不同诱导培养基对糙皮侧耳液体发酵产漆酶活性的影响

利用1株糙皮侧耳Pleurotus ostreatus栽培菌株为材料,研究添加碱性木质素或者配合简单碳源或氮源后对其液体发酵产漆酶活性的影响。结果表明,不同诱导培养基对糙皮侧耳漆酶活性具有极显著的影响（P<0.001）,而且不同诱导培养基对糙皮侧耳菌丝生物量也产生了极显著的影响（P<0.001）。此外,只利用碱性木质素或者是再添加碳源葡萄糖均有利于糙皮侧耳产漆酶,既包括产漆酶酶活性的提升,同时也包括产漆酶时间的提前,但只利用碱性木质素诱导不利于菌丝生物量的积累;而富含简单碳/氮源的诱导培养基,无论是否含碱性木质素,均有利于菌丝生物量的积累,其中,富含简单碳/氮源的培养基中再添加碱性木质素后的菌丝生物量和漆酶活性均高于不添加碱性木质素时的菌丝生物量和漆酶活性。相比而言,含碱性木质素的培养基中测得的漆酶活性大部分时间下都要高于不含木质素的简单碳/氮源培养基,含碱性木质素的培养基对糙皮侧耳菌株产漆酶的诱导作用更强。     

不同碳源和氮源对金针菇降解木质纤维素酶活性的影响

以3株栽培的金针菇Flammulina velutipes为材料,研究它们在玉米芯和棉子壳以及不同碳源、氮源培养条件下纤维素、半纤维素和木质素降解酶活性的规律。结果表明,不同金针菇菌株的羧甲基纤维素酶、木聚糖酶和漆酶活力显著不同（P<0.001）,同时,培养条件对羧甲基纤维素酶、木聚糖酶和漆酶的活力都有显著影响（P<0.001）。在简单碳源存在的条件下,金针菇的羧甲基纤维素酶和木聚糖酶活力远远低于复杂碳源培养基（P<0.05）。全营养培养基上生长的金针菇的羧甲基纤维素酶和木聚糖酶活力低于缺乏碳源和氮源的培养基（P<0.05）。漆酶活力在无简单氮源培养基上低于全培养基（P<0.05）和无葡萄糖培养基（P<0.05）,即复杂碳源和氮源培养基上的漆酶活力低于简单碳源和氮源培养基（P<0.05）。     

马铃薯干腐病菌硫色镰孢的生物学特性

从碳源、氮源、酸碱度及生长温度等方面对引起马铃薯干腐病的硫色镰孢Fusarium sulphureum的生物学特性进行了研究。结果表明,该病原菌在不同发育阶段对营养和环境条件的要求存在差异。在固体培养基上,菌落生长最佳碳源为葡萄糖、麦芽糖,最佳氮源为蛋白胨,pH8?为最佳;在液体培养基中,菌丝体生长以麦芽糖为最佳碳源,以硝酸钠为最佳氮源,pH6?为最佳;在分生孢子萌发阶段,在以羧甲基纤维素钠、蛋白胨和谷氨酸为碳、氮源的营养液中,分生孢子萌发率最高,最适pH 6–8。该病菌最适生长温度为25℃,分生孢子致死     

红霉素发酵工艺优化研究

通过摇瓶正交实验,得出7种营养成分对红霉素生物合成的影响程度,对发酵工艺条件进行了优化研究,找到了红色链霉菌抗噬菌体68#菌种生长的优化组合,得出快速碳源(葡萄糖)与慢速碳源(淀粉)配比为2.64时,有利于红霉素的生物合成。还原糖/氮为20,总糖/氮为80～120时对红霉素发酵极为有利。借助磷酸三钙、沸石对NH+的独特吸附和释放作用,将二者按5∶1混合配成吸附和吐纳效果很好的捕集剂,对发酵液中游离无机氮源进行控制,可使抗生素生物合成提高15%～29%。     

Adenylate level in the mycelium of Penicillium nigricans Thom. grown on various carbon sources]

