Feeding biology of Diplogasteritus nudicapitatus and Rhabditis curvicaudata (Nematoda) related to food concentration and temperature, in sewage treatment plants

Woombs, Mark; Laybourn‐Parry, Johanna

doi:10.1007/bf00376865

Cited by 23 publications

(6 citation statements)

References 15 publications

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“…Pumping rates were quantified by eye using a Fisher Scientific Stereomaster dissecting microscope as described elsewhere (2,54). Briefly, pharyngeal pumps were counted during five successive 1-min periods, and the average of the five counts was taken as the worm's pumping rate.…”

Section: Methodsmentioning

confidence: 99%

A Functional Phenylacetic Acid Catabolic Pathway Is Required for Full Pathogenicity of Burkholderia cenocepacia in the Caenorhabditis elegans Host Model

et al. 2008

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Burkholderia cenocepacia is a member of the Burkholderia cepacia complex, a group of metabolically versatile bacteria that have emerged as opportunistic pathogens in cystic fibrosis and immunocompromised patients. Previously a screen of transposon mutants in a rat pulmonary infection model identified an attenuated mutant with an insertion in paaE, a gene related to the phenylacetic acid (PA) catabolic pathway. In this study, we characterized gene clusters involved in the PA degradation pathway of B. cenocepacia K56-2 in relation to its pathogenicity in the Caenorhabditis elegans model of infection. We demonstrated that targeted-insertion mutagenesis of paaA and paaE, which encode part of the putative PA-coenzyme A (CoA) ring hydroxylation system, paaZ, coding for a putative ring opening enzyme, and paaF, encoding part of the putative beta-oxidation system, severely reduces growth on PA as a sole carbon source. paaA and paaE insertional mutants were attenuated for virulence, and expression of paaE in trans restored pathogenicity of the paaE mutant to wild-type levels. Interruption of paaZ and paaF slightly increased virulence. Using gene interference by ingested doublestranded RNA, we showed that the attenuated phenotype of the paaA and paaE mutants is dependent on a functional p38 mitogen-activated protein kinase pathway in C. elegans. Taken together, our results demonstrate that B. cenocepacia possesses a functional PA degradation pathway and that the putative PA-CoA ring hydroxylation system is required for full pathogenicity in C. elegans.

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Section: Methodsmentioning

confidence: 99%

A Functional Phenylacetic Acid Catabolic Pathway Is Required for Full Pathogenicity of Burkholderia cenocepacia in the Caenorhabditis elegans Host Model

et al. 2008

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“…This consumption rate was equivalent to 7% of the nematode biomass day-i and was considered as a minimum value. Much higher rates for some bacterial feeding nematodes, in the order of 400% of nematode biomass consumed per day (Woombs and Laybourn-Parry, 1984), have been reported. Thus 314/zg bacterial C g-~ was calculated as a maximum value, assuming that 400% of biomass day ~ would be an upper value for consumption.…”

Section: Net Mineralisationmentioning

confidence: 99%

Microbial biomass and mineral N transformations in soil planted with barley, ryegrass, pea or turnip

Wheatley¹,

Ritz²,

Griffiths³

1990

Plant Soil

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Plants of barley (Hordeum vulgare), ryegrass (Lolium perenne), pea (Pisum sativum) or turnip (Brassica campestris rapifera) were grown in pots of unfertilised soil for 10 weeks together with unplanted control pots. A wide range of soil microbiological parameters was measured on bulk soil samples 2, 4, 7 and 10 weeks after seedlings were transplanted. There was no effect of planting or differential effect of plant species upon respiration rate, microbial biomass N, or biomass of microbial predators, but these parameters all varied significantly over time. Respiration, biomass N and nematode biomass all increased, whilst protozoan biomass decreased. Microbial biomass C showed no significant temporal changes or effect of planting. There was evidence for differential plant effects on potential nitrification and denitrification. Nitrification rates were depressed, compared with the fallow, in all treatments except the pea, at some time in the experiment. Conversely denitrification rates were enhanced in all treatments, except the grass, at specific times. Denitrification rates were greater in the pea treatment than the fallow on all occasions. These results demonstrate that plants do not necessarily influence the gross microbiology of the soil, but may affect physiologically distinct sub-components of the microbial biomass.

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“…Most are grazers on the bacteria which bring about the bio-oxidation process upon which sewage processing is based. The high grazing rates of nematodes (Woombs & Laybourn-Parry, 1984b), together with the other bacterial grazers, largely protozoa, must clearly have an impact on the bacteria. From the limited evidence (Abrams & Mitchell, 1980;Woombs & Laybourn-Parry, 1986a) it may be deduced that the bacterial grazers keep the bacterial populations actively growing and distributed on the sewage substrate, and hence enhance energy flow and mineralization processes.…”

Section: Discussionmentioning

confidence: 99%

The temporal and spatial distribution of nematodes in percolating filters

Laybourn‐Parry

Woombs

1988

Hydrobiologia

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The spatial and temporal distribution of nematodes in two low rate percolating filter bed sewage treatment plants at Carnforth and Caton, Lancashire, were investigated. Nematodes were abundant reaching densities up to 900 cm-2 of media surface. Numbers decreased down the bed and species composition displayed spatial differences with bed depth. Eight orders of nematode were represented, members of the sub-family Diplogasterinae and Rhabditinae were particularly common. A seasonal pattern of abundance was clearly apparent; two peaks occurred, one in May and a second during the winter months. Lowest numbers corresponded with periods of highest temperature. The demise of the nematodes in the spring was related to the sloughing of the surface film on the media.

show abstract

Feeding biology of Diplogasteritus nudicapitatus and Rhabditis curvicaudata (Nematoda) related to food concentration and temperature, in sewage treatment plants

Cited by 23 publications

References 15 publications

A Functional Phenylacetic Acid Catabolic Pathway Is Required for Full Pathogenicity of Burkholderia cenocepacia in the Caenorhabditis elegans Host Model

A Functional Phenylacetic Acid Catabolic Pathway Is Required for Full Pathogenicity of Burkholderia cenocepacia in the Caenorhabditis elegans Host Model

Microbial biomass and mineral N transformations in soil planted with barley, ryegrass, pea or turnip

The temporal and spatial distribution of nematodes in percolating filters

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