AUTOMATED PROCESS FOR THE PRODUCTION AND / OR ACCUMULATION OF PHA IN BACTERIAL CULTURES

Description

Page 1 of 14 TITLE Automated process for the production and / or accumulation of PHA in bacterial cultures DESCRIPTION TECHNICAL FIELD

[001] The present invention relates to an automated process for the production and / or for PHA accumulation in bacterial cultures. STATE OF THE ART

[002] PHAs (polyhydroxyalkanoates) are intracellular products of several species bacterial species belonging mainly to the genera Bacillus, Rhodococcus, Ralstonia and Pseudomonas obtained by fermentation using sugars or lipids.

[003] These linear macromolecules, under particular culture conditions, such as the absence of certain nutrients such as nitrogen, phosphorus and sulfur, are accumulated by bacteria as a reserve carbon source, in the form of granules (Figure 1). In appropriate cultivation conditions and through an appropriate supply of specific nutrients carbonaceous, the granules can reach high concentrations, up to 90% of the dry weight of the bacterial mass.

[004] PHAs stored in biomass can be recovered and used for industrial applications, thanks to their physical-chemical properties similar to those of conventional petroleum-based plastics, such as polypropylene, polyethylene and polystyrene. Unlike conventional plastics, however, PHAs have the advantage of being completely biodegradable and biocompatible polymers.

[005] A further advantage presented by these biopolymers is that the carbon nutrients needed by bacterial cultures to produce them can be made up of waste or scrap material from sludge or waste water industrial, municipal or agricultural.

[006] Convert sludge or expensive waste for disposal into a value-added raw material it is an increasingly felt need in the industrial sector and with a view to greater environmental sustainability.

[007] Most organic material, expressed for example as COD (Chemical Oxygen Demand), present in industrial, municipal or agricultural wastewater, Page 2 of 14 in fact, it must be removed before proceeding with the subsequent phases of disposal. A part of this COD is represented by the so-called rbCOD (COD rapidly biodegradable), that is, it is made up of low-weight organic molecules molecular, such as amino acids, sugars, alcohols, aldehydes, etc. These organic molecules, present in a quantity varying from 10% to 60% of the entire COD, can constitute the raw material necessary as nourishment for bacterial cultures for the PHA production.

[008] Use industrial, municipal or agricultural sludge or wastewater as raw material for the production of PHA by bacterial cultures, therefore, it would constitute a important step forward in the direction of a circular economy, allowing obtain cheaper and at the same time biodegradable plastics significantly reducing the costs for the disposal and purification of such wastewater.

[009] The main difficulty in applying this virtuous process using as nutrients for bacterial cultures of real wastewater, however, consists in the large variability in the composition of such wastewater.

[0010] Administer nutrients before the carbonaceous material is completely consumed arrangement of the bacteria, in fact, would lead to an overdose which would inhibit biological activity. Wait an excessive amount of time before administering a new dose of nutrients, on the other hand, would slow down the accumulation process of PHA inside the bacteria and would therefore reduce the efficiency of the process itself.

[0011] The process of accumulation of PHA in bacteria, in fact, is guaranteed by the alternation of phases of abundance of carbon nutrients and starvation; a correct frequency of this alternation provides a favorable selective pressure towards microorganisms capable to accumulate PHA inside the cell and, therefore, increases the amount of PHA accumulated.

[0012] The reference parameter for monitoring the PHA accumulation process is the dissolved oxygen (DO) concentration inside the bioreactor. In particular, the trend of the OD-time curve provides useful information on the availability of nutrients or the need to measure them.

[0013] The PHA accumulation process is therefore generally conducted manually, for an overall duration that varies from 6 to 8 hours, resulting in high costs and low process productivity.

[0014] To the knowledge of the Applicant, the scientific literature reports only two cases (Werker et al., 2011; Valentino et al., 2015) in which a method of Page 3 of 14 accumulation of PHA in bacterial cultures by automatic administration of carbonaceous nutrient by means of a dosing pump. This method is based on the calculation of the relative deviation  according to the equation below: t the

[0015] where DO represents the OD value measured at time t, DO is the minimum value of tm OD concentration measured after each nutrient administration and DO r represents the OD value measured under endogenous conditions.

[0016] The above equation has the disadvantage of referring to the minimum oxygen value the recorded following the administration of nutrient (DO), as this value m it is strictly dependent on the type of nutrient and therefore on the actual composition of wastewater used without considering the influence of the characteristics and variability of composition of the wastewater itself.