Concentrations of ATP and ADP and their dynamics during cultivation (2, 5, 9 and 13 days) of a highly productive strains of P. nigricans on a mineral medium in the presence of various carbon sources, such as glucose, succinate or acetate were studied. It was shown that the levels of ATP and ADP in the mycelium depended on the carbon source: the maximum and minimum ATP concentrations were found on the glucose and acetate media respectively, the maximum and minimum ADP concentrations showed inverse dependence. The concentrations of both adenylates on the same carbon source depended on the strain. The dynamics of the adenylates levels during cultivation showed an analogous dependence on the carbon source and the strain. Thus, the highly productive strain was characterized by a constant ATP level on glucose and succinate and variation on acetate, while the ADP level was characterized by a decrease by the 9th day of cultivation on any of the carbon sources. The low productive strain was characterized by variations in the level of ATP in any media used, stability of the ADP level by the 2nd--9th day of cultivation on the glucose medium and by the 2nd--5th day of cultivation on the succinate medium and a decrease by the 9th day of cultivation on the acetate and succinate media. The ratio of ATP/ADP at the phase of griseofulvin biosynthesis (9 days) markedly increased in both the strains when cultivated on the media with any of the carbon sources.     

A chitinolytic actinomycete complex in black soil

A chitinolytic actinomycete complex in chernozem soil has a specific taxonomic composition, which differs from that of the actinomycete complex which is typically isolated on standard nutrient media containing sugars and organic acids as carbon sources. The actinomycete complex that was isolated by using nutrient media with chitin as the source of carbon and nitrogen was dominated by representatives of the genus Streptosporangium, and the actinomycete complex that was isolated by using nutrient media with sugars and organic acids as the carbon sources was dominated by representatives of the genus Streptomyces. The confirmation to the ability of actinomycetes to utilize chitin as a sole source of carbon and nitrogen came from the augmented length and biomass of the mycelium, the increased number and biomass of the actinomycete spores, the production of carbon dioxide, and the accumulation of NH4+ ions in the culture liquid of the actinomycetes that are grown in the nutrient media with chitin.     

Reaction of Oxyhemoglobin with Carbon Monoxide

The reaction of oxyhemoglobin and carbon monoxide was studied kinetically at pH 7.8 in a variety of suspending media. The dielectric constant of the suspending media, as well as the viscosity (and hence the Fick diffusion coefficients), was varied with the use of glycine, glycerol, and sucrose. The results showed that the reaction was unaltered by the various additions to the media, provided that the pO₂ and the concentration of carbon monoxide were held constant. Since the concentration of oxygen varies from medium to medium at constant pO₂ while the pCO varies at constant concentration of carbon monoxide, the differences in the reactions with oxygen and carbon monoxide were emphasized. The lack of variation of the rate constants with changes in dielectric constant can be interpreted as indicating that electrostatic effects are unimportant in this reaction.     

Selective media for three biovars of Agrobacterium

Three selective media for the isolation of the three known biovars of Agrobacterium are described. Selectivity was based on carbon and nitrogen sources; L(—)-arabitol for biovar 1, erythritol for biovar 2 and a combination of tartrate and D-glutamate for biovar 3. The new media were compared with existing selective media. Recovery of agrobacteria from soil was very efficient and discrimination between the three biovars was satisfactory except for tartrate-utilising biovar 1 isolates which grew on the biovar 3 medium. Some strains of Pseudomonas sp. isolated from crown galls on vine could utilise octopine as a source of carbon and nitrogen.     

Cellulase production by Trichoderma reesei when cultured on xylose-based media supplemented with sorbose

The ability of L-sorbose to stimulate cellulase production In shake flask culture of Trichoderma reesei was examined in mineral salts media (initial pH 5.0) containing either 1.0% D-xylose, 1.0% cellulose, and/or 0.1, 0.3, or 0.5% L-sorbose. When sorbose was the only carbon source, growth was limited, little substrate was utilized, pH increased, and cellulase activity was not apparent. The other carbon sources promoted good growth, pH dropped sharply to 2.5-3.0, substrate was utilized rapidly, and cellulase activity was detected. After three weeks of fermentation, twice as much cellulase activity was detected in the medium containing only cellulose as the carbon source, as compared to xylose as the carbon source. Cellulase activity was higher when media contained xylose supplemented with sorbose compared to xylose as the only carbon source. At 0.3 and 0.5% levels of sorbose supplementation of xylose-based media, cellulase activity was similar to that in cellulose-based media.     

