background: much of the environment is affected by petroleum contamination. it imposes serious health problems for humans as well as serious environmental impact. bioremediation is an important consideration for removing environmental pollutants because, compared with other technologies, it incurrs lower costs and is environmentally compatible. methods: crude oil degrading bacteria were isolate...

two different growth media, namely complex and defined media, were used to examine establishment of steady-state conditions in phosphate-limited culture system of saccharomyces cerevisiae cen.pk113-5d strain. using the defined growth medium, it was possible to obtain steady state condition in the continuous culture. the effect of phosphate concentration on the growth of s. cerevisiae in phospha...

the batch fermentation production of human growth hormone (hgh) was studied in a newrecombinant escherichia coli. the effect of different levels of dissolved oxygen and glucoseconcentration on cell density and substrate utilization were evaluated. the results indicated that theoptimum level of dissolved oxygen was 25% of air saturation. the specific growth rate reached amaximum for an optimal g...

context:in this review, we discuss empirical and stoichiometric models, which have been developed recently in ssf processes and the influence of environmental conditions on the variables of these models. additionally, new studies on modeling of product formation are also mentioned. evidence acquisition:solid-state fermentation (ssf) is recognized as a cheap process for producing many valuable p...

In order to improve the traditional freezing crystallization process of calcium nitrate in nitric phosphate process, crystal growth experiments by adding Ca(NO3)2·4H2O seeds in supersaturated calcium nitrate solution in a Circulating Fluidized Bed (CFB) crystallizer were carried out on crystal growth kinetics. The results showed that the growth of C...

Bacterial profile modification (BPM) is being developed as an oil recovery technique that uses bacteria to selectively plug oil depleted zones within a reservoir to divert displacing fluids (typically water) into oilrich zones. Leuconostoc mesenteroides, which produces dextran when supplied with sucrose, is a bacterium that is technically feasible for use in profile modification. However, the t...

We study the kinetics of prion fibril growth, described by the nucleated polymerization model analytically and by means of numerical experiments. The elementary processes of prion fibril formation lead us to a set of differential equations for the number of fibrils, their total mass, and the number of prion monomers. In difference to previous studies we analyze this set by explicitly taking int...