High Precision Measurements Lend No Supporting Evidence of Previously Reported Large Verdet Constants for Olive Oil

Motivated by a previous report of surprisingly large Verdet constant measurements for olive oil at 633 nm and 650 nm (Shakir, et. al., 2013), and the practical utility of materials possessing such large values, we considered it worthwhile to validate those results. In this work, high precision Faraday rotation measurements were performed utilizing ac magnetic fields, phase sensitive detection, and a collection of diode lasers. Specifically, we measured the dispersion of the Verdet constant for a single brand of olive oil from 410 nm to 675 nm. In addition, we determined the Verdet constant for eight different samples of olive oil at 654 nm, very near the wavelength where the “anomalous” results, i.e. large Verdet constants, were reported. Our measurements of the Faraday rotations, and hence the determination of the respective Verdet constants, call into question those previously reported measurements. Generally, our results suggest that their experimental technique most likely led to inaccurate results for all five of the Verdet constant values they reported

Photorhabdus Luminescens Phase II Cells Growth Kinetic Study Using A 5L A Plus Sartorius Stedim Biostat® Fermentation System

Photorhabdus luminescens lives symbiotically with the nematode species Heterorhabditis bacteriophora. This symbiotic couple may become a bio-control key to replacing chemical pesticides. The nematode is able to infect a wide variety of destructive insects without causing harm to beneficial insect species. There are numerous advantages of biocontrol methods including decreased maintenance and less repeated use than chemical pesticides. Nematodes are also resilient to the environment for reproduction. To better assess the growth characteristics of Heterorhabditis bacteriophora, the growth kinetics of the bacterial symbiont Photorhabdus luminescens must be understood. By varying the media composition, optimal conditions were found to present the highest specific growth rate and the shortest doubling time of P. luminescens. These conditions could be scaled into mass production with high yield

Physiological Constants of the Entomopathogenic Bacterium Xenorhabdus Nematophila Determined by Microbial Growth Kinetics

Xenorhabdus nematophila, an entomopathogenic bacterium that symbiotically associates with the entomoparasitic nematode Steinernema carpocapsae, was studied to determine its physiological parameters of glucose utilization. X. nematophila was cultured in chemically defined media containing various concentrations of glucose under optimal conditions utilizing a two-liter fermentation system. Specific growth rates were obtained from each glucose batch. Specific growth rates and their associated glucose concentrations were used to determine physiological parameters. These parameters include the bacterium's substrate utilization constant (K s ) and its maximum specific growth rate (µ max). The bacteria exhibited a K s value of 2.02 mg/L suggesting that X. nematophila has a high affinity for glucose. The µ max of Xenorhabdus was determined to be 1.03 h(-1). Further research is needed to determine if microbial affinities to different substrates have any influence on biological relationships (symbiosis, pathogenicity, parasitism, etc.) between prokaryotes and higher organisms

Electron Irradiation Induced Transformation of (Pb 5 Ca 5 )(VO 4 ) 6 F 2 Apatite to CaVO 3 Perovskite

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65906/1/j.1551-2916.2004.00002.x.pd

Physiological Constants of the Entomopathogenic Bacterium Xenorhabdus nematophila Determined by Microbial Growth Kinetics

Xenorhabdus nematophila, an entomopathogenic bacterium that symbiotically associates with the entomoparasitic nematode Steinernema carpocapsae, was studied to determine its physiological parameters of glucose utilization. X. nematophila was cultured in chemically defined media containing various concentrations of glucose under optimal conditions utilizing a two-liter fermentation system. Specific growth rates were obtained from each glucose batch. Specific growth rates and their associated glucose concentrations were used to determine physiological parameters. These parameters include the bacterium's substrate utilization constant ( ) and its maximum specific growth rate ( max ). The bacteria exhibited a value of 2.02 mg/L suggesting that X. nematophila has a high affinity for glucose. The max of Xenorhabdus was determined to be 1.03 h −1 . Further research is needed to determine if microbial affinities to different substrates have any influence on biological relationships (symbiosis, pathogenicity, parasitism, etc.) between prokaryotes and higher organisms

Modeling the Growth of Lactococcus lactis NCIM 2114 under Differently Aerated and Agitated Conditions in Broth Medium

The study of growth of Lactococcus lactis NCIM 2114, a nisin producer, was modeled using continuously generated concentration data for growth in fermenter. The sigmoidal growth functions, Logistic, Gompertz, and Richards were used to fit the data. A nonlinear regression method was used to fit the data and estimate growth parameter values of L. lactis, using Marquardt algorithm with Statistical Software SPSS, version 20. Bacterial growth data from the exponential phase of the bacteria’s growth was analyzed. An F test showed that the Gompertz and Logistic functions were acceptable 92% and 67% of times respectively in the batch fermenter runs where this particular application was used to derive the lag time, growth rates, and time to maximum growth rates of L. lactis. The maximal specific growth rate ranged between 0.23 h−1 to 0.30 h−1 and the lag time lasted up to a maximum of 1.63 h depending upon aeration conditions provided to the organism. This study will help to estimate specific growth rates and lag time of L. lactis under different growth conditions. Predicted values can be accurately determined

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Not AvailableThe facultative anaerobe, Lactococcus lactis was grown in batch fermentation (1.5 L working volume) at 30°C, using 5% inoculums to initiate growth for the production of the antimicrobial food additive nisin. L. lactis strain NCIM 2114 produced a maximal nisin concentration of 50,400 IU/mL and 8,830 IU/mg biomass in MRS growth medium using a 2 L bioreactor with optimal conditions of 25 rpm and 0.2 vvm determined by a Box Behnken design statistical package. Nisin was obtained from cell-free extracts and quantified using ultra-fast liquid chromatography (UFLC). Maximum bioactive nisin concentration was found at 4 h and harvested. Increasing aeration, agitation or time until harvest had negative impact on bioactive product yield. In a repeated trial under the same conditions, cell-free extracts of nisin were measured by well diffusion assay at 240 IU/mL (antimicrobial activity). Bioactive nisin was confirmed. The optimal specific growth rate for L. lactis was measured to be 0.25 h-1. This study shows that active biomass production can be increased using conditions determined by standard statistical methods.Not Availabl