Solvent production from starch: effect of pH on ?-amylase and glucoamylase localization and synthesis in synthetic medium

1992 ◽  
Vol 37 (5) ◽  
Author(s):  
B.K. Soni ◽  
C. Kapp ◽  
G. Goma ◽  
P. Soucaille
Keyword(s):  
Synthetic Medium ◽  
Effect Of Ph ◽  
Solvent Production

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

Performance of Different Solid and Liquid Culture Media for the Improvement of Tuberculin Production

2020 ◽  
Keyword(s):  
Culture Media ◽  
Synthetic Medium ◽  
Chemical Properties ◽  
Economic Loss ◽  
Delayed Type Hypersensitivity ◽  
Basic Medium ◽  
Primary Methods ◽  
Lowenstein Jensen ◽  
Time Required ◽  
Modified Media

Tuberculosis (TB) is one of the most important zoonotic bacterial diseases. A huge economic loss which could be direct or indirect are associated with the disease. Currently, the primary methods used for detection of TB in humans and cattle include the measurement of a delayed type hypersensitivity to purified protein derivative (PPD). So, the need for preparation of purified PPD with adequate properties and increasing the final PPD yield with decreasing the time of tuberculin production has stimulated the interest in the development of its preparation. Our study was performed to compare between the standard and modified media for improving tuberculin production. Middle brook 7H10 agar medium was used as a modified basic medium for mycobacterial growth, followed by cultivation of mycobacteria on Middle brook 7H9 broth medium. For the production, strains were inoculated onto the culture medium (Dorest Henly synthetic medium). Other steps for tuberculin production was done according to standard Weighbridge protocol. The results demonstrated that the using of both Middle brook 7H10 agar and Middle brook 7H9 broth instead of Lowenstein-Jensen (LJ) and glycerin broth media which used in currently produced tuberculin, have better physical and chemical properties. In addition, reducing the time required for production by accelerating the time of microbial growth. Also, it was found that the tuberculin produced using modified media was slightly more potent or the same as currently tuberculin produced. So, both Middle brook 7H10 agar and Middle brook 7H9 broth media are recommended for production of tuberculin saving time and increasing potency of the product but more investigation was recommended for estimation types of protein present in both locally prepared and modified tuberculin.

Effect of pH and NH4NO3 as a Spray Additive on Penetration of NAA Through Isolated Tomato Fruit Cuticle

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 550a-550 ◽  
Author(s):  
Royal G. Fader ◽  
Martin J. Bukovac
Keyword(s):  
Direct Measurement ◽  
Sodium Citrate ◽  
Tomato Fruit ◽  
Initial Slope ◽  
Control Effect ◽  
Solution Ph ◽  
Ph Change ◽  
Effect Of Ph ◽  
Spray Droplets ◽  
Partition Behavior

We have reported that NH4NO3 (AN, 8 mM, pH 4.2), applied as simulated spray droplets, enhanced penetration of 14C-NAA through isolated leaf and fruit cuticles. One explanation for this response is that AN depresses NAA (pKa= 4.2) dissociation, increasing the nondissociated moiety, which penetrates more readily than the anion (NAA'). Direct measurement of AN (concn. 0-800 mM) effect on NAA (215 μM) dissociation as indexed by change in solution pH revealed no significant effect, with a pH change from 4.19 to 4.05. This change is not sufficient to account for the observed enhancement. When 14C-NAA, buffered (20 mM sodium citrate) at pH 3.2, 4.2, 5.2, 6.2, was partitioned against chloroform, there was a marked increase in NAA partitioning into chloroform as pH was decreased. AN (8 mM) did not alter this partition behavior, also indicating no effect on NAA dissociation. However, in cuticle penetration studies, using a finite dose system with 14C-NAA buffered at pH 3.2, 4.2, 5.2, 6.2, and in the presence and absence of 8 mM AN, there was no marked or consistent pH or AN (-70 to + 232 % of no AN control) effect on penetration as indexed by initial slope (4-12 h) or penetration after 120 h. The possible effects of AN and buffer on penetration of 14C-NAA from the droplet deposit will be discussed.

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