolated by solvent extraction, silicagel column chromatography and preparative HPLC, and their structural elucidation was performed by mass spectrometry, and infrared and nuclear magnetic resonance spectroscopies. The products were identified as dec-3-ene-1,3,4-tricarboxylic acid 3,4-anhydride (product 1 ), undec-3-ene-1,3,4-tricarboxylic acid 3,4-anhydride (product 2 ), dodec-3-ene-I,3,4-tricarboxylic acid 3,4-anhydride (product 3 ), dodec-3,8-diene-1,3,4-tricarboxylic acid 3,4-anhydride (product 4 ) and dodec-3,6-diene-I,3,4-tricarboxylic acid 3,4-anhydride (product 5 ). Accumulation of these compounds in the culture medium started after oleic acid consumption and followed a pattern similar to that found for cell growth and for lipase production. The five compounds were radioactively labeled when [U- 14 C]oleic acid was supplied to the culture medium, thus showing that they were produced by transformation of the acid. When isolated from cultures containing [1,2- 13 C]acetic acid and oleic acid as the sole sources of carbon, the compounds showed to contain the 13 C isotope only in the first five atoms of carbon of the molecule. Several long chain fatty acids also acted as precursors of these compounds, with maximal yields for chain lengths between 11 and 18 atoms of carbon. None of the five compounds acted as lipase inducer when added to the culture medium instead of oleic acid. The compounds showed moderate antibacterial and antifungal activities when tested in solid media bioassays.     

Production of Tricarboxylic Acid Anhydrides from Fatty Acids by a Lipase-producing Strain of Pseudomonas cepacia

A lipase-producing strain of Pseudomonas cepacia isolated from a soil sample was found to produce five compounds when oleic acid was added to the culture medium as lipase inducer. The five compounds were isolated by solvent extraction, silicagel column chromatography and preparative HPLC, and their structural elucidation was performed by mass spectrometry, and infrared and nuclear magnetic resonance spectroscopies. The products were identified as dec-3-ene-1,3,4-tricarboxylic acid 3,4-anhydride (product 1 ), undec-3-ene-1,3,4-tricarboxylic acid 3,4-anhydride (product 2 ), dodec-3-ene-I,3,4-tricarboxylic acid 3,4-anhydride (product 3 ), dodec-3,8-diene-1,3,4-tricarboxylic acid 3,4-anhydride (product 4 ) and dodec-3,6-diene-I,3,4-tricarboxylic acid 3,4-anhydride (product 5 ). Accumulation of these compounds in the culture medium started after oleic acid consumption and followed a pattern similar to that found for cell growth and for lipase production. The five compounds were radioactively labeled when [U- 14 C]oleic acid was supplied to the culture medium, thus showing that they were produced by transformation of the acid. When isolated from cultures containing [1,2- 13 C]acetic acid and oleic acid as the sole sources of carbon, the compounds showed to contain the 13 C isotope only in the first five atoms of carbon of the molecule. Several long chain fatty acids also acted as precursors of these compounds, with maximal yields for chain lengths between 11 and 18 atoms of carbon. None of the five compounds acted as lipase inducer when added to the culture medium instead of oleic acid. The compounds showed moderate antibacterial and antifungal activities when tested in solid media bioassays.     

重组巴斯德毕赤酵母发酵生产内切几丁质酶的培养条件优化

探讨重组巴斯德毕赤酵母发酵生产内切几丁质酶的最适培养条件,以期获得最佳的内切几丁质酶活力。以内切几丁质酶活力为指标,通过部分因子试验设计以及响应面法优化确定重组巴斯德毕赤酵母高产内切几丁质酶的最适培养条件。部分因子试验设计筛选的影响重组巴斯德毕赤酵母高产内切几丁质酶的3个关键因子为甲醇、油酸和吐温-80。响应面法优化的上述3个关键因子的最佳浓度分别为0.71%、0.086%和0.31%。重组巴斯德毕赤酵母发酵生产内切几丁质酶的最适培养条件为：酵母膏1%、酵母氮碱（YNB）1.34%、蛋白胨2%、甲醇0.71%、油酸0.086%、吐温-80 0.31%、PTM₁ 0.8%、pH 6.0。在上述培养条件下,重组巴斯德毕赤酵母产内切几丁质酶的活力高达30.92U/mL。与未优化前相比,酶活力提高了1.44倍。研究结果为内切几丁质酶的产业化生产和应用奠定了良好基础。     

