Cyclization and disproportionation kinetics of triplet generated, medium chain length, localized biradicals measured by time-resolved CIDNP

1985 ◽  
Vol 107 (15) ◽  
pp. 4543-4544 ◽  
Author(s):  
Gerhard L. Closs ◽  
O. David Redwine
Keyword(s):  
Chain Length ◽  
Time Resolved ◽  
Medium Chain ◽  
Medium Chain Length ◽  
Kinetics Of

Kinetics of thermodegradation of palm kernel oil derived medium-chain-length polyhydroxyalkanoates

2012 ◽  
Vol 127 (6) ◽  
pp. 4422-4425 ◽  
Author(s):  
Mei Chan Sin ◽  
Irene Kit Ping Tan ◽  
Mohd Suffian Mohd Annuar ◽  
Seng Neon Gan
Keyword(s):  
Chain Length ◽  
Palm Kernel ◽  
Palm Kernel Oil ◽  
Medium Chain ◽  
Kernel Oil ◽  
Medium Chain Length ◽  
Kinetics Of

scholarly journals Transcriptome Changes in Pseudomonas putida KT2440 during Medium-Chain-Length Polyhydroxyalkanoate Synthesis Induced by Nitrogen Limitation

2020 ◽  
Vol 22 (1) ◽  
pp. 152
Author(s):  
Dorota Dabrowska ◽  
Justyna Mozejko-Ciesielska ◽  
Tomasz Pokój ◽  
Slawomir Ciesielski
Keyword(s):  
Chain Length ◽  
Nitrogen Limitation ◽  
Stringent Response ◽  
Wild Type ◽  
Pseudomonas Putida Kt2440 ◽  
Medium Chain ◽  
Environmental Stimuli ◽  
Medium Chain Length ◽  
In The Wild

Pseudomonas putida’s versatility and metabolic flexibility make it an ideal biotechnological platform for producing valuable chemicals, such as medium-chain-length polyhydroxyalkanoates (mcl-PHAs), which are considered the next generation bioplastics. This bacterium responds to environmental stimuli by rearranging its metabolism to improve its fitness and increase its chances of survival in harsh environments. Mcl-PHAs play an important role in central metabolism, serving as a reservoir of carbon and energy. Due to the complexity of mcl-PHAs’ metabolism, the manner in which P. putida changes its transcriptome to favor mcl-PHA synthesis in response to environmental stimuli remains unclear. Therefore, our objective was to investigate how the P. putida KT2440 wild type and mutants adjust their transcriptomes to synthesize mcl-PHAs in response to nitrogen limitation when supplied with sodium gluconate as an external carbon source. We found that, under nitrogen limitation, mcl-PHA accumulation is significantly lower in the mutant deficient in the stringent response than in the wild type or the rpoN mutant. Transcriptome analysis revealed that, under N-limiting conditions, 24 genes were downregulated and 21 were upregulated that were common to all three strains. Additionally, potential regulators of these genes were identified: the global anaerobic regulator (Anr, consisting of FnrA, Fnrb, and FnrC), NorR, NasT, the sigma54-dependent transcriptional regulator, and the dual component NtrB/NtrC regulator all appear to play important roles in transcriptome rearrangement under N-limiting conditions. The role of these regulators in mcl-PHA synthesis is discussed.

Kinetics of medium-chain-length polyhydroxyalkanoate production by a novel isolate of Pseudomonas putida LS46

2012 ◽  
Vol 58 (8) ◽  
pp. 982-989 ◽  
Author(s):  
Parveen K. Sharma ◽  
Jilagamazhi Fu ◽  
Nazim Cicek ◽  
Richard Sparling ◽  
David B. Levin
Keyword(s):  
Pseudomonas Putida ◽  
Chain Length ◽  
Saturated Fatty Acids ◽  
Dry Mass ◽  
Nucleotide Sequence Analysis ◽  
Glucose Medium ◽  
Medium Chain ◽  
Medium Chain Length ◽  
Pha Production ◽  
Nitrogen Excess

Six bacteria that synthesize medium-chain-length polyhydroxyalkanoates (mcl-PHAs) were isolated from sewage sludge and hog barn wash and identified as strains of Pseudomonas and Comamonas by 16S rDNA gene sequencing. One isolate, Pseudomonas putida LS46, showed good PHA production (22% of cell dry mass) in glucose medium, and it was selected for further studies. While it is closely related to other P. putida strains (F1, KT2440, BIRD-1, GB-1, S16, and W619), P. putida LS46 was genetically distinct from these other strains on the basis of nucleotide sequence analysis of the cpn60 gene hypervariable region. PHA production was detected as early as 12 h in both nitrogen-limited and nitrogen-excess conditions. The increase in PHA production after 48 h was higher in nitrogen-limited cultures than in nitrogen-excess cultures. Pseudomonas putida LS46 produced mcl-PHAs when cultured with glucose, glycerol, or C6–C14 saturated fatty acids as carbon sources, and mcl-PHAs accounted for 56% of the cell dry mass when cells were batch cultured in medium containing 20 mmol/L octanoate. Although 3-hydroxydecanoate was the major mcl-PHA monomer (58.1–68.8 mol%) in P. putida LS46 cultured in glucose medium, 3-hydroxyoctanoate was the major monomer produced in octanoate medium (88 mol%).

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