DESC:FIELD OF THE INVENTION
The present invention provides a capillary bioreactor for algal bioprocess. More particularly, the present invention provides a capillary bioreactor which helps in uniform distribution of nutrients, improved gas transfer and requires less water for algal cultivation having applications not limited to algal cultivation, lipid accumulation, carotenogenesis, in situ cell disruption and in situ cell extraction.

BACKGROUND OF THE INVENTION
Microalgae are unique and potentially valuable microorganisms because they are the light-harvesting “cell factories” that convert carbon dioxide into biomass or a variety of bioactive compounds. Although many can grow heterotrophically, all microalgae are photoautotrophs, requiring mainly sun, water, and inorganic nutrients for growth. Compared to higher plants, microalgae are simple in structure, being unicellular, filamentous or colonial, and energy is directed via photosynthesis into growth and reproduction; they do not need to establish and maintain complex tissues and organs. Microalgae have the potential to produce valuable substances for the food, feed, cosmetic, pharmaceutical, and waste treatment industries.
Commercial culture of microalgae has more than 40 years of history with some of the main species grown being Spirulina for health food, Dunaliella salina and Haematococcus pluvial is for carotenoid production, and several species for aquaculture. While in the past natural waters (lakes, lagoons, ponds) or artificial ponds were used to grow algae, more recently closed photobioreactors have been employed. Open-culture systems have almost always been located outdoors and rely on natural light for illumination. Although they are inexpensive to install and run, open systems suffer from many problems such as cultures are not axenic so contaminants may out compete the desired algal species; predators like rotifers decimate the algal culture, and vagaries of weather make proper control of nutrients, light intensity, and CO2 at best challenging.
Algal culture systems with naturally illuminated large surface areas include open ponds, flat-plate, horizontal/serpentine tubular airlift, and inclined tubular photobioreactors. Generally, laboratory-scale photobioreactors are usually artificially illuminated with fluorescent or other types of lamps. Closed reactors can be sited indoors or outdoors, and offer better control of culture conditions. Unfortunately, they are also usually more expensive to install. As a result, they are under intensive study in an effort to reduce costs to better facilitate their use especially for low value products like algal oils for biodiesel.
In order to produce microalgal biomass at reduced costs and energy requirements, the importance of bioreactor design has been highlighted in several studies. Generally, it is known that plants may be used to produce a number of fuels and edible products. This concept extends to various forms of algae, which have been grown and harvested to produce both animal feed and bio-diesel fuels. Unfortunately, such algae-based technologies are not matured to the point where bio-diesel may be produced at a marketable price. Accordingly, new technologies relating to growing algae and harvesting their by-products may be desirable. Although cultivation of microalgae seems easy, there are many challenges including minimizing contamination, efficient provision of carbon dioxide and light, controlling cultivation conditions, reducing capital and production costs and minimizing space requirements.
US8092685 an exemplary bioreactor for growing algae that includes a chamber, a liquid-permeable membrane that includes a plurality of hollow fibre membranes disposed within the chamber. However, the cited document does not provide the algal biomass cultivation consistency through real time monitoring system. In the cited document the algal growth is achieved in Extra capillary space (ECS) and not on any growth surface/layer/membrane. Hence, it is completely different from our capillary bioreactor, where the various algal bioprocess is explicitly done on the growth surface/layer/membrane. The cited patent focuses on the lipid extraction process whereas capillary reactor in the present invention performs various algal bioprocesses including cultivation, lipid extraction, carotenogeneisis, in situ cell disruption and in situ cell extraction.
The algal biofuel market is rising on the top due to growing demand for low cost, reliable and sustainable energy sources to ease acute vulnerability to petroleum supply chain and meet the rising fuel demand by automotive and aviation sector. Moreover, the algae have the ability to offer 2 to 20 times higher yield than the existing biofuel feedstock like corn, sorghum and beet. The three major hurdles for algal industry are maintaining algae biomass cultivation consistency across various regions and climates, high water demand for algae production and lack of technology innovation to commercial scale up.
