Polyhydroxyalkanoates (PHAs) have gained much attention as biodegradable polymers, many efforts are being made to minimize the cost of PHAs by finding cheap carbon source depending on the type of microorganism and fermentation conditions. The aims of this study were to evaluate the effects of different glucose concentrations and other important conditions on the PHA production by Bacillus cereus isolated from soil. Polyhydroxyalkanoates PHAs accumulated by soil microorganisms were examined by screening the isolated bacteria using Sudan B Black and Nile Blue staining process. A Gram positive strain was identified using the 16s rRNA gene, deposited in the NCBI GenBank sequence database. Different growth conditions (favorite glucose concentrations 1-8 % (w/v), temperatures and pH) were tested and the growth parameters (sugar consumption, cell counting and Cell Dry Weight CDW) were studied. The extracted polymers were analyzed and characterized using an FTIR spectrophotometer followed by a GC-MS analysis. The pure bacterial strain isolated from soil was deposited in the NCBI GenBank database B. cereus strain ARY73, which showed significant black colored granules (or dark blue) using Sudan B Black stain, it also showed positive to Nile blue A as a high indicator stain for PHA accumulation. B. cereus ARY73 showed high production of PHA using (w/v): 2% glucose and 1% nitrogen source at 35 °C and pH7 yields 79% per Cell Dry Weight and 96 h of incubation. The extracted polymers were analyzed and characterized using an FTIR spectrophotometer confirming the PHA structure. The FTIR spectrophotometer, followed by a GC-MS analysis indicated the Scl-co-mcl PHA structure. This research demonstrates that the isolated strain B. cereus ARY73 was a good candidate for PHA production with a better quality for use in biomedical and other applications. The use of biopolymer in soil, enhanced the accumulation of the microorganisms (such as bacteria) capable of degrading biopolymer or biodegradation by-products yields by other species which were isolated in this
Background: fixed orthodontic appliances deleterious influence on gingival health is well documented. Association between weight status and gingival health is presented in many studies. This study aimed to evaluate how early the impact of fixed orthodontic therapy on patients` gingival health, and if there are differences of that impact among different weight status groups. Materials and Methods: Sample consisted of 54 patients (25 males, 29 females; age limits are 16 -18 years) going under the course of treatment with fixed orthodontic appliance. Patients were categorized according to their Body Mass Index (BMI) into 3 weight status groups considering WHO charts in 2007 (underweight, normal weight, overweight and obese), then determinat
... Show MoreThe mutagenic effect of some crucifers widely consumed Lepiduim sativum (Garden cress) and Arugula (Eruca sativa) was studied in comparison to carrot (Daucus carota), using bacterial mutagenic system composed of three bacterial isolates; (Bacillus spp)G3 (Arthrobacter spp)G12, and (Brevibacterium spp)G27 ,. Treatment of isolates with plant extracts led to reduction in survival fraction (Sx)at different levels except that Aurgula extract did not show any inhibitory effect in isolates G12 and G27. Crucifers extracts induced streptomycin resistant mutants in G12 at higher level than G3 , but not in G27. No resistance to rifimpacin was detected in all isolates.
In this study, the effect of fire flame on the punching shear strength of steel fiber reinforced concrete flat plates was experimentally investigated using nine half-scale specimens with dimensions of 1500×1500 mm and a total thickness of 100 mm. The main investigated variables comprised the steel fiber volume fraction 0, 1, and 1.5% and the burning steady state temperature 500 and 600 °C. The specimens were divided into three groups, each group consists of three specimens. The specimens in the first group were tested with no fire effect to be the reference specimens, while the others of the second and third groups were tested after being exposed to fire-flame effect. The adopted characteristics of the fire test were; (one hour) b
... Show MoreThe current research seeks to identify mono-multi Vision and its relation to the psychological rebellion and personality traits of university students. To achieve this aim, the researcher has followed all the procedures of the descriptive correlational approach, as it is the closest approach to the objectives of the current research. The researcher has determined his research community for Baghdad University students for the academic year 2019-2020. As for the research sample, it was chosen by the random stratified method with a sample of (500) male and female students. In order to collect data from the research sample, the researcher adopted a mono-multi-dimensional scale
(Othman, 2007), the researcher designed a psychological r
... Show MorePesticide poisoning is a serious global public health issue and is responsible for a sizable number of annual fatalities. This study was designed to examine the potentially harmful effects of adult rats being exposed to imidacloprid (IMD) as a nanoparticle by determining the chronic effect of inhalation of (5,10 and 20) mg/kg/b.w. of nano-imidacloprid for a duration of 60 days. The most important biochemical parameters of the serum liver function parameters were aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase ALP, kidney function [blood urea, creatinine, and urea], and oxidative stress parameters (MDA, GSH, and CAT) in all treated groups when
Aim of the study: Using surface roughness and tensile bond strength tests, the objective of this investigation was to ascertain the impact of laser surface modification on the binding strength of injectable thermoplastic acrylic denture base material to acrylic-based soft-liner material. Materials and methods: Acrylic base soft liner material was bonded to injectable thermoplastic acrylic resin (Deflex). Forty specimens were created (20 disc, 20 dumbbells) 10 of each specimen type as control specimens, and 10 were treated with nano pulse Nd: YAG laser. The data were analyzed using the Kruskal-Wallis test and unpaired t-test (a=.05) and the roughness test was performed utilizing a double column universal test machine. Results: Compar
... Show MoreTwo oil wells were tested to find the abnormal pressure zones using sonic log technique. We found that well Abu-Jir-3 and Abu-Jir-5 had an abnormal pressure zones from depth 4340 to 4520 feet and 4200 to 4600 feet, respectively. The maximum difference between obtained results and the field measured results did not exceed 2.4%.
In this paper, the formation pressures were expressed in terms of pressure gradient which sometimes reached up to twice the normal pressure gradient.
Drilling and developing such formations were dangerous and expensive.
The plotted figures showed a clear derivation from the normal trend which confirmed the existence of abnormal pressure zones.
This research aims at identifying the level of Moral Awareness and the level of Authoritarian Parenting Style of Secondary School Students in Baghdad. Additionally, the study seeks to identify the significant difference between these two variables in term of gender (male-female), as well as the correlation between Moral Awareness and Authoritarian Parenting Style. To do this, the researchers have adopted the scale of moral awareness prepared by the (Assl 2014), which the number of its items was finalized of (28) items. As for the Authoritarian Parenting Style scale, the researcher designed a questionnaire of (22) items as the number of its finalized form. The two instruments were applied on a sample of (140) male and female Students who
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