Continuous production of 5?-ribonucleotides from yeast RNA by hydrolysis with immobilized 5?-phosphodiesterase and 5?-adenylate deaminase

Abstract

The production of 5'-IMP and 5'-GMP by enzymatic conversion from RNA using a continuous two packed-bed reactor was investigated. 5'-Phosphodiesterase (5'PD) and 5'-adenylate deaminase (5'AD) were immobilized in an acrylic resin to produce derivatives with about 15 U/g of support. The kinetic properties of the enzymes were described by Michaelis-Menten models: no significant differences were found in the K m value of the free and immobilized 5'AD (60 and 20 μM, respectively), whereas for 5'PD the K m value was one order of magnitude higher for the immobilized enzyme (4.85 mg RNA/ml), probably due to diffusional limitations. Both enzymes remained stable after 8 h of use in a continuous packed-bed reactor whereas the half lives of the free enzymes were 193 min and 240 min at 40°C and 70°C for 5'AD and 5'PD, respectively. A procedure is proposed for the design of a continuous two packed-bed column process.

Combined ion exchange and adsorption equilibria of 5′-ribonucleotides on the strong acid cation exchange resin NH-1

“…5′‐ribonucleotides include uridine 5′‐monophosphate, adenosine 5′‐monophosphate, cytidine 5′‐monophosphate, and guanosine 5′‐monophosphate. They have been widely used in the food industry . They can enhance immunity and decrease the risk of diarrhea and sepsis .…”

“…They have been widely used in the food industry. 1,2 They can enhance immunity and decrease the risk of diarrhea and sepsis. 3 -5 The addition of 5 ′ -ribonucleotides in infant formula can improve the composition of intestinal microflora, emulating the attibute of human milk.…”

An innovative protein expression system using RNA polymerase I for large‐scale screening of high‐nucleic‐acid content Saccharomyces cerevisiae strains

“…RNA degradation products and their derivatives have many beneficial uses, especially in food and medical industry, and have important implications for improving the overall economic productivity of the yeast industry. For example, 5′‐inosine monophosphate (5′‐IMP) and 5′‐guanine monophosphate (5′‐GMP) can be safely used as food additives (Olmedo et al ., 1994; Zhao and Fleet, 2005; Cairoli et al ., 2008), while the derivatives of ribonucleotides (e.g. pyrimidines and purines) can be used as raw materials for food and pharmaceutical intermediates and so on (Rudolph et al ., 1990).…”

Increased transcription of NOP15, involved in ribosome biogenesis in Saccharomyces cerevisiae, enhances the production yield of RNA as a source of nucleotide seasoning

“…Yeast (Saccharomyces cerevisiae) is among the premier industrial microorganisms as important sources of RNA, which is an attractive source of 5 0 -ribonucleotides used as flavor enhancers in the food industry (1,2). The majority (80%) of RNA is ribosomal RNA (rRNA) (3).…”