紫色红曲霉Mp-24高产Monacolin K发酵工艺响应面优化

将单因素实验结果与响应面法相结合,对高产Monacolin K的紫色红曲霉Mp-24菌株进行发酵工艺条件优化。通过摇瓶发酵对碳源、氮源、碳源含量、氮源含量、培养时间等进行单因素优化,确定Mp-24菌株摇瓶发酵适宜条件：乳糖为碳源、酵母膏为氮源、碳源含量7%、氮源含量2%、培养时间12 d,Monacolin K产量为167 mg/L。应用Box-Behnken中心组合试验设计建立数学模型,进行响应面分析优化发酵条件,结果显示最佳发酵工艺条件为：碳源(乳糖)8%,氮源(酵母膏)3%,培养时间11 d,在此条件下Monacolin K的含量达到247.8 mg/L,比优化前提高1.5倍。     

金针菇液态发酵培养基的筛选

研究不同碳源、氮源及无机盐对金针菇菌丝体产量的影响,采用正交设计法进行金针菇液态发酵培养基配方筛选和优化,确定了最佳培养基配方为大米粉3%、酵母粉1%、KH2PO40.1%、MgSO4.7H2O 0.05%。同时利用此配方培养测定了发酵过程pH、还原糖和氨基氮含量的变化,结果表明:发酵过程中pH变化很小,培养末期略有上升;还原糖含量呈先增后降的变化,氨基氮含量呈上升趋势。     

嗜热菌Anoxybacillus sp.产淀粉酶培养基优化及产酶条件研究

目的:对产淀粉酶嗜热菌Anoxybacillus sp.菌株进行培养基优化及产酶条件研究,以便提高菌株的产酶能力,并为下一步菌株的诱变育种研究提供基础。方法:常规方法液体培养菌株,用平板初筛和DNS法复筛选择产淀粉酶能力较高的菌株;单因素筛选培养基最适的碳源、氮源、Ca~(2+)浓度和Mg~(2+)浓度,对单因素筛选的最佳碳源、氮源、Ca~(2+)和Mg~(2+)的三个较佳浓度进行四因素三水平正交试验优化培养基;对培养基不同p H值及不同培养温度进行培养条件研究。结果:产淀粉酶菌株筛选结果显示:六株菌中淀粉酶酶活力值最大的是菌株DL4,差异有统计学意义(P0.05)。培养基单因素筛选结果显示:最适碳源为麦芽糖、最适氮源为硝酸铵、最适Ca~(2+)、Mg~(2+)浓度均为0.02%,差异有统计学意义(P0.05)。培养基优化结果显示:C源0.1%,N源0.2%,Mg~(2+)0.04%,Ca~(2+)0.04%为最佳的培养基成分组合。产酶条件筛选结果显示:培养基p H值为6、培养温度为55℃时菌株产酶水平最高,差异有统计学意义(P0.05)。结论:培养基的优化及最适的产酶条件能提高嗜热菌Anoxybacillus sp.DL4产淀粉酶能力,Ca~(2+)、Mg~(2+)离子对菌株产淀粉酶有促进作用。     

黑曲霉GD-6纤维素酶液体发酵条件的研究

采用黑曲霉 (Aspergillusniger)GD 6液体发酵生产纤维素酶 ,研究了碳源、氮源、培养基起始 pH值、接种量、摇床转速、通气量对该菌株产纤维素酶活力的影响。结果表明 ,GD 6的最适发酵温度为 2 8～ 3 0℃ ,产酶pH为 5 .5～ 6.0 ,摇床最适转速为 1 5 0r/min ,最佳接种量为 1 0 %。在以 6.0 %稻草粉为碳源、1 %豆饼粉为氮源时产酶活力最高。在最适培养条件下 ,发酵周期为 1 2 0h,发酵液中CMC酶活为 1 88.6U/mL ,FP酶活为 2 7.0U/mL。     

营养要素对原油降解菌生长的影响

目的:研究营养要素对原油降解菌生长的影响.方法:通过紫外分光光度计于600nm处测量菌体OD值检测6种碳源、5种氮源、无机离子含量和氯化钠含量对原油降解菌K5生长的影响.通过正交实验确定了原油降解菌K5生长的最佳营养条件.结果:当蔗糖含量0.6%、硫酸铵含量0.2%、氯化钠含量0.6%、微量元素含量0.1%时,原油降解菌生长得最好.结论:确定了原油降解菌K5生长的最佳营养条件,并且发现了培养基中的氮源和碳源对菌体生长量的影响最大以及不同微量元素对菌体生长量有不同程度的促进或抑制作用.     

