Production process in <Emphasis Type="Italic">Salicornia europaea</Emphasis> plants as a prospective phototrophic constituent in bioregenerative life support systems

Plant productivity of a common glasswort Salicornia europaea L. was investigated in relation to the type of nitrogen nutrition and as a function of macronutrient concentrations mimicking the mineral composition of human urine. The source of nutrient nitrogen had no substantial effect on productivity of Salicornia europaea. In plants grown on media with amide as a nitrogen source, the content of nitrogenous substances, including glutamic and aspartic amino acids, was higher than in plants grown with nitrate. In plants grown on media with mineral composition analogous to that of human urine, the shoots accumulated Na and K in almost equally high amounts, on the background of high and nearly equal Na and K concentrations in the nutrient media.     

Chemical composition of a preparation of the cell walls of Corynebacterium diphtheriae

The chemical characteristics of 6 batches of the preparation, obtained from the cell wall of C. diphtheriae grown in liquid and solid culture media, with respect to their content of nitrogen, hexoses, pentoses, total amino sugars, lipids and to the possible admixture of nucleic acids are presented. From the results of the chemical analysis of these batches their standardization according to the ratio of total amino sugars and pentoses to total nitrogen in C. diphtheriae cell-wall preparation is proposed.     

Submerged culture conidial germination and conidiation of the bioherbicideColletotrichum truncatum are influenced by the amino acid composition of the medium

Summary Submerged culture experiments were conducted to determine the optimal nitrogen source for rapidly producing conidia of the bioherbicide,Colletotrichum truncatum. Germination ofC. truncatum conidial inocula in submerged culture occurred most rapidly (>95% in 6 h) in media provided with a complete complement of amino acids. When (NH₄)₂SO₄, urea, or individual amino acids were provided as the sole nitrogen source, conidial germination was less than 20% after 6 h incubation. Conidia production was delayed inC. truncatum cultures grown in media with urea or individual amino acids as nitrogen sources compared to cultures supplied with Casamino acids or complete synthetic amino acid nitrogen sources. The use of methionine, lysine, tryptophan, isoleucine, leucine or cysteine as a sole nitrogen source severely inhibitedC. truncatum conidia production. Media with synthetic amino acid mixtures less these inhibitory amino acids produced significantly higher conidia yields compared to media with amino acid mixtures containing these amino acids. When various amounts of each individual inhibitory amino acid were added to media which contained amino acid mixtures, cysteine and methionine were shown to be most effective in reducing conidiation. An optimal nitrogen source forC. truncatum conidiation in submerged culture should contain a complete mixture of amino acids with low levels of cysteine, methionine, leucine, isoleucine, lysine and tryptophan for rapid conidiation and optimal conidia yield.The mention of firm names or trade products does not imply that they are endorsed or recommended by the US Department of Agriculture over other firms or similar products not mentioned.     

Impact of nitrogen assimilation on regulation of antibiotic production in Streptomyces hygroscopicus 155

The enzymes of the assimilation pathways in cultures of S. hygroscopicus grown in the presence of various nitrogen sources were investigated. No assimilation activity of glutamate dehydrogenase (GDH) was observed. Activities of alanine dehydrogenase (ADH), GDH, glutamine: 2-oxoglutarate aminotransferase (GOGAT) and glutamate synthetase (GS) were studied. High concentrations of ammonium and alanine induced ADH formation. The levels of GS remained low in media with NH4Cl. Various nitrogen sources had no impact on the activity of GOGAT which suggested the involvement of constitutive synthesis. ADH was likely to play an alternative role. Determination of the quantitative and qualitative composition of the free amino acids confirmed the involvement of the GS-GOGAT pathway in nitrogen assimilation. The concentration of ammonium ions in the media with one amino acid or in the presence of several amino acids lowered the antibiotic activity while in the media with alanine and the other nitrogen compounds it increased the antibiotic activity.     

