Composting of municipal solid waste (MSW) was studied in an attempt to elaborate transformations of organic matter (OM) during the process and define parameters for the degree of maturity of the product. Composting was performed in 1‐m3 plastic boxes and the following parameters were measured in 13 samples during 132 d of composting: temperature, C/N ratio, ash content, humic substance contents, and fractions (humic acid, fulvic acid, and nonhumic fraction‐HA, FA, and NHF, respectively). Spectroscopic methods (CPMAS 13C‐NMR, DRIFT) were used to study the chemical composition of the OM. A bioassay based on growth of cucumber (Cucumis sativus L. cv. Dlila) plants was correlated to other parameters. The C/N ratio and ash content showed a typical high rate of change during the first 60 d and reached a plateau thereafter. The HA content increased to a maximum at 112 d, corresponding to the highest plant dry weight and highest 1650/1560 (cm−1/cm−1) peak ratios calculated from DRIFT spectra. 13C‐NMR and DRIFT spectra of samples taken from the composting MSW during the process showed that the residual OM contained an increasing level of aromatic structures. Plant‐growth bioassay, HA content, and the DRIFT spectra indicated that MSW compost described in this study, stabilized and achieved maturity after about 110 d.

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SummaryEnteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) are closely related pathogens. During infection, EPEC and EHEC use a type III secretion system (TTSS) to translocate effector proteins into the infected cells and thereby modify specific host functions. These include transient filopodium formation which is Cdc42-dependent. Filopodia formation is followed by assembly of actin pedestals, the process enhanced by inhibition of Cdc42. We discovered that orf 18 of the enterocyte effacement locus encodes a new effector, which we termed EspH . We show that EspH is translocated efficiently into the infected cells by the TTSS and localizes beneath the EPEC microcolonies. Inactivation of espH resulted in enhanced formation of filopodia and attenuated the pedestals formation. Furthermore, overexpression of EspH resulted in strong repression of filopodium formation and heightened pedestal formation. We also demonstrate that overexpression of EspH by EHEC induces marked elongation of the typically flat pedestals. Similar pedestal elongation was seen upon infection of COS cells overexpressing EspH. EspH transiently expressed by the COS cells was localized to the membrane and disrupted the actin cytoskeletal structure. Our findings indicate that EspH is a modulator of the host actin cytoskeleton structure.

The utilization of cattle (Bos sp.) manure as a peat substitute in greenhouses has been proposed. This alternative requires certain preparatory procedures, including composting. The objective of this research was to study the composting process, changes occurring in the product during composting and product properties of relevance to its potential use as a container medium, and to evaluate possible criteria indicating compost maturity. Composting of separated cattle manure (CSM) was studied in 1‐m3 perforated boxes. Most of the physical and some of the chemical properties exhibited a high rate of change during the first 40 to 60 d of the composting process. Total water‐soluble salts, as measured by electrical conductivity (EC), exhibited a constant value for the first 60 d, followed by a sharp increase in EC (from 2.6–5.4 dS m−1). The main ions contributing to this increase were NO−3, Ca2+ and Mg2+. As temperature decreased, nitrate levels increased sharply due to nitrification, from 0.02 cmol L−1 at the beginning to 4.0 cmol L−1 at the end of the composting process. Although most changes took place during the first high temperature phase, slow decomposition persisted after temperature returned to ambient level as measured in the compost water extract. Plant bioassays also indicated that 40‐ to 60‐d old compost inhibited growth and there was limited response to fertilization. Both of these factors were eliminated after 80 to 90 d of composting. Chemical properties of water extracts may therefore serve as indicators of compost maturity and of the material's suitability as an organic component for container media.