Tributyltin chloride (TBTCl)-enhanced exopolysaccharide and siderophore production in an estuarine Alcaligenes faecalis strain

Tributyltin chloride (TBTCl) has been used extensively as an antifouling agent in ship paints, which results in the contamination of aquatic sites. These contaminated sites serve as enrichment areas for TBTCl-resistant bacterial strains. One TBTCl-resistant bacterial strain was isolated from the sediments of Zuari estuary, Goa, India, which is a major hub of various ship-building activities. Based on biochemical characteristics and 16S rDNA sequence analysis, this bacterial strain was identified as Alcaligenes faecalis and designated as strain SD5. It could degrade ≥3 mM TBTCl by using it as a sole carbon source and transform it into the less toxic dibutyltin chloride, which was confirmed by nuclear magnetic resonance and mass spectroscopy. Interestingly, this bacterial strain also showed enhanced exopolysaccharide and siderophore production when cells were exposed to toxic levels of TBTCl, suggesting their involvement in conferring resistance to this antifouling biocide as well as degradative capability respectively.

Isolation and characterization of a heterotrophic nitrifier from coke plant wastewater

This study investigated some factors affecting ammonium removal and nitrite accumulation by Alcaligenes faecalis C16, which was isolated from the activated sludge of a coking wastewater treatment plant. Nitrite was produced from ammonium only in the presence of citrate, acetate, meat extract, peptone or ethanol. The highest amount of nitrite was found with citrate as carbon source. A. faecalis C16 could not use glucose, fructose, sucrose and methanol. Under the optimum conditions of initial pH 6.0, C/N 14, 30 °C and 120 rpm, a maximum nitrite accumulation of 28.29 mg/L NO(2)(-)-N was achieved when the organism grew with citrate in four days. Nitrite accumulation increased with the increase of NH(4)(+)-N. Furthermore, A. faecalis C16 was shown to have phenol-degrading capacity during ammonium removal. Metabolism of phenol resulted in acidification of the media, which is not favorable for nitrification, whereas many other carbon sources made the medium more alkaline. However, no inhibitory effect by phenol was observed when phenol and acetate were used as mixed carbon source at different phenol/sodium acetate (P/S) ratios and their pH values were all controlled above 9.2 or P/S ratios below 5:5. These results suggested that A. faecalis C16 has some potential application in industrial wastewater treatment systems.

Improvement in ammonium removal efficiency in wastewater treatment by mixed culture of Alcaligenes faecalis no. 4 and L1

To improve ammonium removal efficiency in wastewater treatment, a mixed culture of Alcaligenes faecalis no. 4 and its mutant L1, both of which have heterotrophic nitrification and aerobic denitrification abilities, was performed. In a batch culture, no. 4 has a higher denitrification ability than L1, but its ammonium removal rate was lower. In a mixed continuous culture in the ammonium loading range of 750 to 3500 mg-N/l/d, the average ammonium removal rate and the average denitrification ratio were 61 mg-N/l/h and 31%, respectively. In the mixed culture, the ammonium removal rate was twofold higher than that in a single culture of no. 4, the rate was similar to that in a single culture of L1, and the denitrification ratio was very high compared with that in the single culture of L1.

Fluorescence in situ hybridization for rapid identification of Achromobacter xylosoxidans and Alcaligenes faecalis recovered from cystic fibrosis patients

Achromobacter xylosoxidans is frequently isolated from the respiratory secretions of cystic fibrosis (CF) patients, but identification with biochemical tests is unreliable. We describe fluorescence in situ hybridization assays for the rapid identification of Achromobacter xylosoxidans and Alcaligenes faecalis. Both assays showed high sensitivities and high specificities with a collection of 155 nonfermenters from CF patients.

The sulfonated osmolyte N-methyltaurine is dissimilated by Alcaligenes faecalis and by Paracoccus versutus with release of methylamine

Selective enrichments yielded bacterial cultures able to utilize the osmolyte N-methyltaurine as sole source of carbon and energy or as sole source of fixed nitrogen for aerobic growth. Strain MT1, which degraded N-methyltaurine as a sole source of carbon concomitantly with growth, was identified as a strain of Alcaligenes faecalis. Stoichiometric amounts of methylamine, whose identity was confirmed by matrix-assisted, laser-desorption ionization time-of-flight mass spectrometry, and of sulfate were released during growth. Inducible N-methyltaurine dehydrogenase, sulfoacetaldehyde acetyltransferase (Xsc) and a sulfite dehydrogenase could be detected. Taurine dehydrogenase was also present and it was hypothesized that taurine dehydrogenase has a substrate range that includes N-methyltaurine. Partial sequences of a tauY-like gene (encoding the putative large component of taurine dehydrogenase) and an xsc gene were obtained by PCR with degenerate primers. Strain N-MT utilized N-methyltaurine as a sole source of fixed nitrogen for growth and could also utilize the compound as sole source of carbon. This bacterium was identified as a strain of Paracoccus versutus. This organism also expressed inducible (N-methyl)taurine dehydrogenase, Xsc and a sulfite dehydrogenase. The presence of a gene cluster with high identity to a larger cluster from Paracoccus pantotrophus NKNCYSA, which is now known to dissimilate N-methyltaurine via Xsc, allowed most of the overall pathway, including transport and excretion, to be defined. N-Methyltaurine is thus another compound whose catabolism is channelled directly through sulfoacetaldehyde.

