Alginate and Carrageenan Immobilization Effects on Schizosaccharomyces Pombe Activity and Stability

Effects of cell entrapment on nucleic acid content and microbial diversity of mixed cultures in biological wastewater treatment

The effects of entrapment on nucleic acid content and microbial diversity of mixed cultures in biological municipal wastewater treatment were investigated. Deoxyribonucleic acid content increased 1.6-5.5 times more in alginate entrapped cells than in free and polyvinyl alcohol (PVA) entrapped cells. PVA entrapment resulted in 1.1- to 5.9-fold more increases in ribonucleic acid content compared to that experienced by free and alginate entrapped cells. Entrapment in carrageenan changed the bacterial community structure more than the alginate and PVA entrapments (35-80% versus 0-35%) as determined by single-strand conformation polymorphism analyses. The change in the bacterial community structure of alginate entrapped cells was less time dependent than that of PVA entrapped cells. This study enhances understandings on the physiology of entrapped cells and their community evolution in wastewater treatment environments.

Ultrastructure of the murine cervix following infection with Chlamydia trachomatis

We have used electron microscopy to follow the course of Chlamydia trachomatis infection in the mouse cervix. Although numerous elementary bodies (EBs) were observed on the surface of epithelial cells, evidence of coated pits or entry of EBs into epithelial cells were rarely observed. After 2 days postinoculation, inclusions contained numerous reticulate bodies (RBs) and a few intermediate forms (IBs). At 4 days postinoculation, microvilli were no longer present on infected cells and inclusions had often ruptured and released chlamydiae into the cytoplasm of the cells. Aberrant and miniature RBs, similar to those which have been described in in vitro models for persistence, were observed. Unlike the case in vitro where inclusion cause rupture of the cell, infection in vivo may result in rupture of inclusions within the cytoplasm of infected cells. Our observations also suggest that persistent chlamydia can form in some of the cells of the cervical epithelium that are infected by the initial inoculation.