Xi-Hong Lu

High efficiency degradation crude oil by a novel mutant irradiated from Dietzia strain by 12C6+ heavy ion using response surface methodology

Crude oil is an extremely complex mixture of hydrocarbons; also contaminate environmental, leading to carcinogenic, teratogenic and mutagenic. Petroleum hydrocarbons degradation Dietzia strain DMYR9 was isolated from oilfield. Response surface methodology was applied for statistical designing of process parameters for dry weight of biomass production in the process of degradation. The optimization process parameters were successfully employed for degradation crude oil and confirmed through confirmatory experiments. On 28th day, analysis was done by GC-MS, These data show that the crude oil samples of n-Hexadecane, Octadecane, n-Nonadecanec, n-Pentacosane, n-Hexacosane, n-Heneicosane, n-Docosane, n-Tetracosane, n-Octacosane and Tetraethyl removal efficiency could reach up to 0%. RSM optimization and use of effective (12)C(6+)-ion irradiation methods can considerably enhance ability to degradation of microbial. Hence, bioresource Dietzia strain DMYR9, high ability to degradation, can be further used for subsequent repair hydrocarbons polluted of environment.

Comparison of the effects of high energy carbon heavy ion irradiation and Eucommia ulmoides Oliv. on biosynthesis butyric acid efficiency in Clostridium tyrobutyricum

Clostridium tyrobutyricum is well documented as a fermentation strain for the production of butyric acid. In this work, using high-energy carbon heavy ion irradiated C. tyrobutyricum, then butyric acid fermentation using glucose or alkali and acid pretreatments of Eucommia ulmoides Oliv. as a carbon source was carried out. Initially, the modes at pH 5.7-6.5 and 37°C were compared using a model medium containing glucose as a carbon source. When the 72gL(-1) glucose concentration was found to be the highest yield, the maximum butyric acid production from glucose increased significantly, from 24gL(-1) for the wild type strains to 37gL(-1) for the strain irradiated at 126AMeV and a dose of 35Gy and a 10(7)ions/pulse. By feeding 100gL(-1) acid pretreatments of E. ulmoides Oliv. into the fermentations, butyrate yields (5.8gL(-1)) and butyrate/acetate (B/A) ratio (4.32) were achieved.

The effect of microdosimetric 12C6+ heavy ion irradiation and Mg2+ on canthaxanthin production in a novel strain of Dietzia natronolimnaea

BackgroundDietzia natronolimnaea is one of the most important bacterial bioresources for high efficiency canthaxanthin production. It produces the robust and stable pigment canthaxanthin, which is of special interest for the development of integrated biorefineries. Mutagenesis employing 12C6+ irradiation is a novel technique commonly used to improve microorganism productivity. This study presents a promising route to obtaining the highest feasible levels of biomass dry weight (BDW), and total canthaxanthin by using a microdosimetric model of 12C6+ irradiation mutation in combination with the optimization of nutrient medium components.ResultsThis work characterized the rate of both lethal and non-lethal dose mutations for 12C6+ irradiation and the microdosimetric kinetic model using the model organism, D. natronolimnaea svgcc1.2736. Irradiation with 12C6+ ions resulted in enhanced production of canthaxanthin, and is therefore an effective method for strain improvement of D. natronolimnaea svgcc1.2736. Based on these results an optimal dose of 0.5–4.5 Gy, Linear energy transfer (LET) of 80 keV μm-1and energy of 60 MeV u-1 for 12C6+ irradiation are ideal for optimum and specific production of canthaxanthin in the bacterium. Second-order empirical calculations displaying high R-squared (0.996) values between the responses and independent variables were derived from validation experiments using response surface methodology. The highest canthaxanthin yield (8.14 mg) was obtained with an optimized growth medium containing 21.5 g L-1 D-glucose, 23.5 g L-1 mannose and 25 ppm Mg2+ in 1 L with an irradiation dose of 4.5 Gy.ConclusionsThe microdosimetric 12C6+ irradiation model was an effective mutagenic technique for the strain improvement of D. natronolimnaea svgcc1.2736 specifically for enhanced canthaxanthin production. At the very least, random mutagenesis methods using 12C6+ions can be used as a first step in a combined approach with long-term continuous fermentation processes. Central composite design-response surface methodologies (CCD-RSM) were carried out to optimize the conditions for canthaxanthin yield. It was discovered D-glucose, Mg2+ and mannose have significant influence on canthaxanthin biosynthesis and growth of the mutant strain.

The acquisition of Clostridium tyrobutyricum mutants with improved bioproduction under acidic conditions after two rounds of heavy-ion beam irradiation.

End-product inhibition is a key factor limiting the production of organic acid during fermentation. Two rounds of heavy-ion beam irradiation may be an inexpensive, indispensable and reliable approach to increase the production of butyric acid during industrial fermentation processes. However, studies of the application of heavy ion radiation for butyric acid fermentation engineering are lacking. In this study, a second 12C6+ heavy-ion irradiation-response curve is used to describe the effect of exposure to a given dose of heavy ions on mutant strains of Clostridium tyrobutyricum. Versatile statistical elements are introduced to characterize the mechanism and factors contributing to improved butyric acid production and enhanced acid tolerance in adapted mutant strains harvested from the fermentations. We characterized the physiological properties of the strains over a large pH value gradient, which revealed that the mutant strains obtained after a second round of radiation exposure were most resistant to harsh external pH values and were better able to tolerate external pH values between 4.5 and 5.0. A customized second round of heavy-ion beam irradiation may be invaluable in process engineering.

Chemical constituents from Saussurea oligantha

0009-3130/12/4802-0344 2012 Springer Science+Business Media, Inc. Ion-irradiation Medicine Developing Center, Institute of Modern Physics, Chinese Academy of Science, Lanzhou 73000, e-mail: liangjp100@sina.com; lixuehu2009@163.com. Published in Khimiya Prirodnykh Soedinenii, No. 2, March–April, 2012, pp. 308–309. Original article submitted December 29, 2010. Chemistry of Natural Compounds, Vol. 48, No. 2, May, 2012 [Russian original No. 2, March–April, 2012]

A new protoberberine from the bark of Phellodendron chinense

A new protoberberine, named 8,13-dioxo-14-butoxycanadine (1), was isolated from the bark of Phellodendron chinense Schneid, and its structure was elucidated by extensive spectroscopic methods, including IR, UV, HR-ESI-MS, and NMR techniques.