Vol 52, No 9 (2016)

The review summarizes the main approaches applied during the creation of L-tryptophan producing strains based on Escherichia coli for the industrial production of this amino acid. In addition, some prospects for the further improvement of tryptophan producers to increase their productivity and improve their technological characteristics based on systems metabolic engineering approaches are outlined in the review. These approaches can be used to obtain the producers of other aromatic amino acids and tryptophan precursors or derivatives.

This review is devoted to achievements in the study of citrate synthase, an enzyme that plays a key role in cell metabolism and catalyzes the process of citric acid synthesis at the first step of the tricarboxylic acid cycle (TCA). The primary industrial producer of citric acid is Aspergillus niger fungus; therefore, the fundamental molecular-genetic and biochemical characteristics of the enzyme from this producer are discussed in comparison with those of other eukaryotes. The information on the mechanisms of the citric acid overproduction in A. niger and its evolutionary features is analyzed. The current review can be helpful in the development of a strategy for the design of more effective producers of organic acids.

The profitability of vaccine production is less than that of other pharmaceutical goods worldwide. Thus, the cost of the vaccine substance determines the range of vaccines available for use. This is of particular importance for veterinary vaccines. In this review, we have surveyed the published data on exploited vaccines and concluded that the immunogenicity of antigen substances based on whole virions is higher than that of soluble antigens. The physiological basis of this phenomenon remains unknown; however, it may explain why most of the described recombinant vaccines have not yet been put into practice. All practically implemented antiviral vaccines (except that for hepatitis B) are based on viral substances produced by conventional cultural technologies. In light of this observation, an approach to the development of a universal platform for recombinant vaccines produced in the form of virus-like particles is suggested. To this end, a technique of designing fused bifunctional derivatives of bacteriophage proteins containing antigens of interest should be involved. The approach is depicted with the use of the protective anthrax antigen, a conventional vaccine antigen.

The consortium of thermotolerant petroleum-oxidizing bacteria containing strains Gordonia sp. 1D VKM Ac-2720 D, Rhodococcus sp. Par7 VKM Ac-2722 D, and R. pyridinivorans L5A-BSU VKM Ac-2721 for destruction of oil and oil products in hot climates was developed for the first time. The consortium was effective in soils and liquid media at temperature as high as 50°C, at salinity up to 7%, and soil moisture of about 10%. The efficiency of petroleum destruction for 21 days was 70 and 59% at 24 and 45°C, respectively. The consortium of thermotolerant petroleum-destructing strains could be used as basis for the biopreparation for remediation of petroleum-contaminated soils and waters in hot climates.