Efficacy of Metarhizium anisopliae microsclerotial granules

The entomopathogenic fungus Metarhizium anisopliae has very recently been shown to produce microsclerotia (MS) – compact, heavily melanised, hyphal aggregates – in liquid media. Soil incorporation bioassays of dried MS preparations of three isolates of M. anisopliae were conducted using third instar Tetanops myopaeformis (sugarbeet root maggot) in clay and/or clay loam field soils as a model system to demonstrate efficacy. At rates as low as 23 mg MS granules/100 g dry soil, the biocontrol efficacy of MS granules of M. anisopliae Strain F52 produced in liquid media with a high carbon concentration (36 g/L) and high C:N ratios (30:1, 50:1) were superior to MS preparations produced in low carbon (8 g carbon/L) media and a high carbon medium with a 10:1 C:N ratio. Bioassays using MS formulations of M. anisopliae strains MA1200 and TM109 produced in high carbon and high C:N ratio media were superior in efficacy to the other MS production media tested. MS preparations of M. anisopliae F52 showed superior efficacy against the sugarbeet root maggot in comparison with more conventional, conidia-covered nutritive (corn grit) granules in a clay and clay soil. The MS granules were also highly efficacious against the sugarbeet root maggot at soil moisture levels as low as 0.983 A _w (?2.33 MPa). Granular preparations incorporating Metarhizium MS can serve as a viable formulation for the use of this fungus against soil insects.     

A Chitinolytic Actinomycete Complex in Chernozem Soil

A chitinolytic actinomycete complex in chernozem soil has a specific taxonomic composition, which differs from that of the actinomycete complex typically isolated on standard nutrient media containing sugars and organic acids as carbon sources. The actinomycete complex that was isolated by using nutrient media with chitin as the source of carbon and nitrogen was dominated by representatives of the genus Streptosporangium, and the actinomycete complex that was isolated by using nutrient media with sugars and organic acids as the carbon sources was dominated by representatives of the genus Streptomyces. The confirmation of the ability of actinomycetes to utilize chitin as a sole source of carbon and nitrogen came from the augmented length and biomass of the mycelium, the increased number and biomass of the actinomycete spores, the production of carbon dioxide, and the accumulation of NH₄ ⁺ ions in the culture liquid of the actinomycetes grown in the nutrient media with chitin.     

Studies on the effects of carbon:nitrogen ratio, inoculum type and yeast extract addition on jasmonic acid production by Botryodiplodia theobromae Pat. strain RC1

Jasmonic acid is a native plant growth regulator produced by algae, microorganisms and higher plants. This regulator is involved in the activation of defence mechanisms against pathogens and wounding in plants. Studies concerning the effects of carbon: nitrogen ratio (C/Nr: 17, 35 and 70), type of inoculum (spores or mycelium) and the yeast extract addition in the media on jasmonic acid production by Botryodiplodia theobromae were evaluated. Jasmonic acid production was stimulated at the carbon: nitrogen ratio of 17. Jasmonic acid productivity was higher in the media inoculated with mycelium and in the media with yeast extract 1.7 and 1.3 times, respectively.     

甘蔗茎尖培养中减轻酚害

甘蔗茎尖组织预先在无菌水中浸泡30 min后,再接种到附加6-BA 2.0 mg·L-1、NAA 0.1 mg·L-1的MS培养基中,可减轻外植体的褐变;茎尖诱导培养基中直接附加适量的活性炭(AC,以0.02%为宜,最高不超过0.05%),减轻茎尖组织酚害的效果最理想.另外,在培养基中附加抗氧化剂(如:聚乙烯吡咯烷酮,PVP),或根据外植体的褐变情况及时转移到新鲜的培养基中,均能减轻甘蔗茎尖组织的酚害.     

Influence of food quality on growth and reproduction in Daphnia

SUMMARY. 1. Growth and reproduction were measured for Daphnia pulex (Leydig) fed Scenedesmus obliquus (Turp.) Kutz. grown with nitrogen-sufficient and nitrogen-deficient media. The incorporation of carbon into the body of D. pulex was traced using ¹⁴C-labelled algae and biochemical fractionation.
2. Scenedesmus cultured on N-defkient media allocated more carbon to lipid and less to protein than when cultured on N-sufficient media.
3. In a short-term feeding experiment, Daphnia accumulated more lipid when fed N-deficient algal cells high in lipid content than when fed algae grown on N-sufficient media that were lower in lipid.
4. Animals grew faster and produced larger broods when fed algae grown on an N-sufficient medium over an 8-day period. Daphnids fed N-deficient algae had higher quantities of body lipid, suggesting it was not a lack of energy which limited their growth and reproduction.
5. Daphnia fed algae grown on N-deficient media allocated more lipid to eggs, and their offspring lived longer under starvation conditions.     

