Study on the Fermentation Conditions of a Mucopolysaccharide-producing Bacterium LV-1

bacterium LV-1 which isolated from soil sample were studied bacterium was isolated by serial dilution method, the effects of carbon source, nitrogen source, the initial pH and temperature on producing polysaccharide by it were discussed to confirm the optimum fermentation conditions. [ Result] The physicochemical properties showed that the polysaccharide was water-soluble, but insoluble in organic solvents including ethanol, butanol, and chloroform. It was neutral polysaccharide with negative charge and without reducing terminal. The pH of its solution was pH =7.5. There were no protein, fructose, uronic acid, sulphate and starch-like structure included in po/ysacchadde molecules. The optimum fermentation conditions for po/ysaccharide produc- tion were 3% mannitol as carbon source, 0.25% yeast extract as nitrogen source, culture temperature 28 ~（3 and pH =7.5. [Coadu^en] The re- search could provide basis for development and utilization of LV-1 and industrialized production of mucopolysaccharide.

Study on Fermentation Conditions of Pycnoporus sanguineus

[Objective] The purpose was to study the optimum conditions of Pycnoporus sanguineus for producing ligninase. [Method] A strain of lignindegrading white-rot fungus was selected from 5 strains of collected fungi and its ligninase production and the optimum conditions for producing ligninolytic enzyme were measured. [Result] It could produce two kinds of ligninase with good thermal stability. Different temperatures, carbon sources, nitrogen sources, acidities, as well as the additions of surfactant had distinct influence on the development of lignin-degrading enzymes of the fungus. The optimum condition was drawn out：38℃, pH = 4.5, 10.0 g/L glucose, 1.0 g/L tartaric acid ammonium. [Conclusion] The aim of research was to provide a basis for lignin degradation in practical production.

Research on the Fermentation Conditions of Bacillus subtillus B-332

[Objective] The paper was to ascertain the fermentation conditions and medium formula of Bacillus subtilis B-332. [Method] Using single factor and orthogo- nal experimental designs, the fermentation medium and culture conditions for B. sub- i tills B-332 were optimized through shaking flask culture. [Result] The optimal culture and inoculation time was 18 h, and the optimized medium formula was as follows： soybean powder 0.60 g/L, sucrose 0.25 g/L, ammonium sulfate 0.07 g/L, trisodium citrate 0.03 g/L, dipotassium hydrogen phosphate 0.003 g/L, magnesium sulfate 0.005 g/L, ferrous sulfate 0.000 5%; the fermentation condition was as follows： tem- perature 30 ℃, shaking bed speed 180 r/min, shaking bottle volume 80 ml/500 ml. In the optimal fermentation conditions, the fermented spore quantity was 1.43×10^11 cfu/ml, which was 34.48 times higher than the spore quantity of 4.03×10^9 cfu/ml in initial condition. [Result] The study laid the foundation for factory production of the strain.

Study on Fermentation Conditions of Trichoderma aureoviride sp.for the Production of Chitinase

[Objective] The paper was to study the best fermentation conditions of Trichoderma aureoviride sp. for the production of chitinase, thus provide new enzyme source for chitinsse industry. [Method] Using orthognnal experimental design, with the variation of sugar content after enzymatic hydrolysis measured by DNS method as the indicator, the fermentation conditions were optimized. [Result] Taking colloidal chitin as the carbon source and 2% peptone as the nitrogen source with the shaking speed of 170 r/rain, the optimum fermentation conditions of T. aureoviride for the production of chitinase were as follows ： initial pH value of medium, 5.0; inoculation amount, 8% ; bottle volume, 20 ml; 6 d cultivation at 28℃. [Conclusion] The optimum conditions for the production of chitinase were confirmed, which provided basis for the utilization of T. aureoviride.

Study on Identification and Fermentation Condition of Strain ZY-19-2 with Inhibitory Effect against Tobacco Black Shank (Phytophtora parasitica var. nicotianae Tucker)

[Objective] The paper was to identify stain ZY-19-2 with inhibitory effect against tobacco black shank （Phytophtora parasitica var.nicotianae Tucker）, and study the fermentation condition of the strain. [Method]A strain ZY-19-2 with strong inhibitory effect against P. parasitica were isolated and screened from tobacco rhizosphere soil samples, and identified according to its morphological characteristics. The chitinase production activity of the strain under different culture conditions was also studied. [Result] For stain ZY-19-2 Paecilomyces lilacinus, the optimal fermentation conditions were as follows： 1.2% colloidal chitin as carbon source, 1% peptone as nitrogen source, 0.1% Tween 80 as surfactant, initial pH of fermentation broth at 6.0, the fermentation time of 60 h, inoculum amount at 1%, shaker speed at 120 r/min. The highest enzyme activity reached 0.216 U/ml. [Conclusion]The optimization of fermentation condition of strain ZY-19-2 lay foundation for large-scale production of cheap and efficient chitinase and chitin oligosaccharides, as well as application of the strain for control of tobacco black shank.

