Screening and identification of amylase producing strains of Bacillus

An attempt was made to isolate and screen efficient amylolytic strains of Bacillus sp. Initial screening basedon the starch hydrolysis ratio resulted in the selection of 72 amylolytic bacterial strains. Among these, 18strains were selected for further studies. Secondary screening based on amylase production in starch brothmedium led to the selection of six amylolytic strains of Bacillus sp. The selected strains were grown in fourdifferent fermentation media (FMI-FMIV) in order to screen for three most efficient amylolytic strains foroptimization and characterization. FMIV was the best basal medium as it provided required nutrients, whichstimulated highest amylase production in bacterial strains within shortest incubation time ( 24 hours). Molecularidentification based on 16S rDNA sequence revealed that three most efficient strains [BCM36 (KR1), BCM33(KR2), and BCM25 (KR3)] belonged to Bacillus sp

Optimization of technique for add itional liquid fermentation of Poria cocos and comparison on chemical constituents from different sources of Poria / 中草药

Objective To optimize the technique for additional liquid fermentation of Poriacocos in fermentor and to compare the chemical constituents in natural Poria, fermented Poria, medicinal fermented Poria, and compound medicinal fermented Poria. Methods The additional liquid fermentations of Poriacocos in fermentor had been carried out among different initial fermentation media, such as nutrition medium, medicinal medium, and compound medicinal medium. An optimum initial fermentation medium had been screened and an optimum time of additional liquid fermentation had been determined. The chemical constituents fromthedifferent sources of Poria had been isolated and detected according to their physicochemical properties. Results The compound medicinal medium with Coicis Semen and Lycii Fructus was an optimum initial fermentation medium, and 120 h was an optimum time of additional liquid fermentation. The total saccharides, polysaccharides, amino acids, trace elements, and ashes in thedifferent sources of Poria had been detected. Conclusion There are considerable influences on liquid fermentation of Poriacocos in different initial fermentation media. There are rather big differences of chemical constituents from the different sources of Poria.

Screening of Poly-?-glutamic Acid High Productive Strain and Optimization of Fermentation Medium / 微生物学通报

Bacillus subtilis B6-1 was used as an original strain for mutagenic treatment and a defined medium was used as the selective medium. A mutant named B. subtilis W003 was isolated after three serial ultraviolet (UV) irradiations and one diethyl sulfate (DES) treatment. The ?-PGA yield on a rotary shaker was enhanced from 10.9 g/L in parental strain to 20.5 g/L in the mutant. It was illustrated by single factor experiments that the optimal carbon and nitrogen sources were glucose and (NH4)2SO4 respectively. The optimal fermentation medium was achieved by orthogonal test. In the optimal medium, a ?-PGA yield of 45.3 g/L was obtained after 36 h cultivation.

Nutrition Factors Influence the Production of Insecticidal Crystal Proteins Cry1 and Cry2 from Bacillus thuringiensis 4.0718 / 微生物学通报

In order to increase the production of insecticidal crystal proteins Cry1 and Cry2, firstly, Plack-ett-Burman design was applied to evaluate the effectiveness of the related nutrition factors; it was found that the soybean powder and MnSO4?H2O were significant factors for Cry1 production, but the yield of Cry2 wasn’t effected remarkably in such medium. Then the steepest ascent experiment was adopted to approach the optimal region of the medium composition. Lastly, the optimal concentration of the soybean powder and MnSO4?H2O was 11.5 and 0.02 g/L, obtained by response surface methodology (RSM). The final yields of Cry1 and Cry2 was 0.32 mg/mL and 0.11 mg/mL, increasing twice more than that in the medium optimized before. The median lethal concentration (LC50) of optimal medium was 1.09 ?L/mL. The toxicity to Heli-coverpa armigera was significantly enhanced than the old one.

Optimization of Fermentation Medium for S-adenosylmethionine Production by Candida sp.YQ5 / 微生物学通报

The optimized cultural medium of fermentation for Candida sp.mutant strain YQ5 to produce S-adenosylmethionine was studied.The results of single factor experiment showed that the most favorable pH value,carbon source,nitrogen source organic nutrient is 6.0,8% sucrose,1.5% tryptone and 2% yeast extract,respectively.As to inorganic salts,MgSO4?7H2O,CaCl2,FeSO4?7H2O,CoCl2,CuSO4?5H2O,H3BO3 could improve accumulation of the intercellular SAM.The ingredients of the culture medium are also opti-mized by the orthogonal experiment.Fermentation for 48 h under the optimal condition resulted in AdoMet production at 1740.0 mg/L.

Optimization of Conditions on Submerged Fermentation of Bacillus cereus / 微生物学通报

The fermentation of Bacillus cereus DLSL-2 was investigated through single-factor test. The optimized fermentation conditions are: temperature 30℃,initial pH 7.0,250 r/min. Uniform design was used in shaking flask to optimize the fermentation medium of bacillus cereus . The most suitable medium was identified as follows:4.88% defated soybean power ,1.45% maize starch, 0.106% K 2HPO 4, 1.78% yeasts extract, 5.6% inoculum. the optimized medium allowed the B.cereus biomass concentration to be increased from 3.2?109 cfu/mL to 7.1?109 cfu/mL.

OPTIMIZATION OF THE MEDIUM AND PROCESS PARAMETERS IN BATCH AMINOGLYCOSIDE ANTIBIOTIC JI-20A FERMENTATION / 微生物学通报

The medium and process parameters were optimized in batchaminoglycoside antibiotic JI-20A fennentation. The optimal medium consists mainly of comstarch 60g/L, peanut meal 30g/L, com slurry 8g/L, maltose 10g/L, inorganic compound and amylase moderate , methionin 1g/L and cobalt chloride 6?g/mL. It was significant to adjust medium pH after autoclaving and oxygenate the fennentation medium for the cell growth and JI-20A product.