Statistical Optimization of Prodigiosin Production by Plackett-burman Design for Bacteria Isolated from Indian Marine Soil

The current investigation was conducted to maximise the production of the natural anticancer drug from the microbe isolated from the marine soil sample of the Coromandel Coast of the Bay of Bengal region of India. Yellow to red colour pigmented microbes separated by crowd plate method. Bacteria are producing strong colour product subjected to future study. The isolated strains were detected based on biochemical, morphological, and genetic characteristics. Pigment formation was found to be influenced strongly by conditions of the environment. The water-insoluble pigment extracted by acidified methanol and showed maximum absorbance at 535nm. A statistical screening procedure was adopted to select the optimum condition to produce the pigment. The carbon, nitrogen, medium pH, growth condition temperature and revolution of agitation were screened using the response surface methodology statistical model. The near optimum conditions for the production medium were affected by the concentration of peanut, L-proline, percentage inoculum pH and incubation time. When these conditions were employed yield increased as two-fold as the concentration of prodigiosin 789 mg/l.

Application of Plackett-Burman and central composite designs for screening and optimization of factor influencing the chromatographic conditions of HPTLC method for quantification of efonidipine hydrochloride

We report here an analytical method for expeditious estimation of efonidipine hydrochloride in tablet formulation with statistical screening and optimization designs using NP-HPTLC. TLC silica gel 60 F254 aluminum plates and ethyl acetate to dichloromethane to triethylamine (3:2:0.5 v/v) were chosen for chromatographic separation of efonidipine hydrochloride. The Rf value for efonidipine hydrochloride turned out to be 0.35 ± 0.25 and quantitative evaluation was done at 251 nm. Plackett-Burman and face-centered central composite design (CCD) were used to obtain the most peak area and well-resolved compact band with an adequate retention factor of efonidipine hydrochloride. Plackett-Burman design at two-level with six independent variables has been employed for screening of prominent factors that affect the responses. The prominent factors have been selected and are optimized through face-centered CCD. The results obtained from face-centered CCD showed that most peak area can be obtained with development distance 8.50 cm and chamber saturation 17 min. Furthermore, the current NP-HPTLC investigation has been validated according to the ICH guidelines for accuracy, precision, sensitivity, robustness, ruggedness, and specificity. The detection and quantification limit was found that 10.41 ng and 31.57 ng, suggesting that the analysis could be accurately and precisely detected the analyte up to nanogram quantity. The current NP-HPTLC investigation is rugged, accurate, and highly sensitive and could be used for routine analysis of efonidipine hydrochloride.

An investigation of amino acid and acylcarnitine levels in neonates from the Tibet Autonomous

Background: The purpose of the study was to establish reference values of amino acids and acylcarnitines in newborns of the Tibet Autonomous Region for the first time and to provide an experimental basis for the diagnosis of genetic metabolic diseases.Methods: We detected concentrations of 43 kinds of amino acids, acylcarnitines and succinylacetone in the dried blood spots of 15029 newborns using liquid chromatography tandem mass spectrometry. We compared the indexes between Tibet and our lab, where most data come from an inland area and Han Chinese people. Then we compared amino acid and acylcarnitine levels of seven regions in Tibet and explored their impact factors. The distribution of amino acid and acylcarnitines were different in Tibet.Results: Reference intervals of amino acids and acyl carnitines in neonates from the Tibet Autonomous Region were defined according to the (P 0.5% ~ P 99.5%) of the values. Given the third reference range, the recall rate of statistical screening was significantly reduced to 2.16%.Conclusions: This study has contributed to the field by determining the actual values of amino acids and acylcarnitines in newborns from the Tibet Autonomous Region, which could be used as reference for a newborn metabolic screening project in this area.