Isolation and characterization of a chlorpyrifos and 3,5,6-trichloro-2-pyridinol degrading bacterium

A bacterium, isolated from contaminated soils around a chemical factory and named strain DSP3 was capable of biodegrading both chlorpyrifos and 3,5,6-trichloro-2-pyridinol. Based on the results of phenotypic features, phylogenetic similarity of 16S rRNA gene sequences, DNA G+C content, and DNA homology between strain DSP3 and reference strains, strain DSP3 was identified as Alcaligenes faecalis. Chlorpyrifos was utilized as the sole source of carbon and phosphorus by strain DSP3. We examined the role of strain DSP3 in the degradation of chlorpyrifos and 3,5,6-trichloro-2-pyridinol under different culture conditions. Parathion and diazinon could also be degraded by strain DSP3 when provided as the sole sources of carbon and phosphorus. An addition of strain DSP3 (10(8)cells g(-1)) to soil with chlorpyrifos (100 mg kg(-1)) resulted in a higher degradation rate than the one obtained from non-inoculated soils. Different degradation rates of chlorpyrifos in six types of treated soils suggested that soils used for cabbage growing in combination with inoculation of strain DSP3 showed enhanced microbial degradation of chlorpyrifos.

Alcaligenes faecalis subsp. phenolicus subsp. nov. a phenol-degrading, denitrifying bacterium isolated from a graywater bioprocessor

A Gram (-) coccobacillary bacterium, J(T), was isolated from a graywater bioprocessor. 16S rRNA and biochemical analysis has revealed strain J(T) closely resembles Alcaligenes faecalis ATCC 8750T and A. faecalis subsp. parafaecalis DSM 13975T, but is a distinct, previously uncharacterized isolate. Strain J(T), along with the type strain of A. faecalis and its previously described subspecies share the ability to aerobically degrade phenol. The degradation rates of phenol for strain J(T) and reference phenol degrading bacteria were determined by photometrically measuring the change in optical density when grown on 0.1% phenol as the sole carbon source, followed by addition of Gibb's reagent to measure depletion of substrate. The phenol degradation rates of strain J(T) was found to exceed that of the phenol hydroxylase group III bacterium Pseudomonas pseudoalcaligenes, with isolate J(T) exhibiting a doubling time of 4.5 h. The presence of the large subunit of the multicomponent phenol hydroxylase gene in strain J(T) was confirmed by PCR. The presence of the nirK nitrite reductase gene as demonstrated by PCR as well as results obtained from nitrite media indicated denitrification at least to N2O. Based on phenotypic, phylogenetic, fatty acid analysis and results from DNA DNA hybridization, we propose assigning a novel subspecies of Alcaligenes faecalis, to be named Alcaligenes faecalis subsp. phenolicus with the type strain J(T) (= DSM 16503) (= NRRL B-41076).

Kerstersia gyiorum gen. nov., sp. nov., a novel Alcaligenes faecalis-like organism isolated from human clinical samples, and reclassification of Alcaligenes denitrificans Rüger and Tan 1983 as Achromobacter denitrificans comb. nov

A polyphasic taxonomic study was performed on nine isolates recovered from various human clinical samples. Phenotypically, these isolates resembled Alcaligenes faecalis. Whole-cell protein analysis distinguished two different species, and this was confirmed by DNA-DNA hybridizations. Cellular fatty acid analysis and 16S rDNA sequence analysis indicated that these isolates were related to the genera Alcaligenes, Bordetella, Achromobacter and Pigmentiphaga and belonged to the family Alcaligenaceae. On the basis of the results of this study, the organisms were classified in a novel genus, Kerstersia gen. nov. This genus comprises one species, Kerstersia gyiorum sp. nov. (type strain LMG 5906(T)=API 184-2-84(T)=CCUG 47000(T)), and several unnamed isolates. The DNA G+C content of members of the genus Kerstersia is between 61.5 and 62.9 mol%. On the basis of previously published DNA-DNA hybridization results and data from chemotaxonomic studies, it is proposed that Alcaligenes denitrificans Rüger and Tan 1983 be reclassified as Achromobacter denitrificans comb. nov.