Optimization of the medium and fermentation condition for the Penicillium aurantiocandidum Z12 strain with molluscicidal actions against Oncomelania hupensis / 中国血吸虫病防治杂志

Objective To optimize the culture and fermentation conditions of the Penicillium aurantiocandidum Z12 strain, a fungal strain with molluscicidal actions against Oncomelania hupensis, so as to provide the basis for the research and development of molluscicidal active substances from the P. aurantiocandidum Z12 strain and its fermentation broth and large-scale fermentation. Methods The carbon source, nitrogen source and mineral salts were identified in the optimal culture medium for the P. aurantiocandidum Z12 strain with a single-factor experiment to determine the best fermentation condition for the P. aurantiocandidum Z12 strain. Factors that significantly affected the growth of the P. aurantiocandidum Z12 strain were identified using the Plackett-Burman design, and the best range of each factor was determined using the steepest climb test. Response surface analyses of temperature, pH value, seeding amount and liquid-filling quantity were performed using the Box-Behnken design to create a regression model for fermentation of the P. aurantiocandidum Z12 strain to identify the optimal culture medium. Results Single-factor experiment preliminarily identified the best culture medium and conditions for the P. aurantiocandidum Z12 strain as follows: sucrose as the carbon source at approximately 20 g/L, tryptone as the nitrogen source at approximately 5 g/L, K2HPO4 as the mineral salt at approximately 5 g/L, initial pH at approximately 8, temperature at approximately 28 °C, seeding amount at approximately 6%, and liquid-filling quantity at approximately 50 mL/100 mL. Plackett-Burman design showed that factors that significantly affected the growth of the P. aurantiocandidum Z12 strain included temperature (t = −5.28, P < 0.05), seeding amount (t = 5.22, P < 0.05), pH (t = −4.30, P < 0.05) and liquid-filling quantity (t = −4.39, P < 0.05). Steepest climb test showed the highest mycelial growth at pH of 7.5, seeding amount of 8%, and liquid-filling quantity of 40 mL/100 mL, and this condition was selected as the central point of response surface analysis for the subsequent optimization of fermentation conditions. Response surface analyses using the Box-Behnken design showed that the optimal conditions for fermentation of the P. aurantiocandidum Z12 strain included sucrose at 15 g/L, tryptone at 5 g/L, K2HPO4 at 5 g/L, temperature at 28.2 °C, pH at 7.5, seeding amount at 10%, and liquid-filling quantity at 35.8 mL/100.0 mL, resulting in 0.132 g yield of the P. aurantiocandidum Z12 strain. Conclusion The optimal culture condition for the P. aurantiocandidum Z12 strain has been identified, and the optimized culture medium and fermentation condition may effectively improve the fermentation yield of the P. aurantiocandidum Z12 strain.

Influencing factors on single-cell protein production by submerged fermentation: a review

Since more than twenty years ago, some species of bacteria and fungi have been used to produce protein biomass or single-cell protein (SCP), with inexpensive feedstock and wastes being used as their sources of carbon and energy. The role of SCP as a safe food and feed is being highlighted more because of the worldwide protein scarcity. Even though SCP has been successfully commercialized in the UK for decades, study of optimal fermentation conditions, various potential substrates, and a broad range of microorganisms is still being pursued by many researchers. In this article, commonly used methods for the production of SCP and different fermentation systems are briefly reviewed, with submerged fermentation being highlighted as a more commonly used method. Emphasis is given to the effect of influencing factors on the biomass yield and productivity in an effort to provide a comprehensive review for researchers in related fields of interest.

