A novel impeller configuration to improve fungal physiology performance and energy conservation for cephalosporin C production.

Effects of impeller configuration on fungal physiology and cephalosporin C production were investigated by an industrial strain Acremonium chrysogenum in a 12 m(3) bioreactor equipped with conventional and novel impeller configuration, respectively. The cell growth and oxygen uptake rate (OUR) profiles were little affected by the impeller configurations. However, differing impeller combinations significantly affected the morphology, which in turn influenced cephalosporin C production. Under the novel impeller configuration, the production of cephalosporin C was 10% higher and an excessive amount of dispersed arthrospores was also observed. Computational fluid dynamics (CFD) simulation further revealed that poor mass and energy exchange as well as inhomogeneous environment existed in the bioreactor equipped with conventional impeller configuration. For equivalent power dissipation, the volume oxygen transfer coefficient (K(L)a) could be enhanced by 15% compared with that of conventional impeller configuration. Power consumption was dramatically decreased by 25% by using novel impeller configuration.

Production of cephalosporin C using crude glycerol in fed-batch culture of Acremonium chrysogenum M35.

In this study, cephalosporin C production by Acremonium chrysogenum M35 cultured with crude glycerol instead of rice oil and methionine was investigated. The addition of crude glycerol increased cephalosporin C production by 6-fold in shake-flask culture, and also the amount of cysteine. In fed-batch culture without methionine, crude glycerol resulted only in overall improvement in cephalosporin C production (about 700%). In addition, A. chrysogenum M35 became highly differentiated in fed-batch culture with crude glycerol, compared with the differentiation in batch culture. The results presented here suggest that crude glycerol can replace methionine and plant oil as cysteine and carbon sources during cephalosporin C production by A. chrysogenum M35.

Analysis of the relationship between growth, cephalosporin C production, and fragmentation in Acremonium chrysogenum.

Mycelial fragmentation in submerged cultures of the cephalosporin C (CPC) producing fungus Acremonium chrysogenum was characterized by image analysis. In both fed-batch and chemostat cultures, the proportion of mycelial clumps seemed to be the most sensitive morphological indicator of fragmentation. In a fed-batch fermentation culture, this declined from roughly 60% at inoculation to less than 10% after 43 h. Subsequent additions of glucose resulted in a sharp increase back to near the initial value, an increase that reversed itself a few hours after glucose exhaustion. Meanwhile CPC production continued to decline steadily. On the other hand, the addition of soybean oil enhanced CPC production, but had no significant effect on the morphology. Although it may sometimes appear that morphology and productivity are related in batch or fed-batch cultures, this study suggests that this is because both respond simultaneously to more fundamental physiological changes, dependent on the availability of carbon. In circumstances, such as supplementary carbon source addition, the relationship is lost. Chemostat cultures supported this belief, as CPC-production rates were hardly affected by the specific growth rate, but the morphology showed significant differences, i.e., lower dilution rates resulted in a lower proportion of clumps and in smaller clumps.

The role of the alternative respiratory pathway in the stimulation of cephalosporin C formation by soybean oil in Acremonium chrysogenum.

Addition of soybean oil to Acremonium chrysogenum cultures growing on sugars doubled the specific production of cephalosporin C during the idiophase of growth. While the addition of soybean oil had no effect on the total rate of respiration, the respiration that proceeded via the alternative, cyanide-insensitive pathway exhibited a more than twofold increase. Addition of soybean oil also stimulated the formation of isocitrate lyase activities. Inhibition of oxidative metabolism of one of the products of isocitrate lyase (succinate) by thenoyltrifluoroacetone completely inhibited the alternative respiratory pathway. The role of soybean-oil-stimulated alternative respiration in the stimulation of cephalosporin C production and the role of isocitrate lyase are discussed.

Effect of glyphosate on fungal population, respiration and the decay of some organic matters in Egyptian soil.

Glyphosate (Roundup), when applied to the soil usually did not exert any significant effect on the total count of soil fungi after all periods of the experiment except after 6 and 10 weeks where the count was inhibited by the two doses used (1.84, 9.2 mg active ingredient/kg dry soil). When the herbicide was incorporated into the agar medium the count of total fungi, Acremonium strictum and Aspergillus fumigatus was significantly increased by the two doses used and of Penicillium glabrum by the high dose only. However, P. funiculosum was completely eliminated by the high dose. Oxygen consumption in soil treated with glyphosate was significantly inhibited by the high dose after 2 weeks and by the two doses after 6, 8 and 10 weeks. Glyphosate exerted two significant effects of stimulation and inhibition on the rate of the decay of stem segments of three plants at certain treatments of dose and time.

The effects of endophyte-infected tall fescue consumption and use of a dopamine antagonist on intake, digestibility, body temperature, and blood constituents in sheep.

