Chemistry. Ecology. Biotechnology – 2015

УДК 54.057 + 504.054 + 504.064.2:54 Х46

Studies in the areas of chemistry, chemical engineering, biotechnology and ecology aimed at the development of energy and resource saving technologies are presented. Problems in the manufacturing of a wide scope of products of chemical industry and biotechnology are discussed.

Приведены результаты исследований в области химии, химической технологии, биотехнологии и экологии, направленных на разработку энерго- и ресурсосберегающих технологий. Рассмотрены проблемы получения широкого кругапродуктовхимическойтехнологииибиотехнологии.

Editorial Board:

Doctor of Chemistry, Prof. V.V. Volkhin, Doctor of Chemistry, Prof. G.V. Leontievа,

Doctor of Pedagogical Sciences, Prof. T.S. Serova.

Редакционная коллегия:

д-р хим. наук, проф. В.В. Вольхин, д-р хим. наук, проф. Г.В. Леонтьева, д-р пед. наук, проф. Т.С. Серова

Proof-readers:

Doctor of Chemistry, Prof. S.V. Ostrovskii (Perm National Research Polytechnic University), Doctor of Chemistry U.S. Chekrishkin

(Institute of Technical Chemistry, Ural Branch, Russian Academy of Science).

Рецензенты:

д-р хим. наук, проф. С.В. Островский (Пермский национальный исследовательский политехнический университет);

д-р хим. наук Ю.С. Чекрышкин

(Институт технической химии УрО РАН, г.Пермь)

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УДК 544.034

N.A. Klimov, D.A. Kazakov, V.V. Vol’khin

PREPARATION OF CATALYSTS FOR BIOCATALYTIC AND CHEMICAL OXIDATION OF GLUCOSE

Perm National Research Polytechnic University

Gluconic acid is a valuable chemical product for the pharmaceutical and food industries. It can be obtained by biocatalytic or chemical oxidation of glucose by oxygen. Biocatalytic oxidation of glucose to gluconic acid occurs in the presence of glucose oxidase (GOD). Chemical oxidation of glucose is carried out in the presence of solid palladium supported catalysts. Kinetic stage of these processes is very fast and the dissolution rate of O2 in the aqueous phase does not provide the needs of chemical reaction. Glucose oxidation reaction is limited by gas-liquid oxygen mass transfer. Therefore, oxygen is absent in the bulk aqueous phase. Thus, only part of the catalyst takes part in the reaction. It can be assumed that increase of the catalyst concentration near the gas-liquid interface can increase the reaction rate. One of the possible ways for catalyst particles concentrating in the boundary layer of liquid is to reduce wettability of catalysts surface by its chemical modification using alkyltrichlorosilane (ATCS). However, the effect of surface modification of palladium supported catalysts has been studied insufficiently. Data on the effect of surface modification of biocatalysts on glucose oxidation are absent in the literature. The aim of this study is synthesis and properties investigation of the surface-modified catalysts for chemical and biocatalytic glucose oxidation. The objectives of the study: 1) isolation of microorganisms producing GOD, study of growth kinetics and GOD activity of isolated culture; 2) production of solid carrier for biocatalyst which can concentrate near gas-liquid interface; 3) production of biocatalyst for glucose oxidation by physical immobilization of GOD producing microorganisms on synthesized solid carrier and studying activity of the biocatalyst;

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4) production of catalysts for glucose oxidation which are able to concentrate near gas-liquid interface, study of their catalytic activity; 5) comparative evaluation of the catalysts for biochemical and chemical oxidation of glucose to gluconic acid.

A culture of GOD producing microorganisms was isolated. The culture was identified as fungi Aspergillus sp. A study of growth kinetics of the isolated culture was carried out. It was shown that the highest specific growth rate is observed at glucose concentration of 15 g/l. It was found that GOD is located inside the cells of isolated culture.

Catalysts for chemical glucose oxidation which are able to concentrate near gas-liquid interface were obtained by chemical modification (treatment by ATCS with alkyl radicals C1-C8) of catalyst Pd/Al2O3 (Sigma-Aldrich, Germany). It was shown that activity of these catalysts depended on the length of alkyl radical attached to its surface (Table 1).