Optimization of Fermentation Medium and Conditions of Antibiotic Active Substances Produced by Antarctic Psychrotrophic Bacterium Rheinheimera sp. 97

[Objective] The aim was to optimize the fermentation medium and conditions of antibiotic active substances produced by Antarctic psychrotrophic bacterium Rheinheimera sp.97.[Method] Single-factor experiment and orthogonal test were adopted to optimize the fermentation medium of antibiotic active substances produced by Antarctic psychrotrophic bacterium R.sp.97,while the fermentation conditions were optimized by single-factor experiment.[Result] The optimum fermentation medium for the antibiotic active substances production was as follows：tryptone 3.0 g/L,ammonium sulfate 1.0 g/L,starch 2.0 g/L,NaCl 15.0 g/L.The optimized fermentation conditions were as follows：the starting pH of medium was 8.0,fermentation temperature was 10 ℃,liquid volume in Erlenmeyer flask was 30 %（V/V）and inoculation amount was 1%（V/V）.Under the optimized fermentation medium and conditions,the antibacterial activity of R.sp.97 was increased by 18.1%.[Conclusion] This study had provided basis for the antibiotic active substances produced by Antarctic psychrotrophic bacterium R.sp.97.

Optimization of Fermentation Conditions for Xylanase Production by Aspergillus niger NS-1

In this study, a xylanase-produeing Aspergillus niger strain, NS-1, was screened and isolated from agricultural and forestry wastes. Based on single-fac- tor experiments, the effects of different carbon sources, composite carbon sources, nitrogen sources, calcium carbonate concentrations, initial pH and surfactants on xylanase production by A. niger NS-1 were investigated. The results indicated that the most appropriate carbon source was corncobs ; the best composite carbon source was corncobs ＋ xylan, which was conducive to xylanase secretion; the most suitable nitrogen source was ammonium sulfate. Xylanase activity reached the highest in the medium added with 1.5% calcium carbonate and SDS as a surfactant with an initial pH of 5.0. This study provided the basis for the production of high-activity xylanase.

Effect of cultivating conditions on α-galactosidase production by a novel Aspergillus foetidus ZU-G1 strain in solid-state fermentation

The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain ,Aspergillusfoetidus ZU-GI in solid-state fermentation （SSF）. Certain fermentation parameters involving moisture content, incubation temperature, cultivation period of seed, inoculum volume, initial pH value, layers of pledget, load size of medium and period of cultivation were investigated separately. The optimal cultivating conditions of α-galactosidase production in SSF were 60% initial moisture of medium, 28 ℃ incubation temperature, 18^h cultivation period of seed, 10% inoculum volume, 5.0-6.0 initial pH of medium, 6 layers of pledget and 10 g dry matter loadage. Under the optimized cultivation conditions, the maximum α-galactosidase production was 2037.51 U/g dry matter near the 144th hour of fermentation.

DES Mutagenesis of Antagonistic Streptomyces of Botryosphaeria dothidea and Optimization of Its Fermentation Conditions

[ Objective] The paper wag to improve the antimicrobial effect of antagonistic Streptomyces on Botryosphaeria dothidea. [ Method ] Different concentrations of DES were adopted for mutagenic treatment of antagonistic Streptomyces F-58. After fermentation, the mutant strain numbered F-58-06 with genetic stability and good antimicrobial effect was selected among 200 mutant strains; the biological activity of the strain was determined with B. dothidea as the indicator fungus, and the best concentration of DES wag 2%. The fermentation conditions of antagonistic substances of Streptomyces strain F-58-06 produced in shake flasks were opti- mized using the method of single factor and orthogonal experimental design. [ Result] The optimal fermentation conditions were carbon source corn flour, nitrogen source KNO3, initial pH 7, loading volume 30 mL in 250 mL shake flask, inoculation volume 3%, incubation time 132 h. Based on orthogonal experiments, the best cultured medium ratio was corn flour 4%, KNO3 0.5%, CaCO3 0.2%, NaCI 0.35%, MgSO4 · 7H2O 0. 15%. [ Conclusion ] After mutation and optimization of culture medium, the antimicrobial activity of Streptomyces F-58 was greatly improved, and the average inhibition zone diameter was 1.35 times of that of the original strain.