毛栓菌(Tramets trogii)液体培养产漆酶的研究

实验研究了碳源、氮源和综合因素对毛栓菌(Tramets trogii)液体培养产漆酶和生长情况的影响。碳源为玉米面、氮源为豆饼粉时,菌株的产漆酶酶活最高;碳源为可溶性淀粉,氮源为麦麸时,对菌株的生长有利;在液体条件下,菌株产漆酶的最佳培养基组成为玉米面3.5%,豆饼粉4.0%,KH2PO40.3%,MgSO40.15%,VB10.04%。     

米曲霉(Aspergillus oryzae)FSO179产α-淀粉酶固体发酵优化的研究

米曲霉(Aspergillus oryzae)FSO179产α-淀粉酶固体发酵优化结果表明:最佳有机碳源为玉米粉,最佳有机氮源为花生饼粉;培养基正交试验表明最佳培养基配方为:花生饼粉20%,玉米粉5%,无机盐为c组配方;初始发酵pH为7.4;最适的发酵温度为33℃;在以上最适条件下固体培养6d,发酵产酶水平可达1300.6u/g,优化结果比初始设计提高了42.9%。该酶酶学特性研究表明:该酶作用的最适温度为55℃;最适作用pH为4.0;Fe2 、Ba2 、Cu2 、Mn2 、Fe3 金属离子对酶具较强抑制作用,而Ca2 对酶具有一定激活作用。     

Study on fermentation hypocrellin by Shiraia bambusicola in submerged cultures

先对不同产地采集的竹黄菌进行筛选,得到优产竹红菌素的菌株,然后采用单因子和3因素3水平正交试验法对竹红菌素液体发酵条件进行优化,在优化培养基的基础上,选用不同浓度的Cr3+、Fe3+、Cu2+和Ca2+对竹红菌素进行离子调控研究.结果表明:从休宁所采集的菌株不仅生长速度最快,发酵所产的竹红菌素含量也最高;竹红菌素最佳发酵碳源是葡萄糖,最佳发酵氮源是硝酸钠,最佳培养基组合为2%葡萄糖,0.2%硝酸钠,pH7.5;Cr3+和Fe3+浓度为0.005%时竹红菌素含量均最高;0.05%的Ca2+最有利于竹红菌素的分泌;Cu2+为0.03%时竹红菌素含量达到最大值.     

竹黄菌液体发酵条件的优化

目的：筛选并优化竹黄菌液体发酵培养基。方法：采用单因子和3因素3水平正交试验法,从生物量和竹红菌素两方面筛选碳源、氮源和pH,探讨该菌生长的最佳培养条件。结果：最佳发酵碳源是葡萄糖,最佳发酵氮源是硝酸钠。竹红菌素生长的最佳配方为2%葡萄糖,0.2%硝酸钠,pH7.5;菌丝体生长的最佳组合为2%葡萄糖,0.3%硝酸钠,pH7.5。     

Alkalitalea saponilacus产木聚糖酶的碳源优化及酶学特性

【目的】确定厌氧盐碱细菌Alkalitalea saponilacus产木聚糖酶所需的碳源,优化木聚糖粗酶的提取条件并分析酶学性质。【方法】应用GC技术分析A.saponilacus发酵木聚糖的主要产物;利用二硝基水杨酸法(DNS)测定木聚糖酶活力以获得最优的碳源、提取粗酶的最佳条件及其酶学特性。【结果】A.saponilacus以不同来源木聚糖为底物时,发酵产生的主要产物丙酸含量都在80%以上。若以0.4%(W/V)蔗糖+0.1%(W/V)桦木木聚糖为复合碳源时,木聚糖酶活力是以桦木木聚糖或者蔗糖为单一碳源时的3.2倍。木聚糖酶的酶活力在盐度2%–6%、pH 7.0和55°C达到最佳且在该条件下的酶活力为590 IU/mg。此外,该酶活力在0.2%Tween 20存在时增加,而在5 mmol/L Mg~(2+)和0.2%Triton X-100存在时无显著影响,但在Cu~(2+)、Fe3+和Ni~(2+)等金属离子存在时则被显著抑制。【结论】A.saponilacus发酵主产物丙酸以及生物合成的木聚糖酶在工业生产中具有广泛的应用前景。     

