Fermentation experiment

The biosynthetic origin of monobactams has been elucidated by fermentation experiments using radioactively labeled amino acids (qv). The... 

The size of beads was uniform and consistent, the mean size of beads with 3% alginate and based on measurement of 20 samples the mean value for the beads diameter was 4.85 mm, with a standard deviation of 0.3 mm and calculated variance of 0.1 mm. The standard deviation was less than 5%. The data for the batch fermentation experiment with 50gl 1... 

The biosynthetic origin of monohactams has been elucidated by fermentation experiments using radioactively labeled amino acids. The monocyclic ring of tile naturally occurring C-4 unsubstituled monohactams is derived from serine. Similar techniques have shown that the methyl moiety of the melhoxyl group in 3a -methoxylated monohactams is derived from methionine. 

We thank all our colleagues for technical support, including fermentation experiments and product analyses, and constructive discussions particularly with Dr. I. Kojima, Dr. N. Kawamura, T. Narita, K. Takeda, Dr. K. Okamura, Dr. M. Okabe, and Dr. R. Okamoto. 

A set of alcoholic fermentations experiments was conducted in order to verify the performance of the model-based substrate sensor. Diluted molasses was used in the experiments as feed substrate and bread yeast, Saccharomyces cerevisiae, as inoculum. The operational conditions and kinetic parameters used are given in Table 1 for two different experiments (tests 1 and 2), and values of ethanol and biomass concentrations were also determined off-line using gas chromatography (CG) and dry cell weight standard (7) methods, respectively. 

Fermentation experiments utilizing sugars present in paper sludge hydrolysate were first carried out on complete medium as presented in Materials and Methods. Results on carbohydrate consumption and hydrogen production of two typical fermentations are shown in Table 2 (conditions D1 and D2). Acetate and lactate were the main byproducts. 

Results on the carbon balances for these fermentation experiments with paper sludge hydrolysate are presented in Table 3. Interference of unidentified components in the hydrolysate with the protein content determination disallowed accurate biomass content determination, resulting in an incomplete mass balance. However, similar OD was measured as observed for the mixture of pure sugars (condition C). 

In a preparative experimental series (Table 2, Fig. 2), 100-mL fractions were collected from columns with each of the different anion exchangers starting from the appearance of glucose in the effluent. These six fractions, obtained with different resins, were used for the fermentation experiments and analyzed as just described. 

For CS 1.94, several treatments were performed as described above in order to obtain enough volume of hydrolysates for fermentation experiments. Thereafter the hydrolysates were mixed, stored at 4°C and several detoxification methods, including activated charcoal and anion-exchange resin treatments, were applied. Nondetoxified hydrolysate was adjusted to pH 5.5 by adding Ca(OH)2. After 1 h the precipitate was removed by centrifuging (Avanti J-25i Beckman Coulter, Fullerton, CA) at 7500g for 25 min. The detoxification treatments were done as follows. 

Figure 14.3. Bioreactor fermentation of mixed sugars (about 10-12.5% w/v each, glucose and xylose) by L. buchneri strain NRRL B-30929, with lOOrpm stirring and constant pH 5.0. Initial volume is 1000 ml final concentrations are calculated after volume adjustment. Data represent the mean of duplicate fermentation experiments (Liu et al., 2008).

Mathews and Jackson did not carry out fermentation experiments nor did they discuss the possible relation between D-fructose anhydrides and the glutose of Lobry de Bruyn and Alberda van Ekenstein. They merely concluded that the well-known reversion products in cane molasses probably consist of these same anhydrides. The term reversion product was first introduced by WohP to describe the sugar anhydrides formed when highly concentrated D-fructose or invert sugar solutions are heated in the presence of acid. He anticipated Mathews and Jackson s... 

The saccharification of potato starch with pure /3-amylase yields 61 % of maltose and not more. In a series of experiments we obtained as the mean value from the reduction, 61.1 %, and from the fermentation experiments, 60.8%. The reduction was (as in most experiments in this laboratory) determined by a modification of the iodometric method of... 

Arrow-root starch (500 g.) in 8 liters of water containing 1 g. of sodium chloride was hydrolyzed at pH 6.5 with 50 ml. of saliva. After twenty-four hours, 50% of maltose had been formed. The reaction mixture was kept under toluene for thirty-two days. The reducing power then corresponded to 89% maltose. Fermentation experiments, however, showed that 63% maltose and 14% D-glucose had been formed, the latter by the secondary action of maltase. As mentioned above, the salivary amylase does not form D-glucose as a primary product but differs in this respect from malt a-amylase. The pancreatic enzyme is... 

Fermentation experiments with Streptomyces fumanus produced additional examples of the pyrrolomycins, chlorinated 2-benzoylpyrroles and structurally related pyrroles with demonstrated antimicrobial activity <05JNP277>. 

Formation of Pigmented Polymers in Model Fermentation Experiments... 

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