Optimization of fermentation conditions of molluscicidal endophyte LL3026 from Buddleia lindleyana / 中国血吸虫病防治杂志

Objective To optimize the fermentation conditions of molluscicidal endophyte LL3026 from Buddleia lindleyana. Method The medium composition and cultivation conditions were optimized by orthogonal and single factor experiments. Re-sults The experiments showed that the conditions of initial pH 3,fermentation temperature 30℃,volume of liquid 100 ml(250 ml Erlenmeyer flask),and 3D-xylitol 0.5 g/L were optimum,and the molluscicidal activity of the fermentation filtrate reached 95%. After three hatches of cultivation,the predicted values were verified by validation experiments. Conclusion Endophyte LL3026 from Buddleia lindleyana has a good molluscicidal activity after the optimization.

Construction Fermentation of Engineered Strain and Properties of Recombinant ?-glutamyltranspeptidase / 中国生物工程杂志

The ?glutamyltranspeptidase encoding gene(ggt) from Bacillus subtilis SYU 20016 was amplified by PCR. The ggt gene was inserted in pBV220 to yield the recombinant expression vector pBV220ggt. Overexpression of ggt in E.coli JM109 was achieved with pBV220ggt. SDSPAGE analysis showed an overexpressed recombinant product at about 65kDa,consistent with the molecular weight predicted from gene sequence. The ferment conditions of r-glutamyltranspeptidase were also discussed. The optimum temperature and pH for the enzyme were determined as 30℃ and 7.2 respectively.The cultures were incubated at 42℃ for 4h with broth volume 20ml/250ml flask and the yield of 6U/ml was obtained, enzyme activity of B. subtilis NX2 was only 3.2 U/ml.

The Study on Fermentation Conditions of Inulase Produced by Aspergillus niger / 中国生物工程杂志

The high production inulase strain was screened from the soil sample where burdock planted in Qin Village,Bayou Town,Pei County,Xuzhou.Inulase activity were determined which produced by 40 strains separated from soil.Three mold stains,C122803、D081506 and D081513,which had higher ability of producing inulase were obtained by using transparent circle method as initial screening and rocker method as re-screening.Enzyme activity of the three strains were 1.411U/ml,1.895U/ml,1.792U/ml,separately.Enzyme activity of D081506,1.895U/ml,was the highest.The fermentation conditions of D081506 were studied and the optimized conditions were lappa juice 2.0%,yeast extraction 1.6%,(NH4)2SO4 0.5%,NaCl 0.5%,K2HPO4 0.5% and pH 5.0.Inulase activity of D081506 was 2.9578U/ml which increased 56.09% under the condition of 27℃,140r/min,24h.

Optimization on Fermentation and Purification of the Fibrinolytic Enzyme from Stenotrophomonas maltophilia / 中国生物工程杂志

The optimization on liquid fermentation and purification of the fibrinolytic enzyme from Stenotrophomonas maltophilia(DR-929) was investigated.The results showed the best fermentation are amidulin 2.0%,soya flour 1.0%,yeast extract 0.5%,NaCl 1.0%,CaCl2 0.02%,MgSO4 0.05%,inoculum of 36 hours,fermental time 4d,initial pH 8.0 or 9.0,temperature 25℃,volume of media 30ml,volume of inoculum 5% or 6%.The purification process includes the following steps: removing cells by the centrifugation,25%~70% saturation ammonium sulfate precipitation,HIC with Phenyl FF(high sub),IEC with Q-Sepharose FF,gel filtration chromatography with Superdex 75.SDS-PAGE electrophoresis was used to examine the purification effect,and the results indicated that homogeneous strap in SDS-PAGE and has a molecular weight around 28.3kDa.The purification factor and activity recovery of the fibrinolytic enzyme are 271.5 and 24.5%,respectively.

Optimal cultivation conditions of marine fungi KLEB-07 / 中国海洋药物

It was found that the metabolites produced by a marine fungi KLEB-07 showed the induction of cell apoptosis activity on mouse tsFT210 cells.In order to find the best fermentation condition,the optimization of fermentation medium was studied.Activities of the ferments of KLEB-07 under different fermentation media and conditions,and the stability of the ferments were investigated.The results showed that the KLEB-07 produced the highest antitumor bioactivity of the ferments under the conditions of 28℃ and 130 r?min~(-1) for 7 days.The bioactive substances of ferments were stable and mainly existed in ethyl acetate layer.These results provide valuable informations for the further study of the antitumor active substances of KLEB-07.