Influence of plant growth hormones on the growth of Mucor rouxii and chitosan production

Supplementation of molasses-salt medium with plant growth hormones, viz., indoleacetic acid, indolebutyric acid, kinetin and gibberellic acid, increased chitosan production by Mucor rouxii as well as its growth at different optimum concentrations. The increase in yield of chitosan was found to range from 34% to 69% and mycelial growth from 12% to 17.4%. Gibberellic acid was the most potent in this respect. Sixty-nine percent more chitosan over the control could be obtained from 1l of the medium supplemented with 3mg gibberellic acid. Degree of acetylation of chitosan ( approximately 13%) was not changed due to addition of hormone in the medium but weight average molecular weight of chitosan increased by more than 50%. Thus, the plant growth hormones add a value to chitosan by increasing its molecular weight.     

Morphological mutants of Gibberella fujikuroi for enhanced production of gibberellic acid

AIMS: To examine the production of gibberellic acid by selected morphological mutants of Gibberella fujikuroi in liquid cultures. METHODS AND RESULTS: Mutants of G. fujikuroi having different morphological characteristics were selected after UV irradiation. The production of gibberellic acid by mutants that had different hyphal lengths was examined in shake flasks in media with different concentrations of nutrients as well as different volumes of the medium. Fed-batch fermenter study was performed to evaluate the mutant Mor-25 for growth and production of gibberellic acid. The broth was analysed by high performance liquid chromatography for fusaric acid, the common mycotoxin produced by strains of Fusarium. A variety of morphological mutants having different mycelial and soluble pigmentation as well as colony morphologies were generated from G. fujikuroi upon exposure to UV radiation. A nonpigmented mutant (Car-1) was selected as intermediate parent and later, mutants Mor-1 and Mor-25 were selected based on their distinct morphology. The colonies on regeneration agar plates were small, compact and dry. In liquid medium, mutant Mor-25 grew in a micro-pelleted form and the mycelium had short, highly branched hyphae, curly at tips with thick, swollen cells. Mutant Mor-25 grew rapidly in a low-cost medium containing defatted groundnut flour, sucrose and salts. In media with higher nutrient concentrations as well as larger volumes, it produced twofold more gibberellic acid than the parent. Fusaric acid, the common mycotoxin, was absent in the fermentation broth of mutant Mor-25. The mutants have been deposited in National Collection of Industrial Microorganisms (NCIM), National Chemical Laboratory, Pune, India under following culture collection numbers (Car-1, NCIM 1323; Mor-1, NCIM 1322; and Mor-25, NCIM 1321). CONCLUSIONS: Growth of unpigmented, morphological mutants of G. fujikuroi that led to lower viscosity in fermentation broth resulted in increased production of gibberellic acid. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of morphological mutants that have lower viscosity in liquid cultures for gibberellic acid production is not reported earlier. Similar mutants can be useful for other types of fungal fermentations also.     

Paecilomyces sp. ZB is a cell factory for the production of gibberellic acid using a cheap substrate in solid state fermentation

Gibberellic acid from the fungi has been widely used in agriculture. In this study, more than 20 fungal isolates were screened and Paecilomyces sp. ZB shown to produce more gibberellic acid than other fungal isolates. Cow dung was used as low cost substrate for gibberellic acid production in solid state fermentation (SSF). Carbon, nitrogen and ionic sources stimulated gibberellic acid production in SSF. Lactose emerged as the significant carbon source supporting more gibberellic acid production (731 µg/g). Among the nitrogen sources, glycine appeared to influence the production of more gibberellic acid (803 µg/g). The process parameters were optimized to enhance gibberellic acid production using a two-level full factorial design and response surface methodology. The amount of gibberellic acid production was influenced mainly by moisture and pH of the substrate. Gibberellic acid production was 1312 µg/g under the optimized conditions and the predicted response was 1339 µg/g. The gibberellic acid yield increased twofolds after medium optimization. The extracted gibberellic acid was sprayed on the growing Mung bean plant and it stimulated the growth of the plant effectively. To conclude, cow dung is a new alternative to produce gibberellic acid in SSF.     