Two experiments were conducted with lambs that consumed endophyte-infected (Acremonium coenophialum) tall fescue diets under elevated temperature and humidity and supplemented with the dopamine antagonist metoclopramide (M). In Exp. 1, 12 ruminally cannulated wethers (average weight 49 kg) were allotted by weight to either an endophyte-free diet (E-) or endophyte-infected diet (E+; 1,170 ppb of ergovaline), or E+ supplemented with M (15 mg/kg of lamb BW; E+M). Ad libitum DM intake and digestibility were lower (P < .05) for E+ than for E- diet. Supplementation of E+ with M increased (P < .05) DM intake by 27.6% but did not change DM digestibility. Body temperature increased (P < .05) when lambs consumed E+ and was further increased when M was supplemented. For Exp. 2, 19 wether lambs (average weight 24 kg) were allotted to treatments to evaluate the effects of endophyte consumption (0 vs 2,430 ppb of ergovaline) and supplementation with M (0 vs 20 mg/kg BW). An interaction (P < .05) of main effects was measured for DM intake. Lambs that consumed E+M consumed more DM than did lambs fed only E+, but lambs offered the E- diet and supplemented with M did not increase DM consumption. Diet DM digestibility was not different among treatments. Skin vaporization decreased (P < .05) due to E+ consumption and M supplementation. The concentration of prolactin in plasma was decreased (P < .05) by consumption of E+ (8 vs 136 ng/mL) and did not increase due to M supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of alkaloids and seed extracts of endophyte-infected tall fescue on prolactin secretion in an in vitro rat pituitary perfusion system.

The objective of this research was to measure the effects of endophyte-infected tall fescue seed extract and various alkaloids associated with the endophyte on in vitro prolactin secretion by rat hemipituitaries. Rat anterior pituitaries (AP) were dissected into halves and placed in temperature-controlled culture chambers (37 degrees C). The tissue was perfused with culture media at a flow rate of 12 mL/h. After perfusion for at least 90 min with control media, AP halves were exposed to their respective treatments for 15 min before they were returned to the control media. The treatments for Exp. 1 were .01 micrograms of alpha-ergocryptine/mL of culture medium, .01 microgram of ergonovine/mL of culture medium, .01 gram-equivalents of endophyte-infected tall fescue seed/mL of culture medium, and .01 gram-equivalents of endophyte free tall fescue seed/mL of culture medium. Treatments for Exp. 2 consisted of 10(-4), 10(-6), and 10(-8) M concentrations of perloline, N-formyl loline, N-acetyl loline, N-methyl loline, and alpha-ergocryptine. alpha-Ergocryptine suppressed (P less than .10) prolactin secretion in both experiments. Ergonovine and perloline both stimulated (P less than .10) prolactin secretion. The loline alkaloids (N-formyl loline, N-acetyl loline, N-methyl loline) had no effect on prolactin secretion. The endophyte-infected seed extract treatment suppressed (P less than .10) prolactin secretion. The endophyte-free seed extract treatment had no effect on prolactin secretion. In Exp. 2, prolactin secretion from AP responded to alpha-ergocryptine treatment in a dose-dependent fashion.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of hydrated sodium calcium aluminosilicate on fescue toxicosis and mineral absorption.

The possibility of supplementing livestock diets with an aluminosilicate to protect them from fescue toxicosis was investigated. An in vitro study showed that hydrated sodium calcium aluminosilicate (HSCAS) removed greater than 90% of the ergotamine from aqueous solutions at pH 7.8 or lower, indicating a high affinity of ergotamine for HSCAS in vitro. Rats fed diets containing tall fescue seed infested (E+) with the endophytic fungus Acremonium coenophialum had lower (P less than .05) feed intakes and weight gains than did rats fed diets containing uninfested (E-) tall fescue seed. When feed intake by rats fed the E- seed diet was limited to that of rats fed the E+ seed diet, weight gains did not differ, but testes weights and serum prolactin (PRL) concentrations were lower (P less than .05 and .10, respectively) in rats receiving E+ seed. Supplementing E+ seed diets with HSCAS did not eliminate effects of E+ seed on intake, PRL, or testes weights. Sheep fed E+ tall fescue hay had higher (P less than .05) rectal temperatures than did sheep fed an equal amount of E- tall fescue hay, but OM and N digestion coefficients did not differ between the two hays. Supplementing E+ hay diets with HSCAS did not eliminate the effect of E+ hay on rectal temperatures. Addition of 2% HSCAS to tall fescue hay diets did not affect apparent absorption by sheep of OM, N, Ca, P, Na, K, or Cu, but it reduced (P less than .05) the apparent absorption of Mg, Mn, and Zn.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy and protected protein supplements to lambs on endophyte-infected tall fescue pasture.