Assessment of tissue damaging effects of mixed micellar absorption enhancers on the intestinal mucosa of common carp (Cyprinus carpio), African catfish (Clarias gariepinus) and rainbow trout (Oncorhynchus mykiss) as a consequence of enhanced intestinal absorption of sGnRH-a

Non-ionic surfactant–polyoxyethylene sorbitan monooleate (Tween-80) and oleic acid are food and pharmaceutical ingredients for oral and parenteral delivery and generally regarded as safe (GRAS). They have the potential as an intestinal absorption enhancer for the development of oral drug delivery systems. However, their safety in terms of mucosal integrity has yet to be evaluated. Therefore, the purpose of the present work was to study the tissue damaging effects of Tween-80, oleic acid and of their mixed micellar formulation (oleic acid + Tween-80). This was investigated at 2 h and 24 h after rectal delivery and compared with the topical effect of polyoxyethylene 9 lauryl ether (Polydocanol). The same experiment was carried out on three species with distinct feeding habits: the common carp, Cyprinus carpio (L.); the African catfish, Clarias gariepinus (Burchell); and the rainbow trout, Oncorhynchus mykiss (Walb.). Based on the findings of this study it was concluded that Tween-80 (4%), or its mixed micelle with oleic acid (0.6%) can be considered as a safe formulation, inducing only a moderate alteration of the intestinal mucosa, comparable to the effect of an isotonic saline. By contrast, in the three species, the same dose of Polydocanol, or of its mixed micelle with oleic acid, induced severe tissue damage of the intestinal mucosa, still present after 24 h. Mixed micelles of oleic acid with Tween-80 were also demonstrated as increasing the intestinal absorption of the salmon gonadotropin releasing hormone analogue (sGnRH-a) in catfish, C. gariepinus , and consequently stimulating GtH II secretion. This effect was compared with the action of other drugs considered as intestinal absorption enhancers.     

Effect of the growth phase and nutrient medium on the survival of lyophilized cells of Pseudomonas denitrificans]

The influence of the growth phase and cultivation condition of Pseudomonas denitrificans on the survival of the culture after lyophilization was examined. The culture removed for drying in the stationary phase showed the highest resistance to lyophilization. The cells dried at the beginning of exponential phase displayed enhanced sensitivity to lyophilization. Addition to the cultivation medium (meat-peptone broth) of Tween-80 (0.25%) caused an increase of proteins, lipids and polysaccharides in cells and an enhancement of their telerance to lyophilization.     

吐温-80对野葛毛状根生长及异黄酮含量的影响

将不同浓度的吐温-80添加到野葛毛状根悬浮培养液中,研究在一定的作用时间内其对毛状根生长及次生代谢物合成与分泌的影响。结果表明,采用2％浓度处理较为适宜,不仅可以提高毛状根内葛根素的含量,而且有利于培养液中葛根素、大豆甙元及总异黄酮的积累,与对照相比,其含量可分别提高24．2％、50％和46．7％。在该浓度下连续处理毛状根72h后,发现毛状根仍生长旺盛,其生长量已是对照的1．5倍。但不同时间的连续处理对毛状根及培养液中几种异黄酮物质的积累与释放作用不同,其中以处理48h最有利于培养液中总异黄酮的累积,其含量是毛状根中的38倍。     

Stability of Lactic Acid Bacteria to Freezing as Related to Their Fatty Acid Composition

