In this study we examine the distribution of Rhizopogon species in spore banks from five California pine forests. Four of the forest sites were discontinuous populations of Pinus muricata and a fifth was a Pinus ponderosa stand in Sierra National Forest. Rhizopogon species were retrieved by bioassaying the soils with pine seedlings followed by isolation of axenic cultures from individual root t...

Chlorella minutissima was co-cultured with Escherichia coli in airlift reactors under mixotrophic conditions (glucose, glycerol, and acetate substrates) to determine possible effects of bacterial contamination on algal biofuel production. It was hypothesized that E. coli would compete with C. minutissima for nutrients, displacing algal biomass. However, C. minutissima grew more rapidly and to h...

The effect of root exudates from non-mycorrhizal and mycorrhizal cucumber (Cucumis sativus L.) plants colonized by one of three arbuscular mycorrhizal fungi (Gigaspora rosea Nicolson & Schenck, Glomus intraradices Smith & Schenck, or Glomus mosseae (Nicolson & Gerdemann) Gerd. & Trappe) on hyphal growth of Gi. rosea and G. intraradices in axenic culture and on root colonization by G. mosseae in...

The inverse fluidized bed bioreactor was adapted for the axenic culture of heterotrophic microorganisms. Penicillin V synthesized by Penicillium chrysogenum ATCC 28089 was used as a model system for secondary metabolite production. The biomass growth rate was controlled by the rate of nutrient addition while an eroder in the inner draft tube limited the maximum biofilm thickness. When a lactose...

In infected mammalian cells, Leishmania parasites reside within specialized compartments called parasitophorous vacuoles (LPVs). We have previously shown that Retro-2, a member of a novel class of small retrograde pathway inhibitors caused reduced LPV sizes and lower parasite numbers during experimental L. mexicana sp. infections. The purpose of this study was to determine if structural analogs...

The occurrence of sesquiterpenes was investigated with the geosmin-producing cyanobacterium Calothrix PCC 7507. The essential oil obtained by vacuum destillation was studied in more detail by GC-MS methods and superposition with authentic compounds. Geosmin was the dominating compound while the other sesquiterpenes were minor components. Sesquiterpenes that have not been described before in cya...

Brucella abortus is an intracellular bacterial pathogen and an etiological agent of the zoonotic disease known as brucellosis. Brucellosis can be challenging to treat with conventional antibiotic therapies and, in some cases, may develop into a debilitating and life-threatening chronic illness. We used multiple independent assays of in vitro metabolism and intracellular replication to screen a ...

Nutrient uptake in obligate parasitism was recently reviewed by Bushnell and Gay (5) for the powdery mildews. In the rust fungi, the experimental approach to solving this question is quite different, because the fungus mycelium grows only in restricted areas within the leaf. The rust pustules act as foci for the accumulation of many metabolites. The fungus derives nutrients by alteration of the...

This study determined the effects of Trichomonas vaginalis trophozoites, subcellular fractions, and medium from axenic T. vaginalis cultures on human sperm motility and viability. Spent medium (pH 7.0) caused complete cessation of sperm motility after 15 minutes incubation. Trophozoite soluble fraction or formalin-killed trophozoites caused a 50 percent reduction in sperm motility, compared to ...

Commercial culture media present interlot variations in biological activity. We have previously designed a homemade and economic culture medium, PEHPS medium, for the axenic cultivation of Entamoeba histolytica and Trichomonas vaginalis. Trophozoites of amoebae and trichomonads grow well in this medium. Furthermore, the medium is stable for several months when stored frozen or refrigerated. The...