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.

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.

Study on Brewing Technology of Pear Wine

[Objectives]The quality of pear wine is directly affected by parameter control in the production process, especially in the fermentation stage. The fermentation parameters of pear wine were controlled by studying the effects of fermentation parameters on the product, in order to optimize the fermentation parameters. [Methods]The fermentation conditions of pear wine were optimized by single factor experiments and an orthogonal experiment. [Results] The optimum fermentation conditions of pear wine were nitrogen source 1.0 g/L, fermentation temperature 20 ℃, and pH of fermentation liquid 4.3. The pear wine brewed was full, mellow and harmonious, and had a unique style. The ethanol content of the pear wine was 12.33 through physical and chemical analysis. [Conclusions] This study provides theoretical basis and technical support for the industrial production and promotion of pear wine.

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.