The viability of Streptococcus lactis and Lactobacillus sp. A-12 after freezing at -17°C for 48 h was better preserved when the cells were grown in medium supplemented with oleic acid or Tween 80 (polyoxyethylene sorbitan monooleate). A pronounced change in the cellular fatty acid composition was noted when the bacteria were grown in the presence of Tween 80. In S. lactis the ratio of unsaturated to saturated fatty acids increased from 1.18 to 2.55 and in Lactobacillus sp. A-12 it increased from 0.85 to 1.67 when Tween 80 was added to the growth medium. The antibiotic cerulenin markedly inhibited the growth of lactic acid bacteria in tomato juice (TJ) medium but had almost no effect on the growth of the bacteria in TJ medium containing Tween 80 (or oleic acid). The antibiotic inhibited markedly the incorporation of [1-¹⁴C]acetate but had no inhibitory effect on the incorporation of exogenous [1-¹⁴C]oleate (or [1-¹⁴C]palmitate) into the lipid fractions of lactic acid bacteria. Thus, the fatty acid composition of lactic acid bacteria, inhibited by the antibiotic cerulenin, can be modulated by exogenously added oleic acid (or Tween 80) without the concurrent endogenous fatty acid synthesis from acetate. The data obtained suggest that cerulenin inhibits neither cyclopropane fatty acid synthesis nor elongation of fatty acid acyl intermediates. The radioactivity of cells grown in the presence of [1-¹⁴C]oleate and cerulenin was associated mainly with cyclopropane Δ19:0, 20:0 + 20:1, and 21:0 acids. As a consequence, cerulenin caused a decrease in the ratio of unsaturated to saturated fatty acids in lactic acid bacteria as compared with cells grown in TJ medium plus Tween 80 but without cerulenin. Cerulenin caused a decrease in the viability of S. lactis and Lactobacillus sp. A-12 after freezing at -17°C for 48 h only when Tween 80 was present in the growth medium. We conclude that the sensitivity of lactic acid bacteria to damage from freezing can be correlated with specific alterations in the cellular fatty acids.     

Cyanide-resistant oxygen consumption of the lysine-synthesizing bacteria Brevibacterium flavum 22 LD

The growth of the culture and biosynthesis of lysin were studied in Brevibacterium flavum 22 LD cultivated in a chemostat. During cultivation the flow rate of the medium and the partial pressure of oxygen dissolved in the medium were varied. The maximum yield of lysine, calculated in respect to the sucrose consumed, (Yp = g lysine . HCl/g sucrose) was registered when cyanide-resistant oxygen consumption was the least. A change of the cultivation conditions provoked a decrease of Yp value and a simultaneous increase in cyanide-resistant respiration. Possible reasons of the phenomena observed are discussed.     

Difference in growth factor requirements of rat 3Y1 cells among growth in mass culture, clonal growth in low density culture, and stimulation to enter S phase in resting culture

A semiserum-free medium was developed for monolayer culture of rat 3Y1 fibroblastic cells. The main components of the developed medium added to Dulbecco's modified Eagle's medium (DMEM) were insulin, transferrin, epidermal growth factor, poly-D-lysine, bovine albumin, oleic acid, and bovine alpha-globulin. In this medium, 3Y1 cells grew in mass culture at much the same rate as in DMEM supplemented with 10% fetal bovine serum (FBS), and colonies, albeit of smaller sizes, did form. Virally transformed derivatives of 3Y1 (simian virus 40-3Y1, polyoma virus-3Y1 and adenovirus type 12-3Y1) also formed colonies in the semiserum-free medium. When trypsinized 3Y1 cells were seeded with the medium lacking alpha-globulin, neither growth in the mass culture nor clonal growth in the low density culture (clonal growth) occurred. In this case, cell spreading was inhibited by albumin, and this inhibition was overcome by adding alpha-globulin or treating dishes with serum. When albumin was excluded from the semiserum-free medium, clonal growth did not occur, whereas growth in mass culture and stimulation of DNA synthesis in the resting mass culture (stimulation of DNA synthesis) were not so drastically affected. When oleic acid was removed, growth in mass culture was inhibited considerably, but no considerable effect was seen on clonal growth or on stimulation of DNA synthesis. In the absence of insulin, stimulation of DNA synthesis was inhibited more markedly than when other components were removed, but such was not the case with growth in mass culture and clonal growth.     

