Probing dipeptide trans/cis stereochemistry using pH control of thiopeptide analogues, and application to the PepT1 transporter

2005 ◽  
Vol 3 (22) ◽  
pp. 4038 ◽  
Author(s):  
Patrick D. Bailey ◽  
C. A. Richard Boyd ◽  
Ian D. Collier ◽  
George L. Kellett ◽  
David Meredith ◽  
...  
Keyword(s):  
Ph Control ◽  
Pept1 Transporter

Example of Waste Water pH Control by Fuzzy

2007 ◽  
Vol 61 (3) ◽  
pp. 305-309
Author(s):  
Takayuki Ohkura
Keyword(s):  
Waste Water ◽  
Ph Control ◽  
Water Ph

Using microbial fatty acids to quantify, characterize and compare biofilm and suspended microbial populations in wastewater treatment systems

1998 ◽  
Vol 38 (4-5) ◽  
pp. 273-280 ◽  
Author(s):  
A. G. Werker ◽  
E. R. Hall
Keyword(s):  
Fatty Acid ◽  
Methyl Esters ◽  
Ph Control ◽  
Microbial Populations ◽  
Total Organic Carbon Removal ◽  
Operating Limits ◽  
Suspended Biomass ◽  
Kraft Mill Effluent ◽  
Microbial Fatty Acid ◽  
Influence Of Ph

Spectra of microbial fatty acid methyl esters were used to assess the influence of pH on the biofilm and suspended biomass populations within bench scale moving bed bioreactors treating bleached kraft mill effluent. The fatty acid spectral data were reduced by logcontrast canonical component analysis. The first canonical component differentiated biofilm from suspended populations and the second two appeared to indicate an influence of pH on microbial ecology. Thus, the biofilm and suspended microbial communities were distinct, as were the populations acclimated at pH 6 and pH 8. Experimental data for total organic carbon removal suggested that the more recalcitrant fraction of the influent was consumed by the slower growing, high SRT biofilm fraction of the biomass. Since the biofilm ecology was sensitive to pH within typical pH operating limits of full-scale systems, tighter pH control might improve treatment reliability in the event of process transients.

The anaerobic treatment of a ligno-cellulosic substrate offering little natural pH buffering capacity

1998 ◽  
Vol 38 (4-5) ◽  
pp. 29-35 ◽  
Author(s):  
C. J. Banks ◽  
P. N. Humphreys
Keyword(s):  
Ph Control ◽  
Anaerobic Treatment ◽  
Buffering Capacity ◽  
Single Stage ◽  
Stable Operation ◽  
Reactor Performance ◽  
Two Stage ◽  
Ph Buffering ◽  
Stage System ◽  
The Stability

The stability and operational performance of single stage digestion with and without liquor recycle and two stage digestion were assessed using a mixture of paper and wood as the digestion substrate. Attempts to maintain stable digestion in both single stage reactors were unsuccessful due to the inherently low natural buffering capacity exhibited; this resulted in a rapid souring of the reactor due to unbuffered volatile fatty acid (VFA) accumulation. The use of lime to control pH was unsatisfactory due to interference with the carbonate/bicarbonate equilibrium resulting in wide oscillations in the control parameter. The two stage system overcame the pH stability problems allowing stable operation for a period of 200 days without any requirement for pH control; this was attributed to the rapid flushing of VFA from the first stage reactor into the second stage, where efficient conversion to methane was established. Reactor performance was judged to be satisfactory with the breakdown of 53% of influent volatile solids. It was concluded that the reactor configuration of the two stage system offers the potential for the treatment of cellulosic wastes with a sub-optimal carbon to nitrogen ratio for conventional digestion.

scholarly journals Genes encoding putative bicarbonate transporters as a missing molecular link between molt and mineralization in crustaceans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shai Abehsera ◽  
Shmuel Bentov ◽  
Xuguang Li ◽  
Simy Weil ◽  
Rivka Manor ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Molecular Mechanisms ◽  
Ph Control ◽  
Functional Genomic ◽  
Single Event ◽  
Tight Coupling ◽  
Molt Cycle ◽  
Mineral Deposition ◽  
Bicarbonate Transporters ◽  
Genes Encoding

AbstractDuring their life, crustaceans undergo several molts, which if theoretically compared to the human body would be equivalent to replacing all bones at a single event. Such a dramatic repetitive event is coupled to unique molecular mechanisms of mineralization so far mostly unknown. Unlike human bone mineralized with calcium phosphate, the crustacean exoskeleton is mineralized mainly by calcium carbonate. Crustacean growth thus necessitates well-timed mobilization of bicarbonate to specific extracellular sites of biomineralization at distinct molt cycle stages. Here, by looking at the crayfish Cherax quadricarinatus at different molting stages, we suggest that the mechanisms of bicarbonate ion transport for mineralization in crustaceans involve the SLC4 family of transporters and that these proteins play a key role in the tight coupling between molt cycle events and mineral deposition. This discovery of putative bicarbonate transporters in a pancrustacean with functional genomic evidence from genes encoding the SLC4 family—mostly known for their role in pH control—is discussed in the context of the evolution of calcium carbonate biomineralization.

scholarly journals pH control of actin polymerization by cofilin.

1985 ◽  
Vol 260 (27) ◽  
pp. 14410-14412
Author(s):  
N Yonezawa ◽  
E Nishida ◽  
H Sakai
Keyword(s):  
Actin Polymerization ◽  
Ph Control

scholarly journals Modelling and pH Control in Raceway and Thin-Layer Photobioreactors for Wastewater Treatment

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1099
Author(s):  
María José Rodríguez-Torres ◽  
Ainoa Morillas-España ◽  
José Luis Guzmán ◽  
Francisco Gabriel Acién
Keyword(s):  
Wastewater Treatment ◽  
Thin Layer ◽  
Large Scale ◽  
Control Period ◽  
Ph Control ◽  
Thin Layers ◽  
Control Algorithms ◽  
Treatment Processes ◽  
Overall Performance ◽  
Reduction Of Co2

One of the most critical variables in microalgae-related processes is the pH; it directly determines the overall performance of the production system especially when coupling with wastewater treatment. In microalgae-related wastewater treatment processes, the adequacy of pH has a large impact on the microalgae/bacteria consortium already developing on these systems. For cost-saving reasons, the pH is usually controlled by classical On/Off control algorithms during the daytime period, typically with the dynamics of the system and disturbances not being considered in the design of the control system. This paper presents the modelling and pH control in open photobioreactors, both raceway and thin-layer, using advanced controllers. In both types of photobioreactors, a classic control was implemented and compared with a Proportional–Integral (PI) control, also the operation during only the daylight period and complete daily time was evaluated. Thus, three major variables already studied include (i) the type of reactors (thin-layers and raceways), (ii) the type of control algorithm (On/Off and PI), and (iii) the control period (during the daytime and throughout the daytime and nighttime). Results show that the pH was adequately controlled in both photobioreactors, although each type requires different control algorithms, the pH control being largely improved when using PI controllers, with the controllers allowing us to reduce the total costs of the process with the reduction of CO2 injections. Moreover, the control during the complete daily cycle (including night) not only not increases the amount of CO2 to be injected, otherwise reducing it, but also improves the overall performance of the production process. Optimal pH control systems here developed are highly useful to develop robust large-scale microalgae-related wastewater treatment processes.

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