[0017] This aspect is very limiting, where the method is to be used for the control of PHA production or accumulation processes that use real wastewater, from highly variable composition.

[0018] For explanatory purposes, the trend of the OD-time curve in the case in Figure 2 is shown. whose carbon nutrient is composed of a mixture of volatile fatty acids (acid acetic, propionic, butyric, etc.). The curve shows a trend with double ascending phase, characteristic of wastewater consisting of different types of acids fats. In fact, bacteria first consume the most easily degradable part of the nutrient (ascending phase a), and only subsequently that consisting of compounds more complex (ascending phase b). Considering the minimum oxygen value the recorded, DO , as a discriminant for the activation of the dosing pump, m the supply of new carbon nutrient would occur in the ascending phase a, that is before the complete consumption of the carbon nutrient. This would lead to a overdose of the carbon nutrient, which would inhibit biological activity.

[0019] Where the production or accumulation of PHA in bacterial cultures is to be implemented using real wastewater, therefore, the use of prior art methods for the automatic nutrient administration is not effective from the point of view of productivity and does not allow adequate control of rbCOD conversion present in PHA wastewater. Page 4 of 14

[0020] In light of this, there is therefore a need for an automated process for the production or for the accumulation of PHA in bacterial cultures that can also be implemented where real wastewater is used to supply the necessary carbon nutrients. DESCRIPTION OF THE INVENTION

[0021] The technical problem solved by the present invention is therefore to provide a process automated for the production or accumulation of PHA in bacterial cultures that can also be implemented where real wastewater is used to provide the necessary carbon nutrients.

[0022] This problem is solved by an automated process for production and / or for the accumulation of PHA in bacterial cultures including the following steps: a) determine the instantaneous concentration of dissolved oxygen in the culture bacterial for each time unit (OD ) using an immersed probe t in said bacterial culture; b) store the dissolved oxygen (OD) concentration values t determined in point a); c) calculate the moving average (OD) of the oxygen concentration values m dissolved stored in step b); d) calculate the threshold value ( ) as:  =(OD – OD ) / (OD – OD ), tmrm where OD is the instantaneous value of the oxygen concentration, OD is the tm moving average as determined in step c), and OD is the r oxygen concentration measured under endogenous conditions; e) if the instantaneous value of the oxygen concentration (OD ) is t higher than the moving average (OD) plus the threshold value m (  , so that the condition is verified: OD > OD +    tm operate a dosing pump that supplies the bacterial culture with nutrients carbonaceous suitable for inducing the synthesis and accumulation of PHA in the bacteria themselves, and stop said dosing pump after a time interval T; f) at the end of the time interval T or if the condition of step c): OD > OD +   tm Page 5 of 14 if it does not occur, go back to step a).

[0023] Specifically, the subject matter of the present invention relates to a process automated for the production and / or accumulation of PHA in bacterial cultures where steps a) to f) are handled by a computer or processor electronic.

[0024] The object of the present invention relates in particular to a process automated for the production and / or accumulation of PHA in bacterial cultures where the carbon nutrients supplied to the bacterial culture in step e) include sludge and / or solutions of industrial, municipal or wastewater from agricultural processes.

[0025] As a further aspect, the present invention also relates to a method for the treatment of sludge and / or solutions of industrial, municipal or wastewater agricultural processes including the automated process for production and / or for the accumulation of PHA in bacterial cultures reported above.

[0026] Further advantages and embodiments of the present invention will be found evident from the detailed description given below. FIGURE

[0027] Figure 1: Electron microscope photograph of PHA granules formed inside of bacteria.

[0028] Figure 2: Graphical representation of the typical trend of dissolved oxygen in the time in a bacterial culture when a complex mixture is administered of elements as a carbon nutrient for the production or accumulation of PHA.

[0029] Figure 3: Dissolved oxygen concentration profile during the process of PHA accumulation, obtained following two doses of carbon substrate.

[0030] Figure 4: Flowchart representing the algorithm of the invention.

[0031] Figure 5: Dissolved oxygen concentration profile during the process of accumulation of PHA, obtained following thirty dosages of carbon substrate in 30 hours. DETAILED DESCRIPTION OF THE INVENTION

[0032] Glossary:

[0033] Bacterial culture: a method for multiplying bacteria in a predetermined culture medium and under controlled conditions.

[0034] Mixed bacterial culture: bacterial culture comprising multiple bacterial species. Page 6 of 14

[0035] Bacterial culture for PHA production or accumulation: to produce PHA, a bacterial culture is grown in a suitable substrate with appropriate nutrients so that it can multiply rapidly. Once the bacterial population has once a good biomass is reached, the nutrient composition is changed induce the microorganism to synthesize and accumulate PHA.