不同碳源下毕赤酵母GS115蛋白组学分析

毕赤酵母(Pichia pastoris)表达系统是目前最为成功的外源蛋白表达系统之一。该表达系统不存在原核表达系统的内毒素难以除去的问题,也不存在哺乳动物细胞表达系统的病毒和支原体污染问题;并能够对目的蛋白进行类似于高等真核生物的信号肽剪切、二硫键形成、糖基化等蛋白翻译后加工。但是不论是胞内表达或是分泌表达,大多数外源蛋白均面临着被降解的问题,这也是影响目的蛋白表达量的一个重要因素,同时还增加了纯化目的蛋白的难度。目的:研究毕赤酵母GS115在不同碳源培养过程中胞内外蛋白质组学的差异,指导毕赤酵母表达系统的优化。方法:利用LC-ESI-MS/MS方法分析了不同碳源的四种培养基中毕赤酵母GS115的胞内和胞外蛋白种类,利用Griffin等的计算方法计算各个蛋白的含量。结果:利用LC-ESI-MS/MS结合Griffin等的归一化非标定量法SI_N得到GS115胞内胞外详尽的蛋白质种类及准确百分比含量。结论:分析不同培养基之间蛋白质组成的差异,从而为以后构建新的毕赤酵母表达体系,为外源蛋白表达系统的优化提供一定的指导意义。     

Effects of the addition of laminaran on β-glucosidase production by Trichoderma viride

β-Glucosidase production by Trichoderma viride WU-36B was studied in media containing laminaran. By the addition of laminaran to the medium containing glycerol as a carbon source, extracellular activities of β-glucosidase and β-1,3-glucanase increased but CMCase activity was not detected during whole culture period. Extracellular activities of β-glucosidase, CMCase, and β-1,3-gluconase were higher in the medium containing both avicel and laminaran than in the media containing avicel or laminaran as a sole carbon source.     

Glyoxylate cycle in Mucor racemosus.

The dimorphic phycomycete Mucor racemosus was grown in media containing acetate, glutamate, and peptone as carbon sources. The component enzymes of the glyoxylate bypass, isocitrate lyase and malate synthase, were present under these conditions throughout the growth cycles. Highest specific activities for each enzyme were found in media with acetate as the carbon source. In an enriched peptone medium containing glucose, neither activity was detected until glucose was exhausted from the medium. Treatment of acetate-grown cells with glucose resulted in a rapid decline in the specific activities of both enzymes. The importance of this cycle in acetate-grown cells was indicated by the ability of itaconic acid (100 mM) to inhibit the growth of M. racemosus in acetate but not glutamate media. Itaconate was also shown to be a potent inhibitor of isocitrate lyase activity in vitro.     

环境因素对香蕉叶斑病菌喙突脐蠕孢生长和产孢的影响

为进一步明确香蕉叶斑病菌喙突脐蠕孢的生物学特性,调查了部分环境因素(碳氮源、植物成分培养基)对供试菌株(CLER09、D087和JL05)的营养生长和产孢的影响。结果显示,分生孢子主要先从基部萌芽,在28℃下约培养10h后出现两端萌芽;供试菌株对测试的20种碳源及26种氮源显示相似的生长反应,均可利用除菊糖外的测试碳源及氮源进行营养生长和产孢;测试的6种植物成分培养基对供试菌株的营养生长效果皆优于PDA培养基;除燕麦培养基外,其余5种培养基对菌株CLER09和D087的产孢作用均优于PDA培养基;测试的6种培养基对菌株JL05的产孢作用均优于PDA培养基。不同植物成分培养基对该菌分生孢子形态影响较大,以米糠、象草培养基对菌株D087和JL05的分生孢子长度和玉米粉培养基对菌株CLER09的分生孢子宽度的增长效果最为明显。