Papers by Keyword: Culture Condition

Abstract: Four photosynthetic bacterium Rhodopseudomonas spp., QDS₂, QDS₃, QDS₄ and QDS₉, were isolated and screened from the bottom sludge of Qingdao coast. In order to get a mass of PSB, we successfully optimized the culture conditions of four strains by orthogonal experiment and obtained the best culture conditions.

Abstract: Fermentation of xylanase produced by Trichoderma reesei was conducted in 250mL shake flasks. Several fermentation conditions was investigated that affected production of xylanase by Trichod erma reesei, including inoculum age, inoculum size, medium volume, shear stress, temperature, shaking speed and initial pH. Results showed that the the optimum culture conditions were as follows: inoculum age 45h, inoculum size 10%,medium volume 50mL/250mL, shaking speed 200rpm and initial pH4.0(natural). The maximum xylanase activity under each condition was occurred at 104h and the maximal activities can reach 1425.27U/mL.

Abstract: Bioflocculant MBF7 was produced by a novel bioflocculant-producing microorganism HHE-P7. In order to reduce the bioflocculant producing cost, culture experiments were conducted. The effects of medium components including carbon and nitrogen sources as well as culture conditions such as pH of molasses diluents, cultivating temperature, inoculum size were investigated. The results showed when the molasses waste was diluted at COD concentration of 2000 mg/L, the optimal culture conditions for MBF7 production by HHE-P7 were inoculum size 1% (v/v), initial pH 5, cultivating temperature 25°C at the rotation speed 150 r/min. Under such conditions, MBF7 had a flocculating activity of 83% for 5 g/L kaolin clay suspension. About 3.19 g crude bioflocculant could be recovered from 1.0 L of molasses fermentation broth.

Abstract: Rhodopseudomonas sp. could be used in wastewater treatment and aquiculture, extensively. Four photosynthetic bacterium Rhodopseudomonas spp., QDS2, QDS3, QDS4 and QDS9, were isolated and screened from the bottom sludge of Qingdao coast. In order to get a mass of PSB, we successfully optimized the culture conditions of four strains by orthogonal experiment and obtained the best culture conditions. The research could provide the bases for the applying of high-effective PSB (Rhodopseudomonas sp).

Abstract: Agaricus brunnescens is a producer for novel biomaterial (exopolysaccharide of Agaricus brunnescens). In this paper, the optimization of culture conditions for the biomass of Agaricus brunnescens through orthogonal methods was reported. The optimal conditions for enhancing production was: inoculum size 10 %, broth volume 100 mL in a 250 mL flask, pH 6.0. This optimization strategy in shake flask culture lead to an biomass 0.8 g/L, which was considerably higher than that obtained in preliminary studied.

Abstract: The morphological, physiological and biochemical characteristics of Saccharomyces boulardii were studied for the preparation of highly active yeast. The optimal condition of the flask culture including inoculum size, culture temperature, pH value, were investigated separately. The results showed that S.boulardii was asporogenous and had better heat tolerance and acid tolerance growing well at 37°C and pH 2.0. We also found that thermal death temperature was 55~56°C and S.boulardii is well ethanol-tolerant, for the highest concentration of ethanol that S.boulardii can tolerate was 20%. The optimal culture conditions in a flask culture was YEPD medium with 50ml/250ml medium volume, natural pH, 5% inoculum size, 32°C culture temperature, 160 r/min shaker speed, and 24 hours cultivation period. Under these conditions, suspension was diluted 10 times and the optical density at 600 nm was up to 0.85.

Abstract: To find a novel exopolysaccharide, marine bacterial strains were isolated from coastal regions of Korea. Strain 00SS11568 was then selected as it produced a mucous exopolysaccharide during the stationary phase in a batch culture. The isolate was identified as Alteromonas sp. based on its 16S rDNA sequence, morphological, and biochemical properties. The exopolysaccharide, designated as p-11568, exhibited an emulsifying ability. The Emulsification Index (E24) of 0.1% p- 11568 was 77.4% with an emulsified kerosene content, and was higher than those of commercial polysaccharides, such as xanthan gum (26.1%), gellan gum (1.3%), and sodium alginate (2.0%). p- 11568 was found to be composed of glucose and galactose as the main natural sugars in a molar ratio of 1.3:1, along with uronic acid (18.9%, w/w) and sulfate groups (1.2% w/w). The average molecular mass was 4.4 x 105 daltons by gel filtration chromatography. The effects of pH, temperature, inorganic compounds, and C and N sources were tested to obtain the optimal medium composition for the production of p-11568. Under optimal growth conditions with the M-11568 medium, 14.9 g of crude p-11568 per liter was obtained.