Therefore, the present invention provides a capillary bioreactor which utilizes less water and maintains the algal biomass cultivation consistency through real time monitoring system.

OBJECT OF THE INVENTION
The main object of the present invention is to provide a capillary bioreactor for algal bioprocess.
Another object of the present invention is to provide a capillary bioreactor for immobilizing the algal cells and thereby facilitating growth and other bioprocesses including lipid accumulation, carotenogenesis, in situ cell disruption and in situ cell extraction which enables colony tracking and monitoring throughout the batch duration which is not possible in current systems of algal bioprocess due to lack of immobilization.
Yet another object of the present invention is to provide a capillary bioreactor comprising of growth chamber, photon delivery chamber, magnetic module, ultrasound module, utility chamber, harvest module and real time monitoring module having applications not limited to algal cultivation, lipid accumulation, carotenogenesis, in situ cell disruption and in situ cell extraction.
Yet another object of the present invention is to provide a method of cultivating algal cells using capillary bioreactor.
Still another object of the present invention is to provide a capillary bioreactor which helps in uniform distribution of nutrients, improved gas transfer and requires less water for algal cultivation.

SUMMARY OF THE INVENTION
In the main embodiment, the present invention provides a capillary bioreactor for algal bioprocess. More particularly, the present invention provides a capillary bioreactor comprising of a growth chamber, a photon delivery chamber, a magnetic module, an ultrasound module, a utility chamber, a harvest module and a real time monitoring module having applications not limited to algal cultivation, lipid accumulation, carotenogenesis, in situ cell disruption and in situ cell extraction.
In yet another embodiment, the present invention provides a method of cultivating algal cells using capillary reactor comprising steps of: (a) sterilizing capillary reactor using ultraviolet rays, steam and chemicals; (b) inoculating algal cells on a growth surface using a micro sparge system; (c) monitoring the growth of algal cells continuously as obtained in step (b) in the growth surface along with contaminants using a real time monitoring module; and (d) harvesting the algal cells from the growth surface using harvesting techniques.
In yet another embodiment, the present invention is to provide a capillary bioreactor which helps in uniform distribution of nutrients, improved gas transfer and requires less water for algal cultivation.
In yet another embodiment, the present invention is to provide a capillary bioreactor which is switched/pivoted from being vertical to horizontal or vice versa before the start of the batch as per the user preference.

BRIEF DESCRIPTION OF THE DRAWINGS
The object of the invention may be understood in more details and more particularly description of the invention briefly summarized above by reference to certain embodiments thereof which are illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate preferred embodiments of the invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective equivalent embodiments.
Figure 1 shows structure of the capillary bioreactor system.
Figure 2 shows various motions of the robotic arm.
Figure 3 shows algal growth in reactor system.
Figure 4 shows algal growth in reusable surface.
Figure 5 shows model of the capillary bioreactor system.
Figure 6 shows an exploded view of various components of the capillary bioreactor.
Figure 7 shows the front view and the side view of the micro sparger.
Figure 8 shows wiper/scraper for harvest process.
Figure 9 shows diagrammatic representation of frame/backbone of the capillary bioreactor system.
Figure 10 shows diagrammatic representation of capillary bioreactor with PLC.
Figure 11(a) shows diagrammatic representation of UV sterilization performed with UV light.
Figure 11(b) shows diagrammatic representation of chemical sterilization performed using narrow pores along the growth block (Vertical black arrows) and micro sparger (Horizontal black arrows).
Figure 11(c) shows diagrammatic representation of steam sterilization.
Figure 12 shows diagrammatic representation of media supply pattern by narrow pores and micro sparger.
Figure 13 shows diagrammatic representation of inoculation.
Figure 14 shows diagrammatic representation of sampling.
Figure 15 shows diagrammatic representation of harvesting.
Figure 16 shows diagrammatic representation of screening.
Figure 17 shows diagrammatic representation of ultrasound transducer (attached to the robotic head) movement along the growth surface.
Figure 18 shows capillary bioreactor vertical configuration (a) and horizontal configuration (b).

DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described hereinafter with reference to the detailed description, in which some, but not all embodiments of the invention are indicated. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. The present invention is described fully herein with non-limiting embodiments and exemplary experimentation.
In the main embodiment, the present invention provides a capillary bioreactor for algal bioprocess. More particularly, the present invention provides a capillary bioreactor comprising of a growth chamber, a photon delivery chamber, a magnetic module, an ultrasound module, a utility chamber, a harvest module and a real time monitoring module having applications not limited to algal cultivation, lipid accumulation, carotenogenesis, in situ cell disruption and in situ cell extraction. Figure 1 and Figure 5 shows structure of the bioreactor system.
In yet another preferred embodiment, the present invention provides a growth chamber comprising of a growth block, a growth surface and a robotic arm. The growth block acts as the scaffold on which the growth surface is aligned. The growth surface includes but not limited to stainless steel material, alloys, composite material, porous material, non-porous coarse material, sintered metals, woven or nonwoven materials, smart materials, gels and gel like material, self-assembling gels, self-assembling nanoparticles and semi-solid materials. The growth surface promotes various algal bioprocesses such as growth, carotenogenesis, lipid accumulation, in situ cell disruption, in situ cell extraction and so on. The growth surface may or may not be pre-treated for improvised growth, adhesiveness and surface reusability. The growth chamber has a robotic arm controlled by a PLC. The robotic arm is present on either side of the growth surface for dual reactor system where each side of the growth surface act as single reactor system. The robotic arm aligns itself in various axis with any particular region on the growth surface at predetermined distance for various bioprocess operations which includes but is not limited to sampling process, operating different tools such as pH sensor, temperature sensor, optical sensor. Figure 2 shows various motions of the robotic arm. Figure 3 shows algal growth in reactor system and Figure 4 shows algal growth in reusable surface.
In yet another preferred embodiment, the present invention provides a photon delivery chamber further comprising of a photon array system which is fabricated for delivery of photons of varying wavelengths of light ranging from infra-red (790 -900 nm), to visible spectrum (390-790 nm), to ultraviolet (200-390 nm), or in combination of a spectrum wherein total quantity of delivery of the photons at any given time ranges from 20-600 mol/m2 wherein wide range in wavelength and quantities accommodates for a diverse set of growth parameters including but not limited to green and red stage, in situ cell disruption, and lipid biosynthesis, strain differences, sterilisation requirements, and experimentation flexibility.
In yet another preferred embodiment, the present invention provides a utility chamber which has several liquid reservoirs having media components, acid, base, antimicrobial solution etc. The media components are supplied in optimal range with the aid of programmable logic controller (PLC). The acid and base are added according to the pH sensor control system.
In yet another preferred embodiment, the present invention provides an ultrasound module comprising of an ultrasound transducer to generate ultrasonic effects. The ultrasound module is not widely possible in current algal growth system and thus it opens a completely new dimension in studying the relationship between the ultrasound and large-scale algal production. The ultrasonic waves enhance the cell permeability which leads to increased nutrient uptake and thereby promoting the growth and carotenogenesis.
In yet another preferred embodiment, the present invention provides a harvest module which includes but is not limited to wiper system, spray system, pressure-controlled efflux system and magnetic separation process. The pressure-controlled efflux system is a unique system having a combination of a wiper system and a vacuum based suction system i.e., the algal biomass is harvested from the growth surface by scrapping the biomass along with the suction supplied from the backside of the wiper to enable easy collection of the harvested biomass into the harvest bag as shown in Figure 8. The magnetic separation process has iron nanoparticles for harvesting and the spray system has micro sparge as shown in Figure 7 where liquid or air is used for harvesting.
In yet another preferred embodiment, the present invention provides a magnetic module having permanent magnets and Helmholtz coil to produce static magnetic field and pulsed magnetic field. The magnetic effect increases the nutrient uptake and thereby increases the biomass.
