Effect of pH on aluminum-driven methanogenesis by Methanococcus thermolithotrophicus

1993 ◽  
Vol 39 (1) ◽  
pp. 138-140 ◽  
Author(s):  
R. Boopathy ◽  
L. Daniels
Keyword(s):  
Effect Of Ph ◽  
Methanococcus Thermolithotrophicus

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.

Effect of pH and VFA on Hydrolysis of Organic Solid Waste

2000 ◽  
Vol 126 (12) ◽  
pp. 1076-1081 ◽  
Author(s):  
Adrie Veeken ◽  
Sergey Kalyuzhnyi ◽  
Heijo Scharff ◽  
Bert Hamelers
Keyword(s):  
Solid Waste ◽  
Effect Of Ph ◽  
Organic Solid Waste ◽  
Organic Solid ◽  
Hydrolysis Of
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