Effects of medium sterilization on the production of zaragozic acids by the fungusLeptodontidium elatius

The production of zaragozic acids by fermentation of the fungusLeptodontidium elatius was examined at the 800-L fermentor scale under two different production medium batch sterilization conditions. Low production-medium heat input (R₀=33.4 min) resulted in a 4-desacetoxy zaragozic acid C:4-O-desacetyl zaragozic acid C:zaragozic acid C ratio of 0.53:0.60:1.0. At a higher heat input (R₀=50.5 min), the ratio shifted to 1.0:0.66:1.0 with a corresponding 26% increase in total zaragozic acid production. This higher total zaragozic acid titer resulted from an increase in the amount of 4-desacetoxy zaragozic acid C produced while the levels of the other two analogues remained unchanged. Batch sterilization conditions also resulted in differences in growth, carbon substrate consumption, and oxygen uptake rates. The structures of the zaragozic acids produced suggest a precursor/end product relationship. A biosynthetic model describing the synthesis of the three zaragozic acids listed above is postulated and used to explain the effects of production-medium heat input during sterilization.     

DNA sequence of a 3.8 kilobase pair region controlling Drosophila chorion gene amplification

During Drosophila oogenesis, two clusters of chorion genes and their flanking DNA sequences undergo amplification in the ovarian follicle cells. Amplification results from repeated rounds of initiation and bidirectional replication within the chorion gene regions, possibly from a single origin, producing nested replication forks. Previously we have shown that following reintroduction into the Drosophila genome, a specific 3.8 kilobase pair DNA segment from the amplified third chromosome domain could induce developmentally regulated amplification at its site of insertion. Here we present the complete nucleotide sequence of this amplification control element and of genes encoding the chorion structural proteins s18-1 and s15-1, which are contained within it. Sequences that may be involved in the regulation of chorion gene amplification and expression are identified.     

Fatty acid composition of various hyphal budding bacteria

The total fatty acid composition of various strains of Hyphomicrobium, Pedomicrobium, and Rhodomicrobium spp. was determined by gas chromatography. In addition, the fatty acid pattern of a new hyphal budding bacterium, strain F-1, was compared with the other patterns obtained. Octadecenoic acid was the main component in most strains, comprising up to 75% of the total fatty acids. Lactobacillic acid and 3-methoxy-tetradecanoic acid were present in varying amounts in the lipids of all organisms except for the new isolate, F-1. This latter strain contained, however, large amounts of iso-heptadecanoic and iso-heptadecenoic acids, not present in the other budding bacteria studied. This composition was consistently found under various culture conditions. The data indicate that, except for the new bacterium F-1, the hyphal budding bacteria studied here are closely related. The total fatty acid composition is thought to be a useful taxonomic criterion for differentiation of these bacteria.     

The Penicillium commune Thom and Penicillium clavigerum Demelius Fungi Producing Fumigaclavines A and B

The type strains Penicillium clavigerum VKM F-447 and P. commune VKM F-3233 are found to produce fumigaclavines A and B. Of the seven other strains of these species, only two strains, P. commune VKM F-3088 and F-3491, possess the ability to synthesize these alkaloids. It is suggested that the five other strains under study either lost such an ability or require very specific conditions for the synthesis of these alkaloids.     

Influence of the culture medium composition on cattle oocyte maturation and embryogenesisin vitro

We studied the capacity of the cattle oocyte for the resumption of meiosis and the achievement of metaphase II in various protein-free culture media (DMEM, TCM-199, Ham’s F-10, and Ham’s F-12) and the pattern of influence of the estrous serum on thein vitro development of fertilized cattle oocytes, with special reference to the time of its addition to the synthetic oviduct fluid containing BSA. In the first experimental series, it was shown that the highest number of oocytes (76.1%) resumed meiosis in DMEM medium. Meiosis was not resumed in Ham’s F-12. Intermediate results were obtained for TCM-199 (55.1%), which is commonly used for the maturation of cattle oocytesin vitro and for Ham’s F-10 (51.7%). The oocytes reached metaphase II in DMEM at a higher rate (45.3%) than in TCM-199 or Ham’s F-10 (29.4 and 8.6%, respectively). In the second experimental series, the estrous serum was added to the culture medium within 20 h (control) or 42 h (experiment) after the beginning of fertilization. The estrous serum did not inhibit the first cleavage division (the percentage of cleaving embryos did not differ reliably: 32.7 and 37.9%, respectively). However, a later serum addition to the culture medium (within 42 h after the beginning of fertilization) reliably increased the percentage of embryos that reached the blastocyst stage (6.5% in the control and 17.8% in the experiment) and the hatched blastocyst stage (2 and 9.2%, respectively).     

