Saturation mutagenesis was used to generate eleven substitutions of toluene-o-xylene monooxygenase (ToMO) at alpha subunit (TouA) positions F176 and F196 among which nine were novel: F176H, F176N, F176S, F176T, F196A, F196L, F196T, F196Y, F196H, F196I, and F196V. By testing the substrates phenol, toluene, and naphthalene, these positions were found to influence ToMO oxidation activity and regio...

A bacterium, strain PC-07, previously isolated as part of a coculture capable of growing on p-cresol under anaerobic conditions with nitrate as the acceptor was identified as an Achromobacter sp. The first enzyme of the pathway, p-cresol methylhydroxylase, which converts its substrate into p-hydroxybenzyl alcohol, was purified. The enzyme had an Mr of 130,000 and the spectrum of a flavocytochro...

The electrooxidation of aqueous solutions containing 5mM of o-, m- and p-cresol at pH 4.0 has been investigated using a flow filter-press reactor with a boron-doped diamond (BDD) under galvanostatic electrolysis. All cresols are degraded at similar rate up to attaining overall mineralization. Comparable treatment of the m-cresol effluent on PbO(2) leads to partial electrochemical incineration. ...

The enzyme p-cresol methylhydroxylase [4-cresol: (acceptor) oxidoreductase (methyl-hydroxylating), EC 1.17.99.1] contains two subunits: a cytochrome c (electron transfer) subunit (cytochrome cpc) and a flavin (catalytic) subunit. When these subunits are separated by isoelectric focusing, a stable cytochrome subunit is obtained. Significant differences are observed between the one-dimensional NM...

Stable flies (Stomoxys calcitrans [Diptera: Muscidae] L.) are blood-feeding synanthropic pests, which cause significant economic losses in livestock. Stable fly antennae contain olfactory sensilla responsive to host and host environment-associated odours. Field observation indicated that the abundance of stable flies increased significantly in grasslands or crop fields when cattle manure slurry...

Mycobacterium sp. strain HL 4-NT-1, isolated from a mixed soil sample from the Stuttgart area, utilized 4-nitrotoluene as the sole source of nitrogen, carbon, and energy. Under aerobic conditions, resting cells of the Mycobacterium strain metabolized 4-nitrotoluene with concomitant release of small amounts of ammonia; under anaerobic conditions, 4-nitrotoluene was completely converted to 6-amin...

A sequencing batch reactor (SBR) was inoculated with p-nitrophenol-degrading activated sludge to biodegrade a mixture of monosubstituted phenols: p-nitrophenol (PNP), PNP and o-cresol; and PNP, o-cresol and o-chlorophenol. Settling times were progressively decreased to promote biomass granulation. PNP was completely biodegraded. The PNP and o-cresol mixture was also biodegraded although some tr...

Plasmid pRO1957 contains a 26.5-kb BamHI restriction endonuclease-cleaved DNA fragment cloned from the chromosome of Pseudomonas pickettii PKO1 that allows P. aeruginosa PAO1c to grow on toluene, benzene, phenol, or m-cresol as the sole carbon source. The genes encoding enzymes for meta cleavage of catechol or 3-methylcatechol, derived from catabolism of these substrates, were subcloned from pR...

Saturation mutagenesis was used to generate 10 mutants of toluene-o-xylene monooxygenase (ToMO) at alpha subunit (TouA) positions A101 and A110: A101G, A101I, A101M, A101VE, A101V, A110G, A110C, A110S, A110P, and A110T; by testing the substrates toluene, o-cresol, m-cresol, p-cresol, phenol, naphthalene, o-methoxyphenol, m-methoxyphenol, p-methoxyphenol, o-xylene, and nitrobenzene, these positi...