Variation in amino acid content and its relationship to nitrogen content and growth rate in Ulva ohnoi (Chlorophyta)

To evaluate the quantitative and qualitative changes in amino acids related to internal nitrogen content and growth rate of Ulva ohnoi, the supply of nitrogen to outdoor cultures of the seaweed was manipulated by simultaneously varying water nitrogen concentrations and renewal rate. Both internal nitrogen content and growth rate varied substantially, and the quantitative and qualitative changes in amino acids were described in the context of three internal nitrogen states: nitrogen‐limited, metabolic, and luxury. The nitrogen limited state was defined by increases in all amino acids with increasing nitrogen content and growth up until 1.2% internal nitrogen. The metabolic nitrogen state was defined by increases in all amino acids with increasing internal nitrogen content up to 2.6%, with no increases in growth rate. Luxury state was defined by internal nitrogen content above 2.6%, which occurred only when nitrogen availability was high but growth rates were reduced. In this luxury circumstance, excess nitrogen was accumulated as free amino acids, in two phases. The first phase was distinguished by a small increase in the majority of amino acids up to ≈3.3% internal nitrogen, and the second by a large increase in glutamic acid, glutamine, and arginine up to 4.2% internal nitrogen. These results demonstrate that the relationship between internal nitrogen content and amino acid quality is dynamic but predictable, and could be used for the selective culture of seaweeds.     

The capability of the algaeChlorella vulgaris andScenedesmus obliquus of utilizing amino acids as the sole nitrogen source

The capability of utilizing 20 amino acids and 2 amides as the sole nitrogen source for growth was studied in two green algae (Chlorophyceae). A comparison was made of the growth rate of algae in a mineral nutrient solution containing nitrate as the nitrogen source, with that in the same solution in which nitrogen in the form of nitrate was substituted by an equivalent nitrogen amount in the form of various amino acids. In addition to this, another series of experiments was carried out in whioh both culture media were supplied with glucose. The results show that both algae utilize a series of amino acids in dependence of their structure (mostly 3-carbon amino acids). The growth rate ofChlorella in the presence of these sources is the same as in nitrate, that ofScenedesmus even much higher. In the cultures containing glucose both algal species exhibit a higher growth rate in the media with the nitrate nitrogen source than in those with amino acids (with the exception of glycine inScenedesmus).     

Amino acids of barley plants in relation to nitrate,urea or ammonium nutrition

Summary When barley seedlings were transplanted into media containing either nitrate, ammonium, or urea their protein and free glutamate content increased during the first few hours. Following the commencement of active growth both the ammonium and urea assimilating plants showed greater increase in free aspartate and organic nitrogen content than the nitrate assimilating plants. Form of nitrogen had no effect on protein concentration and composition, and was of little importance as a source of differences in the total amino acid composition of the plant. re]19740503     

Incorporation of [(15)N] ammonia by the cellulolytic ruminal bacteria Fibrobacter succinogenes BL2, Ruminococcus albus SY3, and Ruminococcus flavefaciens 17

The origin of cell nitrogen and amino acid nitrogen during growth of ruminal cellulolytic bacteria in different growth media was investigated by using (15)NH(3). At high concentrations of peptides (Trypticase, 10 g/liter) and amino acids (15.5 g/liter), significant amounts of cell nitrogen of Fibrobacter succinogenes BL2 (51%), Ruminococcus flavefaciens 17 (43%), and Ruminococcus albus SY3 (46%) were derived from non-NH(3)-N. With peptides at 1 g/liter, a mean of 80% of cell nitrogen was from NH(3). More cell nitrogen was formed from NH(3) during growth on cellobiose compared with growth on cellulose in all media. Phenylalanine was essential for F. succinogenes, and its (15)N enrichment declined more than that of other amino acids in all species when amino acids were added to the medium.     

Changes in amino acid content of an algal feed species (Navicula sp.) and their effect on growth and survival of juvenile abalone (Haliotis rubra)

The growth and survival of juvenile Haliotis rubra, when fed with the diatom Navicula sp. cultured in f/2 medium containing combined nitrogen at 24.71 mg NO₃-N L^–1 (high), 12.35 mg NO₃-N L^–1 (standard) or 2.47 mg NO₃-N L^–1 (low), were compared in a 33-day trial. The alga in the low nitrogen medium contained 37% less total amino acid than that in the high and standard nitrogen media. There was a slightly greater reduction in essential amino acids (40%) compared to non-essential amino acids (35%). Juvenile abalone feeding on Navicula grown in medium with low nitrate and lower total amino acid content grew more slowly than when fed on the same species grown in standard or higher nitrogen medium with a higher amino acid content. The growth rate of juveniles was highest (43 m d^–1) in the high nitrate treatment followed (40 m d^–1) by the standard nitrate treatment and lowest (31 m d^–1) in the low nitrate treatment. The survival of the juveniles was also effected by the diet. Survival was better in the high and standard nitrogen media (88%) than the low nitrogen medium (75%). The results suggest that in order to achieve uniformity in nutritional quality of diatoms and good growth of abalone juveniles in commercial abalone nurseries, the nitrogen concentration in tanks should be monitored and additional nitrate added to provide an optimum concentration of between 2 and 12 mg NO₃-N L^–1.     

