Display options:
Normal
Show Abstracts
Compact
Displaying article 1-2
Research
p. 1-11
Received: 27 December 2005 / Accepted: 30 January 2006 / Published: 31 January 2006
Show/Hide Abstract
| Cited by 2 | PDF Full-text (387 KB)
Abstract: An analysis of the recently published genome sequence of Cytophagahutchinsonii revealed an unusual collection of genes for an organism that can attackcrystalline cellulose. Consequently, questions were being raised by cellulase scientists, as towhat mechanism this organism uses to degrade its insoluble substrates. Cellulose, being ahighly polymeric compound and insoluble in water, cannot enter the cell walls ofmicroorganisms. Cellulose-degrading enzymes have therefore to be located on the surface ofthe cell wall or released extracellularly. The location of most cellulase enzymes has beenstudied. However, basic information on C. hutchinsonii cellulases is almost non-existent. Inthe present study, the location, formation and biosynthetic regulation of cellulases in C.hutchinsonii were demonstrated on different substrates. Various fractions isolated from C.hutchinsonii after cell rupture were assayed for carboxymethyl-cellulase activity (CMC).The cellulases were found to be predominantly cell-free during active growth on solka-flok,although 30% of activity was recorded on cell-bound enzymes. Relatively little CM-cellulase was formed when cells were grown on glucose and cellobiose. Apparently glucoseor labile substrates such as cellobiose seem to repress the formation of CM-cellulase. Thesefindings should provide some insight into possible hydrolysis mechanisms by C.hutchinsonii.
p. 12-34
Received: 16 December 2005 / Accepted: 26 January 2006 / Published: 31 January 2006
Show/Hide Abstract
| Cited by 2 | PDF Full-text (200 KB)
Abstract: Algorithms for classification are proposed based on criteria (information entropyand its production). The feasibility of replacing a given anaesthetic by similar ones in thecomposition of a complex drug is studied. Some local anaesthetics currently in use areclassified using characteristic chemical properties of different portions of their molecules.Many classification algorithms are based on information entropy. When applying theseprocedures to sets of moderate size, an excessive number of results appear compatible withdata, and this number suffers a combinatorial explosion. However, after the equipartitionconjecture, one has a selection criterion between different variants resulting fromclassification between hierarchical trees. According to this conjecture, for a given charge orduty, the best configuration of a flowsheet is the one in which the entropy production is mostuniformly distributed. Information entropy and principal component analyses agree. Theperiodic law of anaesthetics has not the rank of the laws of physics: (1) the properties ofanaesthetics are not repeated; (2) the order relationships are repeated with exceptions. Theproposed statement is: The relationships that any anaesthetic p has with its neighbour p 1are approximately repeated for each period.
Displaying article 1-2
Plain Text
BibTeX
BibTeX (without abstracts)
Endnote
Endnote (without abstracts)
Tab-delimited
PubMed XML
DOAJ XML
AGRIS XML
to open them.