THE APPLICATON OF ULTRASOUND TO THE DI-ALKYLATION AND CYCLO-DI-ALKYLATION OF ETHYL CYANOACETATE UNDER SOLID-LIQUID PHASE TRANSFER CONDITIONS

Comparative experiments show that ultrasonic irradiation reduces the reaction times and improves the yields in the di-alkylation and cyclo-di-alkylation of ethyl cyanoacetate under solid-liquid phase transfer conditions.

Production of Protein Feedstuff by Mixed Fermentation of Waste Lees

[ Objective] To produce protein feedstuff by mix fermentation of waste lees. [ Method] Waste lees was fermented by mixture of Aspergillus niger, Trichoderma vinde and Candida tropicalis to produce protein feedstuff. The fermentation conditions were optimized by single factor test and orthogonal test. [ Result] The optimum fermentation conditions of waste lees are as following： raw materials with fineness of 20 meshes composed of waste lees of 750 g/kg, com meal of 50 g/kg and wheat bran of 200 g/kg; pH value of inoculum culture, 5.0; Aspergillus niger： Trichoderma viHde： Candida tropicalis, 1 ： 1 ： 1 ; inoculum size, 12% （V/V） ; fermentation temperature, 30 ℃; and fermentation time, 6 d. After fermentation, the crude protein content, pure protein content, and crude fiber content were increased by 78.97%, 56.29% and 31.60%, respectively. In addition, the fermented waste lees was rich in beneficial live microorganisms and bioactive substances such as enzymes and vitamins. [ Conclusion] Waste lees can be well fermented to produce protein feedstuff by mix fermentation.

Investigation between Different Amount of Crude Fiber and Fermentation in the Rumen by Beef Suckler Cows

Body condition of suckler cows at the time of calving has an important effect on calving ease and mortality of calves.In the last eight weeks before calving the body condition should be reduced or at least not increased.Rations with a higher amount of crude fibre can be used(rations with straw or late mowed grass silage(GS))to control the body condition score.Eight suckler cows(Charolais)were feeding a total mixed ration(TMR)in the last eight weeks before calving and GS after calving.By the addition of straw(30%in TMR1 vs 60%in TMR2 of dry matter)was varied the amount of crude fibre in the TMR(GS,straw,mineral)before calving.In the period after calving were GS feeding.Last measurement took place on the pasture(PS).Rumen fluid,plasma,body weight and back fat thickness were collected.Rumen fluid pH was assessed immediately after collection using an electronic pH meter.Volatile fatty acids(VFA),sedimentation,methylene-blue and amount of infusorians were measured.From four key figures an“index of rumen fermentation”(IRF)in the rumen was formed.Statistical analysis took place with analysis of variance(ANOVA)with fixed effects of treatment(TMR1,TMR2,GS and PS)and number of lactations(3-7 lactations)using SPSS Version 25.0 for Windows.Rumen fluid pH had significant differences between variants(TMR1 by 6.6,TMR2 by 6.9,GS by 6.6 and PS by 6.9),but was not affected by other effects.The IRF showed a disturbed fermentation in the rumen by feeding the TMR 1+2 with high amount of crude fibre(score:>10.0 points)and a very good situation for fermentation during grazing the PS(score:6.9 points).The long-term use of crude fibre-rich rations in the period before calving may cause deviations from undisturbed fermentation in the rumen and adversely affect the utilization of the feed in the rumen.

Optimization of the Culture Conditions for the Endophytic strain 4-3

Bacillus amyloliquefaciens 4-3 is an excellent plant endophyte that can be used as a good raw material for microecological preparations.For this reason,it is important to optimize the culture conditions of this strain.The number of viable bacteria of strain 4-3 in this study was the evaluation index,and the culture conditions of the liquid fermentation were optimized by single factor experiment.The optimized culture condition was as follows:incubating temperature 32°C,initial pH value 7.2,rotation speed 220 r/min,inoculum concentration 3%and incubating 56 h,under which higher concentrations of Bacillus amyloliquefaciens could be obtained.