History of yield improvements in the production of asperlicin byAspergillus alliaceus

Summary The natural product asperlicin is the first nonpeptide antagonist of cholecystokinin isolated from a microbial source. At discovery, production of asperlicin by the original soil isolate ofAspergillus alliaceus was between 15 and 30 mg/l. Selection of natural variants ofA. alliaceus, use of Plackett & Burman and Simplex experimental designs; formulation of synthetic media; amino acid supplementation of production media; analysis of complex nitrogen sources for their amino acid content; evaluation of promising media in fermentors; substitution of glycerol for glucose as a carbon source and rational mutant selection all contributed to titer increases to >900 mg/l.     

METABOLIC CHANGES ASSOCIATED WITH ISO-OSMOTIC REGULATION IN BRAIN CORTEX SLICES

Abstract— The metabolism of single, first cortical rat brain slices was studied in response to incubation in media of various osmolalities. There was an inverse relationship between osmolality and the magnitude of the increase in tissue water content, and a direct relationship between osmolality and inulin space. Brain sodium varied directly with the media sodium, but hyperosmolal sucrose and glucose resulted in a drop in brain sodium. Brain potassium was constant in hyperosmolal sodium media, but it fell in hypo-osmolal media and hyperosmolal sucrose and glucose media.
Hypo-osmolality depressed the oxidation of [¹⁴C]glucose to ¹⁴CO₂ whereas hyperosmolality obtained with sodium, sucrose, or glucose stimulated glucose oxidation. Lactate production was enhanced only by sodium hyperosmolality. Hypo-osmolality caused a 70% drop in phosphocreatine and a minor decrease in energy charge potential, analagous to the effects of hypoxia. Hyperosmolality had no effect on energy metabolism.
The total amino acid nitrogen released into the media was suppressed by hypo-osmolality but was increased by hyperosmolal incubation. Hyperosmolality also increased production of ammonia fourfold.
The time course of the change in tissue osmolality and ion content following incubation in hyperosmolal sodium media showed the tissue osmolality reached the media osmolality within 5 min, but it took 30 min for the tissue sodium to reach equilibrium with the media sodium. This indicates that unidentified or'idiogenic osmoles'are induced transiently by hyperosmolality associated with changes in amino acid and ammonia metabolism.     

Content of free amino acids and their exosmose from maize kernels in relation to cold resistance

Maize caryopses were exposed in moist, sterile sand to temperatures of 24°, 10° and 6°. The amino acid content of embryo, endosperm and pericarp tissues of kernels and amino acid occurence in sand eluates was analysed by paper chromatography. The lower the temperature to which the seeds were exposed and the greater the delay in start of germination, the greater were the amounts of amino acids exosmosed from the kernel to the surrounding media. The exudation of aspartic acid, proline, alanine, γ-aminobutyric and glutamic acids was especially high. The time-course of amino acid content in various kernel parts proves that cold does not check the enzymic hydrolysis of reserve nitrogen compounds. There is, however, an inhibition of translocation and use of amino acids in the embryo. Therefore, amino acids diffuse out from the caryopse into the media. Although mainly the peripheral parts of endosperm take part in exosmose, participation of the embryo in the exudation of certain amino acids (proline) can be supposed as well. In cold resistance of emerging maize kernels the remarkable interaction of microorganisms is causally related to the high amino acid exosmose found in these experiments. The mechanism of amino acid exosmose and its relationship to cold resistance are discussed in detail.     

施氮水平对小麦籽粒发育过程中氨基酸含量的影响

施氮能提高小麦籽粒蛋白质氨基酸的含量,并与施氮水平呈正相关;但对普通小麦必需氨基酸与蛋白质氨基酸的比值没有影响,而硬粒小麦4286随施氮水平的提高,该比值下降。在开花后32d以前,籽粒发育过程中游离氨基酸与施氮水平呈正相关,以后,籽粒中游离氨基酸趋于相近,表明施氮增加了游离氨基酸的库源,不同基因型小麦对施氮水平的反应不同,在同等施氮水平和栽培条件下,籽粒中蛋白质氨基酸和游离氨基酸含量为硬粒小麦4286＞小偃6号＞小偃107,不同施氮水平下,籽粒中氨基酸含量为高氮＞中氮＞低氮。     

Physiological studies on Phymatotrichum omnivorum X. Influence of nitrogen sources on free and bound amino acid pools

The effect of nitrogen source on the free and bound amino acids of mycelium of Phymatotrichum omnivorum (Shear) Dugg was investigated. The largest free amino acid pool was present in the natural medium and the smallest in the synthetic medium. Phymatotrichum omnivorum was able to utilize different nitrogen sources with the best growth occurring with NH₄NO₃. The ratio of glycine to alanine and aspartic to glutamic was around 0.25 in the free amino acid pool and around 1 in the bound amino acid pool. The free pool of glutamic acid ranged from 5.6 % to 27.2 % depending upon the nitrogen source in the media. The free pool of alanine ranged from 35.7 % to 17.2 % in relation to the nitrogen source. Most other amino acid ratios did not vary significantly between the free amino acids and the bound amino acids.     

