新酵母菌株之分離及利用

• Main Author: 黃寶村
• Other Authors: 蘇遠志
• Format: Others
• Language: zh-TW
• Published: 1966
• Online Access: http://ndltd.ncl.edu.tw/handle/54823984360411122418

碩士 === 國立臺灣大學 === 農業化學研究所 === 54 === 　　1. The screening test is followed to some yeast strains isolated from soils and some stock cultures of yest, and the yeast strein NO. W - 3 inolated from soils is the best strain. 　　2. The optimel composition of medium and culture condition of strain NO. W - 3 are investigated by reciproccal shaker (7 cm, 120 o. p. m.) and 5L - Jar fermenter. The experimental results are as foll we: 　　The sugar concentration (based on glucose) is 5%. Urea is the best nitrogen source. C / N ratio is 1 : 0.048. The concentration of phosphate needed is 10 m mole / 1. The culture conditions are pH 5.5, temperature 30℃, aeration 1 : 3 (V / V), and agitation 400 r. p.m.。 　　The yeast strain NO. W - 3 is cultivated at the conditions described soove the viard of dry cell (dried at 105℃) and RNA content of dry cell (dried at 60℃) have a makinal value when the cultivation time reaches 18 hours 　　3. The dry cell yield of strain NO, W - 3 based on total sugar and consumed sugar is 62.9% and 70.8% respectively. The RNA content of dry cell (dried at 60℃) is 7.96%, the ratio of the weight of the cell to the dry yeast cell (dried at 105℃) weight is 0.9221, so that the RNA content of the dry cell is 8.63%. 　　4. with taxonomical study of yeast strain NO. W - 3, it is found to belong to Candida arborea. 　　5.Some different methods of extracting RNA from the wet cell of candide arborea W - 3 are compared, and the best one is extracted with No 01. solution, it is the simplest method and the materials used are also cheap. The best coniition for RNA extraction is determined as follows: It is extracted at 95℃ for 60 minutes, then adjusted the filtrate to pH 3.0 by cold concentrated HCI. 　　From 100 grams of the yeast powder which contains 7.78% of RNA dried at 60℃, we may obtain 6.28 grams of RNA with the purity of 85.86% 　　6. The yield of dried yeast (dried at 105℃) based on total sugar ard the RNA content of yeast cell (dried at 60℃) of Candida arborea W - 3 is higher than that of Torulopsis utilis NRRL - Y - 900. The RNA yield based on the total sugar of the former (the dry yeast yield multiplying the RNA content of the dry yeast dried at 60℃) is 5.01%, equal to 131.15% of the latter. The crude protein yield of the former (the dry yeast yield multiplying the crude protein content of the dry yeast) is 28.80%, equal to 93.5% of the lattor. 　　7. The amino acid compositions of the both yeast straine are analyzed by amino acid autcanslyzer, they are very similar except lysine and histidine content. The contents of lysine and histidine of Candida arborea W - 3 are oqual to 147.78% of Torulopois utilts NRRL - Y - 900.