Physiology-biochemical properties of the cyanobacterium <Emphasis Type="Italic">Oscillatoria deflexa</Emphasis>

The optimal cultivation conditions for the cyanobacterium Oscillatoria deflexa were studied: temperature (25–27°C), pH (9.0–11.0), and illumination (7 klx). A nutrient medium providing for optimum cyanobacterium growth was selected, as well as media containing an aqueous extract of human urine ash and an inedible material of wheat and vegetables with added nitrates and bicarbonate. The chemical composition (macro and microelements, content of proteins, lipids, carbohydrates, and vitamins, amino acid and fatty acid composition, ash residue) of O. deflexe was studied for the first time. An analysis of the results indicates that O. deflexa is not inferior to the cyanobacterium Spirulina platensis and the green laver Chlorella vulgaris in practical use, for its mineral composition, content of vitamins, essential amino acids and fatty acids, and exceed them in its content of vitamin E and microelements, such as Fe, Mn, Ni. The bacterium’s ability to transport NaCl up to 30 g/l within the medium was studied, and its unique ability for survival and long-term storage was shown. The enhibitory effect of the biomass of O. deflexa on the germination of wheat grains, and growth of daphnids and rotifers was shown.     

Effect of exogenous gibberellic acid,abscisic acid,and benzylaminopurine on epicotyl dormancy of cultured herbaceous peony embryos

Epicotyl dormancy was broken in cultured peony (Paeonia lactiflora Pall.) embryos after topical application of agarose gels containing gibberellic acid, with optimum growth at 1.5 mM gibberellic acid. Addition of 100 M abscisic acid to the medium resulted in complete inhibition of gibberellic acid-stimulated promotion of dormant epicotyls. Epicotyl dormancy was also broken in embryos by culture on media containing 1 or 10 M benzylaminopurine. A highly significant increase in leaf number occurred when embryos were both cultured on medium containing benzylaminopurine and treated topically with gibberellic acid. Anatomical and morphological studies indicated that the increase in shoot growth was due to the development and growth of 1) buds formed at the cotyledonary node, 2) axillary buds, and 3) adventitious meristems originating from subepidermal parenchymatous tissue.Abbreviations ABA abscisic acid - BA N⁶-benzylaminopurine - DMSO dimethyl sulfoxide - GA₃ gibberellic acid - LS Linsmaier and Skoog     

Plant regeneration of Solanum lycopersicoides Dun. from stem explants,callus and suspension cultures

Protocols were established for achieving plant regeneration from stem internode, callus, and cell suspension cultures of Solanum lycopersicoides Dun. Two accessions of S. lycopersicoides exhibited different responses as to callus formation on various media, requirement of gibberellic acid for shoot regeneration, and ability to grow in suspension culture. The optimum medium for initiation and maintenance of cell suspension cultures was Murashige and Skoog [9] medium with 15 mg l^– NAA. For shoot regeneration, of three cytokinins tested, zeatin was found most effective relative to number, rapidity of response and overall quality of shoots. Shoot regeneration from stem explants, callus and suspension cultures was optimum on MS + 3.0 mg l^–1 zeatin + 0.1 mg l^–1 gibberellic acid.Michigan Agricultural Experiment Station Journal Article No. 11589.     

Somatic embryogenesis and plant regeneration from hypocotyl protoplasts of sunflower (Helianthus annum L.)

A sunflower genotype (Helianthus annuus L. cv. Florom-328) able to regenerate plants from in vitro cultures was identified by screening hybrids and inbred lines. Protoplasts of this genotype were isolated from dark grown hypocotyls and were cultured in droplets of agarose-solidified V-KM medium covered by liquid V-KM supplemented with naphthaleneacetic acid (NAA) and benzylaminopurine (BAP). One week later colonies were subjected to 2,4-dichlorophenoxyaceticacid for a one week period. Further culture in V-KM with reduced concentrations of NAA and BAP resulted in the appearence of somatic embryos. Maturation of embryos was achieved by culture on MS medium supplemented with NAA, BAP, gibberellic acid A₃ and the ethylene inhibitor AgNO₃. Embryos were then transferred onto hormone free MS medium for germination. The frequency of shoot formation in the best case was 9.6 percent of viable colonies (1.3 percent of protoplasts plated). Some of the shoots with roots could be transplanted into soil, others were grafted on hypocotyls of in vivo germinated seedlings. Eighty percent of grafted shoots and over 95 percent of rooted shoots survived. The plants flowered and produced 5 to 10 seeds each. Factors affecting the frequency of embryo formation and plant regeneration are discussed.Abbreviations BAP 6-benzylaminopurine - GA3 gibberellic acid - MES morpholinoethanesulfonic acid - MS Murashige and Skoog medium - NAA naphthaleneacetic acid - V-KM protoplast culture medium of Binding and Nehls - 2,4D 2,4-dichlorophenoxyacetic acid     