Powdery mildew of tobacco (Erysiphe cichoracearum DC.)

In water culture experiments, tobacco plants of Hicks variety were supplied with factorial combinations of high and low concentrations of nitrogen, phosphorus and potassium. Incidence of powdery mildew and growth and chemical composition of infected and healthy plants were compared.
There was more disease when all elements were supplied at the higher of two concentrations, but the increase in infection was less than the increase in growth. Plants grown in media containing a low ratio of potassium to nitrogen produced the least susceptible leaves; their disease indices were up to 30 times less than those of plants that received the full nutrient treatment. Potassium-deficient leaves had thinner cell walls, larger water content, smaller sugar and potassium contents, and greater amino nitrogen and magnesium contents, compared with those of plants grown in any of the other media. The possible relation between these characteristics and susceptibility to Erysiphe cichoracearum DC. are discussed.     

Influence of amino nitrogen in the culture medium enhances the production of δ-endotoxin and biomass of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> var. <Emphasis Type="Italic">israelensis</Emphasis> for the large-scale production of the mosquito control agent

We reported here the role of amino nitrogen in the commercial production of Bacillus thuringiensis var. israelensis media design. The insect pathogen B. thuringiensis var. israelensis was cultured in different media containing varying initial levels of amino nitrogen sources obtained from three different commercial venders. The biomass, mosquito larval toxicity and spore count produced were measured during the fermentation process. The results showed that the higher level of initial amino nitrogen concentrations in the medium led to higher yield of biomass (dry weight 4.78 g l(-1)), larvicidal activity (LC(50) 18.52 ng ml(-1)) and spore count (3.24 x 10(11) CFU ml(-1)). Similarly decreasing the initial amino nitrogen concentration in the medium led to a decreased biomass (dry weight 1.64 g l(-1)), larvicidal activity (LC(50) 27.01 ng ml(-1)) and spore count (3.7 x 10(10) CFUml(-1)).     

氮素水平对花生氮素代谢及相关酶活性的影响

 在大田高产条件下研究了氮素水平对花生(Arachis hypogaea)可溶性蛋白质、游离氨基酸含量及氮代谢相关酶活性的影响, 结果表明, 适当提高氮素水平既能增加花生各器官中可溶性蛋白质和游离氨基酸的含量, 又能提高硝酸还原酶、谷氨酰胺合成酶和谷氨酸脱氢酶等氮素同化酶的活性, 使其达到同步增加; 氮素水平过高虽能提高硝酸还原酶和籽仁蛋白质含量, 但谷氨酰胺合成酶(GS)和谷氨酸脱氢酶(GDH)的活性下降; N素施肥水平不改变花生植株各器官中可溶性蛋白质、游离氨基酸含量以及硝酸还原酶(NR)、谷氨酰胺合成酶、谷氨酸脱氢酶活性的变化趋势, 但适量施N (A2和A3处理)使花生各营养器官中GS、GDH活性提高; 氮素水平对花生各叶片和籽仁中GS、GDH活性的高低影响较大, 但对茎和根中GDH活性大小的影响较小。     

Incorporation of [15N]Ammonia by the Cellulolytic Ruminal Bacteria Fibrobacter succinogenes BL2, Ruminococcus albus SY3, and Ruminococcus flavefaciens 17

The origin of cell nitrogen and amino acid nitrogen during growth of ruminal cellulolytic bacteria in different growth media was investigated by using ¹⁵NH₃. At high concentrations of peptides (Trypticase, 10 g/liter) and amino acids (15.5 g/liter), significant amounts of cell nitrogen of Fibrobacter succinogenes BL2 (51%), Ruminococcus flavefaciens 17 (43%), and Ruminococcus albus SY3 (46%) were derived from non-NH₃-N. With peptides at 1 g/liter, a mean of 80% of cell nitrogen was from NH₃. More cell nitrogen was formed from NH₃ during growth on cellobiose compared with growth on cellulose in all media. Phenylalanine was essential for F. succinogenes, and its ¹⁵N enrichment declined more than that of other amino acids in all species when amino acids were added to the medium.     

