DD151005A3 - PROCESS FOR THE CONSERVATION AND DISPOSAL OF MICROORGANISMS - Google Patents

Abstract

The invention relates to a method for culturing and separating microorganisms, wherein the cultivation takes place in the presence of a self-dispersed oil phase. The use of nonionic surfactants based on adducts of propylene oxide and ethylene oxide as a fermentation and separation aid is well known. Optimal effective properties are achieved primarily as a fermentation aid. In order to further improve the specific performance parameters by using the adducts of ethylene oxide-propylene oxide also in the stage of the separation, it has been found that nucleic acids or nucleotides which can be easily separated from microorganisms and when used alone for fermentation or separation have no positive effects show, in combination with sAethylenoxid-propylene oxide both in the fermentation and in the separation can serve as an aid.

Description

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Title of the invention

Process for growing and separating microorganisms

Field of application of the invention

The invention relates to a method for breeding and Ab-. separation of microorganisms, wherein the cultivation takes place in the presence of a self-dispersed oil phase.

The invention is applicable to the growth and separation of microorganisms for the production of proteinaceous or other valuable products »

Characteristic of the known solutions

The use of certain nonionic surfactants as fermentation aids for improving the mass transfer processes of aerobic fermentation processes according to DD-PS 36,727 * is also well known. Furthermore, a process is known from DE-OS 2,544 * 625 and British Patent Specification 1 »499» 118, in which the same fermentation aid is also known for separation of the oil phase from the microorganism suspension is advantageously used as the only separation aid.

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This process, in the case of the sole auxiliary used for both breeding (fermentation) and separation (separation), is an adduct of propylene oxide and ethylene oxide with an average molecular weight of 1750-220 _e. This excipient is normally used only as a fermentation aid effective

In order to make this excipient also act as a separation tool for Ölaotrennung, the concentration is increased in accordance o · g · patents and the separation immediately after heating to 60 - carried out 90 ⁰ C * The need for this tool in the stated amounts of "up to 2 g / kg leads to a significant cost burden of the process ·

In addition, measurable proportions of the o. G · polyethylene oxide-propylene oxide adduct at 60 - 90 ⁰ C in the oil phase, if the task of oil separation exists «For certain applications of the oil to be used, the presence of polyethylene oxide-propylene oxide adducts only in certain Quantities are tolerated, so that a removal by means of additional process steps is necessary. This disadvantage also exists for biogenic high molecular surfactants or surfactant mixtures which are used for the same purpose. Furthermore, according to DD patent 104-099 _, a process is known according to which a combination of two chemically synthesized surfactants is advantageously used for the fermentation and separation process.

However, it has proved to be a disadvantage for the production of protein-containing products or other recyclables from microorganisms to use surfactants as adjuvants, since they are adsorbed on the cell walls of microorganisms and can interfere with the further processing or are undesirable in the final products _e

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Overall, from an economic and operational point of view, a high demand for foreign auxiliary agents, as they are known to surfactants, in principle from disadvantage «- · ·,. -. ·> ... · · · · ·. ·. -. -. · ··. '. ..: ·. '

Aim of the invention

The aim of the invention is to reduce the need for adjuvants of the ethylene oxide-propylene oxide adduct class for the fermentation and separation process with constant or improved specific performance parameters of these process stages.

Explanation of the essence of the invention

The invention has for its object to provide physical chemical conditions in the fermentation - Separationsge-Eiisch under which a qualitatively new effect of the above aids is made possible, This task should be achieved by substances produced by the microorganisms themselves or by separate methods can be separated from these and fed to the process, these substances have because of the both chemical and biogenic surfactants possible disadvantages surfactant and especially at temperatures of 50 - 90 ⁰ C in oils should be almost insoluble.

Surprisingly, it has been found that nucleic acids or nucleotides which can be easily separated from microorganisms by known processes and which, when used alone for fermentation or separation, have no positive effect on the fermentation process

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or separation process in combination with ethylene oxide-propylene oxide adducts can serve as auxiliaries both in the fermentation and in the separation *

It was found that in the fermentation process, the addition of ethylene oxide-propylene oxide adduct by 10 - * 40 % could be reduced without the mass transfer parameters decreased when the fermentation mixture, an aqueous nucleic acid solution was added in such an amount that the concentration of nucleic acids at least 50 mg / l of fermentation mixture.

In the case of the required oil separation from this fermentation ationsgemisch by means of separators at 60 - 90 ⁰ C, the 'need for ethylene oxide-propylene oxide adduct also in the same order of magnitude • There is a synergistic effect when combining the non-surfactant nucleic acids and surfactant ethylene oxide -Prpylene oxide adducts «

example

The invention will be explained with reference to a typical method example.

In a 500 liter stirred fermentor, Candida guilliermondii is continuously grown on petroleum distillate as a carbon source under aerobic conditions.

The following conditions and process parameters are set:

Filling quantity in the fermenter: · 200 kg

amount of air supplied: 23 cubic meters per

hour

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specific stirrer power

entry: 1.5 watts / kilogram

Petroleum distillate content in. '' ·

Fermentation mixture .: 15 weight percent

average residence time in the per-mentor: 5 hours

The perforator was further fed a nutrient solution containing nitrogen, potassium, phosphorus and nutrients and trace elements sufficiently. In addition, the aqueous solution of the excipient combination of nucleic acids and ethylene oxide-propylene oxide adduct was dosed into the fermenter. "This solution contained 10 g / l nucleic acids and 40 g / l ethylene oxide-propylene oxide adduct with an average molecular weight of 1850" Solution in the Permentor introduced that during the entire continuous operation, the concentration of nucleic acid between 60 - 50 mg / 1 and that of the ethylene oxide-propylene oxide adduct between 240 - '20O mg / 1 fermentation liquid was maintained. In the permentor, a biomass concentration of 23 grams of yeast dry matter per liter of fermentation liquid was achieved during the experiment.

40 liters per hour were continuously withdrawn from the fermenter «

This product stream, in which the adjuvant combination added to the fermenter was contained in the o.g _o concentration, since both adjuvants are adsorbed by the microorganisms in only very small amounts, was again mixed with ethylene oxide-propylene oxide solution in such an amount that the concentration then 500 mg / 1 and immediately separated at 60 ⁰ C.

The resulting microorganism phase was sent for further processing to a protein vitamin concentrate.

Claims (1)

2 1 5 79 8 Erfindu ngsanspr u ch Method for breeding and separation of. Microorganisms by adding. Ethylene oxide-propylene oxide adducts characterized in that the fermentation and Se.parationshilfsmittel a combination of nucleic acids and / or nucleotides and ethylene oxide-propylene oxide adducts is used, wherein the concentration of nucleic acids or nucleotides at least 50 milligrams per liter, based on the Wass.erph.ase in the cultivation and separation of the microorganisms, is.