Biogenic Amines Profile of Serbian Traditional Sausage in Relation to Raw Material and Production Conditions

Petrovska klobasa is a traditional dry fermented sausage produced in the Autonomous Province of Vojvodina. Formation of nine hiogenic amines was determined in three sausage groups produced from hot deboned （A1） and cold meat （B1, B3） during drying and ripening in traditional room （A1, B1） and in industrial ripening chamber （B3）. Dansyl chloride derived amines were analysed by high-performance liquid chromatography with diode-array detector （HPLC-DAD） on Eclipse XDB-C18 column. Histamine, the most important amine from food safety point of view, was not found in any of the analyzed samples. Serotonin and spermidine were also not detected in any samples, while spermin was determined in all analyzed samples. At the end of drying, phenylethylamine was the predominant amine in A1 sausage group （51.6 mg/kg）, and tryptamine in B1 （38.1 mg/kg） and B3 （28.7 mg/kg） sausage groups. At the end of ripening, tryptamine was the predominant biogenic amine in all sausage groups （133, 121 and 39.8 mg/kg in A1, B1 and B3 groups, respectively）. Total level of biogenic amines in all investigated sausages did not exceed 174 mg/kg at the end of drying and 238 mg/kg at the end of ripening period. Tryptamine and cadaverine may be used as indicators of total biogenic amines for sausages produced in traditional and indusrial conditions from hot deboned and cold meat.

生防枯草芽孢杆菌Czk1固体发酵工艺条件优化

枯草芽孢杆菌(Bacillus subtilis)Czk1是一株具广谱拮抗、促生和诱导植株产生抗病性的根际益生菌。为了全面资源化利用农业废弃物中的有机养分和促进对植物土传病害的生物防治,本研究以Czk1为研究对象,以鸡粪为底肥,分别利用玉米秸秆、菌糠、椰糠堆肥为原料,采用液固两相发酵工艺,以稀释平板菌落计数法测定活菌总数和芽孢数,经过单因素和正交试验方法,明确Czk1固体发酵物料的配方、工艺参数和培养条件。得出Czk1固体发酵的最优条件:最佳原料为菌糠鸡粪堆肥,Czk1接种重量为10%,黄豆粉添加量为10%,含水量为40%,发酵温度为37℃,翻抛1次/72h,在此条件下,Czk1菌株中的芽孢活菌数量总量可以达到8.63×10^(8)CFU/g,芽孢数为8.37×10^(8)CFU/g。其次,发酵效果较佳的原料为秸秆鸡粪堆肥,Czk1接种量为10%,添加5%黄豆粉,40%含水量,发酵温度为37℃,翻抛1次/72 h,此条件下,Czk1接种菌株中的活菌数量总量可达到6.53×10^(8)CFU/g,芽孢数为5.97×10^(8)CFU/g;另外,在此配方条件下再添加30%菌糠,Czk1菌株的活菌数量总量及芽孢数分别可达到8.70×10^(8)CFU/g和6.90×10^(8)CFU/g。4种发酵生物肥原料的理化性质测定表明,其有机质含量、碳氮比均有较大差异,其中以鸡粪为原料其pH、全磷和全钾含量均最高,碳氮比最低,氮、磷、钾总含量均高于秸秆、椰糠和菌糠;秸秆为原料其电导率、有机质含量最高;椰糠为原料其全氮含量最高,菌糠为原料碳氮比最高。不同鸡粪与菌糠、秸秆及椰糠组合的生物有机肥的种子发芽指数均大于80%。因此,枯草芽孢杆菌Czk1具有良好的开发利用价值,选择合适的发酵生产条件可将农业废弃物制备出高质量的生物有机肥。

花生粕发酵工艺条件优化及其提取物体外抗氧化活性研究

试验以花生粕为原料,利用乳酸菌、芽孢杆菌和酵母复合发酵技术进行固态发酵,探究不同含水量、接种量、发酵时间对发酵花生粕体外抗氧化活性的影响。利用3因素3水平的响应面试验设计对花生粕发酵条件进行优化,以发酵花生粕水溶性提取物对1,1-二苯基-2-三硝基苯肼(DPPH)清除率为评价指标,确定最适发酵条件。同时考察提取物对2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐自由基(ABTS^(+)·)、羟自由基(·OH)、DPPH自由基清除率和铁还原能力的影响,来评估其体外抗氧化活性。响应面优化结果为含水量52%、接种量5%、发酵时间85 h,在此条件下发酵的花生粕,其水溶性提取物对DPPH的清除率可达到60.58%,比未发酵花生粕的52.96%提高了14.39%(P<0.05)。体外抗氧化活性研究结果显示:当提取物质量浓度大于0.2 mg/mL时,发酵组对ABTS^(+)·、·OH清除能力以及铁还原能力显著高于对照组(P<0.05),当提取物质量浓度大于0.8 mg/mL时,发酵组对DPPH自由基清除能力显著高于对照组(P<0.05),但均显著低于L-抗坏血酸(VC)组(P<0.05)。研究表明,发酵显著提高了花生粕的抗氧化活性,可为花生粕功能性物质的研发和高值化利用提供参考。

