A positive temperature coefficient is the term which has been used to indicate that an increase in solubility occurs as the temperature is raised, whereas a negative coefficient indicates a decrease in solubility with rise in temperature.

Effect of Temperature

http://ntur.lib.ntu.edu.tw/bitstream/246246/90085/1/126.pdf

Aerobic granular sludge: Recent advances

Genetic exchange between bacteria in the environment.

Bioaugmentation as a strategy for cleaning up of soils contaminated with aromatic compounds

The dramatic spread of antibiotic resistance is a crisis in the treatment of infectious diseases that affect humans Several studies suggest that wastewater treatment plants (WWTP) are reservoirs for diverse mobile antibiotic resistance elements This review summarizes findings derived from genomic analysis of IncP-1 resistance plasmids isolated from WWTP bacteria Plasmids that belong to the IncP-1 group are self-transmissible, and transfer to and replicate in a wide range of hosts Their backbone functions are described with respect to their impact on vegetative replication, stable maintenance and inheritance, mobility and plasmid control Accessory genetic modules, mainly representing mobile genetic elements, are integrated in-between functional plasmid backbone modules These elements carry determinants conferring resistance to nearly all clinically relevant antimicrobial drug classes, to heavy metals, and quaternary ammonium compounds used as disinfectants All plasmids analysed here contain integrons that potentially facilitate integration, exchange and dissemination of resistance gene cassettes Comparative genomics of accessory modules located on plasmids from WWTP and corresponding modules previously identified in other bacterial genomes revealed that animal, human and plant pathogens and other bacteria isolated from different habitats share a common pool of resistance determinants

Genomics of IncP-1 antibiotic resistance plasmids isolated from wastewater treatment plants provides evidence for a widely accessible drug resistance gene pool

Three types of phenol and p-cresol catabolism in phenol- and p-cresol-degrading bacteria isolated from river water continuously polluted with phenolic compounds.

The
herbicide 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterium
 Achromobacter xylosoxidans subsp. denitrificans 
strain EST4002 contains plasmid pEST4011. This plasmid ensures its host
a stable 2,4-D + phenotype. We determined the
complete 76,958-bp nucleotide sequence of pEST4011. This plasmid is a
deletion and duplication derivative of pD2M4, the 95-kb highly unstable
laboratory ancestor of pEST4011, and was self-generated during
different laboratory manipulations performed to increase the stability
of the 2,4-D + phenotype of the original strain,
strain D2M4(pD2M4). The 47,935-bp catabolic region of pEST4011 forms a
transposon-like structure with identical copies of the hybrid insertion
element IS 1071 ::IS 1471 at the two
ends. The catabolic regions of pEST4011 and pJP4, the best-studied
2,4-D-degradative plasmid, both contain homologous, tfd -like
genes for complete 2,4-D degradation, but they have little sequence
similarity other than that. The backbone genes of pEST4011 are most
similar to the corresponding genes of broad-host-range
self-transmissible IncP1 plasmids. The backbones of the other three
IncP1 catabolic plasmids that have been sequenced (the
2,4-D-degradative plasmid pJP4, the haloacetate-catabolic plasmid pUO1,
and the atrazine-catabolic plasmid pADP-1) are nearly identical to the
backbone of R751, the archetype plasmid of the IncP1 β
subgroup. We show that despite the overall similarity in plasmid
organization, the pEST4011 backbone is sufficiently different (51 to
86% amino acid sequence identity between individual backbone
genes) from the backbones of members of the three IncP1 subgroups (theα
, β, and γ subgroups) that it belongs to a new
IncP1subgroup, the δ subgroup. This conclusion was also
supported by a phylogenetic analysis of the trfA2 ,
 korA , and traG gene products of different IncP1
plasmids.

The completely sequenced plasmid pEST4011 contains a novel IncP1 backbone and a catabolic transposon harboring tfd genes for 2,4-dichlorophenoxyacetic acid degradation.

Biodegradation efficiency of functionally important populations selected for bioaugmentation in phenol- and oil-polluted area

Horizontal transfer of genes of selective value in an environment 6 years after their introduction into a watershed has been observed. Expression of the gene pheA, which encodes phenol monooxygenase and is linked to the pheBA operon (A. Nurk, L. Kasak, and M. Kivisaar, Gene 102:13-18, 1991), allows pseudomonads to use phenol as a growth substrate. Pseudomonas putida strains carrying this operon on a plasmid were used for bioremediation after an accidental fire in the Estonia oil shale mine in Estonia in 1988. The water samples used for studying the fate of the genes introduced were collected in 1994. The same gene cluster was also detected in Pseudomonas strains isolated from water samples of a nearby watershed which has been continuously polluted with phenols due to oil shale industry leachate. Together with the more frequently existing counterparts of the dmp genes (V. Shingler, J. Powlowski, and U. Marklund, J. Bacteriol. 174:711-724, 1992), the pheA gene was also represented in the phenol-degrading strains. The area where the strains containing the pheA gene were found was restricted to the regular route of phenolic leachate to the Baltic Sea. Nine Pseudomonas strains belonging to four different species (P. corrugata, P. fragi, P. stutzeri, and P. fluorescens biotypes B, C, and F) and harboring horizontally transferred pheBA operons were investigated. The phe genes were clustered in the same manner in these nine phe operons and were connected to the same promoter as in the case of the original pheBA operon. One 10.6-kb plasmid carrying a pheBA gene cluster was sequenced, and the structure of the rearranged pheBA operon was described. This data indicates that introduced genetic material could, if it encodes a beneficial capability, enrich the natural genetic variety for biodegradation.

Ain Heinaru

Papers

Three types of phenol and p-cresol catabolism in phenol- and p-cresol-degrading bacteria isolated from river water continuously polluted with phenolic compounds.

The completely sequenced plasmid pEST4011 contains a novel IncP1 backbone and a catabolic transposon harboring tfd genes for 2,4-dichlorophenoxyacetic acid degradation.

Biodegradation efficiency of functionally important populations selected for bioaugmentation in phenol- and oil-polluted area

Acquisition of a deliberately introduced phenol degradation operon, pheBA, by different indigenous Pseudomonas species.

Dynamic changes in the structure of microbial communities in Baltic Sea coastal seawater microcosms modified by crude oil, shale oil or diesel fuel.