DD298284A5 - METHOD FOR CONTROLLING CARBON SUBSTRATE DOSES IN MICROBIAL SUPPLY METHODS - Google Patents

Abstract

The invention relates to a method for controlling carbon substrate dosages in microbial product formation processes according to the Zufuetterungs- and cyclic Zufuetterungsprinzip. Carbon substrate pulses having process-specific substrate amounts and substrate constituents are repeatedly introduced into the culture medium. Their respective utilization period is measured and determined from observation data. The existing utilization capacity is used for Dosierungsnachfuehrung. For the subsequent period of product formation, the new rate value is selected in a process-specific manner with a fixed proportional or with a process-related proportional reference to the recovery capacity. In the extended procedure, the follow-up of the carbon substrate dosage is based on the series of recovery date data and subsequent trend estimates for the exploitation development. Carbon substrate dosage; Product formation processes, microbial; Zufuetterungsprinzip; Zufuetterungsprinzip, cyclic; Realization period}

Description

(registered carbon substrate amount)

(associated utilization period)

is used for dosing tracking by selecting, for the subsequent period of product formation, the new rate value with fixed proportional reference to the recovery capability and in the extended procedure justifying the tracking of the carbon substrate dosing on the series of recovery date data and subsequent trend estimates for recovery development and for tracking the carbon substrate dosage for the subsequent period of product formation, the new rates will be chosen with fixed proportional reference to the predicted values of the development of the recovery capacity.

2. The method according to claim 1, characterized in that is selected for the subsequent period of product formation of the new rate value with a weighted by the process age proportional reference to the recovery capacity.

3. The method according to claim 1 and 2, characterized in that as an alternative to the direct form of determining the recovery capacity in Produktbildungsfermenter whose estimate on the basis of one or more measuring reactors, are transferred to the specific amounts of culture solution from the Produktbildungsfermenter and in which then meßreaktorbezogene determinations the recovery capacity and the recovery capacity of the product formation reactor as an estimation result, is determined in evaluation of meßreaktorbezogene data carried out.

4. The method according to claim 1 to 3, characterized in that as observation variables for assessing the course of the utilization intensity digitally and / or analog evaluated measuring devices for hydrogen ion concentration and / or dissolved oxygen partial pressure and / or oxygen content in the exhaust air and / or carbon dioxide in the exhaust air and / or from these sizes inferred sizes which contain at least one of the aforementioned sizes as a component can be used.

5. The method according to claim 1 to 4, characterized in that in the culture medium and / or as feed substrates nutrient substrates are used, which are all or partially complex in nature.

Field of application of the invention

Preferred fields of application are microbial product formation processes according to the feeding and cyclic feeding principle, in which the microbial product-forming agent in the feed component of the carbon substrate or substrates is supplied in a limited manner and the product formation process is conducted via the defined supply of carbon substrates.

Characteristic of the known state of the art

In the generally multistage processes for microbial product formation, the measures taken upstream of the product formation section serve to provide a sufficiently large amount of microbial product former. The cultivation stages also serve the expression of metabolic properties and advantageous morphological properties for process control. The guidance of carbon substrate dosages to control microbial product formation is currently underway

- Time program,

- time program and control analysis of carbon substrates,

- physical / chemical properties of submerged cultures,

- Growth models with control analytics for substrates and biomass

- Balance models for economical substrate utilization, related to product formation

- The specific digestion rate of oligosaccharides.

The guiding methods have the following disadvantages:

- They do not adequately relate to the level of development of available biosynthetic capacity, lack of reference to individual process history in product formation, delayed dosage adjustments due to time-consuming analytics or model analysis, and failure prone culture solution analysis work together,

- after disturbances in the planned procedure, the adaptation of the process continuity with malfunction-compensating measures is only insufficiently supported,

- The adaptation of the microwave product formation to different reactors, the varying composition of the nutrient substrates used and substrate changes is not achieved.

Object of the invention

The aim of the invention is:

- to create powerful, robust microbial product formation processes,

- enforce optimal product yields with the most economical use of materials,

to improve the reproducibility of the fermentations and thus their economy,

- speed up all forms of process adjustments and conversions and reduce associated unproductive material costs,

- Include reactor conditions, culture solution conditions and utilization characteristics of the product formers in the leadership of product formation so that the process receives self-adaptive character.

Explanation of the essence of the invention

The invention has for its object to provide for carbon-limited microbial product formation processes, a method for controlling the carbon substrate dosing by determining the recoverability of the product-forming agent and the dosage based on this process-specific adaptedf. The complex effects of the plant and the developmental changes of the product culture are included in the complex, so that the tracking in each case meets the individual circumstances, has a disturbance-balancing character and allows the utilization of the currently available recovery capacity. Surprisingly, it has been found that these substrate supply control measures moreover result in a guiding agent which produces production-enhancing processes which increase production and thus yield increases in the product yield of the fermentations. The biotechnological reactors used for the aseptic operation have means for feeding the carbon substrate (s) and for measuring and / or observing the recovery time of substrate pulses which are introduced into the culture solution.