In yet another preferred embodiment, the present invention provides a real time monitoring module which controls the entire reactor and its components and manages processes real-time through user inputs as well as its own predictions, through a PLC based controller as shown in Figure 10.
In yet another preferred embodiment, the present invention provides a method of cultivating algal cells using capillary reactor comprising steps of: (a) switching/pivoting the capillary reactor from vertical to horizontal or vice versa before the start of the batch as shown in Figure 18; (b) sterilizing capillary reactor using ultraviolet rays, steam and chemicals as shown; (c) inoculating algal cells on a growth surface using a micro sparge system; (d) monitoring the growth of algal cells continuously as obtained in step (c) in the growth surface along with contaminants using a real time monitoring module; and (e) harvesting the algal cells from the growth surface using harvesting techniques. The algal cells are harvested from the growth surface by any one of the following harvest techniques such as wiper system, spray system, pressure-controlled efflux system and magnetic separation process. The real time monitoring module controls the entire capillary reactor and its components and manages the processes in real-time through user inputs as well as by its own predictions, through a PLC.
In yet another preferred embodiment, the present invention is to provide a capillary bioreactor which helps in uniform distribution of nutrients, improved gas transfer and requires less water for algal cultivation. Table 1 shows the experimental data for less water utilization by the capillary reactor. Table 2 shows the moisture holding capacity of each tested membrane done after uniform distribution of nutrients by the nutrient mist technology.
Figure 6 shows an exploded view of various components of the capillary bioreactor. Capillary bioreactor is a solid-state cultivation technology to augment various algal bioprocesses. The reactor includes many modules such as bioprocess chamber, ultrasound module, photon delivery system, utility chamber, harvest module, real time monitoring module and so on. The combined operation of these modules enhances the algal bioprocess with low production cost and water requirement.
Figure 9 shows a diagrammatic representation of the frame/backbone structure of the capillary bioreactor system on which the robotic arms are mounted and guided along the X & Y axes in order to perform various operations and functions of the capillary reactor system.
Sterilization is the process of deactivating/killing all forms of microorganisms to ensure contaminants free cultivation. In capillary bioreactor, the sterility is achieved using UV, steam or chemicals. Figure 11(a) shows diagrammatic representation of UV sterilization performed with UV light while Figure 11(b) shows diagrammatic representation of chemical sterilization performed using narrow pores along the growth block (Vertical black arrows) and micro sparger (Horizontal black arrows). Also, Figure 11(c) shows diagrammatic representation of steam sterilization.
Media supply is given in two ways based on the requirement, one is primary supply and the other is alternate supply. In primary supply, narrow pores along the growth block provides media for the entire growth surface at specified time interval with the aid of PLC whereas the Alternate supply (micro sparger) provides media for the specific nutrient deprived region with the aid of algAI and PLC. Figure 12 shows front view and side view of the media supply pattern. The media from the feeder vessel is pumped through the peristaltic pump to the narrow pores where it is being uniformly distributed on the growth surface under the influence of gravity (Vertical Black arrows). The robotic head with the micro sparger sprays the media on the nutrient deprived region on the growth surface (Horizontal black arrows).
Figure 13 shows diagrammatic representation of inoculation. The culture is sprayed onto the growth surface with the help of micro sparger attached to the robotic head. The robotic head movement is controlled through a PLC based controller. The robotic head movement is from left to right as indicated by black arrows. The X and Y axes region should be mentioned in the inoculation control unit for automated inoculation.
Figure 14 shows diagrammatic representation of sampling. The robotic head collects the sample [a box marked (1-4) with crossed line] using a “sample pick” system and the collected sample is handed over to the sample handover box. The robotic head movement is from top to bottom for sampling /harvesting. The sample control unit collects the sample using a “sample pick” system in the chosen area from a minimum number of points, which can be modified in the system. The algAI analyses the growth of the particular area with the help of the optical sensor available in the robotic head and keeps a track of it based on the stored data. If algAI identifies any abnormalities during the process, it analyses the particular area with the help of stored data available in the system library and fixes the issue. The robotic head collects the sample with the aid of wiper and pressure-controlled efflux system. The collected sample is handed over into the sample handover box.