Influence of some oils and surfactants on ligniolytic activity,growth and lipid fatty acids of Phanerochaete chrysosporium

Summary Ligninase production by Phanerochaete chrysosporium MZKIBK-B 186 was increased when the culture medium was supplemented with an emulsion of oleic acid. Addition of linseed oil enhanced fungal biomass synthesis. Under the growth conditions used in our tests, the fungus was capable of accumulating fatty acids from the culture medium into cell lipids. Addition of oleic acid, Tween 80, or 3-[(cholamidopropyl)-dimethylammonio]-1-propanesulphonate (CHAPS), which are known to increase ligninase production by fungi, resulted in oleic acid enrichment of whole cell and polar lipids. Offprint requests to: D. Le相似文献   

Difference in growth factor requirements of rat 3Y1 cells among growth in mass culture,clonal growth in low density culture,and stimulation to enter S phase in resting culture

Summary A semiserum-free medium was developed for monolayer culture of rat 3Y1 fibroblastic cells. The main components of the developed medium added to Dulbecco's modified Eagle's medium (DMEM) were insulin transferrin epidermal growth factor, poly-d-lysine, bovine albumin, oleic acid, and bovine α-globulin. In this medium, 3Y1 cells grew in mass culture at much the same rate as in DMEM supplemented with 10% fetat bovine serum (FBS), and colonies, albeit of smaller sizes, diddform. Virally transformed derivatives of 3Y1 (simian virus 40-3Y1, polyoma virus-3Y1 and adenovirus type 12-3Y1) also formed colonies in the semiserum-free medium. When trypsinized 3Y1 cells were seeded with the medium lacking α-globulin, neither growth in the mass culture nor clonal growth in the low density culture (clonal growth) occurred. In this case, cell spreading was inhibited by albumin, and this inhibition was overcome by adding α-globulin or treating dishes with serum. When albumin was excluded from the semiserum-free medium, clonal growth did not occur, whereas growth in mass culture and stimulation of DNA synthesis in the resting mass culture (stimulation of DNA synthesis) were not so drastically affected. When oleic acid was removed, growth in mass culture was inhibited considerably, but no considerable effect was seen on clonal growth or on stimulation of DNA synthesis. In the absence of insulin, stimulation of DNA synthesis was inhibited more markedly than when other components were removed, but such was not the case with growth in mass culture and clonal growth.     

The effect of surfactants on the phytase production and the reduction of the phytic acid content in canola meal byAspergillus carbonarius during a solid state fermentation process

Summary During the growth of A. carbonarius, the rates of biomass growth, phytase production and phytic acid content reduction in canola meal media during solid state fermentation were higher in the presence of Na-oleate or Tween-80 than in the control medium which was not supplemented with these surfactants. Addition of Triton X-100 had a negative effect on the studied processes.The optimum concentration of Na-oleate in solid state culture media was 1%.     

Effect of aeration on lysine biosynthesis in nutrient media with different concentrations of components]

The lysine synthesis by the culture M. glutamicus T-3 on nutrient media with varying molasses concentrations was studied during cultivation under different aeration conditions. With an increase in the nutrient concentration the relationship between the lysine yield and aeration rate became very manifest. An elevation of aeration (Kv) from 1.2 to 6.3 g O2 1/hr increased the yield of lysine in the 15, 20 and 28% molasses medium by 3, 6 and 11 times, respectively. A decline in aeration decreased the biomass yield and increased the content of lactic acid and alanine in the culture liquid (to 19 and 4 g/l, respectively). The rate of respiration of the culture in the filtrate of the culture liquid measured in the Warburg apparatus depended on the cell age and molasses concentration in the nutrient medium and not on the aeration rate.     

Phospholipid and fatty acid enrichment of Phanerochaete chrysosporium INA-12 in relation to ligninase production

Summary Ligninase activity of Phanerochaete chrysosporium INA-12 was increased when vegetable oils emulsified with sorbitan polyoxyethylene monooleate (Tween 80) were added to growth medium. Maximal enzyme yield was 22.0 nkat·ml^-1 in olive oil cultures after 4 days incubation. P. chrysosporium INA-12 was also able to utilize tall oil fatty acids for ligninase synthesis. An extracellular lipase activity was detected during the primary phase of growth in culture containing vegetable oils. On the other hand, ligninase production was 1.5-fold enhanced when olive oil cultures were supplemented with soybean asolectin as a phospholipid source. In cultures supplied with olive oil plus asolectin, P. chrysosporium INA-12 mycelium exhibited a preferential enrichment of oleic acid (C18:1), phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) as compared to lipid-free medium. PC and LPC enrichment was associated with an increased ratio of saturated versus unsaturated fatty acids of phospholipids.     