According to the invention, a carbon substrate pulse is introduced into the culture medium for this purpose, the amount of substrate of which is selected in a process-specific manner, and the required recovery time is measured or determined from the observation data. The reference value for the control of the carbon substrate supply is the value

(registered carbon substrate amount)

(associated utilization period)

hereinafter referred to as MCIVR - maximum pulse utilization rate. As an alternative to the direct form of MCIVR determination in the product formation fermenter, the MCIVR is estimated on the basis of one or more replication gradients in the product formation fermenter - from multiple measurement reactors into which specific amounts of culture solution are transferred from the product formation fermenter and then to dimensional reactor related MCIVR data are determined. The MCiVR value of the product formation reactor then results from estimation methods in evaluation of the measurement reactor-related data. For the control of the carbon dosage, the new rate value for the subsequent period of product formation is selected process-specifically with a fixed proportional or with a process-related proportional proportional reference to the MCIV1. The process for tracking is repeatedly performed in the product formation process. In the extended approach, tracking of carbon substrate dosage is based on the series of post-tracking MCIVR values and subsequent trend estimates for MCIVR evolution. For tracking the carbon dosage, for the subsequent period of product formation, the new rate choice is process specific with fixed proportional or process-fair proportional to the predicted values of MCIVR evolution.

Ausführungebeispiel

The method for tracking the carbon substrate dosage is demonstrated using the example of a penicillin fermentation. The penicillin fermentation is carried out in the form of a submerged culture in a 3 m ³ stirred tank. The microbial product-forming agent used is a selectin of Penicillium crysogenum. Its selection and cultivation takes place via Lyophilkonservc, Emersan breeding in Petri dishes, Eprouvettenkulturen with stress media, shake cultures, barley rice culture, passes through two Impffermentationsstufen and product culture as the primary growth phase. Subsequently, the fermentation takes place on the basis of unlimited oxygen supply and limited supply of carbon substrate. The oxygen is supplied via ventilation and carrying out, with a stirring rate of 135U / min and an air flow rate of 1.6 nm. ³ Further, the process is carried out at a pH of 6.5 and a fermentation temperature of 25 ⁰ C. These values remain unchanged during the product formation phase. Sucrose is added as the only carbon substrate. For this is on the fermentation plant a Nachdosierungseinrichtung available, the dosing under

aseptic conditions. The sucrose is supplied as an aqueous solution (450 g of sucrose in 11 solution). As further additions ammonium sulphate, ammonia and phenylacetic acid are required during the fermentation phase, which serve to concentration corrections in the culture solution. These additions are guided by value analyzes from the culture solution analysis, which accompanies the process. The Produktbüdungsinbetriebnahme took place at the 30th fermentation hour. The process for tracking the carbon substrate dosage at the 90th fermentation hour is demonstrated below. Previous dosing follow-up procedures were performed at the 35th and 65th fermentation hours. The carbon substrate pulses consist of sucrose solution, which is of the nature of the feed substrate. The pulses used are entered into the culture solution via the replenishment device of the fermentation plant. The utilization period is not measured directly, it results from a set of observation variables, derived from the value curves of the system measuring probes of the process variables pH, pOj and oxygen consumption, carbon dioxide formation. For dosing tracking, the current sucrose feed is first taken out of service. After 1 lb of dosing stop, the residual concentrations of recoverable carbon from the culture solution are used up. The indication of the end of use by constantly decreasing carbon dioxide formation, decreasing oxygen consumption, constant increase in the measured data for pH and pO ₂ provides sufficient accuracy and safety with 15-minute control of the tendency stability. The addition of the substrate pulse requires a dosing duration of less than 3 minutes. The end of use, as observed in the form described, is reached after a recovery time of 1.5 hours, resulting in an MCIVR of 8 (l / h). For all rate tracking in the product formation period, the process-specific, constantly selected proportionality factor 0.7 is used as the assignment quantity, so that the sucrose dosage is operated at the rate 5.6 (l / h). Up to the 90th fermentation hour, the following tracking protocol results in tabular listing:

Fermente- previous sucrose - MCIVR tracked

Age of age Rate impulse rate

(h) (l / h) JI) ll / h) (l / h)

35 2 6 0 3,5

65 3.5 10 6 4.2

90 4.2 12 8 5.6

Claims (1)

1. A method for controlling carbon substrate dosages in microbieilen feeding method, characterized in that in microbieilen product formation processes according to the feeding and the cyclic Zufütterungsprinzip repeatedly carbon substrate pulses are entered into the culture medium, the respective utilization period is measured and determined from observation data, and the respective existing recoverability, characterized by the relationship