Figure 15 shows diagrammatic representation of harvesting. The cells grown in optimized condition is harvested by using wiper and pressure-controlled efflux system with the help of PLC based controller and algAI. The robotic head movement for harvest control unit is from top to bottom (as shown by orange colour arrows) and the harvested biomass is collected in the collection vessel.
Figure 16 shows diagrammatic representation of screening. Screening is performed for analyzing nutrient depletion, contamination, growth, general quality control/quality analysis like dryness and other inconsistencies. The algAI assist the robotic head to spray the media and antibiotic respectively, in the specified region on the growth surface. The robotic head screens the growth surface for any nutrient depletion (the box marked with crossed line) or contamination (the box marked with circles) with the help of algAI and performs the corrective measure in terms of media or antibiotic spraying using micro sparger.
Figure 17 shows diagrammatic representation of ultrasound transducer (attached to the robotic head) movement along the growth surface. In capillary bioreactor, the ultrasound transducer is attached with the robotic head to produce ultrasonic effect for stimulating the nutrient uptake by the algal cells and to thereby increase the algal biomass.
Figure 18 shows capillary bioreactor at vertical configuration (a) and horizontal configuration (b).

Table 1
Shows the experimental data for less water utilization by the capillary reactor
S. No Media Light intensity (µ mol m-2 s-1) Temp (°C) pH Suspension Reactor Biomass (g/L) Capillary Bioreactor Biomass (g/L) Water required to Produce 5 g biomass
Fold reduction of water requirement for Capillary
Bioreactor
Capillary reactor (L)
Suspension Reactor (L)

1 CL-AM 30 25 7.5 0.878 3.82 1.31 5.69 4.35
2 CL-AM 30 25 7.5 0.896 4.96 1.01 5.58 5.54
3 CL-AM 30 25 7.5 0.902 5.34 0.94 5.54 5.92
4 CL-AM 30 25 7.5 0.858 2.67 1.87 5.83 3.11
5 CL-AM 30 25 7.5 0.921 5.23 0.96 5.43 5.68
6 CL-AM 30 25 7.5 0.982 5.46 0.92 5.09 5.56
7 CL-AM 30 25 7.5 1.141 5.54 0.90 4.38 4.86

Table 2
Shows the moisture holding capacity of each tested membrane done after uniform distribution of nutrients by the nutrient mist technology

The below equations (1) and (2) are mass balance equations of capillary reactor and suspension reactor respectively.
157CO2 + 55.55 H2O + 0.04 NO3? 0.204CH0.128N0.178O0.684 + 0.215 O2 + 156.79 CO2 + 55.53H2O ………. (1)
157CO2 + 55.55 H2O + 0.006NO3? 0.036CH0.128N0.178O0.684 + 0.042 O2 + 156.96 CO2 + 55.54H2O ………. (2)
From the above equations, it is evident that the CO2 fixation rate is more in Capillary Bioreactor compared to conventional suspension-based system. i.e., the mole of CO2 fixed is 0.21 gmol for capillary reactor whereas it is 0.04 gmol for conventional suspension-based system. Thus, proving that the capillary reactor has an improved gas transfer as compared to conventional systems.
Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
,CLAIMS:CLAIMS

We claim:
1. A capillary bioreactor for algal bioprocess comprising of:
a growth chamber comprising of a growth block, a growth surface and a robotic arm;
a photon delivery chamber comprising of a photon array system;
a magnetic module comprising of a permanent magnet and a Helmholtz coil to produce a static magnetic field and a pulsed magnetic field;
an ultrasound module comprising of an ultrasound transducer to generate ultrasonic effects of an ultrasonic waves;
a utility chamber comprising of several liquid reservoirs having a media component, an acid, a base, and an antimicrobial solution;
a harvest module comprising of a wiper system, a spray system, a pressure-controlled efflux system and a magnetic separation process; and
a real time monitoring module;
wherein,
said growth block acts as a scaffold to align the growth surface;
said growth surface promotes various algal bioprocesses such as growth, carotenogenesis, lipid accumulation, in situ cell disruption, and in situ cell extraction;
said growth surface is optionally pre-treated for increased growth, adhesiveness and surface reusability;
said robotic arm is controlled by a programmable logic controller (PLC) and is present on either side of the growth surface for dual reactor system wherein each side of the growth surface acts as single reactor system;
said robotic arm aligns itself in various axis with a particular region on the growth surface at a predetermined distance for various bioprocess operations including but not limited to sampling process, operating different tools including a pH sensor, a temperature sensor, and an optical sensor;
said photon array system is fabricated for delivery of photons of varying wavelengths of light ranging from infra-red (790-900 nm), to visible spectrum (390-790 nm), to ultraviolet (200-390 nm), or in combination of a spectrum wherein total quantity of delivery of the photons at any given time ranges from 20-600 umol/m2 wherein wide range in wavelength and quantities accommodates for a diverse set of growth parameters including but not limited to green and red stage, in situ cell disruption, and lipid biosynthesis, strain differences, sterilization requirements, and experimentation flexibility;
said media components are supplied in optimal range with aid of the PLC and the acid and base are added according to the pH sensor control system; and
said magnetic separation process has iron nanoparticles for harvesting and the spray system has micro sparge wherein liquid or air is used for harvesting.
2. The capillary bioreactor for algal bioprocess as claimed in Claim 1, wherein said growth surface includes but is not limited to stainless steel material, alloys, composite material, porous material, non-porous coarse material, sintered metals, woven or nonwoven materials, smart materials, gels and gel like material, self-assembling gels, self-assembling nanoparticles and semi-solid materials.
3. The capillary bioreactor for algal bioprocess as claimed in Claim 1, wherein magnetic effect of said magnetic module increases a nutrient uptake and thereby increases the biomass.
4. The capillary bioreactor for algal bioprocess as claimed in Claim 1, wherein said real time monitoring module controls the entire capillary bioreactor and its components and manages processes real-time through user inputs as well as its own predictions through the PLC based controller.
5. The capillary bioreactor for algal bioprocess as claimed in Claim 1, wherein the ultrasonic waves generated in said ultrasound module enhances cell permeability which leads to increased nutrient uptake for promoting the algal growth and carotenogenesis.
6. The capillary bioreactor for algal bioprocess as claimed in Claim 1, wherein said pressure-controlled efflux system is having a combination of the wiper system and a vacuum based suction system wherein an algal biomass is harvested from the growth surface by scrapping the algal biomass along with a suction supplied from backside of a wiper to enable easy collection of the harvested biomass into a harvest bag.
7. The capillary bioreactor for algal bioprocess as claimed in Claim 1, wherein said capillary bioreactor has carbon dioxide (CO2) fixation rate of 0.21 gmol which improves gas transfer than conventional systems.
8. The capillary bioreactor for algal bioprocess as claimed in Claim 1, wherein said capillary bioreactor aids in uniform distribution of nutrients, improved gas transfer, requires less water for algal cultivation, and increased moisture holding capacity up to 93.2% after uniform distribution of nutrients by a nutrient mist technology.
9. A method of cultivating algal cells using capillary bioreactor comprising steps of:
a. switching/pivoting a capillary bioreactor from vertical to horizontal or vice versa before start of a batch process;
b. sterilizing the capillary bioreactor using ultraviolet rays, steam, or chemicals;
c. inoculating algal cells on a growth surface using a micro sparge system;
d. monitoring continuously growth of the algal cells obtained in the step (c) in a growth surface along with contaminants using a real time monitoring module; and
e. harvesting the algal cells from the growth surface using harvesting techniques including but not limited to a wiper system, a spray system, a pressure-controlled efflux system and a magnetic separation process
10. The method of cultivating algal cells using capillary bioreactor as claimed in Claim 9, wherein said real time monitoring module controls the entire capillary bioreactor and its components and manages the processes in real-time through user inputs as well as by its own predictions, through a programmable logic controller (PLC).