Screening of alginate producing strain and optimization of fermentation condition / 中国海洋药物

Objective A strain with high alginase activity was screened and isolated by decomposing sodium alginate from the decaying parts of brown alga Laminaria japonica and Undaria pinnatifida,in order to produce alginase.Methods The strain s4 with high alginase activity was chosen by filtration.The alginase producing media was optimized and the alginase was produced and its characterization was investigated.Results The optimum fermentation conditions for alginate lyase producing as follows: media AlgNa 1.2%,NH4Cl 0.9%,NaCl 1.5%,pH=7.5,and temperature 25℃.Conclusion The alginase produced by strain s4 showed high alginase activity and good stability.

Effects of Several Factors on the Chlamydospores Production of Trichoderma aureoviride T-33 / 微生物学通报

The effects of several factors on the chlamydospores production of Trichoderma aureoviride T-33 during the fermentation were researched.Based on the results above, the orthogonal test was made to screen out the best prescription.The results showed that, the best single-factor conditions for the chlamydospores production of T.aureoviride T-33 were, liquid culture of oat powder, 30℃, pH4.0, 120r/min, 24 hours oscillate incubating as well as liquid culture volume of 80mL/bottle when the 250mL size triangle bottle was used.The result of orthogonal test showed that, the best prescription for temperature, pH and oscillating speed was 30℃, pH4.0 and 140r/min.3.37?10~ 7 spore/mL chlamydospores were obtained at this combined condition.

STUDY ON THE OPTIMUM FERMENTATION CONDITION FOR PRODUCTION OF PROTOPECTINASE BY ASPERGILLUS SP / 微生物学通报

Effects of carbon resource, nitrogen resource, metal irons and surface detergents on the production of pro topectinase by strain Aspergillus sp XZ 131 were studied The results showed that pectin substances were essential for the strain to produce protopectinase The enzyme activity reached to 300 U/mL, when(NH 4) 2SO 4 and(NH 4) 2HPO 4 were used as nitrogen resource Ca 2+ and Tween 20 were able to enhance the production of the enzyme The optimum composition of the medium was citrus peel powder 1g,(NH 4) 2SO 4 2g,CaCl 2 0 015g,Tween 20 0 2mL,KH 2PO 4 3 8g,K 2HPO 4?3H 2O 0 2g,H 2O 100mL,pH 6 5。

ISOLATION OF A DEEP-SEA STRAIN THAT PRODUCES ALKALINE PROTEASE AND STUDIES ON ITS FERMENTATION CONDITION / 微生物学通报

From 38 pieces of deep\|sea samples,a strain,DY\|A,which produces protease was isolated.It can grow at a wide range of pH and salt concentration and best at 10℃.The strain produced maximum protease activity after growth at 10℃,initial pH 10 0 and inoculation volume 0 5%for 48～72h on a shaker by speed of 200r/min.The optimum pH and temperature for the protease activity production are pH 10.0 and 40℃.The enzyme is alkaline protease.Some other properties of the strain and the protease were discussed in detail.

EFFECT OF FERMENTATION CONDITIONS ON ANTIBIOTIC PRODUCTION OF XENORHABDUS NEMATOPHILUS / 微生物学通报

The optimum medium and fermentation conditions of the Xenorhabdus nematophilus from Steinernema carpocapsae BJ strain were studied. The relationship between antibiotic activity and pH, reducing sugar, total sugar, amino nitrogen in process of fermentation was analyzed. The optimal medium contained trypton1.5%, corn powder1%, soybean flour 3%, sucrose1%, KH 2PO 4 0.02%,MgSO 4 0.2% and activator 0.1%, Stock cultured for 16h, inoculum size at 4%(V/V)and primary pH of medium ranged from 6.0 to 8.0, fermentation for 72h were of benefit to the yield of antibiotic. The pH, reducing sugar,total sugar and amino nitrogen in process of fermentation were related to the antibiotic activity. The yield of antibiotic increased by 56.3% comparison with nutrient broth.