[0036] Biomass: a set of animal or plant organisms present in a certain quantity in a given environment.

[0037] Bio-reactor: equipment capable of providing an environment suitable for growth of biological organisms.

[0038] Carbonaceous nutrients or carbonaceous substrate: substances rich in carbon content and low in elements such as nitrogen, phosphorus and sulphur.

[0039] Average: the middle value between the upper and lower extremes in the set of several values ​​considered.

[0040] Moving average: average based on a constant time span in which the highest values remote ones are gradually replaced with newer ones.

[0041] OD: dissolved oxygen concentration determined in the bacterial culture.

[0042] OD : instantaneous value of the concentration of dissolved oxygen determined in the t bacterial culture

[0043] OD : moving average of the dissolved oxygen concentration determined in the m bacterial culture.

[0044] OD : dissolved oxygen concentration determined in the bacterial culture in r endogenous conditions, that is, in the absence of carbon nutrients.

[0045] The object of the present invention is based on the automatic control of two main signals (input and output). The input signal concerns the measurement of the concentration of OD inside the bioreactor in which the process takes place. The output signal concerns the switching on / off of an organic substrate dosing pump inside the bioreactor.

[0046] Specifically, the method is based on the analysis of the trend of the OD curve – time during the phases of carbon nutrient abundance and starvation. For example, Figure 3 shows the trend over time (OD curve – time) of the OD concentration profile inside the bio-reactor in which explains the process, obtained following two doses of organic substrate. From the analysis of the curve shown in Figure 3 it is evident that following the first dosage of carbon substrate (occurred at point 1), the concentration of OD Page 7 of 14 in the mixture contained inside the bio-reactor is reduced until it reaches of a relative minimum (decreasing section 1-2 of the OD-time curve). The reduction of the OD concentration in the decreasing section 1-2 of the curve occurs at following the oxidation and / or consumption of the substrate by microorganisms carbonaceous and intracellular accumulation of PHA. The trend of the OD concentration assumes an increasing trend starting from the minimum point 2 of the OD-time curve which represents the beginning of the starvation phase. During the starvation phase the external substrate has been completely oxidized and the microorganisms use the accumulated substrate for their metabolic functions in accordance with endogenous metabolism. Therefore, with the same flow rate of air blown in, the oxygen concentration increases up to a relative maximum (point 3, second dosage).

[0047] The method proposed in this invention allows to identify in a automatic, thanks to the implementation of a new algorithm, as reported in Figure 4, the ideal on / off point of the dosing pump carbon nutrients (output signal) based on concentration measurement of OD (input signal) which allows to optimize efficiency and productivity of the accumulation of PHA in the cytoplasm of bacteria, even when the composition varies and the characteristics of the carbon substrate administered.

[0048] It has indeed been surprisingly found that the method of automation and optimization of the PHA accumulation process proposed in the present invention allows for greater recovery of PHA even when used complex compositions of carbonaceous nutrients such as industrial, municipal or agricultural.

[0049] As an example, Figure 5 shows the trend of the profile over time. concentration of OD and PHA obtained following multiple dosages of nutrients carbon for a period of 30 hours.

[0050] From the analysis of Figure 5 it is evident that the longer the duration of the process accumulation of PHA, the greater the amount of PHA that can be accumulated (and then extracted) inside the bacterial cell.

[0051] The application of the method which is the object of the present invention requires the presence of a probe for monitoring dissolved oxygen (which returns the signal of input) and a carbon nutrient dosing pump (which returns the signal of The method is based on the calculation of the moving average (OD) of the concentration m Page 8 of 14 of measured OD and comparison of this average with the first instantaneous value (OD) t acquired after the calculation of the moving average.

[0052] The present invention, therefore, relates to an automated process for the production and / or accumulation of PHA in bacterial cultures including following steps: a) determine the instantaneous concentration of dissolved oxygen in the bacterial culture for each time unit (OD ) using a probe t immersed in said bacterial culture; b) store the dissolved oxygen (OD) concentration values t determined in point a); c) calculate the moving average (OD) of the oxygen concentration values m dissolved stored in step b); d) calculate the threshold value ( ) as:  =(OD – OD ) / (OD – OD ), tmrm where OD is the instantaneous value of the oxygen concentration, OD is the tm moving average as determined in step c), and OD is the r oxygen concentration measured under endogenous conditions; e) if the instantaneous value of the oxygen concentration (OD ) is t higher than that of the moving average (OD) added to the value of m threshold (  , such that the condition is verified: OD > OD +    tm operate a dosing pump that supplies the bacterial culture with nutrients carbonaceous suitable for inducing the synthesis and accumulation of PHA in bacteria same, and stop said dosing pump after a time interval T; f) at the end of the time interval T or if the passage condition e): OD > OD +   tm if it does not occur, go back to step a).

