Biotechnology and the future of agriculture in Zimbabwe: strategic issues

A research paper on the importance of biotechnology to the future well-being of Zimbabwe's agriculture.Biotechnology is a collection of scientific disciplines that integrate natural, life and engineering sciences. The broad definition of biotechnology is simply the industrial use of living organisms or parts of living organisms to produce food, drugs or other products. Traditional biotechnology includes fermentation and the use of tissue culture in plant and animal breeding. Fermentation is used in the processes of making bread, beer, wine and cheese. Plant breeding employs vegetative, micro-propagation and tissue culture, while animal breeding uses techniques such as artificial insemination, super-ovulation and embryo transfer. Modem biotechnology permits the transfer of genes among species regardless of origin, resulting in an organism with an entirely new combination of properties (Marvier, 2001). Other definitions of modem biotechnology include specific techniques such as marker-assisted selection used in both animal and plant breeding

Experimental and modeling studies of mass transfer in microencapsulated cell systems

Gaining a better understanding of mass transfer problems in encapsulated cell systems and in tissue engineering requires both experimental investigations and mathematical modelling. Specific mass transfer studies are reviewed including oxygen transfer in immobilised animal cell culture systems, modelling of electrostatic polymer droplet formation, and growth of plant somatic tissue encapsulated in alginate using electrostatics. Trop J Pharm Res, June 2002; 1(1): 3-1

Growing Meat on Plants: Using intermediate CBD-RGD fusion proteins to improve bovine satellite cell attachment on cellulose-based scaffolds

Cellular agriculture is an emerging technology aiming to replace existing methods for animal agriculture with tissue engineering and cell culture-based technologies. Cultured meat falls within this purview, using a biomimetic approach to recreate animal muscle tissue through tissue engineering. In the attempt to diminish the necessity of animal-derived materials within this process, plant-based scaffolds can be used as a substrate upon which stem cells are cultured. Due to the unfavorable environment of cellulose for mammalian cell-surface proteins, the approach was taken of coating cellulose nanofiber films with a fusion protein composed of a cellulose binding domain (CBD) protein and the cell-adhesion peptide motif RGD, upon which bovine satellite cells were then cultured. Using this protein as an intermediate upon which each component can bind, our results indicate statistically-significant enhancement of cell attachment within this system when using an FBS-containing media formulation

A 3-dimensional fibre scaffold as an investigative tool for studying the morphogenesis of isolated plant pells.

BACKGROUND: Cell culture methods allow the detailed observations of individual plant cells and their internal processes. Whereas cultured cells are more amenable to microscopy, they have had limited use when studying the complex interactions between cell populations and responses to external signals associated with tissue and whole plant development. Such interactions result in the diverse range of cell shapes observed in planta compared to the simple polygonal or ovoid shapes in vitro. Microfluidic devices can isolate the dynamics of single plant cells but have restricted use for providing a tissue-like and fibrous extracellular environment for cells to interact. A gap exists, therefore, in the understanding of spatiotemporal interactions of single plant cells interacting with their three-dimensional (3D) environment. A model system is needed to bridge this gap. For this purpose we have borrowed a tool, a 3D nano- and microfibre tissue scaffold, recently used in biomedical engineering of animal and human tissue physiology and pathophysiology in vitro. RESULTS: We have developed a method of 3D cell culture for plants, which mimics the plant tissue environment, using biocompatible scaffolds similar to those used in mammalian tissue engineering. The scaffolds provide both developmental cues and structural stability to isolated callus-derived cells grown in liquid culture. The protocol is rapid, compared to the growth and preparation of whole plants for microscopy, and provides detailed subcellular information on cells interacting with their local environment. We observe cell shapes never observed for individual cultured cells. Rather than exhibiting only spheroid or ellipsoidal shapes, the cells adapt their shape to fit the local space and are capable of growing past each other, taking on growth and morphological characteristics with greater complexity than observed even in whole plants. Confocal imaging of transgenic Arabidopsis thaliana lines containing fluorescent microtubule and actin reporters enables further study of the effects of interactions and complex morphologies upon cytoskeletal organisation both in 3D and in time (4D). CONCLUSIONS: The 3D culture within the fibre scaffolds permits cells to grow freely within a matrix containing both large and small spaces, a technique that is expected to add to current lithographic technologies, where growth is carefully controlled and constricted. The cells, once seeded in the scaffolds, can adopt a variety of morphologies, demonstrating that they do not need to be part of a tightly packed tissue to form complex shapes. This points to a role of the immediate nano- and micro-topography in plant cell morphogenesis. This work defines a new suite of techniques for exploring cell-environment interactions

A 3-dimensional fibre scaffold as an investigative tool for studying the morphogenesis of isolated plant cells

