The Laccase from Micromonospora sp.044 30-1 as a biocatalyst for synthesis of antioxidant compounds

Laccases (EC 1.10.3.2) are blue multicopper oxidases that catalyse a single electron oxidation of various phenolic substrates with an associated four-electron reduction of dioxygen to water. The varied uses of laccase as a biocatalyst can be attributed to its ability to produce a free radical from a suitable substrate. Of importance to the pharmaceutical, chemical, and industrial sectors, are the laccase-catalysed reactions providing means for the synthesis of dimeric phenolics showing biological activity, including antioxidant activity. The objective of this research was to investigate the production of value-added compounds, with biological activity, via laccase-catalysed oxidation reactions. Our laboratory has access to several unique and previously unexploited culture collections obtained from extreme environments spanning the globe. Potentially novel strains were screened for the ability to produce laccases: 14 environmental isolates, of which 2 strains were fungi, 7 were streptomycetes, and 5 were non-streptomycetes, representing the rare actinomycete genera Gordonia, Rhodococcus, Mycobacterium, Amycolatopsis, and Micromonospora were screened. This is the first report of laccase production in these species. A screening protocol, using criteria specifically suited to bioprocess development, was developed to investigate variables affecting the production of laccase by the native strains. Variables investigated included different types of media (nutritional variables), pH, temperature, incubation times, aeration and agitation, salt concentrations, and the effect of inducers on laccase production by the native strains. Of the isolates investigated, actinomycete strain Micromonospora sp. 044 30-1 showed the greatest potential for the production of laccase. This strain may be novel and the role of laccase in this strain may be related to sporulation. Various growth requirements were investigated in order to optimise for maximal laccase production by strain 044 30-1. The optimal medium for laccase production was M172F medium, pH 5, supplemented with a high concentration of Cu2+ (8 mM), and 2.0% sodium chloride. Extracellular laccase production was higher than intracellular laccase production. The successful application of a Micromonospora strain in an airlift bioreactor specifically for the synthesis of laccase was demonstrated. The biocatalytic potential of the laccase from Micromonospora sp. 044 30-1 was investigated. Laccases are responsible for the formation of radicals that can react non-enzymatically with each other to form dimers or oligomers linked by C-C or C-O bonds. This study reports on laccasecatalysed oxidative reactions involving, primarily, tyrosol, monoacetyltyrosol, and to a lesser extent, reactions with totarol, 3-hydroxyanthranilic acid, and 8-hydroxyquinoline. This study reports for the first time the isolation and structure determination of novel biocatalysis reaction products, specifically the dimeric products obtained through biocatalytic reaction of monoacetyltyrosol with Trametes versicolor laccase, and Micromonospora sp. 044 30-1 laccase. The biocatalysis reaction products of the laccase-catalysed oxidation of tyrosol and monoacetylated tyrosol showed higher antioxidant activity than the parent compounds, as determined by the 2,2- diphenyl-1-picrylhydrazyl (DPPH) and low density lipoprotein (LDL) assays, showing that the dimeric derivatives of laccase-catalysed reactions with phenolic compounds have enhanced antioxidant capabilities. The biocatalysis products were also evaluated as antimicrobials and showed antimicrobial activity against E. coli, a vancomycin resistant clinical strain of Enterococcus faecium, a clinically relevant strain of Micrococcus, and Mycobacterium aurum, a strain that displays a similar antibiotic susceptibility profile to Mycobacterium tuberculosis, the causative agent of the prevalent disease tuberculosis

Relational Markets in Intimate Goods

Prof. Michelle B. Goodwin, Professor of Medicine and Public Health Everett Fraser Professor of Law University of Minnesota Law School

A Study into the Effects of a Reading Intramurals Program on Students\u27 Attitudes toward Reading

The purpose of this study was to determine whether or not an after school Reading Intramurals program positively affected students\u27 interest and attitude toward reading. The subjects of this study consisted of an experimental group of third and fourth grade students who participated in the Reading Intramurals program and a control group of third and fourth grade students who did not participate in the program. The Elementary Reading Attitude Survey was used to determine the reading attitudes of the students in the experimental group and in the control group. An independent t test was first used to compare the mean pretest scores of both groups to verify that the reading attitudes of the students in the two groups were comparable at the onset of the study. A t test for related samples was used next to compare the control group\u27s pretest and posttest scores on the Elementary Reading Attitude Survey with the experimental group\u27s pretest and posttest scores on the same attitude survey, to determine whether there was a statistically significant difference in reading interest and attitude between the two groups. The results of the study found that although participation in the Reading Intramurals program did not necessarily increase reading attitudes, it did not decrease them either, whereas the group of students who did not participate in a Reading Intramurals program had a significant decrease in reading attitudes

