Moss bioreactor

A moss bioreactor is a special form of the photobioreactor and serves the growing and cultivation of moss. Generally transgenic moss to produce recombinant protein is cultured in a moss bioreactor. This biotechnological process is known as molecular pharming. In environmental science bioreactors are used, such as peat moss to multiply, as in the Moss clones research group to monitor air pollution, particularly by heavy metals.

Since it is relatively undemanding, photoautotrophic organisms in mosses, various types of mosses were cultured in vitro already at the beginning of the 20th century. In order to meet the safety guidelines for dealing with genetically modified organisms and to win biomass for experimental investigations sufficient first bioreactors for the model organism Physcomitrella patens were developed in the 1990s by Reski.

Operation

A moss bioreactor is based on the principle of a suspension culture: The moss is grown in a liquid nutrient medium under moving lighting and ventilation at constant temperature. The culture medium is often a minimal medium containing the required growth nutrients and trace elements; the pH value is kept constant by the addition of acid or alkali into the medium.

In order to achieve the strongest possible increase in biomass, the moss is kept in the protonema stage. This is done by continuous, mechanical crushing of the growing filaments protonema, for example by means of rotating blades. If the density of the biomass reaches a critical point, it comes as a result of decreasing nutrient supply and the increasing content of plant signaling substances ( phytohormones ) in the medium increasingly to differentiate Protonemas to the actual " moss plant". If the culture will continue to be a part of the culture is heavily diluted with fresh culture medium and re-scheduled.

This operating principle can, depending on the desired yield, through various shapes and sizes can be realized by bioreactors. In addition to column reactors of different volumes for example, tubular reactors and reactors exist with changeable plastic bags culture for protein production in an industrial scale.

Production of biopharmaceuticals

In moss Physcomitrella patens bioreactors with various biopharmaceuticals have already been made ​​. In this case, the recombinant protein can be purified in the optimum case, from the culture medium. An example of this factor is H: This molecule is a component of human complement, a defect of the corresponding gene lead to different kidney and eye disease. Biologically active, recombinant factor H was first produced in early 2011 in moss bioreactors.