The effect of supplements on intake, digestibility, N retention, ADG and blood and body composition of growing lambs fed cut herbage or grazing KY 31 tall fescue (Festuca arundinacea Schreb.) pastures at two levels of N fertilization (92 and 318 kg/ha) was determined. Supplements were corn (C), corn with soybean meal (U-SBM) and corn with heat-treated SBM (H-SBM). Metabolism trials were run at three growth stages in the 1st yr with 24 lambs. Although all supplements increased total DMI and DM digestibility, they decreased NDF digestibility relative to grass (G), with no difference between supplements; C depressed apparent CP digestibility. Nitrogen retention increased from -2.5 g/d on G to -.4 g/d on C and 3.2 and 4.1 g/d on U-SBM and H-SBM, respectively, for combined periods and N rates. Blood urea N (BUN) concentrations differed (P less than .01) in the following order: G greater than U-SBM greater than H-SBM greater than C. In the 2nd yr, lambs (n = 64) grazed fescue pastures at the same N fertilizer rates and were given the same supplements. Gains were not different (P less than .05) on low-N (LN) and high-N (HN) pastures. Seasonal ADG were 80, 115, 122 and 130 g/d for G, C, U-SBM and H-SBM treatments, respectively, with no difference (P less than .05) between U-SBM and H-SBM. At slaughter, lambs from G had lower dressing percentages (P less than .05) and fat content (P less than .01) than lambs on C, U-SBM and H-SBM treatments, with no differences between supplements. Results indicated a better performance of growing lambs on fescue with both energy and protein supplements. Response to protected vs unprotected protein was small.

[Effect of the quality of fat substrate on the dynamics of fatty acid utilization during biosynthesis of cephalosporin C]. / Izuchenie vliianiia kachestva zhirovogo substrata na dinamiku potrebleniia zhirnykh kislot v protsesse biosinteza tsefalosporina C.

Influence of the quality of the fats used on their utilization in the process of cephalosporin C fermentation and accumulation was studied. A decrease in the level of all the fractions of the fatty acids was observed during the fermentation process. The antibiotic yield with the use of oxidized fats was lower. Treatment of the fats with gaseous nitrogen prevented their oxidation. It was supposed that the decreased yields of the antibiotic were associated with the influence of the oxidized fats on the biosynthetic processes.

Neuroendocrine measurements in steers grazed on endophyte-infected fescue.

Dopamine (DA), serotonin (5HT) and selected precursors and metabolites were measured in the anterior pituitary gland, hypothalamus and pineal gland, along with serum prolactin (PRL) and average daily gains (ADG), in steers (n = 6/group) grazing endophyte (Acremonium coenophialum)-infected and noninfected fescue (Festuca arundinacea Schreb). Paddocks (two/treatment) were designated 100F and 0F (100 and 0% infection, respectively). After 6 wk, three animals from one of the 100F paddocks were exchanged with three animals from one of the 0F paddocks, yielding 0F, 100F/0F, 0F/100F and 100F groups (n = 3). Compared to 0F steers, 100F steers had reduced serum PRL (9.23 vs 32.55 ng/ml, P less than or equal to .0001) and trial ADG (-.07 vs .28 kg, P less than or equal to .0002) but increased pituitary dihydroxyphenylacetic acid (DOPAC, a major metabolite of DA; 108 vs 59 ng/g, P less than or equal to .02) and 5-hydroxyindoleacetic acid (5HIAA, a major metabolite of 5HT; 265 vs 148 ng/g, P less than or equal to .04). Pituitary 5HIAA was greater in the steers rotated from the 0F to 100F paddocks than in steers maintained on the 0F paddocks (296 vs 148 ng/g, P less than or equal to .04). In addition pineal 5-hydroxytryptophan (5HTP, a precursor of 5HT) was increased (502 vs 280 ng/ml; P less than .08), whereas 5-methoxyindoleacetic acid (MIAA, a major metabolite of 5HIAA) and the 5HT/5HTP ratio were reduced (P less than .07) in 100F vs 0F steers. No differences among the treatment groups were observed in hypothalamic neurotransmitter and metabolite concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Thiamin supplementation and the ingestive behavior of beef cattle grazing endophyte-infected tall fescue.

Livestock grazing endophyte (Acremonium coenophialum Morgan-Jones and Gams)-infected tall fescue (Festuca arundinacea Schreb.) perform poorly due to tall fescue toxicosis, especially when animals are under heat stress. In order to determine whether thiamin promotes recovery from tall fescue toxicosis, 1 or 0 g of thiamin per day, as mononitrate, was fed orally to adult Angus (Bos taurus) cows (380 +/- 8 kg) grazing either tall fescue pasture with and without endophyte or alfalfa (Medicago sativa L.). A tethered grazing system employing a split-plot design was used to estimate intake and components of ingestive behavior. No significant differences attributable to thiamin supplements were seen in rates of intake and biting, grazing time and intake per bite when cows grazed endophyte-infected tall fescue during the first 4 d of exposure. When cows grazed endophyte-infected (greater than 95%) tall fescue with 2,091 micrograms/g loline alkaloids after 4 d of exposure, the untreated animals ingested herbage dry matter (DM) at 1.19 kg/h, whereas the cows receiving thiamin ate 1.57 kg/h (P less than .05). Cattle achieved these rates of DM intake by forming bites of 1.0 and 1.2 g DM at 24 and 26 bites/min when treated with 0 and 1 g of thiamin per day, respectively. Thiamin supplements had no effect on ingestive behavior of cows grazing endophyte-free tall fescue or alfalfa after exposure to these forages for 4 d. Responses to thiamin generally were greater when cattle grazing endophyte-infected tall fescue were exposed to heat stress. Oral thiamin supplementation may alleviate tall fescue toxicosis of beef cattle during warm weather.