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Abstract Background Reproduction and sustainability are important for future society, and bioprocesses are one technology that can be used to realize these concepts. However, there is still limited variation in bioprocesses and there are several challenges, especially in the operation of energy-requiring bioprocesses. As an example of a microbial platform for an energy-requiring bioprocess, we established a process that efficiently and enzymatically synthesizes 2′-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase. This method consists of the coupling reactions of the reversible nucleoside degradation pathway and energy generation through the yeast glycolytic pathway. Results Using E. coli that co-express deoxyriboaldolase and phosphopentomutase, a high amount of 2′-deoxyribonucleoside was produced with efficient energy transfer under phosphate-limiting reaction conditions. Keeping the nucleobase concentration low and the mixture at a low reaction temperature increased the yield of 2′-deoxyribonucleoside relative to the amount of added nucleobase, indicating that energy was efficiently generated from glucose via the yeast glycolytic pathway under these reaction conditions. Using a one-pot reaction in which small amounts of adenine, adenosine, and acetone-dried yeast were fed into the reaction, 75 mM of 2′-deoxyinosine, the deaminated product of 2′-deoxyadenosine, was produced from glucose (600 mM), acetaldehyde (250 mM), adenine (70 mM), and adenosine (20 mM) with a high yield relative to the total base moiety input (83%). Moreover, a variety of natural dNSs were further synthesized by introducing a base-exchange reaction into the process. Conclusion A critical common issue in energy-requiring bioprocess is fine control of phosphate concentration. We tried to resolve this problem, and provide the convenient recipe for establishment of energy-requiring bioprocesses. It is anticipated that the commercial demand for dNSs, which are primary metabolites that accumulate at very low levels in the metabolic pool, will grow. The development of an efficient production method for these compounds will have a great impact in both fields of applied microbiology and industry and will also serve as a good example of a microbial platform for energy-requiring bioprocesses.

Results demonstrate that 2-deoxyribose 5-phosphate is produced by deoxyriboaldolase encoding gene of Klebsiella pneumoniae, which is overexpressed in Escherichia coli, in the presence of ATP using glucose and acetaldehyde. Data indicate that under the optimal conditions, 100 millimolar 2-deoxyribose 5-phosphate is produced, which is further transformed to 2'-deoxyribonucleoside.

The article presents a study which synthesizes 4-hydroxyisoleucine (4-HIL) by aldolase-transaminase coupling reaction and basic characterization of the aldolase purified Arthrobacter simplex AKU 626. It describes the screening of an aldolase-producing bacterium. It is revealed that A. simplex AKU 626 synthesized 4-HIL from acetaldehyde, alpha-ketobutyrate and L-glutamate with Escherichia coli harboring the branched chain amino acid transaminase gene.

The article presents a study which investigated 2-deoxyribose 5-phosphate production through coupling of the alcoholic fermentation system of baker's yeast and deoxyriboaldolase-expressing Escherichia coli (E. coli). Baker's yeast generates fructose 1,6-diphosphate from glucose and inorganic phosphate, and the E. coli convert the fructose 1,6-diphosphate into 2-deoxyribose 5-phosphate through D-glyceraldehyde 3-phosphate. The produced 2-deoxyribose 5-phosphate was converted to 2-deoxyribose.

The article presents a study on the bioprocessing of compounds to be used as catalyst for green chemistry in Japan. The procedure were taken in different steps, first, is the screening for biological reactions among versatile and diversity of micro-organisms. This bioprocess development were done to further discover unique metabolic processes, reactions and metabolism of microbe's enzymes.

A succinimide-assimilating bacterium, Pseudomonas putida s52, was found to be a potent producer of pyruvate from fumarate. Using washed cells from P. putida s52 as catalyst, 400 mM pyruvate was produced from 500 mM fumarate in a 36-h reaction. Bromopyruvate, a malic enzyme inhibitor, was used for the selection of mutants with higher pyruvate productivity. A bromopyruvate-resistant mutant, P. putida 15160, was found to be an effective catalyst for pyruvate production. Moreover, under batch bioreactor conditions, 767 mM of pyruvate was successfully produced from 1,000 mM fumarate in a 72-h reaction with washed cells from P. putida 15160 as catalyst.