Optimization of Recombinant E. coli High-density Fermentation for Expressing Human-like CollagenⅡ / 微生物学通报

To study and optimize the fermentation parameters for expressing human-like collagenⅡduring E. coli high-density fermentation. The effects of pH, temperature, dissolved oxygen and induction instant on the cell growth and human-like collagenⅡproduction were investigated to optimize the fermentation conditions. The results demonstrated that the following conditions were beneficial for cell growth and foreign gene expression, controlling pH in phase induction at 6.8 and initial pH at 6.5, maintaining fermentation temperature and dissolved oxygen concentration was controlled at 34?C and 20% respectively, and implementing induction at the later logarithmic growth phase. Under the optimized condition, the cell density and human-like collagenⅡyield could reach 88.4 g/L and 14.2 g/L, respectively.

Optimization of Fermentation Conditions for Proteases Produced by Mucor / 微生物学通报

A strain of Mucor named M2,which could produce protease,was isolated from a traditional fermented soybean product.Culture conditions of proteases produced by M2 were studied therefore.The results showed that nitrogen source and carbon source preferred for protease production were soybean protein isolate and glucose,while inorganic salts preferred were KH2PO4,CaCl2 and MgCl2.The suitable culture conditions for protease production were as follows:culture temperature was 28℃,inoculation volume was 2%,liquid level was 100 mL in 300 mL triangle bottle at pH 5,rotating speed was 150 r/min and culture time was 48 h.The obtained protease activity in culture was about 4.35 U/mL.The protease produced by Mucor was analyzed with SDS-PAGE.The protease had a molecular weight of 36.4 kD.

Optimization of Saccharomyces cerevisiae sp.Strain by1.1b Culture Conditions for Efficient Biosynthesis of D-(-)-mandelate Dehydrogenase / 微生物学通报

The culture conditions of Saccharomyces cerevisiae sp.strain by 1.1 b were optimized for the production of D-(-)-mandelate dehydrogenase which is useful for the asymmetric bioreduction of benzoylformate to form D-(-)-mandelate.The optimum medium(per liter)consistes of 60 g peptone,30 g maltose, 0.5 g MgSO_4,0.01 g ZnSO_4,1.0 g KCl.After optimization of the culture medium,the enzyme production in shake flasks is enhanced from 2.56 to 20.21 U/L.The optimum fermentation conditions were determined as follows:medium volume 100 mL(i.e.,40%for a 250-mL shake flask),pH 6.5,inoculum size 10%,temperature 30℃,and cultivation time 25 h.

Screening of Ganoderma Strain of High Yield Intracellular Triterpenes and Optimization of Its Fermentation Conditions / 微生物学通报

According to the yield of intracellular triterpene, the strain GL31 was screened out from 22 strains of Ganoderma collected from various regions. The optimal fermentation conditions were studied by single factor experiments and orthogonal test. The optimal parameters of carbon source, nitrogen source, initial pH, the medium volume in the flask and cell density were obtained. In addition, the metabolic curves of intracellular triterpene and biomass were determined. It was found that the yield of intracellular triterpenes was up to 3.51?10~(-2)g/100 mL medium at the 84th hour. In addition the stram was staticly fermented 144 hours flowing 84hours shaking-flask culture, the IT (intracellular triterpenes) content was increased by 48.6% and the yield of IT was increased by 65% compared with those of the mycelia cultured 84hours using shaking-flask method. This indicated that static fermentation method is helpful for improving the total IT content. The result also show that the highest yield of intracellular triterpenes of mycelia staticly fermented flowing 84hours shaking-flask culture is higher than that of mycelia using shaking flask culture method.