Background: Cell culture methods allow the detailed observations of individual plant cells and their internal processes. Whereas cultured cells are more amenable to microscopy, they have had limited use when studying the complex interactions between cell populations and responses to external signals associated with tissue and whole plant development. Such interactions result in the diverse range of cell shapes observed in planta compared to the simple polygonal or ovoid shapes in vitro. Microfluidic devices can isolate the dynamics of single plant cells but have restricted use for providing a tissue-like and fibrous extracellular environment for cells to interact. A gap exists, therefore, in the understanding of spatiotemporal interactions of single plant cells interacting with their three-dimensional (3D) environment. A model system is needed to bridge this gap. For this purpose we have borrowed a tool, a 3D nano- and microfibre tissue scaffold, recently used in biomedical engineering of animal and human tissue physiology and pathophysiology in vitro. Results: We have developed a method of 3D cell culture for plants, which mimics the plant tissue environment, using biocompatible scaffolds similar to those used in mammalian tissue engineering. The scaffolds provide both developmental cues and structural stability to isolated callus-derived cells grown in liquid culture. The protocol is rapid, compared to the growth and preparation of whole plants for microscopy, and provides detailed subcellular information on cells interacting with their local environment. We observe cell shapes never observed for individual cultured cells. Rather than exhibiting only spheroid or ellipsoidal shapes, the cells adapt their shape to fit the local space and are capable of growing past each other, taking on growth and morphological characteristics with greater complexity than observed even in whole plants. Confocal imaging of transgenic Arabidopsis thaliana lines containing fluorescent microtubule and actin reporters enables further study of the effects of interactions and complex morphologies upon cytoskeletal organisation both in 3D and in time (4D). Conclusions: The 3D culture within the fibre scaffolds permits cells to grow freely within a matrix containing both large and small spaces, a technique that is expected to add to current lithographic technologies, where growth is carefully controlled and constricted. The cells, once seeded in the scaffolds, can adopt a variety of morphologies, demonstrating that they do not need to be part of a tightly packed tissue to form complex shapes. This points to a role of the immediate nano- and micro-topography in plant cell morphogenesis. This work defines a new suite of techniques for exploring cell-environment interactions

Bio-technology: its potential impact on food security in Southern Africa

A conference paper on the potential of bio-technology on food security in Southern Africa.My assigned topic is "Biotechnology and its potential impact on Food Security in Southern Africa." Biotechnology can and does encompass many things. As it is currently rather trendy, it seems to encompass almost anything to do with biology, agriculture or medicine. My definition will, however, be fairly narrow-simply because today I have been allotted 20 minutes. Biotech is an assembly of modern techniques which gives us skills in two broad areas: tissue culture and recombinant DNA manipulation. First, tissue culture allows us to culture, keep alive, animal and plant cells in the lab, in the petri dish, in the test-tube, under sterile conditions--which permits growth and development of those cells. Some of these cells can be manipulated with hormones and nutrition and physical conditions to express their totipotency, i.e., their inherent ability to develop from a single cell into a whole plant, a normal plant. If you start with one cell you get one plant, but if you start with a thousand cells (e.g., leaf mesophyll cells) you can potentially finish with a thousand plants, a thousand copies, a thousand clones of an original cell. I speak of plants because in some plants this is now routine. In animals, cloning is confined to a few experimental animals derived from embryos removed, split, cultured, and reinserted into the mother. When brought to term, the mother delivers cloned identical sibs (twins, triplets, etc.). In humans, no one has dared try as yet, but it is technically possible

Plant tissue cultures from a hormone point of view

A botanist, Haberlandt,(1) first pointed out the possibilities of the culture of isolated tissues. He suggested that not only could the potentialities of individual cells be determined, but that also some insight might be gained as to the reciprocal influences of tissues upon one another, that is, as to "correlation.

Scaffolds for 3D Cell Culture and Cellular Agriculture Applications Derived From Non-animal Sources

For decades, two-dimensional cell culture has been regarded as a major tool in cellular and molecular biology due to its simplicity, reproducibility and reliable nature. However, it is now recognized that 2D cell culture underrepresents the in vivo environment of living cells. The development and use of 3D scaffolds and biomaterials provide researchers an ability to more closely mimic the in vivo environment. However, many biomaterials are of animal origin, leading to variability, environmental and ethical concerns. Here we present three animal-free scaffolds: decellularized plant tissue, chitin/chitosan and recombinant collagen. Decellularized plant tissue provides a wide array of structures with varying biochemical, topographical and mechanical properties; chitin/chitosan-based scaffolds have shown synergistic bactericidal effects and improved cell-matrix interaction; and lastly, recombinant collagen has the potential to closely resemble native tissue, as opposed to the other two. These benefits, alongside potential scalability and tunability, open the door to applications beyond the biomedical realm, such as innovations in cellular agriculture and future food technologies