Table 1 Influence of surface alkyl radical length on catalyst activity

(stirring rate 100 s–1, catalyst concentration 1 g/l, concentration of ATCS in solution for modification 0.1 vol. %)

Note: R, R0 – rates of glucose oxidation in the presence of the modified and unmodified catalyst respectively.

It can be seen (Table 1) that catalyst С1-Pd/Al2O3 is the most effective for glucose oxidation. The study of influence of methyltrichlorosilane concentration in solution for modification on catalyst activity was carried out (Table 2).

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Table 2 Influence of methyltrichlorosilane concentration in solution

for modification on catalyst activity (stirring rate 100 s–1, catalyst concentration 1 g/l)

The data (Table 2) show that optimal concentration of methyltrichlorosilane in chloroform solution is 0.3 % vol.

УДК 544

N.S. Voronina, I.A. Permyakova, V.V. Vol’khin

DEVELOPMENT OF THE STAGE OF ESTERIFICATION OF WASTE VEGETABLE OILS TO CREATE LOW-WASTE TECHNOLOGY OF SECOND GENERATION BIODIESEL

Perm National Research Polytechnic University

Biodiesel fuel production is one of the most promising areas of biotechnology investigation because it is produced from renewable sources such as vegetable oils and animal fats.

The use of pure oils for biofuel production is inexpedient because oils are food products. Therefore, it is necessary to find an alternative feedstock. Using non-conditioned oils as a raw material for biodiesel is one of feasible ways because these oils are unsuitable for further application for food purposes (for example, used frying oils or ones beyond their shelf life).

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Using recycled raw materials for biodiesel production one-stage technology is difficult because fatty acids saponification takes place, leading to the formation of stable emulsions. In this work a two-stage technology is considered: in the first stage there is an esterification reaction of free fatty acids, and in the second stage oil interesterification occurs. The products of these two stages are esters of fatty acids, i.e. biodiesel.

The limiting stage of a two-phase process is esterification of fatty acids. In this work we study the preliminary extraction of fatty acids from the oil. The end product of the extraction process is pure oil. In this form it can be used directly in the reaction, and extracted fatty acids can be subjected to esterification.

The process of obtaining biodiesel from vegetable oils has a permanent waste. One of the major byproducts of this process is glycerol. Currently, there is an overproduction of glycerol. Therefore, it is needed to convert glycerol into other marketable products. This approach would make the technology of biodiesel production low-waste. For these purposes this work considers a possibility of transforming glycerol by means of biotechnology using the yeast of Saccharomyces cerevisiae. Experiments of the kind are in progress.

УДК 543.86

A.A. Rukavitsyna, A.V. Bazhutin, L.D. Asnin

DETERMINATION OF PHENYLALANINE ENANTIOMERS IN CELL CULTURE MEDIUM BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

Perm National Research Polytechnic University

Amino acids are present in nature in the form of two optical isomers, L- and D-enantiomers. For a long time it has been considered that all living organisms contain and use in their vital activity only L-amino

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acids, biological functions of D-amino acids have not been studied. Subsequently it was shown that D-amino acids are part of some proteins and metabolized by microorganisms. When studying such processes, a problem of measuring concentration of amino acid enantiomers in biological samples arises*.

The present work is devoted to the solution of this task by example of the determination of phenylalanine enantiomers in cell culture medium by high performance liquid chromatography. Issues of organizing a biochemical experiment and further sample preparation are discussed. It is shown that autoclave processing of solutions of enantiomerically pure phenylalanine in the Raymond nutrient medium does not lead to racemization of the enantiomer, which makes it possible to include phenylalanine enantiomers to cultivation process under sterile conditions.

The procedure of the analysis includes separation of the enantiomers on the Shimadzu LC-20XR chromatograph with an UV-detector on the Nautilus-E chiral column (4.6 mm×250 mm) at the temperature of 25 °C. An acetate buffer solution (pH = 5.2) prepared in a mixed solvent water-methanol (60:40, v/v) was used as a mobile phase. The mobile phase was modified by addition of a complexing agent (0.001 N EDTA) in order to mask heavy metals contained in the nutrient medium. Under these conditions, the enantiomers were separated completely, with symmetrical peaks. A detector wavelength of 254 nm was chosen for quantitative analysis, because the calibration curve was linear under these conditions.

*Corrigan J.J. D-Amino acids in animals // Science. – 1969. – Vol. 164. – P. 142–149.

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