枯草芽孢杆菌G10合成表面活性素的发酵条件优化

为提高表面活性素的产量,该研究以具有合成表面活性素能力的枯草芽孢杆菌(Bacillus subtilis)G10菌株为研究对象,利用酸沉淀和甲醇抽提法相结合提取表面活性素,对其表面活性及抑菌性能进行测定,并通过单因素试验和正交试验优化枯草芽孢杆菌G10合成表面活性素的发酵条件及培养基组成。结果表明,表面活性素具有明显的表面活性和抑菌活性,其对大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)和酿酒酵母(Saccharomyces cerevisiae)的抑菌圈直径分别为1.8 cm、1.9 cm、1.4 cm。合成表面活性素最优发酵条件为:转速200 r/min,发酵温度30℃,发酵培养基初始pH值为7.5;最优发酵培养基组分为:葡萄糖22 g/L,L-谷氨酸5.0 g/L,Mg SO_(4)0.5 g/L,KCl 0.5 g/L,KH_(2)PO_(4)1 g/L,Fe SO_(4)·7H_(2)O 0.15 g/L,MnSO_(4)0.65 g/L,CuSO_(4)·5H_(2)O 0.16 g/L。在此优化条件下,枯草芽孢杆菌G10发酵表面活性素平均产量为9.89 g/L,表面活性素产量较优化前提高了46.7%。

燃料乙醇混合原料发酵技术研究进展

生产燃料乙醇的淀粉质原料受储存周期及运输半径等因素的影响,不同种类原料的价格会因时因地出现较大差别。由于原料在燃料乙醇生产综合成本中占比较大,动态优化原料种类及比例、实时降低综合生产成本的混合原料发酵技术,自然受到了乙醇行业及其科研机构的广泛关注。混合原料发酵技术不仅有助于燃料乙醇行业的良性发展,还可以消化“问题粮”,为原料区域平衡和国储定期轮换提供蓄水池。

重组木聚糖酶的高密度发酵及其定向制备低聚木糖

为提高酶水解杨木木聚糖定向转化低聚木糖的效率,同时降低酶法制备低聚木糖的成本,围绕重组大肠杆菌(PET-PdoXyn10A-DE3)高密度发酵制备拟杆菌来源木聚糖酶PdoXyn10A的诱导表达条件和酶水解制备低聚木糖的工艺条件开展了研究。考察了在5 L发酵罐水平下诱导剂浓度、诱导光密度(OD_(600))值、诱导温度和诱导pH值等因素对PET-PdoXyn10A-DE3产重组木聚糖酶PdoXyn10A的影响,反应温度、pH值对玉米芯木聚糖酶水解过程中酶活力的影响,以及酶添加量、酶水解时间对杨木乙酸水解液制备低聚木糖的影响。研究结果表明:在诱导剂浓度0.25 mmol/L、诱导OD_(600)值55、诱导温度34℃和诱导pH值7.0的最佳诱导条件下,经高密度发酵重组酶酶活力可达362.67 U/mL,重组大肠杆菌生物量可达28.83 g/L。酶水解制备低聚木糖的最佳条件为酶反应温度40℃、pH值5.2、酶添加量12 U/mL和反应时间6 h,此条件下低聚木糖的量为3.21 g/L,其中木二糖、木三糖、木四糖、木五糖和木六糖的量分别为1.09、 0.97、 0.84、 0.18、 0.13 g/L,木糖为1.82 g/L。

一株除臭固氮菌的筛选、鉴定及发酵条件优化

为提高食品加工原料质量、降低环境污染,从自然界分离筛选出一株能有效减少鸡粪臭味及氮素流失的菌株JFN-1。通过形态学特征、生理生化试验和16S rDNA序列分析鉴定,JFN-1为假肠杆菌(Empedobacter falseni)。通过液态发酵得出:JFN-1菌株在硝酸还原酶和亚硝酸还原酶作用下,可以提高硝态氮、减少铵态氮含量以及减少氮类物质分解为氨气,从而减少氮素损失。通过单因素和正交优化试验,得到JFN-1菌株增殖培养基组成为可溶性淀粉8 g/L、牛肉膏20 g/L、硫酸镁4 g/L、氯化钠5 g/L,30℃培养20 h发酵液OD600可达到3.14,相比未优化培养基提高12.91倍,总氮含量提高2.14倍。通过固态发酵条件优化,得到JFN-1菌株固定氮素含量最多的固态发酵基质为菌糠15 g、麸皮15 g、豆粕1 g、糠醛渣2 g、硫酸铵0.165 g,在此条件下,总氮量提高196.42%。