Preliminary report on the biological effects of space flight on the producing strain of a new immunosuppressant, Kanglemycin C

Kanglemycin C (K-C) is a new immunosuppressant isolated from the culture broth of Nocardia mediterranei var. kanglensis 1747-64. To improve the productivity of K-C and to study the biological effects of space flight on its producing strain, spores from five K-C producing strains (U-10, U-15, U-7, M-13, γ-33) mutated from the wild strain N. mediterranei var. kanglensis 1747-64 were carried into space by an unmanned spaceship, “Shenzhou III” (Divine Vessel III) on March 25, 2002. Comparatively, the strain U-7 was the highest K-C producing strain among the above five starting strains when cultivated in 500-ml Erlenmeyer flasks. After a 6 day and 18 h flight, the treated spores went through serial screening processes to screen for high-yield K-C mutant strains, using thin layer chromatography and high performance liquid chromatography (HPLC). The K-C yield produced by one mutant strain, designated as F-16, derived from the starting strain U-7 was increased by up to 200% when compared to that produced by the starting strain U-7 in 500-ml Erlenmeyer flasks after careful postflight HPLC analysis. Another mutant strain, designated as F-210, derived from the starting strain M-13 showed reduced productivity of K-C as well as exhibited changes in some morphological and physiological characteristics. For example, the broth color of the strain F-210 changed from yellow to purple after 96 h of culture, but that of the ground control strain M-13 remained yellow. Similarly, the mycelium morphological change from filamentous to coccoid of F-210 occurred later than that of ground control M-13. Examination of the survivability of postflight spores indicated that exposure to radiation, during the 162 h of space flight, plays a critical role in the survival rates of spores such that spores exposed to strong radiation exhibited lower survival rates than spores exposed to weak radiation.Jianqin Zhou and Chenghang Sun have contributed equally to this work.     

Differentiation of Fraction 1 protein in relation to age and distribution of Angiosperm groups

Fraction 1 protein (F-1-protein) (ribulose bisphosphate carboxy-lase-oxygenase) contained inLemnaceae has been evolving for at least 50 million years because fossils of these plants have been identified in strata belonging to the Upper Cretaceous. Electrofocusing F-1-protein resolves the large subunit polypeptides coded by extranuclear DNA and the small subunit polypeptides coded by nuclear DNA. Four differences affecting isoelectric points of the large subunit polypeptides and eight affecting the small subunit polypeptides are now present among eleven species representing the four genera comprising theLemnaceae. In comparison, four differences in the large and 13 in the small subunit polypeptides exist among 63 species ofNicotiana; four differences in the large and eight differences in the small subunit polypeptides exist among 19 species ofGossypium. The number of differences in F-1-protein composition being of the same order of magnitude for the generaNicotiana, Gossypium, and the familyLemnaceae, we infer that these Angiosperms are of similar antiquity. Nicotiana species indigenous to Australia and Africa contain F-1-proteins whose large subunit polypeptides are different but some of whose small subunit polypeptides are like those found in species from the Western Hemisphere. The same situation is found for the F-1-protein inGossypium. These results are in harmony with the view that species ofNicotiana andGossypium have arrived in Australia via former land connections between S. America, Antarctica, and Australia.     

Larval development of Aeshna cyanea (Müller, 1764) (Odonata: Aeshnidae) in Central Italy

A three-year investigation was carried out on the life cycle of Aeshna cyanea (Müller, 1764) (Odonata, Aeshnidae) in temporary freshwater pools in Central Italy. The instars were discriminated by size and scatter plot, based on measurements of labium length, head width, metafemur length, forewing-pad length and total larval body length. The prolarvae instar was derived by Dyar's law. The mean increase value index between following and previous instar was between 1.26 and 1.33 for isometric variables, and around 1.96 for the wing-pad allometric variable. A. cyanea entered diapause mainly at the F-2 instar, placing it almost intermediate between the Southern Spain populations, which usually overwintered in the F-3 instar, and those of England and Central Europe, who spent their last winter in F-1. A. cyanea appeared to be a `summer species', as defined by Corbet (1962), and the population we studied had a semivoltine life cycle.     