Mathematical modeling for bioprocess optimization of a protein drug, uricase, production by Aspergillus welwitschiae strain 1–4

Microbial uricase is effective protein drug used to treat hyperuricemia and its complications, including chronic gout, also in prophylaxis and treatment of tumor lysis and organ transplants hyperuricemia. Uricase is commonly used as diagnostic reagent in clinical analysis for quantification of uric acid in blood and other biological fluids. Also, it can be used as an additive in formulations of hair coloring agents. A newly isolated strain, Aspergillus sp. 1–4, was able to produce extracellular uricase on a medium containing uric acid as inducer. Phylogenetic analysis based on ITS region sequence analysis and phenotypic characteristics showed that Aspergillus sp. strain 1–4 is closely related to Aspergillus welwitschiae and its nucleotide sequence was deposited in the GenBank database and assigned sequence accession number MG323529. Statistical screening using Plackett-Burman design with 20 runs was applied to screen fifteen factors for their significance on uricase production by Aspergillus welwitschiae. Results of statistical analysis indicated that incubation time has the most significant positive effect on uricase production followed by yeast extract and inoculum size with the highest effect values of 13.48, 5.26 and 4.75; respectively. The interaction effects and optimal levels of these factors were evaluated using central composite design. The maximum uricase production was achieved at incubation time (5 days), yeast extract (2 g/L) and inoculum size (4 mL/50 mL medium) are the optimum levels for maximum uricase production (60.03 U/mL). After optimization, uricase production increased by 3.02-folds as compared with that obtained from the unoptimized medium (19.87 U/mL).

Optimization of swelling response of pH sensitive hydrogels using Box-Behnken design

Hydrogels are three-dimensional crosslinked hydrophilic polymer networks capable of swelling or de-swelling reversibly in water and retaining a large volume of liquid in swollen state. Hydrogels can be designed with controllable responses to shrink or expand with changes in external environmental conditions. Among stimulisensitive hydrogels, the pH-sensitive ones are widely-studied and used. Despite these advances, we currently lack a systematic way to optimize the synthesis protocols. Here we propose to use techniques from chemometrics, namely Box–Behnken statistical screening design to optimize the chemical composition of pH-responsive hydrogels for an improved responsiveness as quantified by swelling index. Polymer blends were prepared by mixing different suitable volume of pvp (poly vinyl pyrrolidone) and chitosan aqueous solution in order to obtain a mixture, glutardialdehyde solution was added as crosslinkers to the chitosan/pvp mixture to form semi-IPN(semi-interpenetrating polymeric hydrogel). The pH-dependent swelling properties have been measured and used to obtain a regression model. We characterized the descriptive and predictive abilities of our model. We found a remarkable correlation (correlation coefficient = 0.954) between the observed responses and the responses predicted by the model. Our results demonstrate that Box-Behnken is an appropriate statistical design that can be successfully used in the development of pH-sensitive hydrogels with a predictable swelling ratio. This technology will remarkably reduce the time and cost that is needed for chemical synthesis of hydrogels with a desired pH-sensitivity.

Job applicant screening in China and its four pillars

Chinese employers practise extensive personal screening of applicants during the recruitment process. This study identifies four motives for these practices – statistical, customer taste, employer taste and regulatory. It discusses their distinctive roles in the Chinese labour market and in regard to labour-market regulations. Using a convenience sample of large Chinese employers, the study evaluates the economic and institutional determinants of screening approaches and implications for firms’ performance. Statistical screening, based on the assumption that social group membership is an indicator of productivity or loyalty, is found to be related positively to employers’ capitalisation, labour-market power and private ownership, and negatively to skill supply in provincial markets. Customer-taste screening is prevalent in the services and sales sectors, and interestingly in wealthy first-tier cities. Employer-taste screening endures in privately owned firms, and in skill-intensive industries and first-tier cities, and appears linked to customer-taste screening. Some forms of screening breach anti-discrimination laws and persist because of lax enforcement of such laws, but requests for personal data on job applications forms may also reflect compliance with equity indicators. Regulatory compliance-based screening is related positively to firms’ market power, capitalisation and state ownership. The implications of the different screening practices for public policy and corporate strategy are examined.