Influence of cytokinins on growth of Phycomyces blakesleeanus and on the activities of the glyoxylate cycle enzymes isocitrate lyase and malate synthase

Treatment of the 1 + strain of Phycomyces blakesleeanus Bgff. with various cytokinins resulted in a stimulation of growth. The magnitude of growth stimulation depended on both the structure of the hormone used and the carbon source in the culture medium. Most of the cytokinin derivatives were active effect in glucose and oleic acid cultures. Benzyladenine (BA) and benzyladenosine stimulated the fungal growth only when oleic acid was the sole carbon source, while they had no effect in glucose cultures within the tested range of concentrations. [¹⁴C]-BA was accumulated by the mycelium of oleic acid cultures. Therefore, differences in BA uptake between glucose and oleic acid cultures could account mainly for the specific growth-promoting effect of BA. In oleic acid cultures isocitrate lyase (EC 4.1.3.1) and malate synthase (EC 4.1.3.2) activities were enhanced by 40 and 34%, respectively, in the presence of BA. A time course of the hormone effect suggests that BA is not involved in induction, but in the regulation of the mentioned enzymes in Phycocmyces. In contrast, acetate when presented as the sole carbon source or after addition to a glucose culture medium, induced isocitrate lyase activity. This enzyme induction was prevented by simultaneous addition of cycloheximide.     

Growth yield increase and ATP formation linked to succinate decarboxylation in Veillonella parvula

Veillonella parvula strain 259 (=DSM 2007) was able to grow on a mineral salts medium supplemented with (per litre) 1 g yeast extract, 1 g Tween-80, and 3 mg putrescine. 2 HCl, with 6 mM thioglycolate as reductant and lactate as growth substrate. Succinate did not serve as a growth substrate, but when added in conjunction with lactate, it was decarboxylated to propionate and resulted in a measurable increase in growth yield, corresponding to the formation of 2.4 g cell dry mass per mol succinate. A growth yield increase linked to succinate metabolism occurred only while lactate was also being metabolised. Experiments with cell suspensions showed that succinate decarboxylating activity was constitutive. Addition of succinate produced clear increases in cellular ATP levels in ATP-depleted washed cells.     

Physiology of Saccharomyces cerevisiae in anaerobic glucose-limited chemostat cultures

The physiology of Saccharomyces cerevisiae CBS 8066 was studied in anaerobic glucose-limited chemostat cultures in a mineral medium supplemented with ergosterol and Tween 80. The organism had a mu max of 0.31 h-1 and a Ks for glucose of 0.55 mM. At a dilution rate of 0.10 h-1, a maximal yield of 0.10 g biomass (g glucose)-1 was observed. The yield steadily declined with increasing dilution rates, so a maintenance coefficient for anaerobic growth could not be estimated At a dilution rate of 0.10 h-1, the yield of the S. cerevisiae strain H1022 was considerably higher than for CBS 8066, despite a similar cell composition. The major difference between the two yeast strains was that S. cerevisiae H1022 did not produce acetate, suggesting that the observed difference in cell yield may be ascribed to an uncoupling effect of acetic acid. The absence of acetate formation in H1022 correlated with a relatively high level of acetyl-CoA synthetase. The uncoupling effect of weak acids on anaerobic growth was confirmed in experiments in which a weak acid (acetate or propionate) was added to the medium feed. This resulted in a reduction in yield and an increase in specific ethanol production. Both yeasts required approximately 35 mg oleic acid (g biomass)-1 for optimal growth. Lower or higher concentrations of this fatty acid, supplied as Tween 80, resulted in uncoupling of dissimilatory and assimilatory processes.