[0053] The terms "includes", "comprising" or any other variation thereof, as used in this document, are intended to cover a non-exclusive inclusion, so that a process, use, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent in such process, use, or apparatus.

[0054] As used herein, the term "and / or," when used in a list of two or more items, means that any one of the listed items can be used Page 9 of 14 alone, or in any combination of two or more of the items listed. For example, if a composition is described as containing components A, B and / or C, the composition may contain only A; only B; only C; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

[0055] According to the present invention, the steps from a) to f) are preferably managed by a computer and / or an electronic device.

[0056] According to a preferred aspect, the bacterial culture of step a) is a culture mixed bacterial.

[0057] According to a particularly preferred aspect, the carbonaceous nutrients supplied to the crop bacterial in step e) include sludge and / or industrial wastewater solutions, municipal or from agricultural processes.

[0058] According to a preferred aspect, the carbonaceous nutrients supplied to the bacterial culture in the passage e) include sludge and / or solutions of industrial, municipal or coming from agricultural processes, where such solutions are used as such or after having undergone previous treatments.

[0059] According to an even more preferred aspect, the steps from a) to f) are performed in continuously for a period of 30 hours.

[0060] According to another preferred aspect, in step a) the time unit for the determination of OD concentration values ​​in bacterial culture are the second.

[0061] According to another preferred aspect, in step e) the time interval T during the which the dosing pump is kept running is between 5 and 30 minutes.

[0062] According to a particularly preferred aspect, in step e) the time interval T during which the dosing pump is kept in operation is 10 minutes.

[0063] According to another preferred aspect, in step e) the metering pump supplies the bacterial culture carbon nutrients with a flow rate in the range of 100 and 300 mL / min.

[0064] According to a particularly preferred aspect, in step e) the metering pump supplies the bacterial culture with carbon nutrients at a flow rate of 150 mL / min.

[0065] The present invention also relates to a system for the production and / or storage of PHA in bacterial cultures including a bio-reactor equipped with a probe for the determination of the concentration of dissolved oxygen, a dosing pump and a electronic device connected at least to said probe and said dosing pump, where such electronic device is equipped with software, where such software is configured to perform the process according to the present invention. Page 10 of 14

[0066] The present invention therefore also concerns a system for the production and / or for the accumulation of PHA in bacterial cultures including a bio-reactor equipped with probe for determining the concentration of dissolved oxygen, a pump dosing machine and an electronic device equipped with software for performing the following algorithm: a) determine the instantaneous concentration of dissolved oxygen in the bacterial culture for each time unit (OD ) using a probe t immersed in said bacterial culture; b) store the dissolved oxygen (OD) concentration values t determined in point a); c) calculate the moving average (OD) of the oxygen concentration values m dissolved stored in step b); d) calculate the threshold value ( ) as:  =(OD – OD ) / (OD – OD ), tmrm where OD is the instantaneous value of the oxygen concentration, OD is the tm moving average as determined in step c), and OD is the r oxygen concentration measured under endogenous conditions; e) if the instantaneous value of the oxygen concentration (OD ) is t higher than that of the moving average (OD) added to the value of m threshold ( ), such that the condition is verified: OD > OD +  tm operate a dosing pump that supplies the bacterial culture with carbonaceous nutrients suitable for inducing the synthesis and accumulation of PHA in bacteria themselves, and stop the dosing pump after an interval of time T; f) at the end of the time interval T or if the passage condition e): OD > OD +  tm if it does not occur, go back to step a).

[0067] According to a preferred aspect, the present invention also relates to a method for the treatment of sludge and / or solutions of industrial, municipal or wastewater from agricultural processes comprising the process of the present invention.

[0068] The present invention therefore also relates to a method for the treatment of sludge and / or solutions of industrial, municipal or agricultural wastewater according to the algorithm of the present invention. Page 11 of 14

[0069] According to a preferred aspect, the present invention therefore relates to a method for the treatment of sludge and / or solutions of industrial, municipal or wastewater from agricultural processes including the following steps: a1) provide said sludge and / or industrial, municipal or wastewater solutions coming from agricultural processes, where such solutions are used as is or after pre-treatment in a purification plant, at a bacterial culture according to the process of the present invention; b1) recover the solutions depleted in rbCOD content resulting from the passage a1); c1) convey the solutions obtained in step b1) to the subsequent phases of purification provided for their disposal.

