ABSTRACT
BACKGROUND: The supplementation of betaine, an osmoprotective compatible solute, in the cultivation media has been widely used to protect bacterial cells. To explore the effects of betaine addition on industrial fermentation, Escherichia coli THRD, an L-threonine producer, was used to examine the production of L-threonine with betaine supplementation and the underlying mechanism through which betaine functions was investigated. RESULTS: Betaine supplementation in the medium of E. coli THRD significantly improved L-threonine fermentation parameters. The transcription of zwf and corresponding enzyme activity of glucose-6-phosphate dehydrogenase were significantly promoted by betaine addition, which contributed to an enhanced expression of zwf that provided more nicotinamide adenine dinucleotide phosphate (NADPH) for L-threonine synthesis. In addition, as a result of the betaine addition, the betaine-stimulated expression of enhanced green fluorescent protein (eGFP) under the zwf promoter within a plasmid-based cassette proved to be a transcription-level response of zwf. Finally, the promoter of the phosphoenolpyruvate carboxylase gene ppc in THRD was replaced with that of zwf, while L-threonine fermentation of the new strain was promoted by betaine addition. Conclusions: We reveal a novel mode of betaine that facilitates the microbial production of useful compounds. Betaine supplementation upregulates the expression of zwf and increases the NADPH synthesis, which may be beneficial for the cell growth and thereby promote the production of L-threonine. This finding might be useful for the production of NADPH-dependent amino acids and derivatives in E. coli THRD or other E. coli strains.
Subject(s)
Threonine/metabolism , Betaine/metabolism , Escherichia coli/metabolism , Osmosis , Pentose Phosphate Pathway , Reverse Transcriptase Polymerase Chain Reaction , Escherichia coli/enzymology , Fermentation , Glucosephosphate Dehydrogenase/metabolism , NADPABSTRACT
OBJECTIVE: This study aims to evaluate the betaine supplementation and its possible ergogenic potential in physically active adults. Data source: In the present review, articles were searched using indexed databases (SciELO and NCBI) and the following keywords were selected for the search: "supplement", "betaine", "performance" and "adults", including terms of lexical proximity, limited to articles in English, published between 2000 and the present date. Inclusion criteria: adults, physically active individuals or individuals under physical test and betaine supplementation. Data synthesis: According to the applied search criteria, 20,750 articles were found, from which only seven obeyed to inclusion parameters after judicious reading of the texts. In these, betaine supplementation was capable to increase anaerobic potency, muscular and isometric endurance, and stimulate an anabolic environment. In contrast, no increase was observed in the plasmatic levels of nitrate/nitrite and, when compared to creatine, betaine supplementation was not able to raise the levels of phosphorylcreatine or strength in sedentary individuals. CONCLUSIONS: The present work showed that betaine supplementation plays an important role as an ergogenic resource, mainly in biomarkers and muscular strength and power; nevertheless, it is apparently ineffective when given to sedentary individuals
OBJETIVO: Este estudo teve como objetivo avaliar a suplementação de betaína e seu possível potencial ergogênico em adultos fisicamente ativos. Fonte de dados: Na presente revisão, artigos foram pesquisados usando bancos de dados indexados (e.g., SciELO e NCBI) e as seguintes palavras-chave foram selecionados para a procura: "suplemento", "betaína", "desempenho" e "adultos", incluindo termos de proximidade léxica, limitado-se a artigos em inglês e português publicados entre 2000 e a presente data. Critérios de inclusão: referirem-se a adultos, indivíduos fisicamente ativos ou sob teste físico e suplementação de betaína. Síntese dos dados: De acordo com os critérios de pesquisa aplicada, 20.750 artigos foram encontrados, dos quais apenas sete obedeceram aos parâmetros de inclusão após leitura criteriosa do texto. Nesses estudos, a suplementação de betaína foi capaz de elevar potência anaeróbica, resistência muscular e isométrica e estimular um ambiente anabólico. Em contraste, não foram encontradas elevações nos níveis plasmáticos de nitrato/nitrito e, quando comparada à suplementação de creatina, não foi capaz de elevar níveis de fosforilcreatina ou força em indivíduos sedentários. CONCLUSÕES: O presente trabalho mostrou que a suplementação de betaína desempenha um papel importante como ergogênico, principalmente em níveis de marcadores biológicos e sobre força e potência muscular, embora aparentemente seja inefetiva quando fornecida a indivíduos sedentários
Subject(s)
Humans , Male , Female , Betaine/analysis , Betaine/metabolism , Sports Nutritional Sciences/methods , Sports Nutritional Sciences/statistics & numerical dataABSTRACT
Changes in biomass yield rates, cell membrane stability (CMS), malondialdehyde (MDA) content and in the levels of physiological stress markers such as proline and glycine betaine in two high yielding genotypes (S1 and ATP, salt tolerant and salt sensitive, respectively) of mulberry under NaCl salinity were studied. Biomass yield rates and CMS were significantly decreased in both the genotypes under stress conditions. Per cent of decrease in biomass yield rate and CMS was relatively less in S1 than in ATP. Salt stress results a significant increase in the accumulation of proline, by 6-fold in S1 and 4-fold in ATP. Glycine betaine content was also increased significantly in stressed plants. However, the per cent increase was more in S1 than in ATP. The level of lipid peroxidation as indicated by MDA formation was greater in ATP than in S1. These results clearly support the better salt tolerant nature of S1 compared to ATP genotype.