Limosilactobacillus fermentum F-6的遗传背景和功能基因组

【目的】Limosilactobacillus fermentum具有增强免疫力、产胞外多糖(exopolysaccharide,EPS)等多种功能特性,广泛应用于食品领域,具有较高经济价值。本文从群体遗传学角度,解析L. fermentum F-6的遗传背景和功能基因特征,为其开发利用提供遗传学基础。【方法】本研究对NCBI已公开的23株L. fermentum全基因组序列和1株模式菌株ATCC 14931T的基因组序列进行比较基因组学分析。利用Roary软件识别核心基因集与泛基因集;采用rapid annotation using subsystem technology(RAST)网站对基因组进行功能注释,以探究F-6基因组特征。【结果】以识别到的997个核心基因构建系统发育树,发现聚类趋势与分离源无关,但F-6与3株食品分离株聚在同一分支。功能注释分析发现,24株L. fermentum中仅F-6含有参与支链氨基酸合成途径的基因(ilvD、leuA等),可为机体提供必需氨基酸。F-6含有大量编码糖基转移酶和UDP-葡萄糖4-表异构酶的基因,且含有1个完整的eps基因簇。与其他L...     

16S rRNA及rpoC1基因用于螺旋藻、节旋藻系统发育的比较北大核心CSCD

【目的】利用16S rRNA和rpoC1基因分子标记研究螺旋藻、节旋藻的系统发育关系,并对其区分能力进行比较。【方法】以84株螺旋藻、节旋藻为研究对象,对其进行16S rRNA、rpoC1基因序列的扩增、测序及分析,并对构建的系统发育树进行对比。【结果】rpoC1基因序列保守位点所占比例49.7%、平均G+C百分含量47.7%和序列相似度76%–100%明显低于16S rRNA基因序列的79.4%、55.6%和91%–100%,其变异程度高于16S rRNA基因;基于16S rRNA、rpoC1基因构建的系统发育NJ树拓扑结构基本一致,84株实验藻株分为2个属3个类群,其中仅F-351、F-904-2、F-1070和TJBC14-1藻株为螺旋藻,其余均为节旋藻;虽然2个基因都不能区分形态种和地理种,但rpoC1基因NJ树的置信度(100%)高于16S rRNA基因(99%),属内分群效果也明显优于16S rRNA基因。【结论】支持了螺旋藻、节旋藻为两个不同属的结论,且在属内分类时rpoC1基因比16S rRNA基因具有更高的区分度。     

Phorphorylative electron transport chains lacking a cytochromebc 1 complex

Electron transport-coupled phosphorylation with fumarate as terminal acceptor inWolinella succinogenes yields less than 1 ATP/2 electrons. The generated by the electron transport is 0.18V and the H⁺/electron ratio is 1. The electron transport chain is made up of two dehydrogenases (hydrogenase and formate dehydrogenase) that catalyze the reduction of menaquinone, and fumarate reductase which catalyzes the oxidation of menaquinol.C-type cytochromes are not involved. The phosphorylative electron transport with sulfur as terminal acceptor inW. succinogenes orDesulfuromonas acetoxidans does not involve known quinones. The ATP yields should be even smaller than those with fumarate. Succinate oxidation by sulfur, which is a catabolic reaction inD. acetoxidans, is accomplished by reversed electron transport.     

Effect of zearalenone (F-2) on pea stem,maize root,and rat liver mitochondria

At 5 and 10 g ml^-1 concentration, zearalenone (F-2), a mycotoxin produced by a number of species of the genus Fusarium, causes an inhibition of the oxidative phosphorylation of isolated plant mitochondria, while at 20 and 40 g ml^-1 it causes uncoupling. However, when the mitochondria are pre-incubated for 20 min with F-2, the uncoupling appears to be the prevailing effect. F-2 is also able to inhibit the mitochondrial ATPase activity (Mg²⁺-dependent). Conversely, F-2 (40 g ml^-1) does not alter the ATP level of maize roots and only slightly affects the ATPase activity of pea stem and maize root microsomal fractions. In addition, F-2 (10–40 g ml^-1) inhibits ATP synthesis catalyzed by rat liver mitochondria. It is suggested that the phytotoxicity of F-2, also known for its ability to collapse the transmembrane electric potential of maize roots, may be mainly linked to its ability to increase the proton permeability of the cell, similar to the common uncouplers.Abbreviations F-2 zearalenone - DCCD N,N-dicyclohexylcarbodiimide - PCCP carbonyl cyanide, p-trifluoromethoxiphenylhydrazone - CBT Cerospora beticola toxin     