[0070] According to a particularly preferred aspect, the present invention relates to a method for the conversion of the present rbCOD material by bacterial culture in sludges and / or solutions of industrial, municipal or process wastewater agricultural, in PHA.

[0071] The present invention therefore also relates to a method for the conversion by bacterial culture of rbCOD material present in sludge and / or solutions industrial, municipal or agricultural wastewater in PHA including: a2) provide said sludge and / or industrial, municipal or wastewater solutions coming from agricultural processes, where such solutions are used as is or after pre-treatment in a purification plant, at a bacterial culture according to the process of the present invention; b2) recover the biomass containing PHA obtained in step a2); c2) isolate and purify the PHA obtained in step b2) according to the techniques of known art.

[0072] According to a particularly preferred aspect, the present invention relates to a method for the conversion of the present rbCOD material by bacterial culture in sludges and / or solutions of industrial, municipal or process wastewater agricultural, in PHA including the execution of the algorithm: a) determine the instantaneous concentration of dissolved oxygen in the bacterial culture for each time unit (OD ) using a probe t immersed in said bacterial culture; b) store the dissolved oxygen (OD) concentration values t determined in point a); Page 12 of 14 c) calculate the moving average (OD) of the oxygen concentration values m dissolved stored in step b); d) calculate the threshold value ( ) as:  =(OD – OD ) / (OD – OD ), tmrm where OD is the instantaneous value of the oxygen concentration, OD is the tm moving average as determined in step c), and OD is the r oxygen concentration measured under endogenous conditions; e) if the instantaneous value of the oxygen concentration (OD ) is t higher than that of the moving average (OD) added to the value of m threshold ( ), such that the condition is verified: OD > OD +  tm operate a dosing pump that supplies the bacterial culture with carbonaceous nutrients suitable for inducing the synthesis and accumulation of PHA in bacteria themselves, and stop the dosing pump after an interval of time T; f) at the end of the time interval T or if the passage condition e): OD > OD +  tm if it does not occur, go back to step a).

[0073] The present invention also relates to an electronic device connectable to a bioreactor equipped with a probe for reading the dissolved oxygen concentration and to a dosing pump, where said electronic device comprises a software configured to perform the process according to the present invention.

[0074] The present invention therefore also concerns a connectable electronic device to a bioreactor equipped with a probe for reading the oxygen concentration dissolved and to a dosing pump, where said electronic device comprises a software configured to run the algorithm: a) determine the instantaneous concentration of dissolved oxygen in the bacterial culture for each time unit (OD ) using a probe t immersed in said bacterial culture; b) store the dissolved oxygen (OD) concentration values t determined in point a); c) calculate the moving average (OD) of the oxygen concentration values m dissolved stored in step b); d) calculate the threshold value ( ) as: Page 13 of 14  =(OD – OD ) / (OD – OD ), tmrm where OD is the instantaneous value of the oxygen concentration, OD is the tm moving average as determined in step c), and OD is the r oxygen concentration measured under endogenous conditions; e) if the instantaneous value of the oxygen concentration (OD ) is t higher than that of the moving average (OD) added to the value of m threshold ( ), such that the condition is verified: OD > OD +  tm operate a dosing pump that supplies the bacterial culture with carbonaceous nutrients suitable for inducing the synthesis and accumulation of PHA in bacteria themselves, and stop the dosing pump after an interval of time T; f) at the end of the time interval T or if the passage condition e): OD > OD +  tm if it does not occur, go back to step a).

[0075] The present invention also relates to a computer and / or device software electronic comprising program codes configured to perform the steps of the process according to the present invention, when said software is executed on a computer and / or electronic device.

