Effects of cultivation conditions on the diversity of microbes involved in the conversion of rice straw to fodder

To confirm the optimum cultivation conditions for analyzing lactic acid bacterial communities and to provide the cultivation foundation for lactic acid bacterial communities that were used to convert straw into fodder, fermented rice straw was inoculated into 13 different broths. After 48 h of cultivation, pH values, volatile products, and microbial diversity were analyzed. Except for LAB broth, the pH values of the other broths could decrease to approximately 4.5. GC/MS analysis showed that lactic acid in Tomato MRS broth, MRS broth, LAB broth, and Tomato juice broth was higher than that in the other broths. DNA concentration analysis showed that the counts of microbes in Tomato MRS broth were 2.5 times of those in other broths and that tomato juice favored the reproduction of the microbes. Denaturing gradient gel electrophoresis （DGGE） analysis showed that the number of lactic acid bacterial species in HYA broth, Tomato juice broth, and Tomato MRS broth were higher than those in the other broths.

Enhanced production of elastase by Bacillus licheniformis ZJUEL31410:optimization of cultivation conditions using response surface methodology

Sequential methodology based on the application of three types of experimental designs was used to optimize the fermentation conditions for elastase production from mutant strain ZJUEL31410 of Bacillus licheniformis in shaking flask cul- tures. The optimal cultivation conditions stimulating the maximal elastase production consist of 220 r/min shaking speed, 25 h fermentation time, 5% (v/v) inoculums volume, 25 ml medium volume in 250 ml Erlenmeyer flask and 18 h seed age. Under the optimized conditions, the predicted maximal elastase activity was 495 U/ml. The application of response surface methodology resulted in a significant enhancement in elastase production. The effects of other factors such as elastin and the growth factor (corn steep flour) on elastase production and cell growth were also investigated in the current study. The elastin had no significant effect on enzyme-improved production. It is still not clear whether the elastin plays a role as a nitrogen source or not. Corn steep flour was verified to be the best and required factor for elastase production and cell growth by Bacillus licheniformis ZJUEL31410.

Optimization of cultural conditions for thermostable β-1,3-1,4-glucanase production by Bacillus subtilis ZJF-1A5

The optimization of cultural conditions for β glucanase production by Bacillus subtilis ZJF 1A5 was investigated in flask trials. Temperature had great effect on β glucanase production which maximized at optimal temperature of 37℃ and decreased significantly when temperature was over 37℃.Charge quantity affected β glucanase production significantly. Adding oxygen vector N dodecane or acetic ether benefited β glucanase production, but it depended on the concentration and charge quantity. The results of fractional factorial design showed that age and size of inoculum and shaking speed were the key factors affecting β glucanase production and the cultivation time span to reach the highest β glucanase activity. The optimal cultural conditions for β glucanase production obtained with CCD were as follows: inoculum age and size (16 h, 3.82%(v/v)), shaking speed 210 r/min, charge quantity of 30 mL in 250 mL flask and initial pH 7.0, cultured at 37℃ for 50 h. Repeated experimental results accorded with those predicted by a second order polynomial model. The amount of β glucanase, α amylase and neutral protease produced by B subtilis ZJF 1A5 was associated partially with cell growth. Those three enzymes' activities increased following the cell growth and increased significantly when cells entered the stationary phase.

Key Techniques of Cultivation of Stropharia rugosoannulata

Stropharia rugosoannulata is a straw rotting edible fungus that has developed rapidly in recent years.In the process of cultivation,key technologies have a huge impact on its yield.The key techniques for the cultivation conditions and modes of S.rugosoannulata were summerized to promote the realization of stable and high yield of S.rugosoannulata.

Effects of Fertility and Density on Biomass Production,Translocation and Lodging Resistance of Millet(Setaria italica L.)in North China

In this study, the plant biomass production, biomass translocation rates across tissues and the lodging resistant-associated traits of millet （ Setaria italica L.） in North China were investigated. Among the four summer millet cultivars, Baogu 19 exhibited improved plant biomass （PB） production at flowering and maturity stages, biomass translocation amount （BTA） from vegetative tissues to seeds during filling period, and lodging resistant-associated （LRA） traits compared with other cultivars, including enhanced stem lignin contents, increased anti-broken resistance （ABR）, anti-puncturing resistance （APR）, and stem diameter （SD） of plants. Compared with treatment regular cultivation （RC）, high fertility treatment （HF） increased the plant BP, BTA from vegetative tissue to seed at filling stage, and the plant LRA traits; whereas high density treatment （HD） decreased the plant BP at plant level, plant BTA from vegetative tissues to seeds at filling stage, and the plant LRA traits. Correlation analysis revealed that stem ABR is significantly correlated with the plant lodging resistant-associated traits including APR and SD in the summer millet cultivars examined under various cultivation treatments. Our investigation indicates that cultivar Baogu 19 together with suitable fertilization and density can promote the plant biomass production, enhance vegetative tissue biomass translocation to seeds, and improve the lodging resistance of summer millet plants in North China.