Plants have been genetically engineered to serve as bioreactors for producing valuable biomolecules. Key advantages of plant bioreactors include low production costs, ease of scale-up and storage, and the ability to produce many products like vaccines, therapeutics, and industrial compounds. However, challenges remain around enhancing product yields, addressing storage and commercialization issues, and assessing social and environmental impacts.

1. Plant as Bioreactor Submitted by : Arun & Udhaya 1

3. From earlier days - Microbes &animal cell culture used to produce biomolecules.

4. Advancement in Plant genetic engineering : Possible to use as Bioreactors.

5. Plants are important food resources from the earliest times.

6. Plants as bioreactors: Biomolecules, industrial, chemical & pharmaceutical etc.

7. Number of products are successfully produced in plants using this ‘molecular farming’2

9. Post translational modifications

10. Easy storage and distribution

11. Low upstream production cost

13. Plant Suspension Cultures

14. Hairy Root System Bioreactor

15. Chloroplast bioreactor3

17. Simple & Cost effective.

18. Plant pathogens do not infect humans or animals.

19. Easy scale up & rapid harvesting.

20. Chimeric plant viruses can be used in production of vaccines.

21. Produce large biomass.

22. Easy storage for long time.4

23. Key process… 5

25. High seed protein content (7 to 10%).

26. High biomass yield.

27. Ease of transformation.

28. Ease of scale-up.

29. Major disadvantageof Maize is: Cross pollination

30. But ricehas advantage of self-pollination.

31. Rice as bioreactors : Oral delivery system for vaccine antigens, immunotherapy and therapeutic proteins are recent advances.6 Streatfield SJ et al., 2003

34. Both self-pollinating plants & low risk of contamination.

36. Safflower : High protein yield, Low acreage, and Self-pollinating.

37. Oilseed-derived protein: Commercial production of Hirudin, an anti-coagulant for treatment of thrombosis in rapeseed by SemBioSys(Bootheet al., 1997)8

38. Where they are produced? Shown are various Intracellular organelles or Extracellular spaces (ES) that can be used to store the recombinant proteins expressed in a plant bioreactor. Targeting strategies in plant bioreactors. G- Golgi; PSV- Protein storage vacuole; OB - Oil body; C- Chloroplast; ES- Extracellular space; PVC - Prevacuolar compartment. 9

40. Therapeutics products

41. Nutritional components

42. Industrial products

43. Bio plastics10 Tree depicting biotechnological advances using plants as bioreactors Source: www.plantbioreactor.co.in/images/00_112.jpg

45. Recent Development : “Edible Vaccines” now more popular as “Plant Vaccines”

46. From Seeds, freeze-dried fruits and leaves: powder form vaccines are produced.

47. Antigenic determinantsfor Pathogens causing diseases have been produced from plants.(Diarrhea, anthrax, rabies, cancer, HIV, tuberculosis etc)

48. Antigens like Insulin, rotavirus enterotoxin, anthrax lethal factor, HIV antigen, foot and mouth disease virus antigen, heat stable toxin have been produced in plants as a fusion partner of CTB or LTB.11 http://www.dowagro.com/uk/media/General/20061017.htm, Khandelwalet al., 2003; Sharma et al., 2004, Streatfield and Howard, 2003, Tiwariet al., 2009 and Youm et al., 2008.

50. Production of immunoglobulin fragments and their assembly in plants –reported in tobacco.

51. Recently known as “plantibodies” – immunochromatography or medical therapy.12 Schillberget al., 1999, Ma et al., 2003, Goldstein and Thomas, 2004

53. (Full size recombinant antibody, chimeric antibody, secretory antibody)

54. Sub cellular destination - high level expression.

55. Further research is concentrated on Humanizing the Plant N-glycans. 13 Schillberget al., 1999, Ma et al., 2003, Goldstein and Thomas, 2004

58. Expression was increased by targeting plastids, (40% of dry weight was obtained).14

60. Most expensive Drug – hGC (Human glucocerebrosidase) in tobacco (Kaiser 2008).

61. hST (Human somatotropin) was produced in tobacco (Staubet al. 2000).

62. Which treats : Turner syndrome, Chronical renal failure & Dwarfism in Children.

63. rHLF (Recombinant human lactoferrin) : Produced from dehusked rice grain(Nandi et al., 2002). Which is identical to native HLF.

64. Synthetic fiber: Produced from Potato and tobacco. (Schelleret al., 2001)15

66. Plant bioreactors : Investigated for making enzymes (Suitable for Food).

67. Another use of plants is to make genetically engineered plants that can produce seeds which can function as a delivery mechanism for various industrial enzymes.

68. As you can see these processes go far beyond the application of biotechnology in traditional agriculture, and so today, transgenic plants can produce on a mass scale proteins for agricultural, veterinary and pharmaceutical use.16

69. Conclusion (Cont.…) 17 Table source: Yansongmiaoet al., 2008

71. Most inserted genes are expressed at very low level in plants.

72. Enhancing the stability of products obtained.

73. Standardization of dosage in case of edible vaccine.

74. Examining issues related to commercialization.

75. Issues relating to the ethical, social, biosafety and environmental impact.

76. Some plants produce allergenic compounds.18

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