[0076] The present invention therefore also concerns a computer software and / or electronic device comprising program codes configured to execute, when such software is run on a computer and / or electronic device, the following steps: a) determine the instantaneous concentration of dissolved oxygen in the bacterial culture for each time unit (OD ) using a probe t immersed in said bacterial culture; b) store the dissolved oxygen (OD) concentration values t determined in point a); c) calculate the moving average (OD) of the oxygen concentration values m dissolved stored in step b); d) calculate the threshold value ( ) as:  =(OD – OD ) / (OD – OD ), tmrm Page 14 of 14 where OD is the instantaneous value of the oxygen concentration, OD is the tm moving average as determined in step c), and OD is the r oxygen concentration measured under endogenous conditions; e) if the instantaneous value of the oxygen concentration (OD ) is t higher than that of the moving average (OD) added to the value of m threshold ( ), such that the condition is verified: OD > OD +  tm operate a dosing pump that supplies the bacterial culture with carbonaceous nutrients suitable for inducing the synthesis and accumulation of PHA in bacteria themselves, and stop the dosing pump after an interval of time T; f) at the end of the time interval T or if the passage condition e): OD > OD +  tm if it does not occur, go back to step a).

[0077] Another aspect of the present invention concerns the use of the algorithm which is the subject of the present invention for determining the frequency of nutrient supply to a bacterial culture.

[0078] According to a particularly preferred aspect, the present invention relates to the use of the algorithm which is the subject of the present invention for the determination of the frequency of supply of sludge and / or industrial, municipal or wastewater solutions coming from agricultural processes to a bacterial culture.

Claims

1) Automated process for the production and / or accumulation of PHA in bacterial cultures including the following steps: a) determine the instantaneous concentration of dissolved oxygen in the bacterial culture for each time unit (OD ) by means of a probe immersed in said culture t bacterial; b) store the dissolved oxygen concentration (OD ) values ​​determined at t point a); c) calculate the moving average (OD) of the dissolved oxygen concentration values m stored in step b); d) calculate the threshold value ( ) as:  =(OD – OD ) / (OD – OD ), tmrm where OD is the instantaneous value of the oxygen concentration, OD is the average tm mobile as determined in step c), and OD is the oxygen concentration r measured under endogenous conditions; e) if the instantaneous value of the oxygen concentration (OD ) is higher than t that of the moving average (OD) added to the threshold value (  , in such a way m that the condition is verified: OD > OD +    tm operate a dosing pump that supplies the bacterial culture with nutrients carbonaceous suitable for inducing the synthesis and accumulation of PHA in the bacteria themselves, and stop said dosing pump after a time interval T; f) at the end of the time interval T or if the passage condition e): OD > OD +   tm if it does not occur, go back to step a). 2) Process according to claim 1, wherein the steps from a) to f) are managed by a computer and / or an electronic device. 3) Process according to any of claims 1 to 2, wherein the bacterial culture is a mixed bacterial culture. 4) Process according to any of claims 1 to 3, wherein the carbon nutrients supplied to the bacterial culture in step e) include sludge and / or wastewater solutions industrial, municipal or from agricultural processes, where such solutions are used as is or after having undergone previous treatments. 5) Process according to any of claims 1 to 4, wherein the steps a) to f) are performed continuously for a period of 30 hours. 6) System for the production and / or accumulation of PHA in bacterial cultures comprising a bioreactor equipped with a probe for determining the oxygen concentration dissolved, a dosing pump and an electronic device connected at least with said probe and said dosing pump, where said electronic device is equipped with a software, where said software is configured to execute the process according to a any of claims 1 to 5. 7) Method for the treatment of sludge and / or solutions of industrial, municipal or coming from agricultural processes including the following steps: a1) supply said sludge and / or solutions of industrial, municipal or wastewater from agricultural processes, where such solutions are used as they are or after pre- treatment in a sewage treatment plant, to a bacterial culture and carry out the process according to any of claims 1 to 5; b1) recover the solutions depleted in rbCOD content resulting from the passage a1); c1) convey the solutions obtained in step b1) to the subsequent phases of purification provided for their disposal. 8) Method for the conversion by bacterial culture of rbCOD material present in sludge and / or solutions of industrial, municipal or agricultural wastewater in PHA including: a2) supply said sludge and / or solutions of industrial, municipal or wastewater from agricultural processes, where such solutions are used as they are or after pre- treatment in a sewage treatment plant, to a bacterial culture and carry out the process according to any of claims 1 to 5; b2) recover the biomass containing PHA obtained in step a2); c2) isolate and purify the PHA obtained in step b2) according to the techniques of known art. 9) Electronic device connectable to a bio-reactor equipped with a probe for reading the dissolved oxygen concentration and to a dosing pump, where said device electronic includes software configured to run the process according to a any of claims 1 to 5. 10) Computer and / or electronic device software comprising program codes configured to perform the process steps according to any of the claims from 1 to 5, when said software is run on a computer and / or electronic device. 11) Use of the algorithm according to any of claims 1 to 5, for the determining the frequency of nutrient supply to a bacterial culture.