Studies on Mucor Lipases

Lipases produced by Mucor lipolyticus Aac-0102 were separated into three different fractions (F-1, F-2 and F-3) by CM-Sephadex column chromatography.

Molecular weights of them were estimated to be higher in the order of F-1, F-2, and F-3 by gel filtration on a Sephadex G-100 column. F-1 and F-2 could hydrolyze water soluble substrate such as Tweens. F-3 showed a strong hydrolytic activity toward triglycerides but the activity toward Tweens was almost negligible.

Sodium lauryl sulfate inhibited the olive oil hydrolyzing activity of F-3. However, Tween hydrolyzing activity of F-2 was not affected with it. These results suggested that they are different with each other with respect to their molecular weights, substrate specificities and sensitivities to some inhibitors.     

Strong and weak immune responses across the same major histocompatibility barrier in rats

Inbred rat strains, Fischer 344 (F-344) and Lewis (LEW), share the serologicalAg-Bl allele and react very weakly in mixed lymphocyte culture (MLC). Despite this apparent identity atAg-B, these strains differ markedly in their immune responses to anAg-B disparate third strain Marshall 520 (M-520) (Ag-B6). F-344 recipients allowed M-520 heart grafts an extended survival, whereas LEW recipients rejected them rapidly. F-344 and M-520 showed a weak response in MLC in contrast to a strong response for LEW and M-520. F-344 produced antisera in response to injection of M-520 cells that had a relatively high antibody titer but low cytotoxic activity. F-344 responded to another strain, Buffalo (BUF) (alsoAg-B6), in a similar fashion. F-344 apparently can produce a strong allogeneic response, as it was able to rapidly reject heart grafts from (LEW x Brown-Norway) F₁ donors (LBN) (Ag-B 1/3). The low response of F-344 to M-520 probably was not due to shared antigens between the two strains because M-520 heart grafts underwent rapid rejection in LEW hosts highly tolerant to F-344. To explain the contrasting response of F-344 and LEW to theAg-B6 disparity, we propose that it is controlled by an immune-response gene(s); that F-344 has a low-responding allele and LEW has a high-responding allele. The data do not reveal a location for this proposed gene. The high-responding allele appears to be dominant, as M-520 hearts were rejected rapidly by (F-344 x LEW) F₁ recipients.     

Expression of nuclear and chloroplastic genes coding for fraction-1 protein in somatic hybrids of Nicotiana tabacum + rustica

In the sexual interspecific cross, Nicotiana rustica L.xN. tabacum L., N. rustica can serve as the female but not as the male parent. By fusion of protoplasts, the barrier to fertilization was overcome and somatic hybrids containing N. tabacum cytoplasm were produced as shown by isoelectric focusing of the Fraction-1 protein (F-1-protein). All somatic hybrids displayed polypeptides of the large subunit of F-1 protein (which is coded by the chloroplast genome) characteristic of only one or the other parental species. Two hybrids had large subunits of the N. tabacum type and two hybrids had those of the N. rustica type. Three hybrids contained three smallsubunit polypeptides (coded by the nuclear genome), one being characteristic of N. rustica, one characteristic of N. tabacum, and one with an isoelectric point common to both species. A fourth hybrid contained only two small-subunit polypeptides of the N. tabacum type but in a F-1 protein macromolecule whose large subunits were of the N. rustica type. One somatic hybrid was self-fertile and its F₂ progeny contained large- and small-subunit polypeptides indistinguishable in their isoelectric points from those in the parent F₁ hybrid. All somatic hybrids showed an aneuploid chromosome number and morphological characteristics intermediate between those of N. rustica and N. tabacum.     