Degradation of nitrocellulose by fungi

Three lignocellulolytic fungi, Trametes versicolor, Pleurotus ostreatus, and Coprinus cinereus, and two cellulolytic fungi Trichoderma reesei andChaetomium elatum were tested for their ability to degrade nitrocellulose. They were provided with different carbon and nitrogen sources in liquid cultures. Nitrocellulose (N content above 12%) was added as nitrogen source (in solution in acetone) alongside amino acids or as sole N source. Either starch or carboxy-methyl cellulose were provided as carbon sources. After 28 days of growth the highest decrease of nitrocellulose was observed with Chaetomium elatum when up to 43% was degraded in a medium containing nitrocellulose as the only nitrogen source. Coprinus cinereus caused a 37% decrease of nitrocellulose when provided with amino acids and starch as co-substrate. In cultures of Trametes versicolor, Pleurotus ostreatus andTrichoderma reesei, only 10%–22% decrease of nitrocellulose was measured in all media. In the presence of nitrocellulose with N content below 12% supplied as 3 mm pellets as the only carbon source, or with nitrocellulose with carboxy-methyl cellulose, the release of nitrite and nitrate from liquid cultures of Chaetomium elatum was measured. Between 6 and 9 days of growth in these media, an increase in both nitrite and nitrate was observed with a loss in weight of nitrocellulose up to 6% achieved after 34 days. The physical nature of the NC pellets may have reduced the rate of degradation in comparison with supplying NC in solution in the cultures.     

稻田温室气体减排措施对稻米氨基酸含量的影响

为探索稻田中温室气体减排措施对稻米氨基酸含量的影响,用10个不同方法对双季稻田进行处理,并使用高效液相色谱分别测定了各处理稻田中所产稻米中的16种氨基酸的含量,其中色谱柱为Agilent Zorbax AAA分析柱,柱前衍生使用邻苯二甲醛(OPA)和9-芴甲基氯甲酸酯(FMOC-CL)为衍生试剂。结果发现:1)10个处理中的稻米16种氨基酸种类齐全,施氮肥+添加生物质炭48 t/hm2+间歇灌溉(NPK+HBC+IF)处理中所得氨基酸总量为6520.7 mg/100g,效果最佳;对照组处理(不施加氮肥+无稻草还田+间歇灌溉)所得氨基酸含量4338.0 mg/100g为最低。以对照组处理所得必需氨基酸百分含量36.8%为最高值;无稻草还田+长期淹水(NPK+CF)处理方法所得必需氨基酸百分含量33.1%为最低值。10个处理中16种氨基酸中含量较高的氨基酸均为天冬氨酸、谷氨酸和精氨酸,含量最低的均为甲硫氨酸;2)施氮肥量相同时,长期淹水与间歇灌溉相比,氨基酸总量增加185.1 mg/100g,非必需氨基酸百分含量增加3%,谷氨酸、组氨酸和丝氨酸含量明显升高,但亮氨酸含量显著降低;3)施用氮肥能提高稻米中的氨基酸含量,且随着氮肥使用量的增加,氨基酸含量也随之增加,组氨酸含量增加显著;4)供氮量相同时,添加猪粪使氨基酸总含量升高了286.0 mg/100g,此结果表明,在供氮量相同的情况下,施用猪粪更有利于稻米氨基酸含量的提高;5)灌溉模式相同时,稻草还田配施氮肥对必需氨基酸和氨基酸总量均有提高,天冬氨酸、谷氨酸和组氨酸的含量增加较多,甲硫氨酸含量略有下降;随着稻草还田量的增加,对非必需氨基酸影响较为明显;当稻草半量还田(还田量为3 t/hm2)时,稻米中氨基酸总量增加最多;稻草全量还田+长期淹水(NPK+HRS+CF)与稻草半量还田+间歇灌溉(NPK+LRS+IF)处理中的氨基酸含量基本接近,但必需氨基酸含量前者略高于后者,说明稻草还田与水肥管理对氨基酸含量影响可能存在交互作用;6)添加生物质炭配施氮肥提高了稻米必需氨基酸与非必需氨基酸含量,且随着生物质炭添加量的增加而增加;与稻草还田、添加猪粪处理相比,生物质炭的添加对氨基酸总含量提升的效果最为显著,对稻田实际生产具有指导意义且具有一定的环境效益。