A simple method for RNA extraction from yeasts

Abstract

Disodium 5 '-inosinate (IMP) and disodium 5'-guanylate (GMP) are flavor enhancers that can be used as food additives.' Sodium salts of cytidine 5'-phosphate (CMP), and RNA Extractionfa) Batch Mode uridine 5'-phosphate (UMP) have important applications in the pharmaceutical industry. These 5'-ribonucleotides can be manufactured by enzymatic degradation of RNA, yeasts being the usual source of RNA.*The economic feasibility of such a process is related to the development of cheap methods to produce both RNA and the 5'-phosphodiesterase enzyme.Ribonucleic acid preparations are usually obtained from yeasts because the ratio RNA-DNA is the highest in these microorganisms. Moreover, the fermentation and recovery techniques for yeasts are well established. The extraction Solutions containing different concentrations of sodium hydroxide and sodium chloride and ammonia solutions were investigated as extraction agents (see Table I for the amounts). Batch experiments were carried out in a stirred tank of 100 mL working volume, employing 10 g (dry weight) of yeasts as raw material. The agitation speed was 320 rpm, and the flask was submerged in a constanttemperature bath at the d e s d temperature. After the extraction, the mixture was centrifuged and RNA was recovered from the supernatant liquid by precipitation.of RNA has been extensively reported by several procedures, especially at the laboratory level, to obtain highfbl Column Extraction A mixture of brewer's yeasts and celite was packed into a jacketted column (1.3 X 240 mm) in a dry state, and the extraction solution was pumped through the column. The extracted fraction was treated by precipitation to RNA. molecular-weight RNA. Thus, the well-known phenol method3 is extensively used, although it is obviously too complex and expensive to be used at industrial scale. On the other hand, alkali and salt solutions have been reported as extraction agents to obtain less pure crude RNA preparations more In this article, the effect of the last mentioned agents has RNA Precipitation been compared, and a methodology for RNA extraction and recovery has been developed in batch and semicontinuous modes. The raw material used was brewer's yeasts because of their low cost, but the methodology could be easily extended to other kinds of yeasts.In order to choose an appropriate method to recover RNA, three methodologies were tested: (1) ethanol precipitation (by adding one-half volume of ethanol, 1M NaCl); (2) precipitation by adjusting the pH of the extract to pH 2 MATERIALS AND METHODS

Use of polyelectrolytes for purification of crude ribonucleic acid

“…Several procedures are used for separation of protein from RNA [4]: (1) treatment of a suspension of crude RNA with a 0.5 M NaCl solution; (2) treatment of a suspension with chloroform-octanol mixtures, strontium nitrate, and sodium dodecyl sulfate; and (3) treatment with proteolytic enzymes. The use of enzymes is considered to be the most effi cient and convenient.…”

Complete fractionation of saccharomyces cerevisiae biomass

“…Nucleic acids are also useful components of baker's yeast. Industrial production of RNA is based on an extraction with NaCl or NaOH and subsequent precipitation by acidification (Andrev, 1988). RNA isolated by this method can be used for the preparation of food flavorings (5'-nucleotides).…”

Comparison of various ways of extraction of nucleic acids and of preparation of yeast extract from saccharomyces cerevisiae and candida utilis

“…Yeast extracts represent concentrates of soluble components of the yeast cell obtained by the autolytic, plasmolytic or physico-chemical process and the full advantage of them can be taken in the food and fermentation industry. A comparison of the basic types of industrial or laboratory extraction procedures used for fractionation of yeast biomass [4,5] was carried out with the baker's yeast ( S . Alternatively, they are occasionally produced from debittenzed brewer's yeasts S. cerevisiue or S. uvurum.…”