Gibberellic acid biosynthesis from whey and simulation of cultural parameters

This article examines the potential of lactose from whey permeate as a substrate for gibberellic acid production. In addition, the paper reports the derivation of mathematical models which simulate the various fermentation conditions to predict precise values. Of the five Fusarium moniliforme isolates screened for their ability to synthesize the gibberellic acid, F. moniliforme-1 proved to be the best strain (670 mg gibberellic acid/l) when fermentation was carried out at 28°C for 12 days. The product started to accumulate at the end of maximum growth phase (day 9) and continued until the curve reached a plateau (day 12). From the observed data and expected values, a temperature range of 27–30°C, pH range of 3.5–5.5 and an inoculum level of 10–12.5% (v/v) were considered optimal for attaining the highest product yield. However, nitrogen sources supplemented in whey permeate medium suppressed the ability of the culture under study to synthesize metabolite and utilize lactose.     

The development of dormancy in bulblets of Lilium speciosum generated in vitro

We have studied the effect of various in-vitro conditions on dormancy of bulblets generated on scale explants of Lilium speciosum Thunb. cv. Rubrum nr. 10. The bulblets were harvested after 11 weeks of culture. Dormancy was measured by determining the percent emergence in soil of viable, non-cold-treated bulblets. A study of the physical conditions showed that temperature had a strong effect on the induction of dormancy (15°C induced hardly any dormancy; 25°C induced a high level of dormancy), whereas short or long day and light or dark had no effect. Of the medium components, a low concentration of sucrose (1 gl^–1 or less) or a high concentration of gibberellic acid (1 mg 1^–1) reduced the level of dormancy. Application of various concentrations of abscisic acid, 6-benzylaminopurine, -naphthaleneacetic acid, indole-3-acetic acid, 2,3,5-triiodobenzoic acid or a Murashige and Skoog macro- and microelement mixture did not affect the dormancy status.Abbreviations ABA abscisic acid - BAP 6-benzylaminopurine - GA₃ gibberellic acid - IAA indole-3-acetic acid - MS Murashige & Skoog macro- and microelements - NAA -naphthalene-acetic acid - TIBA 2,3,5-triiodobenzoic acid     

Barley aleurone layers secrete a nuclease in response to gibberellic Acid : purification and partial characterization of the associated ribonuclease, deoxyribonuclease, and 3'-nucleotidase activities

Incubation of barley (Hordeum vulgare L. cv Himalaya) half-seeds with gibberellic acid enhances the secretion of ribonuclease and deoxyribonuclease from aleurone tissue (MJ Chrispeels, JE Varner 1967 Plant Physiol 42: 398-406; L Taiz, JE Starks 1977 Plant Physiol 60: 182-189). These activities were over 50-fold greater in medium of half-seeds incubated with gibberellic acid than in control medium. Ribonuclease and deoxyribonuclease activities initially appeared in the medium 24 to 48 hours after hormone induction and increased for up to 96 hours. Both activities had a pH optimum of 6.0 and a temperature optimum of 55°C. When the medium from gibberellic acid-treated half-seeds was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, the major ribonuclease and deoxyribonuclease activity bands comigrated. The two enzyme activities remained associated throughout a 2,700-fold purification employing ammonium sulfate fractionation, Heparin-Agarose affinity chromatography, and Reactive Blue 2-Agarose affinity chromatography. Also accompanying the ribonuclease and deoxyribonuclease activities throughout purification was the ability to hydrolyze the 3′-phosphoester linkage of 3′-AMP. The purified protein was composed of a single polypeptide with an apparent molecular weight of 36 kilodaltons as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. It is concluded that in response to gibberellic acid, barley aleurone tissue secretes a nuclease having ribonuclease, deoxyribonuclease, and 3′-nucleotidase activities.