The kinetics of riboflavin secretion by Eremothecium ashbyii nrrl 1363

Abstract

For ribo¯avin production a highly¯avinogenic strain Eremothecium ashbyii is used. Vitamins are classi®ed as chemical substances that control and effect the physiological processes; Ribo¯avin is one among them. The de®ciency of ribo¯avin in human beings results in the cracking of lips and corners of mouth (cheilosis); nerve tissues are affected. For ribo¯avin production a highlȳ avinogenic strain Eremothecium ashbyii NRRL 1363 was used. Investigations were conducted in shake¯ask using inexpensive and abundantly available raw materials. Among the stimulants, a combination of hog casings and beef extract stimulated the highest and promoted the maximum ribo¯avin yield followed by the combination of ®sh meal and beef extract. The fermented broth (an enriched, ribo¯avin concentrate) can be directly used as a feed grade ribo¯avin. To upgrade it to pharmaceutical grade further investigations are required. List of symbolsb blood meal (as stimulant) kg m À3 e beef extract (as stimulant) kg m À3 f fish meal (as stimulant) kg m À3 h hog casings (as stimulant) kg m À3 M Molasses (dextrose equivalent À50 kg m À3 ) P Peanut seed cake (deoiled) as nitrogen source 50 kg m À3 (weight/volume) v Specific production rate fg riboflavin (g micro organism) À1 h À1 g l Specific growth rate of mycelium h À1 Cc Carbon concentration consumed kg m À3 S b Substrate + blood meal kg m À3 S e Substract + beef extract kg m À3 S f Substrate + fish meal kg m À3 S h Substrate + hog casings kg m À3 Icc Initial carbon concentration kg m À3 Mbc Maximum biomass concentration kg m A3 (on dry weight basis) Mrc Maximum riboflavin concentration kg m À3 Ry Riboflavin yield

Nutritional requirements and strain heterogeneity in Ashbya gossypii

“…The specific growth rate of 0.33 ± 0.02 h -1 observed here for ATCC10895 in YPD was comparable to that expected of S. cerevisiae in complex medium. It was higher than previously reported specific growth rates of A. gossypii, which have been between 0.02 h -1 (NRRL1363/ ATCC12995; [49,50]) and 0.16 h -1 (ATCC10895 and derivatives; [51], including that of an ATCC10895 transformant (0.09 ± 0.00 h -1 ) in AFM in flasks [52]. However, we have observed similar rates in other cultivations (e.g.…”

Improvement of medium components for high riboflavin production by Aspergillus terreus using response surface methodology

“…Prabhakar et al (1993) reported that riboflavin quantity in fermentor contain bran was higher than the riboflavin produced in fermentation medium supplemented with molasses (84 mg/l by E. ashbyii). Molasses appeared to be a good carbon source for riboflavin production (Kalingan 1998). It was indicated that the optimal concentrations for enhanced production of riboflavin from E. ashbyii was molasses 30.85 g/l (Pujari and Chandra 2000).…”

The influence of cultivation conditions on biosynthetic ability of Eremothecium ashbyi Guillierm.

“…В якості джерела азоту запропоновано використовувати деякі недорогі відходи, які не є їстівними -це жмих кунжутного та арахісового насіння після відділення олії [6,13,14]. В якості стимуляторів флавіногенезу застосовують додаткові компоненти, наприклад, недорогі органічні відходи -м'ясний екстракт, кров'яне та рибне борошно [6,7,13,14]. Для визначення оптимального рівня поживних компонентів середовища використані статистичні методи, які дають можливість збільшити вихід рибофлавіну при його виробництві [14].…”