From our analysis, the guidelines of IOM can be applied to all the classes of obesity. More accurate boundaries for each obesity class should be established to evaluate the maternal and fetal risks. Diverse populations are thus necessary for more studies in the future.

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BACKGROUND: Hyperoside is a valuable natural pharmaceutical that has many biomedical functions. By the traditional method of alcohol extraction, only hyperoside solution of very low concentration can be obtained, so a new method is urgently needed to produce pure hyperoside more effectively. Reverse micellar extraction has been widely used in the purification of biological macromolecules. Theoretically, this method could also be used to purify materials with small molecules. Therefore it would seem appropriate to consider the extraction of hyperoside, a material with small molecules, using reverse micelles. In this study the factors affecting hyperoside extraction using cetyl trimethylammonium bromide (CTAB) reverse micelles were comprehensively investigated.

BACKGROUND: Phenylalanine dehydrogenase (PheDH; L-phenylalanine: NAD + oxidoreductase, deaminating (EC 1.4.1.20)) is widely used in the pharmaceutical industry. It is the main biocatalyst in the enantioselective synthesis of L-phenylalanine, related L-amino acids as well as some non-natural amino acids which are important pharmaceutical intermediates. However, growing demands for PheDH and its limited production result in the shortage of the enzyme's supply so that it is necessary to explore and establish an industrial production process for PheDH. RESULTS: In this study, the high-cell-density fermentation of recombinant Escherichia coli for expression of an engineered mutant R272M/E331Q/E196N of PheDH was investigated, which is a key catalyst with improved catalytic capability during the important intermediate production of saxagliptin. Cultivation media and induction conditions of recombinant E. coli were tested in shake flask experiments. A fed-batch fermentation strategy using MR2 as cultivation medium and lactose as inducer was developed in a 30 L fermenter. After 24 h of cultivation, the dry cell weight reached 52.32 g L-1 (based on OD 600), and the specific activity of crude extracts was 0.49 U mg-1. By applying the aqueous two-phase system strategy, a purified PheDH productivity of 191.96 mg•L −1 •h −1 was obtained. The specific activity, recovery, yield and purification fold of PheDH were 3.21 U mg-1 , 104.19%, 84.53% and 6.55, respectively. CONCLUSIONS: This study shows that the application of high-cell-density fermentation in conjunction with aqueous two-phase system strategy provides vital support for large-scale production of recombinant PheDH.