Perceptions of Exemplary Teachers in Urban Schools

Regardless of increased standards created by policymakers, urban schools which serve higher populations of diverse and / or at risk students have continued to achieve at lower levels than national norms. The purpose of this study was to solicit the wisdom of exemplary teachers, recognized for their success in urban settings, to assess their perceptions of what teachers should know and do in order to positively impact student achievement within urban schools. The fundamental questions which guided this study were: 1.) What do exemplary teachers perceive teachers should know and be able to do in order to provide instruction in urban elementary classrooms? And, 2.) What curricula and practices do exemplary teachers perceive teacher preparation programs should employ in order to prepare teachers for service in urban elementary classrooms? Ten exemplary teachers, identified as recipients of prestigious teaching awards, were interviewed for the study. According to the findings, factors that are widely known to be important for good teaching are absolutely critical for effective urban teaching. Successful urban teachers are competent in the content they teach and utilize current educational literature, especially research relating to diversity in culture and learning theory, to improve their practice. Because urban children are more diverse in their ethnicity, race, wealth, life experiences, and other learning needs, urban teachers must be able to assess their students and differentiate instruction accordingly. Successful urban teachers possess extraordinary managerial skills because they do not solely rely on direct instruction; they have articulate procedures and routines in place so students can be working on different engaging tasks at the same time. Successful urban teachers have the ability to seek support systems for themselves and their students. They collaborate with colleagues and ascertain community resources to form a network of support, consistency, and safety for their students. Preparation for the complex work of serving in urban schools must begin the first year of college with candidates receiving numerous dissimilar field experiences supervised by master teachers. They must be able to reflect on their own personal values and, in turn, how to work with people who hold very different values

Investigations into actinomycetes isolated from coastal environments, with a special emphasis on the genus Micromonospora

Includes bibliographical references.Marine environments were investigated and actinomycetes were isolated on selective media. Thirty-four (34) actinomycete strains were isolated and identified: 21 Micromonospora strains, 10 Streptomyces strains, and 3 Pseudonocardia strains. A polyphasic approach was employed to determine the novelty of the isolates. Potentially, all 21 Micromonospora strains are novel, as revealed by an original identification scheme developed to assess quickly and easily the novelty of newly isolated environmental Micromonospora strains. Standardized media for testing physiological characters of Micromonospora strains were developed, and additional physiological characteristics of 15 of the validly published members of the genus Micromonospora are described. Furthermore, 14 of the 15 validly published Micromonospora species, and 20 of the 21 environmental Micromonospora isolates grew under anaerobic conditions

Study of low flow rate ladle bottom gas stirring using triaxial vibration signals

Secondary steelmaking plays a great role in enhancing the quality of the final steel product. The metal quality is a function of metal bath stirring in ladles. The metal bath is often stirred by an inert gas to achieve maximum compositional and thermal uniformity throughout the melt. Ladle operators often observe the top surface phenomena, such as level of meniscus disturbance, to evaluate the status of stirring. However, this type of monitoring has significant limitations in assessing the process accurately especially at low gas flow rate bubbling. The present study investigates stirring phenomena using ladle wall triaxial vibration at a low flow rate on a steel-made laboratory model and plant scale for the case of the vacuum tank degasser. Cold model and plant data were successfully modeled by partial least-squares regression to predict the amount of stirring. In the cold model, it was found that the combined vibration signal could predict the stirring power and recirculation speed effectively in specific frequency ranges. Plant trials also revealed that there is a high structure in each data set and in the same frequency ranges at the water model. In the case of industrial data, the degree of linear relationship was strong for data taken from a single heat

Have No FEAR: Developing a Field Experience Assessment Rubric that Really Works!

This presentation summarized the efforts of teacher education faculty collaborating to create a unified field experience tool for candidates seeking initial teaching licensure. The tool was configured to accurately assess and track progress of teacher candidates in their various field placements throughout their program

An Action Plan: Your ACE in the Hole!

This presesntation provides a Power Point and corresponding handouts to assist local chapters of Kappa Delta Pi to win the distinguished ACE Award

Linker Histone H1 and H3K56 Acetylation are Antagonistic Regulators of Nucleosome Dynamics

H1 linker histones are highly abundant proteins that compact nucleosomes and chromatin to regulate DNA accessibility and transcription. However, the mechanisms that target H1 regulation to specific regions of eukaryotic genomes are unknown. Here we report fluorescence measurements of human H1 regulation of nucleosome dynamics and transcription factor (TF) binding within nucleosomes. H1 does not block TF binding, instead it suppresses nucleosome unwrapping to reduce DNA accessibility within H1-bound nucleosomes. We then investigated H1 regulation by H3K56 and H3K122 acetylation, two transcriptional activating histone post translational modifications (PTMs). Only H3K56 acetylation, which increases nucleosome unwrapping, abolishes H1.0 reduction of TF binding. These findings show that nucleosomes remain dynamic, while H1 is bound and H1 dissociation is not required for TF binding within the nucleosome. Furthermore, our H3K56 acetylation measurements suggest that a single-histone PTM can define regions of the genome that are not regulated by H1