Enzymatic hydrolysis and simultaneous saccharification and fermentation of steam-pretreated spruce using crude Trichoderma reesei and Trichoderma atroviride enzymes

The aim of this study was to compare the performance of the enzymes produced by Trichoderma reesei Rut C30 and the good extracellular β-glucosidase-producing mutant Trichoderma atroviride TUB F-1663 to that of commercial preparations in the enzymatic hydrolysis and the simultaneous saccharification and fermentation (SSF) of steam-pretreated spruce (SPS).The concentrated TUB F-1663 enzyme was found to be the most efficient in the hydrolysis of washed SPS at 50 g/L water-insoluble solids (WIS) in terms of the glucose produced (18.5 g/L), even in comparison with commercial cellulases (14.1–16.7 g/L). The enzyme preparations were studied at low enzyme loadings (5 FPU/g WIS) in SSF to produce ethanol from SPS. The enzyme supernatant and whole fermentation broth of T. atroviride as well as the whole broth of T. reesei proved to be as efficient in SSF as the commercial cellulase mixtures (ethanol yields of 61–76% of the theoretical were achieved), while low ethanol yields (<40%) were obtained with the β-glucosidase-deficient T. reesei supernatant.Therefore, it seems, that instead of using commercial cellulases, the TUB F-1663 enzymes and the whole broth of Rut C30 may be produced on-site, using a process stream as carbon source, and employed directly in the biomass-to-bioethanol process.     

Protection induced in BALB/c mice by the high-molecular-mass (hMM) fraction of <Emphasis Type="Italic">Paracoccidioides brasiliensis</Emphasis>

Paracoccidioidomycosis (PCM) is a granulomatous disease caused by a dimorphic fungus, Paracoccidioides brasiliensis. The present study investigated the protective activity of the P. brasiliensis high-molecular-mass (hMM) fraction (~380 kDa) in experimental murine PCM. In the first step, lymphocyte proliferation and production of IFNγ (but not IL-4) were observed in “in vitro” spleen cells (from female BALB/c mice infected (i.v.) with P. brasiliensis) that were stimulated with hMM fractions. In the second step, female BALB/c mice were previously immunized (s.c.) with hMM fraction (25 μg/protein = F-25 and 50 μg/protein = F-50), and the colony-forming units (CFU) of the lung and spleen, the histopathological characteristics of the granulomatous lesions, and plasmatic gp43 soluble antigens and anti-hMM IgG levels were analyzed at 28 and 56 days after infection. The lung and liver CFU were lower in mice previously immunized with the hMM fraction (P < 0.05). The granulomatous lesions revealed a greater degree of compaction and organization, with no dissemination of the fungus to other organs. Lower soluble antigen levels (P < 0.05) and higher IgG anti-hMM fraction (P < 0.05) were observed in immunized groups. The results for CFU, histopathology and antigenemia suggest that the hMM fraction has a protective effect in experimental paracoccidioidomycosis in BALB/c mice.     

Effects of Pluronic F-68 on shoot regeneration from cultured jute cotyledons and on growth of transformed roots

The effects have been studied of the non-ionic surfactant, Pluronic F-68, on the growth in culture of jute (Corchorus capsularis L.) cotyledons with attached petioles, cotyledon explants and transformed roots. Supplementation of culture medium with 0.001–0.5% (w/v) of either commercial grade Pluronic F-68 or a purified fraction prepared by passage through silica gel, stimulated shoot production from the petioles of C. capsularis var. D154 and C134 cotyledons. This effect was most marked in C134, because of the failure of control cotyledons to produce shoots in the absence of Pluronic. Plants regenerated from Pluronic-treated cotyledons were morphologically normal. Growth of transformed roots of C. capsularis var. D154 was stimulated in medium supplemented with commercial grade or purified Pluronic F-68, with maximum increases in both fresh and dry weights with 0.1% (w/v) of the surfactant. Roots cultured in the presence of Pluronic F-68 could be maintained without sub-culture for up to 70 days, whereas roots cultured in the absence of Pluronic required subculture every 7 days, to prevent necrosis. Transformed roots also produced callus in the presence of 0.001–1.0% (w/v) of either commercial grade or purified Pluronic. The biotechnological implications of these results are discussed in relation to the potential value of non-ionic surfactants as growth-stimulating additives to plant culture media.Abbreviations NAA -naphthaleneacetic acid - BA 6-benzyladenine - IAA indole-3-acetic acid - MS Murashige & Skoog (1962)